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Sample records for polarized electron-ion collider

  1. Polarized Parton Distributions at an Electron-Ion Collider

    CERN Document Server

    Ball, Richard D.; Guffanti, Alberto; Nocera, Emanuele R.; Ridolfi, Giovanni; Rojo, Juan

    2014-01-01

    We study the potential impact of inclusive deep-inelastic scattering data from a future electron-ion collider (EIC) on longitudinally polarized parton distribution (PDFs). We perform a PDF determination using the NNPDF methodology, based on sets of deep-inelastic EIC pseudodata, for different realistic choices of the electron and proton beam energies. We compare the results to our current polarized PDF set, NNPDFpol1.0, based on a fit to fixed-target inclusive DIS data. We show that the uncertainties on the first moments of the polarized quark singlet and gluon distributions are substantially reduced in comparison to NNPDFpol1.0, but also that more measurements may be needed to ultimately pin down the size of the gluon contribution to the nucleon spin.

  2. Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab

    Energy Technology Data Exchange (ETDEWEB)

    Abeyratne, S; Ahmed, S; Barber, D; Bisognano, J; Bogacz, A; Castilla, A; Chevtsov, P; Corneliussen, S; Deconinck, W; Degtiarenko, P; Delayen, J; Derbenev, Ya; DeSilva, S; Douglas, D; Dudnikov, V; Ent, R; Erdelyi, B; Evtushenko, P; Fujii, Yu; Filatov, Yury; Gaskell, D; Geng, R; Guzey, V; Horn, T; Hutton, A; Hyde, C; Johnson, R; Kim, Y; Klein, F; Kondratenko, A; Kondratenko, M; Krafft, G; Li, R; Lin, F; Manikonda, S; Marhauser, F; McKeown, R; Morozov, V; Dadel-Turonski, P; Nissen, E; Ostroumov, P; Pivi, M; Pilat, F; Poelker, M; Prokudin, A; Rimmer, R; Satogata, T; Sayed, H; Spata, M; Sullivan, M; Tennant, C; Terzic, B; Tiefenback, M; Wang, M; Wang, S; Weiss, C; Yunn, B

    2012-08-01

    Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectively utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very

  3. LEIC - A Polarized Low Energy Electron-ion Collider at Jefferson Lab

    International Nuclear Information System (INIS)

    A polarized electron-ion collider is envisioned as the future nuclear science program at JLab beyond the 12 GeV CEBAF. Presently, a medium energy collider (MEIC) is set as an immediate goal with options for a future energy upgrade. A comprehensive design report for MEIC has been released recently. The MEIC facility could also accommodate electron and proton/ion collisions in a low CM energy range, covering proton energies from 10 to 25 GeV and ion energies with a similar magnetic rigidity, for additional science reach. In this paper, we present a conceptual design of this low energy collider, LEIC, showing its luminosity can reach above 10 33 cm -2 s -1 . The design specifies that the large booster of the MEIC is converted to a low energy ion collider ring with an interaction region and an electron cooler integrated into it. The design provides options for either sharing the detector with the MEIC or a dedicated low energy detector in a third collision point, with advantages of either a minimum cost or extra detection parallel to the MEIC operation, respectively. The LEIC could be positioned as the first and low cost phase of a multi-stage approach to realize the full MEIC

  4. Progress on the design of the polarized Medium-energy Electron Ion Collider at JLAB

    Energy Technology Data Exchange (ETDEWEB)

    Lin, F.; Bogacz, A.; Brindza, P.; Camsonne, A.; Daly, E.; Derbenev, Ya. S.; Douglas, D.; Ent, R.; Gaskell, D.; Geng, R.; Grames, J.; Guo, J.; Harwood, L.; Hutton, A.; Jordan, K.; Kimber, A.; Krafft, G.; Li, R.; Michalski, T.; Morozov, V. S.; Nadel-Turonski, P.; /Jefferson Lab /Argonne /DESY /Moscow , Inst. Phys. Tech., Dolgoprydny /Dubna, JINR /Northern Illinois U. /Old Doominion U. /Novosibirsk, GOO Zaryad /SLAC /Texas A-M

    2015-07-14

    The Medium-energy Electron Ion Collider (MEIC) at JLab is designed to provide high luminosity and high polarization needed to reach new frontiers in the exploration of nuclear structure. The luminosity, exceeding 1033 cm-2s-1 in a broad range of the center-of-mass (CM) energy and maximum luminosity above 1034 cm-2s-1, is achieved by high-rate collisions of short small-emittance low-charge bunches made possible by high-energy electron cooling of the ion beam and synchrotron radiation damping of the electron beam. The polarization of light ion species (p, d, 3He) can be easily preserved and manipulated due to the unique figure-8 shape of the collider rings. A fully consistent set of parameters have been developed considering the balance of machine performance, required technical development and cost. This paper reports recent progress on the MEIC accelerator design including electron and ion complexes, integrated interaction region design, figure-8-ring-based electron and ion polarization schemes, RF/SRF systems and ERL-based high-energy electron cooling. Luminosity performance is also presented for the MEIC baseline design.

  5. Physics Opportunity with an Electron-Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Patrizia [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-12-01

    Understanding the emergence of nucleons and nuclei and their interactions from the properties and dynamics of quarks and gluons in Quantum Chromodynamics (QCD) is a fundamental and compelling goal of nuclear science. A high-energy, high-luminosity polarized electron-ion collider (EIC) will be needed to explore and advance many aspects of QCD studies in the gluon dominated regions in nucleon and nuclei. The federal Nuclear Science Advisory Committee unanimously approved a high-energy electro-ion collider to explore a new frontier in physics research. In fact, the committee calls the collider the country's next "highest priority" in new facility construction, and is one of four main recommendations contained in its 2015 Long Range Plan for Nuclear Science. Two proposals for the EIC are being considered in the U.S.: one each at Jefferson Laboratory (JLab) and at Brookhaven National Laboratory (BNL). An overview of the physics opportunities an EIC presents to the nuclear science community in future decades is presented.

  6. Electron-Ion Collider : The next QCD frontier

    NARCIS (Netherlands)

    Accardi, A.; Albacete, J. L.; Anselmino, M.; Armesto, N.; Aschenauer, E. C.; Bacchetta, A.; Boer, D.; Brooks, W. K.; Burton, T.; Chang, N. -B.; Deng, W. -T.; Deshpande, A.; Diehl, M.; Dumitru, A.; Dupre, R.; Ent, R.; Fazio, S.; Guzey, V.; Hakobyan, H.; Hao, Y.; Hasch, D.; Holt, R.; Horn, T.; Huang, M.; Hutton, A.; Hyde, C.; Jalilian-Marian, J.; Klein, S.; Kopeliovich, B.; Kovchegov, Y.; Kumar, K.; Kumericki, K.; Lamont, M. A. C.; Lappi, T.; Lee, J. -H.; Lee, Y.; Levin, E. M.; Lin, F. -L.; Litvinenko, V.; Ludlam, T. W.; Marquet, C.; Meziani, Z. -E.; McKeown, R.; Metz, A.; Milner, R.; Morozov, V. S.; Mueller, A. H.; Muller, B.; Mueller, D.; Nadel-Turonski, P.; Paukkunen, H.; Prokudin, A.; Ptitsyn, V.; Qian, X.; Qiu, J. -W.; Ramsey-Musolf, M.; Roser, T.; Sabatie, F.; Sassot, R.; Schnell, G.; Schweitzer, P.; Sichtermann, E.; Stratmann, M.; Strikman, M.; Sullivan, M.; Taneja, S.; Toll, T.; Trbojevic, D.; Ullrich, T.; Venugopalan, R.; Vigdor, S.; Vogelsang, W.; Weiss, C.; Xiao, B. -W.; Yuan, F.; Zhang, Y. -H.; Zheng, L.

    2016-01-01

    This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL)

  7. Design studies for the next generation electron ion colliders

    Energy Technology Data Exchange (ETDEWEB)

    Sayed, Hisham Kamal [BNL; Bogacz, Slawomir A. [JLAB; Krafft, Geoffrey A. [JLAB

    2014-04-01

    The next generation Electron Ion Collider (EIC) at Thomas Jefferson National Accelerator Facility (JLAB) utilizes a figure-8 shaped ion and electron rings. EIC has the ability to preserve the ion polarization during acceleration, where the electron ring matches in footprint with a figure-8 ion ring. The electron ring is designed to deliver a highly polarized high luminous electron beam at interaction point (IP). The main challenges of the electron ring design are the chromaticity compensation and maintaining high beam polarization of 70% at all energies 3–11 GeV without introducing transverse orbital coupling before the IP. The very demanding detector design limits the minimum distance between the final focus quadrupole and the interaction point to 3.5 m which results in a large β function inside the final focus quadrupoles leading to increased beam chromaticity. In this paper, we present a novel chromaticity compensation scheme that mitigates IP chromaticity by a compact chromaticity compensation section with multipole magnet components. In addition, a set of spin rotators are utilized to manipulate the polarization vector of the electron beam in order to preserve the beam polarization. The spin rotator solenoids introduce undesired coupling between the horizontal and vertical betatron motion of the beam. We introduce a compact and modular orbit decoupling insert that can fit in the limited space of the straight section in the figure-8 ring. We show a numerical study of the figure-8 ring design with the compact straight section, which includes the interaction region, chromaticity compensation section, and the spin rotators, the figure-8 design performance is evaluated with particle tracking.

  8. Interaction Region Design for the Electron-Ion Collider eRHIC

    CERN Document Server

    Montag, Christoph; Tepikian, Steven; Wang, Dong

    2005-01-01

    To facilitate the study of collisions between 10 GeV polarized electrons and 100 GeV/u heavy ions or 250 GeV polarized protons at high luminosities, adding a 10 GeV electron storage ring to the existing RHIC complex has been proposed. The interaction region of this electron-ion collider eRHIC has to provide the required low-beta focusing, while simultaneously accomodating the synchrotron radiation fan generated by beam separation close to the interaction point, which is particularly challenging. The latest design status of the eRHIC interaction region is presented.

  9. Novel Plasmonic Photocathodes for Electron-Ion Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Lukaszew, Rosa Alejandra [College of William and Mary, Williamsburg, VA (United States)

    2017-06-20

    Our aim was to explore new photocathode materials and schemes to develop strategies and technologies for next generation nuclear physics accelerator capabilities, particularly for Electron Ion Colliders (EIC). We successfully implemented an experimental setup for light incidence at an acute angle onto metallic photocathodes in UHV, in order to excite surface Plasmon resonance, hence increasing light absorption by the metallic surface and tested the photoemitted current. We successfully tested the setup with a hot cathode as well as Plasmonic silver-MgO samples and obtained excellent results. We extended our studies to shorter wavelengths to help defeat the work function of the metal. We also used oblique incidence thin film deposition onto gratings to achieve optimized Plasmonic excitation leading to stronger EM field and also lower emittance. We tested and used adequate software to model our samples and simulate our experimental results. We incorporated the concept of Fano resonances applied to gratings to better interpret our experimental results.

  10. Crabbing system for an electron-ion collider

    Energy Technology Data Exchange (ETDEWEB)

    Castilla, Alejandro [Old Dominion Univ., Norfolk, VA (United States)

    2017-05-01

    As high energy and nuclear physicists continue to push further the boundaries of knowledge using colliders, there is an imperative need, not only to increase the colliding beams' energies, but also to improve the accuracy of the experiments, and to collect a large quantity of events with good statistical sensitivity. To achieve the latter, it is necessary to collect more data by increasing the rate at which these processes are being produced and detected in the machine. This rate of events depends directly on the machine's luminosity. The luminosity itself is proportional to the frequency at which the beams are being delivered, the number of particles in each beam, and inversely proportional to the cross-sectional size of the colliding beams. There are several approaches that can be considered to increase the events statistics in a collider other than increasing the luminosity, such as running the experiments for a longer time. However, this also elevates the operation expenses, while increasing the frequency at which the beams are delivered implies strong physical changes along the accelerator and the detectors. Therefore, it is preferred to increase the beam intensities and reduce the beams cross-sectional areas to achieve these higher luminosities. In the case where the goal is to push the limits, sometimes even beyond the machines design parameters, one must develop a detailed High Luminosity Scheme. Any high luminosity scheme on a modern collider considers|in one of their versions|the use of crab cavities to correct the geometrical reduction of the luminosity due to the beams crossing angle. In this dissertation, we present the design and testing of a proof-of-principle compact superconducting crab cavity, at 750 MHz, for the future electron-ion collider, currently under design at Jefferson Lab. In addition to the design and validation of the cavity prototype, we present the analysis of the first order beam dynamics and the integration of the

  11. Nuclear structure functions at a future electron-ion collider

    Science.gov (United States)

    Aschenauer, E. C.; Fazio, S.; Lamont, M. A. C.; Paukkunen, H.; Zurita, P.

    2017-12-01

    The quantitative knowledge of heavy nuclei's partonic structure is currently limited to rather large values of momentum fraction x —robust experimental constraints below x ˜10-2 at low resolution scale Q2 are particularly scarce. This is in sharp contrast to the free proton's structure which has been probed in Deep Inelastic Scattering (DIS) measurements down to x ˜10-5 at perturbative resolution scales. The construction of an electron-ion collider (EIC) with a possibility to operate with a wide variety of nuclei, will allow one to explore the low-x region in much greater detail. In the present paper we simulate the extraction of the nuclear structure functions from measurements of inclusive and charm reduced cross sections at an EIC. The potential constraints are studied by analyzing simulated data directly in a next-to-leading order global fit of nuclear Parton Distribution Functions based on the recent EPPS16 analysis. A special emphasis is placed on studying the impact an EIC would have on extracting the nuclear gluon parton distribution function, the partonic component most prone to nonlinear effects at low Q2. In comparison to the current knowledge, we find that the gluon parton distribution function can be measured at an EIC with significantly reduced uncertainties.

  12. A New Simulation Framework for the Electron-Ion Collider

    Science.gov (United States)

    Arrington, John

    2017-09-01

    Last year, a collaboration between Physics Division and High-Energy Physics at Argonne was formed to enable significantly broader contributions to the development of the Electron-Ion Collider. This includes efforts in accelerator R&D, theory, simulations, and detector R&D. I will give a brief overview of the status of these efforts, with emphasis on the aspects aimed at enabling the community to more easily become involved in evaluation of physics, detectors, and details of spectrometer designs. We have put together a new, easy-to-use simulation framework using flexible software tools. The goal is to enable detailed simulations to evaluate detector performance and compare detector designs. In addition, a common framework capable of providing detailed simulations of different spectrometer designs will allow for fully consistent evaluations of the physics reach of different spectrometer designs or detector systems for a variety of physics channels. In addition, new theory efforts will provide self-consistent models of GPDs (including QCD evolution) and TMDs in nucleons and light nuclei, as well as providing more detailed physics input for the evaluation of some new observables. This material is based upon work supported by Laboratory Directed Research and Development (LDRD) funding from Argonne National Laboratory, provided by the Director, Office of Science, of the U.S. Department of Energy under Contract DE-AC02-06CH11357.

  13. Recent Progress on Design Studies of High-Luminosity Ring-Ring Electron-Ion Collider at CEBAF

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y; Bruell, A; Chevtsov, P; Derbenev, Y S; Ent, R; Krafft, G A; Li, R; Merminga, L

    2009-05-01

    The conceptual design of a ring-ring electron-ion collider based on CEBAF has been continuously optimized to cover a wide center-of-mass energy region and to achieve high luminosity and polarization to support next generation nuclear science programs. Here, we summarize the recent design improvements and R&D progress on interaction region optics with chromatic aberration compensation, matching and tracking of electron polarization in the Figure-8 ring, beam-beam simulations and ion beam cooling studies.

  14. Probing Sea Quarks and Gluons: The Electron-Ion Collider Project

    Directory of Open Access Journals (Sweden)

    Horn Tanja

    2014-03-01

    Full Text Available The 21st century holds great promise for reaching a new era for unlocking the mysteries of the structure of the atomic nucleus and the nucleons inside it governed by the theory of strong interactions (QCD. In particular, much remains to be learned about the dynamical basis of the structure of hadrons and nuclei in terms of the fundamental quarks and gluons. One of the main goals of existing and nearly completed facilities is to map out the spin flavor structure of the nucleons in the valence region. A future Electron-Ion Collider (EIC would be the world’s first polarized electron-proton collider, and the world’s first e-A collider, and would seek the QCD foundation of nucleons and nuclei in terms of the sea quarks and gluons, matching to these valence quark studies. The EIC will provide a versatile range of kinematics and beam polarization, as well as beam species, to allow for mapping the spin and spatial structure of the quark sea and gluons, to discover the collective effects of gluons in atomic nuclei, and to understand the emergence of hadronic matter from color charge.

  15. Design Studies of High-Luminosity Ring-Ring Electron-Ion Collider at CEBAF

    Energy Technology Data Exchange (ETDEWEB)

    Bogacz, Alex; Bogacz, Slawomir; Bogacz, Alex; Bogacz, Slawomir; Brindza, Paul; Bruell, Antje; Derbenev, Yaroslav; Ent, Rolf; Krafft, Geoffrey; Merminga, Nikolitsa; Musson, John; Wojtsekhowski, Bogdan; Yunn, Byung; Zhang, Yuhong; Qiang, Ji; Li, Rui

    2008-06-01

    An electron-ion collider of a center-of-mass energy up to 90 GeV at luminosity up to 1035 cm-2s-1 with both beams highly polarized is essential for exploring the new QCD frontier of strong color fields in nuclear and precisely imaging the sea-quarks and gluons in the nucleon. A conceptual design of a ring-ring collider based on CEBAF (ELIC) with energies up to 9 GeV for electrons/positrons and up to 225 GeV for protons and 100 GeV/u for ions has been proposed to fulfill the science desire and to serve as the next step for CEBAF after the planned 12 GeV energy upgrade of the fixed target program. Here, we summarize recent design progress for the ELIC complex with four interaction points (IP); including interaction region optics with chromatic aberration compensation scheme and complete lattices for the Figure-8 collider rings. Further optimization of crab crossing angles at the IPs, simulations of beam-beam interactions, and electron polarization in the Figure-8 ring and its matching at

  16. Probing Sea Quarks and Gluons: The Electron-Ion Collider Project

    Science.gov (United States)

    Horn, Tanja

    2014-03-01

    The 21st century holds great promise for reaching a new era for unlocking the mysteries of the structure of the atomic nucleus and the nucleons inside it governed by the theory of strong interactions (QCD). In particular, much remains to be learned about the dynamical basis of the structure of hadrons and nuclei in terms of the fundamental quarks and gluons. One of the main goals of existing and nearly completed facilities is to map out the spin flavor structure of the nucleons in the valence region. A future Electron-Ion Collider (EIC) would be the world's first polarized electron-proton collider, and the world's first e-A collider, and would seek the QCD foundation of nucleons and nuclei in terms of the sea quarks and gluons, matching to these valence quark studies. The EIC will provide a versatile range of kinematics and beam polarization, as well as beam species, to allow for mapping the spin and spatial structure of the quark sea and gluons, to discover the collective effects of gluons in atomic nuclei, and to understand the emergence of hadronic matter from color charge.

  17. Pre-Town Meeting on spin physics at an Electron-Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Aschenauer, Elke-Caroline; Bland, Leslie; Huang, Jin; Tarasov, Andrey [Brookhaven National Laboratory, Physics Department, Upton, NY (United States); Balitsky, Ian; Radyushkin, Anatoly [Old Dominion University, Physics Department, Norfolk, VA (United States); Jefferson Lab, Newport News, VA (United States); Brodsky, Stanley J. [Stanford University, SLAC National Accelerator Laboratory, Stanford, CA (United States); Burkardt, Matthias [New Mexico State University, Department of Physics, Las Cruces, NM (United States); Burkert, Volker; Chen, Jian-Ping; Kubarovsky, Valery; Melnitchouk, Wally; Qiu, Jian-Wei; Richards, David [Jefferson Lab, Newport News, VA (United States); Deshpande, Abhay [Brookhaven National Laboratory, RIKEN BNL Research Center, Upton, NY (United States); Stony Brook University, SUNY, Department of Physics and Astronomy, Stony Brook, NY (United States); Diehl, Markus [Deutsches Elektronen-Synchroton DESY, Hamburg (Germany); Gamberg, Leonard [Penn State University-Berks, Division of Science, Reading, PA (United States); Grosse Perdekamp, Matthias [University of Illinois at Urbana-Champaign, Urbana, IL (United States); Hyde, Charles [Old Dominion University, Physics Department, Norfolk, VA (United States); Ji, Xiangdong [Shanghai Jiao Tong University, INPAC, Department of Physics, and Shanghai Key Lab for Particle Physics and Cosmology, Shanghai (China); Peking University, Center for High-Energy Physics, Beijing (China); University of Maryland, Maryland Center for Fundamental Physics, College Park, MD (United States); Jiang, Xiaodong; Liu, Ming [Los Alamos National Laboratory, Los Alamos, NM (United States); Kang, Zhong-Bo [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); University of California, Mani L. Bhaumik Institute for Theoretical Physics, Los Angeles, CA (United States); Lajoie, John [Iowa State University, Ames, IA (United States); Liu, Keh-Fei [University of Kentucky, Dept. of Physics and Astronomy Center for Computational Sciences, Lexington, KY (United States); Liuti, Simonetta [University of Virginia, Department of Physics, Charlottesville, VA (United States); Mulders, Piet [VU University Amsterdam, Nikhef and Department of Physics and Astronomy, Amsterdam (Netherlands); Prokudin, Alexei [Jefferson Lab, Newport News, VA (United States); Penn State University-Berks, Division of Science, Reading, PA (United States); Sichtermann, Ernst; Yuan, Feng [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Stratmann, Marco; Vogelsang, Werner [Tuebingen University, Institute for Theoretical Physics, Tuebingen (Germany)

    2017-04-15

    A polarized ep/eA collider (Electron-Ion Collider, or EIC), with polarized proton and light-ion beams and unpolarized heavy-ion beams with a variable center-of-mass energy √(s) ∝ 20 to ∝ 100 GeV (upgradable to ∝ 150 GeV) and a luminosity up to ∝ 10{sup 34} cm{sup -2}s{sup -1}, would be uniquely suited to address several outstanding questions of Quantum Chromodynamics, and thereby lead to new qualitative and quantitative information on the microscopic structure of hadrons and nuclei. During this meeting at Jefferson Lab we addressed recent theoretical and experimental developments in the spin and the three-dimensional structure of the nucleon (sea quark and gluon spatial distributions, orbital motion, polarization, and their correlations). This mini-review contains a short update on progress in these areas since the EIC White paper (A. Accardi et al., Eur. Phys. J. A 52, 268 (2016)). (orig.)

  18. Polarized proton colliders

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. This will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. This allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 x 10 32 cm -2 s -1

  19. Predictions for exclusive vector meson production in the electron-ion collider

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, V.P. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas C. P. 354, 96010-090 Pelotas, RS (Brazil); Kugeratski, M.S. [Instituto de Fisica, Universidade de Sao Paulo C. P. 66318, 05315-970 Sao Paulo, SP (Brazil); Machado, M.V.T. [Centro de Ciencias Exatas e Tecnologicas, Universidade Federal do Pampa Campus de Bage Rua Carlos Barbosa, 96400-970 Bage, RS (Brazil); Navarra, F.S. [Instituto de Fisica, Universidade de Sao Paulo C. P. 66318, 05315-970 Sao Paulo, SP (Brazil)

    2010-02-15

    We calculate the nuclear cross section for coherent and incoherent vector meson production within the QCD color dipole picture, including saturation effects. Predictions for scattering on both light and heavy nuclei are given over a wide range of energy. Our analysis shows that coherent process should be dominant in the future electron-ion collider.

  20. RF System Requirements for a Medium-Energy Electron-Ion Collider (MEIC) at JLab

    International Nuclear Information System (INIS)

    JLab is studying options for a medium energy electron-ion collider that could fit on the JLab site and use CEBAF as a full-energy electron injector. A new ion source, linac and booster would be required, together with collider storage rings for the ions and electrons. In order to achieve the maximum luminosity these will be high-current storage rings with many bunches. We present the high-level RF system requirements for the storage rings, ion booster ring and high-energy ion beam cooling system, and describe the technology options under consideration to meet them. We also present options for staging that might reduce the initial capital cost while providing a smooth upgrade path to a higher final energy. The technologies under consideration may also be useful for other proposed storage ring colliders or ultimate light sources.

  1. Heavy ion beam loss mechanisms at an electron-ion collider

    Directory of Open Access Journals (Sweden)

    Spencer R. Klein

    2014-12-01

    Full Text Available There are currently several proposals to build a high-luminosity electron-ion collider, to study the spin structure of matter and measure parton densities in heavy nuclei, and to search for gluon saturation and new phenomena like the colored glass condensate. These measurements require operation with heavy nuclei. We calculate the cross sections for two important processes that will affect accelerator and detector operations: bound-free pair production and Coulomb excitation of the nuclei. Both of these reactions have large cross sections, 28–56 mb, which can lead to beam ion losses, produce beams of particles with altered charge:mass ratio, and produce a large flux of neutrons in zero degree calorimeters. The loss of beam particles limits the sustainable electron-ion luminosity to levels of several times 10^{32}/cm^{2}/s.

  2. Preliminary cryogenic loads requirements for the electron-ion collider at Brookhaven National Laboratory

    Science.gov (United States)

    Than, R.; Ravikumar, D. K.

    2017-12-01

    The proposed electron ion collider at Brookhaven National Laboratory will consist of using one existing hadron ring and developing a new electron accelerator. This paper presents the cryogenic loads for the hadron ring’s superconducting magnets as well as related upgrades to handle the additional loads. The cryogenic loads for the superconducting RF injector/accelerator and storage ring for the electron beam are summarized. The proposed cryogenic plant, and the configuration and flow distribution of the related cryogenic systems are also presented.

  3. Analyses of 476 MHz and 952 MHz Crab Cavities for JLAB Electron Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Park, HyeKyoung [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Old Dominion Univ., Norfolk, VA (United States); Castilla, Alejandro [Old Dominion Univ., Norfolk, VA (United States); Delayen, Jean R. [Old Dominion Univ., Norfolk, VA (United States); De Silva, Subashini U. [Old Dominion Univ., Norfolk, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-05-01

    The Center for Accelerator Science at Old Dominion University has designed, fabricated and successfully tested a crab cavity for Electron Ion Collider at Jefferson Lab (JLEIC) [1]. This proof-of-principle cavity was based on the earlier MEIC design which used 748.5 MHz RF system. The updated JLEIC (called MEIC earlier) design [2] utilizes the components from PEP-II. It results in the change on the bunch repetition rate of stored beam to 476.3 MHz. The ion ring collider will eventually require 952.6 MHz crab cavities. This paper will present the analyses of crab cavities of both 476 MHz and 952 MHz options. It compares advantages and disadvantages of the options which provide the JLEIC design team important technical information for a system down selection.

  4. Polarized proton collider at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S.Y.; Luccio, A.; MacKay, W.W. E-mail: mackay@bnl.govhttp://www.rhichome.bnl.gov/People/waldowaldo@bnl.gov; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.N

    2003-03-01

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to {radical}s=500 GeV.

  5. Analysis of Beam-Beam Kink Instability in a Linac-Ring Electron-Ion Collider

    International Nuclear Information System (INIS)

    V. Lebedev; J. Bisognano; R. Li; B. Yunn

    2001-01-01

    A linac-ring collision scheme was considered in recent proposals of electron-gold colliders (eRHIC) and polarized-electron light-ion colliders (EPIC). The advantages of using an energy-recovered linac for the electron beam is that it avoids the limitation of beam-beam tune shift inherent in a storage ring, pertains good beam quality and easy manipulation of polarization. However, the interaction of the ion beam in the storage ring with the electron beam from the linac acts analogously to a transverse impedance, and can induce unstable behavior of the ion beam similar to the strong head-tail instability. In this paper, this beam-beam kink instability with head-tail effect is analyzed using the linearized Vlasov equation, and the threshold of transverse mode coupling instability is obtained

  6. Transverse-momentum-dependent parton distribution/fragmentation functions at an electron-ion collider

    International Nuclear Information System (INIS)

    Anselmino, M.; Avakian, H.; Chen, J.P.; Musch, B.; Prokudin, A.; Qiang, Y.; Sulkosky, V.; Zhang, Y.; Boer, D.; Bradamante, F.; Burkardt, M.; Cisbani, E.; Contalbrigo, M.; Crabb, D.; Dutta, D.; Gamberg, L.; Gao, H.; Huang, M.; Laskaris, G.; Ye, Q.; Ye, Q.J.; Zheng, W.; Hasch, D.; Rossi, P.; Huang, J.; Kang, Z.; Keppel, C.; Liang, Z.T.; Liu, M.X.; Makins, N.; Peng, J.C.; Mckeown, R.D.; Qian, X.; Metz, A.; Meziani, Z.E.; Soffer, J.; Zhou, J.; Qiu, J.W.; Schweitzer, P.; Wang, Y.; Xiao, B.; Yuan, F.; Zhan, X.

    2011-01-01

    We present a summary of a recent workshop held at Duke University on Partonic Transverse Momentum in Hadrons: Quark Spin-Orbit Correlations and Quark-Gluon Interactions. The transverse-momentum-dependent parton distribution functions (TMDs), parton-to-hadron fragmentation functions, and multi-parton correlation functions, were discussed extensively at the Duke workshop. In this paper, we summarize first the theoretical issues concerning the study of partonic structure of hadrons at a future electron-ion collider (EIC) with emphasis on the TMDs. We then present simulation results on experimental studies of TMDs through measurements of single-spin asymmetries (SSA) from semi-inclusive deep inelastic scattering (SIDIS) processes with an EIC, and discuss the requirement of the detector for SIDIS measurements. The dynamics of parton correlations in the nucleon is further explored via a study of SSA in D (anti D) production at large transverse momenta with the aim of accessing the unexplored tri-gluon correlation functions. The workshop participants identified the SSA measurements in SIDIS as a golden program to study TMDs in both the sea and valence quark regions and to study the role of gluons, with the Sivers asymmetry measurements as examples. Such measurements will lead to major advancement in our understanding of TMDs in the valence quark region, and more importantly also allow for the investigation of TMDs in the unexplored sea quark region along with a study of their evolution. (orig.)

  7. Electron Ion Collider: The Next QCD Frontier - Understanding the glue that binds us all

    CERN Document Server

    Accardi, A.; Anselmino, M.; Armesto, N.; Aschenauer, E.C.; Bacchetta, A.; Boer, D.; Brooks, W.K.; Burton, T.; Chang, N.B.; Deng, W.T.; Deshpande, A.; Diehl, M.; Dumitru, A.; Dupré, R.; Ent, R.; Fazio, S.; Gao, H.; Guzey, V.; Hakobyan, H.; Hao, Y.; Hasch, D.; Holt, R.; Horn, T.; Huang, M.; Hutton, A.; Hyde, C.; Jalilian-Marian, J.; Klein, S.; Kopeliovich, B.; Kovchegov, Y.; Kumar, K.; Kumerički, K.; Lamont, M.A.C.; Lappi, T.; Lee, J.H.; Lee, Y.; Levin, E.M.; Lin, F.L.; Litvinenko, V.; Ludlam, T.W.; Marquet, C.; Meziani, Z.E.; McKeown, R.; Metz, A.; Milner, R.; Morozov, V.S.; Mueller, A.H.; Müller, B.; Müller, Dieter; Nadel-Turonski, P.; Paukkunen, H.; Prokudin, A.; Ptitsyn, V.; Qian, X.; Qiu, J.W.; Ramsey-Musolf, M.; Roser, T.; Sabatié, F.; Sassot, R.; Schnell, G.; Schweitzer, P.; Sichtermann, E.; Stratmann, M.; Strikman, M.; Sullivan, M.; Taneja, S.; Toll, T.; Trbojevic, D.; Ullrich, T.; Venugopalan, R.; Vigdor, S.; Vogelsang, W.; Weiss, C.; Xiao, B.W.; Yuan, F.; Zhang, Y.H.; Zheng, L.

    2016-01-01

    This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics and, in particular, the focused ten-week program on "Gluons and quark sea at high energies" at the Institute for Nuclear Theory in Fall 2010. It contains a brief description of a few golden physics measurements along with accelerator and detector concepts required to achieve them, and it benefited from inputs from the users' communities of BNL and JLab. This White Paper offers the promise to prope...

  8. High-performance DIRC detector for the future Electron Ion Collider experiment

    Science.gov (United States)

    Kalicy, G.; Allison, L.; Cao, T.; Dzhygadlo, R.; Horn, T.; Hyde, C.; Ilieva, Y.; Nadel-Turonski, P.; Park, K.; Peters, K.; Schwarz, C.; Schwiening, J.; Stevens, J.; Xi, W.; Zorn, C.

    2016-07-01

    A radially-compact subsystem providing particle identification (e/π, π/K, K/p) over a wide momentum range is an essential requirement for the central detector of an Electron-Ion Collider (EIC). With a radial size of only a few cm, a detector based on Detection of Internally Reflected Cherenkov light (DIRC) principle is a very attractive solution. The R&D undertaken by the EIC PID consortium achieved the goal of showing feasibility of a high-performance DIRC that would extend the momentum coverage well beyond state-of-the-art allowing 3σ separation of π/K up to 6 GeV/c, e/K up to 1.8 GeV/c and p/K up to 10 GeV/c. A key component to reach such a performance is a special 3-layer spherical compound lens. This article describes the status of the design and R&D for the DIRC at EIC detector, with a focus on the detailed Monte Carlo simulation results for the high-performance DIRC.

  9. Simulation Studies of Beam-Beam Effects of a Ring-Ring Electron-Ion Collider Based on CEBAF

    Energy Technology Data Exchange (ETDEWEB)

    Yuhong Zhang,Ji Qiang

    2009-05-01

    The collective beam-beam effect can potentially cause a rapid growth of beam sizes and reduce the luminosity of a collider to an unacceptably low level. The ELIC, a proposed ultra high luminosity electron-ion collider based on CEBAF, employs high repetition rate crab crossing colliding beams with very small bunch transverse sizes and very short bunch lengths, and collides them at up to 4 interaction points with strong final focusing. All of these features can make the beam-beam effect challenging. In this paper, we present simulation studies of the beam-beam effect in ELIC using a self-consistent strong-strong beam-beam simulation code developed at Lawrence Berkeley National Laboratory. This simulation study is used for validating the ELIC design and for searching for an optimal parameter set.

  10. Polarized electron sources for linear colliders

    International Nuclear Information System (INIS)

    Clendenin, J.E.; Ecklund, S.D.; Miller, R.H.; Schultz, D.C.; Sheppard, J.C.

    1992-07-01

    Linear colliders require high peak current beams with low duty factors. Several methods to produce polarized e - beams for accelerators have been developed. The SLC, the first linear collider, utilizes a photocathode gun with a GaAs cathode. Although photocathode sources are probably the only practical alternative for the next generation of linear colliders, several problems remain to be solved, including high voltage breakdown which poisons the cathode, charge limitations that are associated with the condition of the semiconductor cathode, and a relatively low polarization of ≤5O%. Methods to solve or at least greatly reduce the impact of each of these problems are at hand

  11. Effects of Crab Cavities' Multipole Content in an Electron-Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Satogata, Todd J. [Jefferson Lab., Newport News, VA (United States); Morozov, Vasiliy [Jefferson Lab., Newport News, VA (United States); Delayen, Jean R. [Old Dominion Univ., Norfolk, VA (United States); Jefferson Lab., Newport News, VA (United States); Castillo, Alejandro [Old Dominion Univ., Norfolk, VA (United States)

    2015-09-01

    The impact on the beam dynamics of the Medium Energy Electron-Ion Colider (MEIC) due to the multipole content of the 750 MHz crab cavity was studied using thin multipole elements for 6D phase space particle tracking in ELEGANT. Target values of the sextupole component for the cavity’s field expansion were used to perform preliminary studies on the proton beam stability when compared to the case of pure dipole content of the rf kicks. Finally, important effects on the beam sizes due to non-linear components of the crab cavities’ fields were identified, and some criteria for their future study were proposed.

  12. The Proton Spin, Semi-Inclusive processes, and measurements at a future Electron Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Abhay, Deshpande

    2018-01-12

    We discuss spin physics, Guido’s contribution to it, and what we still have to learn. We set out in particular a programme for incorporating constraints from semi-inclusive data into global fits of polarized PDFs, and discuss the need for the EIC to increase the precision and kinematic coverage of current measurements.

  13. A Harmonic Kicker Scheme for the Circulator Cooler Ring in the Proposed Medium Energy Electron-Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Nissen, Edward W.; Hutton, Andrew M.; Kimber, Andrew J.

    2013-06-01

    The current electron cooler design for the proposed Medium Energy Electron-Ion collider (MEIC) at Jefferson Lab utilizes a circulator ring for reuse of the cooling electron bunch up to 100 times to cool the ion beams. This cooler requires a fast kicker system for injecting and extracting individual bunches in the circulator ring. Such a kicker must work at a high repetition rate, up to 7.5 to 75 MHz depending on the number of turns in the recirculator ring. It also must have a very short rise and fall time (of order of 1 ns) such that it will kick an individual bunch without disturbing the others in the ring. Both requirements are orders of magnitude beyond the present state-of-the-art as well as the goals of other on-going kicker R&D programs such as that for the ILC damping rings. In this paper we report a scheme of creating this fast, high repetition rate kicker by combining RF waveforms at multiple frequencies to create a kicker waveform that will, for example, kick every eleventh bunch while leaving the other ten unperturbed. We also present a possible implementation of this scheme as well as discuss its limitations.

  14. Harmonic Kicker RF Cavity for the Jefferson Lab Electron-Ion Collider EM Simulation, Modification, and Measurements

    Science.gov (United States)

    Overstreet, Sarah; Wang, Haipeng

    2017-09-01

    An important step in the conceptual design for the future Jefferson Lab Electron-Ion Collider (JLEIC) is the development of supporting technologies for the Energy Recovery Linac (ERL) Electron Cooling Facility. The Harmonic Radiofrequency (RF) kicker cavity is one such device that is responsible for switching electron bunches in and out of the Circulator Cooling Ring (CCR) from and to the ERL, which is a critical part of the ion cooling process. Last year, a half scale prototype of the JLEIC harmonic RF kicker model was designed with resonant frequencies to support the summation of 5 odd harmonics (95.26 MHz, 285.78 MHz, 476.30 MHz, 666.82 MHz, and 857.35 MHz); however, the asymmetry of the kicker cavity gives rise to multipole components of the electric field at the electron-beam axis of the cavity. Previous attempts to symmetrize the electric field of this asymmetrical RF cavity have been unsuccessful. The aim of this study is to modify the existing prototype for a uniform electric field across the beam pathway so that the electron bunches will experience nearly zero beam current loading. In addition to this, we have driven the unmodified cavity with the harmonic sum and used the wire stretching method for an analysis of the multipole electric field components.

  15. R&D of a High-Performance DIRC Detector for a Future Electron-Ion Collider

    Science.gov (United States)

    Allison, Stacey Lee

    An Electron-Ion Collider (EIC) is proposed as the next big scientific facility to be built in the United States, costing over $1 billion in design and construction. Each detector concept for the electron/ion beam interaction point is integrated into a large solenoidal magnet. The necessity for excellent hadronic particle identification (pion/kaon/proton) in the barrel region of the solenoid has pushed research and development (R&D) towards a new, high-performance Detection of Internally Reflected Cherenkov light (DIRC) detector design. The passage of a high energy charged particle through a fused silica bar of the DIRC generates optical Cherenkov radiation. A large fraction of this light propagates by total internal reflection to the end of the bar, where the photon trajectories expand in a large volume before reaching a highly segmented photo-detector array. The spatial and temporal distribution of the Cherenkov light at the photo-detector array allows one to reconstruct the angle of emission of the light relative to the incident charged particle track. In order to reach the desired performance of 3sigma pi/K separation at 6 GeV/c particle momentum a new 3-layer spherical lens focusing optic with a lanthanum crown glass central layer was designed to have a nearly flat focal plane. In order to validate the EIC DIRC simulation package, a synergistic test beam campaign was carried out in 2015 at the CERN PS with the PANDA Barrel DIRC group using a prototype DIRC detector. Along with the analysis of the CERN test beam data, measurements of the focal plane of the 3-layer lens were performed using a custom-built laser setup at Old Dominion University. Radiation hardness of the lanthanum crown glass was tested using a 160 keV X-ray source and a monochromator at the Catholic University of America. Results of these test-bench experiments and the analysis of the 2015 CERN test beam data are presented here.

  16. R&D of a high-performance DIRC detector for a future electron-ion collider

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Staceu L. [Old Dominion Univ., Norfolk, VA (United States)

    2017-08-01

    An Electron-Ion Collider (EIC) is proposed as the next big scientific facility to be built in the United States, costing over $1 billion in design and construction. Each detector concept for the electron/ion beam interaction point is integrated into a large solenoidal magnet. The necessity for excellent hadronic particle identification (pion/kaon/proton) in the barrel region of the solenoid has pushed research and development (R&D) towards a new, high-performance Detection of Internally Reflected Cherenkov light (DIRC) detector design. The passage of a high energy charged particle through a fused silica bar of the DIRC generates optical Cherenkov radiation. A large fraction of this light propagates by total internal reflection to the end of the bar, where the photon trajectories expand in a large volume before reaching a highly segmented photo-detector array. The spatial and temporal distribution of the Cherenkov light at the photo-detector array allows one to reconstruct the angle of emission of the light relative to the incident charged particle track. In order to reach the desired performance of 3sigma pi/K separation at 6 GeV/c particle momentum a new 3-layer spherical lens focusing optic with a lanthanum crown glass central layer was designed to have a nearly at focal plane. In order to validate the EIC DIRC simulation package, a synergistic test beam campaign was carried out in 2015 at the CERN PS with the PANDA Barrel DIRC group using a prototype DIRC detector. Along with the analysis of the CERN test beam data, measurements of the focal plane of the 3-layer lens were performed using a custom-built laser setup at Old Dominion University. Radiation hardness of the lanthanum crown glass was tested using a 160 keV X-ray source and a monochromator at the Catholic University of America. Results of these test-bench experiments and the analysis of the 2015 CERN test beam data are presented here.

  17. Polarized electronic sources for future e+/e- linear colliders

    International Nuclear Information System (INIS)

    Tang, H.; Alley, R.K.; Clendenin, J.E.

    1997-05-01

    Polarized electron beams will play a crucial role in maximizing the physics potential for future e + /e - linear colliders. We will review the SLC polarized electron source (PES), present a design for a conventional PES for the Next Linear Collider (NLC), and discuss the physics issues of a polarized RF gun

  18. Acceleration of polarized protons and deuterons in the ion collider ring of JLEIC

    Energy Technology Data Exchange (ETDEWEB)

    Kondratenko, A. [Novosibirsk State Univ. (Russian Federation); Kondratenko, M. [Novosibirsk State Univ. (Russian Federation); Filatov, Yu. N. [Moscow Inst. of Physics and Technology (MIPT), Moscow (Russian Federation); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Novosibirsk State Univ. (Russian Federation); Lin, Fanglei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasily S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2017-07-01

    The figure-8-shaped ion collider ring of Jefferson Lab Electron-Ion Collider (JLEIC) is transparent to the spin. It allows one to preserve proton and deuteron polarizations using weak stabilizing solenoids when accelerating the beam up to 100 GeV/c. When the stabilizing solenoids are introduced into the collider's lattice, the particle spins precess about a spin field, which consists of the field induced by the stabilizing solenoids and the zero-integer spin resonance strength. During acceleration of the beam, the induced spin field is maintained constant while the resonance strength experiences significant changes in the regions of "interference peaks". The beam polarization depends on the field ramp rate of the arc magnets. Its component along the spin field is preserved if acceleration is adiabatic. We present the results of our theoretical analysis and numerical modeling of the spin dynamics during acceleration of protons and deuterons in the JLEIC ion collider ring. We demonstrate high stability of the deuteron polarization in figure-8 accelerators. We analyze a change in the beam polarization when crossing the transition energy.

  19. Colliders

    CERN Document Server

    Chou, Weiren

    2014-01-01

    The idea of colliding two particle beams to fully exploit the energy of accelerated particles was first proposed by Rolf Wideröe, who in 1943 applied for a patent on the collider concept and was awarded the patent in 1953. The first three colliders — AdA in Italy, CBX in the US, and VEP-1 in the then Soviet Union — came to operation about 50 years ago in the mid-1960s. A number of other colliders followed. Over the past decades, colliders defined the energy frontier in particle physics. Different types of colliers — proton–proton, proton–antiproton, electron–positron, electron–proton, electron-ion and ion-ion colliders — have played complementary roles in fully mapping out the constituents and forces in the Standard Model (SM). We are now at a point where all predicted SM constituents of matter and forces have been found, and all the latest ones were found at colliders. Colliders also play a critical role in advancing beam physics, accelerator research and technology development. It is timel...

  20. EPIC - an electron-polarized ion collider

    International Nuclear Information System (INIS)

    Cameron, J.M.

    1999-01-01

    As discussed earlier in this workshop, we have been studying at the Indiana University Cyclotron Facility (IUCF) for some time the potential of a facility-the Light Ion Spin Synchrotron (LISS)- focusing on reactions induced by polarized nucleons at ∼ 1 to 20 GeV. The technology would extrapolate from what we have learned using our existing Cooler ring using internal polarized targets. Indeed, these techniques are most viable at higher energies where the loss of the stored beam is due to the nuclear reactions which are of interest and not that of multiple Coulomb scattering which dominate in our present energy range. However, while the internal targets are not exactly fixed, they certainly do not contribute to the available energy in the center of momentum frame. Consequently, the energy and momentum which can be effective explored are 6 GeV and 3 GeV/c respectively, about the same range that we expect to explore using electromagnetic probes using the enhanced Thomas Jefferson National Accelerator Laboratory electron beam. Looking at the structure of hadrons, as we currently understand it, one can divide it into four size scales. The LISS facility would permit studies of the manifestation of the nucleon substructure but generally would not get to scales where one would only have incoherent interactions at the partonic level. Following in a path already trodden by our European colleagues, we have recently started to look at the possibility of adding an electronic collider option to our plans. This would significantly increase the kinematic range, with 25 GeV protons and 4 GeV electrons (one gets over 20 GeV in the center of mass-equivalent to about 200 GeV on a fixed proton target). The accessible range provides coverage up to Q 2 = 20 GeV/ c 2 and down to x ∼ 10 -2 (here x = Q 2 /2Mv, the usual Bjorken scaling variable). As the energy of both beams would be variable, one can cover the whole range between HERMES and CERN/FNAL muon beams. Examples of the range of

  1. Configuration Manual Polarized Proton Collider at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S. Y.; Luccio, A.; MacKay, W. W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Svirida, D.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.

    2006-01-01

    In this report we present our design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. We provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.

  2. CONFIGURATION MANUAL POLARIZED PROTON COLLIDER AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    ROSER,T.; MACKAY,W.W.; ALEKSEEV,I.; BAI,M.; BROWN,K.; BUNCE,G.; CAMERON,P.; COURANT,E.; ET AL.

    2001-03-01

    In this report, the authors present their design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. They provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.

  3. Development of a Bunched Beam Electron Cooler based on ERL and Circulator Ring Technology for the Jefferson Lab Electron-Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Benson, Stephen V. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hannon, Fay E. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hutton, Andrew M. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Rimmer, Robert A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Roblin, Yves R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wang, Haipeng [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, He [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2018-01-01

    Jefferson Lab is in the process of designing an electron ion collider with unprecedented luminosity at a 45 GeV center-of-mass energy. This luminosity relies on ion cooling in both the booster and the storage ring of the accelerator complex. The cooling in the booster will use a conventional DC cooler similar to the one at COSY. The high-energy storage ring, operating at a momentum of up to 100 GeV/nucleon, requires novel use of bunched-beam cooling. There are two designs for such a cooler. The first uses a conventional Energy Recovery Linac (ERL) with a magnetized beam while the second uses a circulating ring to enhance both peak and average currents experienced by the ion beam. This presentation will describe the design of both the Circulator Cooling Ring (CCR) design and that of the backup option using the stand-alone ERL operated at lower charge but higher repetition rate than the ERL injector required by the CCR-based design.

  4. Polarized parton distributions at an electron–ion collider

    Energy Technology Data Exchange (ETDEWEB)

    Ball, Richard D. [Tait Institute, University of Edinburgh, JCMB, KB, Mayfield Rd, Edinburgh EH9 3JZ, Scotland (United Kingdom); Forte, Stefano [Dipartimento di Fisica, Università di Milano and INFN, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Guffanti, Alberto [The Niels Bohr International Academy and Discovery Center, The Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen (Denmark); Nocera, Emanuele R. [Dipartimento di Fisica, Università di Milano and INFN, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Ridolfi, Giovanni [Dipartimento di Fisica, Università di Genova and INFN, Sezione di Genova, Genova (Italy); Rojo, Juan [PH Department, TH Unit, CERN, CH-1211 Geneva 23 (Switzerland)

    2014-01-20

    We study the potential impact of inclusive deep-inelastic scattering data from a future electron–ion collider (EIC) on longitudinally polarized parton distributions (PDFs). We perform a PDF determination using the NNPDF methodology, based on sets of deep-inelastic EIC pseudodata, for different realistic choices of the electron and proton beam energies. We compare the results to our current polarized PDF set, NNPDFpol1.0, based on a fit to fixed-target inclusive DIS data. We show that the uncertainties on the first moments of the polarized quark singlet and gluon distributions are substantially reduced in comparison to NNPDFpol1.0, but also that more measurements may be needed to ultimately pin down the size of the gluon contribution to the nucleon spin.

  5. Polarized parton distributions at an electron–ion collider

    International Nuclear Information System (INIS)

    Ball, Richard D.; Forte, Stefano; Guffanti, Alberto; Nocera, Emanuele R.; Ridolfi, Giovanni; Rojo, Juan

    2014-01-01

    We study the potential impact of inclusive deep-inelastic scattering data from a future electron–ion collider (EIC) on longitudinally polarized parton distributions (PDFs). We perform a PDF determination using the NNPDF methodology, based on sets of deep-inelastic EIC pseudodata, for different realistic choices of the electron and proton beam energies. We compare the results to our current polarized PDF set, NNPDFpol1.0, based on a fit to fixed-target inclusive DIS data. We show that the uncertainties on the first moments of the polarized quark singlet and gluon distributions are substantially reduced in comparison to NNPDFpol1.0, but also that more measurements may be needed to ultimately pin down the size of the gluon contribution to the nucleon spin

  6. Polarized positron sources for the future linear colliders

    International Nuclear Information System (INIS)

    Chaikovska, I.

    2012-01-01

    This thesis introduces the polarized positron source as one of the key element of the future Linear Collider (LC). In this context, the different schemes of the polarized positron source are described highlighting the main issues in this technology. In particular, the main focus is on the Compton based positron source adopted by the CLIC as a preferred option for the future positron source upgrade. In this case, the circularly polarized high energy gamma rays resulting from Compton scattering are directed to a production target where an electromagnetic cascade gives rise to the production of positrons by e + -e - pair conversion. To increase the efficiency of the gamma ray production stage, a multiple collision point line integrated in energy recovery linac is proposed. The simulations of the positron production, capture and primary acceleration allow to estimate the positron production efficiency and provide a simple parametrization of the Compton based polarized positron source in the view of the future LC requirements. The storage ring based Compton source option, so-called Compton ring, is also described. The main constraint of this scheme is given by the beam dynamics resulting in the large energy spread and increased bunch length affecting the gamma ray production rate. An original theoretical contribution is shown to calculate the energy spread induced by Compton scattering. Moreover, an experiment to test the gamma ray production by Compton scattering using a state-of-art laser system developed at LAL has been conducted in the framework of the 'Mighty Laser' project at the ATF, KEK. The experimental layout as well as the main results obtained are discussed in details. The studies carried out in this thesis show that the polarized positron source based on Compton scattering is a promising candidate for the future LC polarized positron source. (author)

  7. Electron-ion temperature ratio estimations in the summer polar mesosphere when subject to HF radio wave heating

    Science.gov (United States)

    Pinedo, H.; La Hoz, C.; Havnes, O.; Rietveld, M.

    2014-10-01

    We have inferred the electron temperature enhancements above mesospheric altitudes under Polar Mesospheric Summer Echoes (PMSE) conditions when the ionosphere is exposed to artificial HF radio wave heating. The proposed method uses the dependence of the radar cross section on the electron-to-ion temperature ratio to infer the heating factor from incoherent scatter radar (ISR) power measurements above 90 km. Model heating temperatures match our ISR estimations between 90 and 130 km with 0.94 Pearson correlation index. The PMSE strength measured by the MORRO MST radar is about 50% weaker during the heater-on period when the modeled electron-to-ion mesospheric temperature is approximately 10 times greater than the unperturbed value. No PMSE weakening is found when the mesospheric temperature enhancement is by a factor of three or less. The PMSE weakening and its absence are consistent with the modeled mesospheric electron temperatures. This consistency supports to the proposed method for estimating mesospheric electron temperatures achieved by independent MST and ISR radar measurements.

  8. Revealing Fundamental Interactions: the Role of Polarized Positrons and Electrons at the Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Moortgat-Pick, G.; /CERN /Durham U., IPPP; Abe, T.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke,; Clendenin, J.E.; Dainton, J.; Desch, K.; Diehl, M.; Dobos, B.; Dorland, T.; Eberl, H.; Ellis, John R.; Flottman, K.; Frass, H.; /CERN /Durham U., IPPP /Colorado U. /Tel-Aviv

    2005-07-06

    The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization.

  9. The Role of polarized positrons and electrons in revealing fundamental interactions at the linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Moortgat-Pick, G.; /CERN /Durham U., IPPP; Abe, T.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke,; Clendenin, J.E.; Dainton, J.; Desch, K.; Diehl, M.; Dobos, B.; Dorland, T.; Eberl, H.; Ellis, John R.; Flottman, K.; Frass, H.; /CERN /Durham U., IPPP /Colorado U. /Tel-Aviv

    2005-07-01

    The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization.

  10. RHIC Performance as a 100 GeV Polarized Proton Collider in Run-9

    International Nuclear Information System (INIS)

    Montag, C.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dottavio, T.; Drees, A.; Fedotov, A.V.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.; Hahn, H.; Harvey, M.; Hayes, T.; Huang, H.; Ingrassia, P.; Jamilkowski, J.; Kayran, D.; Kewisch, J.; Lee, R.C.; Luccio, A.U.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Menga, P.M.; Michnoff, R.; Minty, M.; Morris, J.; Oerter, B.; Pilat, F.; Pile, P.; Pozdeyev, E.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Sivertz, M.; Smith, K.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2010-01-01

    During the second half of Run-9, the Relativisitc Heavy Ion Collider (RHIC) provided polarized proton collisions at two interaction points. The spin orientation of both beams at these collision points was controlled by helical spin rotators, and physics data were taken with different orientations of the beam polarization. Recent developments and improvements will be presented, as well as luminosity and polarization performance achieved during Run-9.

  11. RHIC Performance as a 100 GeV Polarized Proton Collider in Run-9

    Energy Technology Data Exchange (ETDEWEB)

    Montag, C.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; DOttavio, T.; Drees, A.; Fedotov, A.V.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.; Hahn, H.; Harvey, M.; Hayes, T.; Huang, H.; Ingrassia, P.; Jamilkowski, J.; Kayran, D.; Kewisch, J.; Lee, R.C.; Luccio, A.U.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Menga, P.M.; Michnoff, R.; Minty, M.; Morris, J.; Oerter, B.; Pilat, F.; Pile, P.; Pozdeyev, E.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Sivertz, M.; Smith, K.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2010-05-23

    During the second half of Run-9, the Relativisitc Heavy Ion Collider (RHIC) provided polarized proton collisions at two interaction points. The spin orientation of both beams at these collision points was controlled by helical spin rotators, and physics data were taken with different orientations of the beam polarization. Recent developments and improvements will be presented, as well as luminosity and polarization performance achieved during Run-9.

  12. Polarized e-e+ physics in linear colliders

    International Nuclear Information System (INIS)

    Prescott, C.Y.

    1980-11-01

    Electroweak interactions at high energies are expected to be dominated by spin-dependent forces. Recent advances in the production of polarized electron beams in linear machines provide the opportunity for studying these spin-dependent effects. Polarized e - e + annihilation at the Z 0 pole can provide precise measurements of neutral current parameters and the best experimental challenge to the standard model of electroweak interactions

  13. Linear polarization of gluons and photons in unpolarized collider experiments

    NARCIS (Netherlands)

    Pisano, C.; Boer, D.; Brodsky, S. J.; Buffing, M.G.A.; Mulders, P.J.G.

    2013-01-01

    We study azimuthal asymmetries in heavy quark pair production in unpolarized electron-proton and proton-proton collisions, where the asymmetries originate from the linear polarization of gluons inside unpolarized hadrons. We provide cross section expressions and study the maximal asymmetries allowed

  14. Polar Coding for the Large Hadron Collider: Challenges in Code Concatenation

    CERN Document Server

    AUTHOR|(CDS)2238544; Podzorny, Tomasz; Uythoven, Jan

    2018-01-01

    In this work, we present a concatenated repetition-polar coding scheme that is aimed at applications requiring highly unbalanced unequal bit-error protection, such as the Beam Interlock System of the Large Hadron Collider at CERN. Even though this concatenation scheme is simple, it reveals significant challenges that may be encountered when designing a concatenated scheme that uses a polar code as an inner code, such as error correlation and unusual decision log-likelihood ratio distributions. We explain and analyze these challenges and we propose two ways to overcome them.

  15. Bhabha vs. Moeller scattering as a contact-interaction analyzer at a polarized linear collider

    International Nuclear Information System (INIS)

    Pankov, A.; Paver, N.

    2002-10-01

    We discuss electron-electron contact-interaction searches in the processes e + e - →e + e - and e - e - →e - e - at planned Linear Colliders run in the e + e - and e - e - modes with both beams longitudinally polarized. Our analysis is based on the measurement, for the two processes, of polarized differential cross sections, and allows to simultaneously take into account the general set of electron contact interaction couplings as independent, non-zero, parameters thus avoiding the simplifying choice of a model. We evaluate the corresponding model-independent constraints on the contact coupling constants, emphasizing the role of the available beam polarization and the complementarity, as far as the chirality of the constants is concerned, of the two processes in giving the best constraints. We also make a comparison with the potential of e + e - →μ μ- at the same energy and initial beams polarization. (author)

  16. Realization of beam polarization at the linear collider and its application to EW processes

    Energy Technology Data Exchange (ETDEWEB)

    Franco-Sollova, F.

    2006-07-15

    The use of beam polarization at the future ILC e{sup +}e{sup -} linear collider will benefit the physics program significantly. This thesis explores three aspects of beam polarization: the application of beam polarization to the study of electroweak processes, the precise measurement of the beam polarization, and finally, the production of polarized positrons at a test beam experiment. In the first part of the thesis the importance of beam polarization at the future ILC is exhibited: the benefits of employing transverse beam polarization (in both beams) for the measurement of triple gauge boson couplings (TGCs) in the W-pair production process are studied. The sensitivity to anomalous TGC values is compared for the cases of transverse and longitudinal beam polarization at a center of mass energy of 500 GeV. Due to the suppressed contribution of the t-channel {nu} exchange, the sensitivity is higher for longitudinal polarization. For some physics analyses the usual polarimetry techniques do not provide the required accuracy for the measurement of the beam polarization (around 0.25% with Compton polarimetry). The second part of the thesis deals with a complementary method to measure the beam polarization employing physics data acquired with two polarization modes. The process of single-W production is chosen due to its high cross section. The expected precision for 500 fb{sup -1} and W{yields}{mu}{nu} decays only, is {delta}P{sub e{sup -}}/P{sub e{sup -}}=0.26% and {delta}P{sub e{sup +}}/P{sub e{sup +}}=0.33%, which can be further improved by employing additional W-decay channels. The first results of an attempt to produce polarized positrons at the E-166 experiment are shown in the last part of the thesis. The E-166 experiment, located at the Final Focus Test Beam at SLAC's LINAC employs a helical undulator to induce the emission of circularly polarized gamma rays by the beam electrons. These gamma rays are converted into longitudinally polarized electron

  17. Investigation of beam self-polarization in the future e+e− circular collider

    CERN Document Server

    AUTHOR|(CDS)2075800

    2016-10-24

    The use of resonant depolarization has been suggested for precise beam energy measurements (better than 100 keV) in the eþe− Future Circular Collider (FCC-eþe−) for Z and WW physics at 45 and 80 GeV beam energy respectively. Longitudinal beam polarization would benefit the Z peak physics program; however it is not essential and therefore it will be not investigated here. In this paper the possibility of selfpolarized leptons is considered. Preliminary results of simulations in presence of quadrupole misalignments and beam position monitors (BPMs) errors for a simplified FCC-eþe− ring are presented.

  18. Intense γ-ray generation for a polarized positron beam in a linear collider

    Directory of Open Access Journals (Sweden)

    Y. Miyahara

    2001-12-01

    Full Text Available γ-ray generation by Compton backscattering in an optical lens series with periodic focal points is considered to produce a polarized positron beam for a linear collider. The lens series is composed of 20 unit cells with a length of 210 mm. Each lens has a hole to pass an electron beam with an energy of 5.8 GeV and the generated γ rays. It is shown by diffraction analysis that laser beam loss in the series is very small, and the beam size is periodically reduced to 26 μm. Electron beam size is reduced to 34 μm in a superconducting solenoid with a field of 15 T. To get a required γ-ray yield of 7×10^{15} γ/s, only one circularly polarized CO_{2} laser source with a power of 24 kW is needed.

  19. Distinguishing new physics scenarios at a linear collider with polarized beams

    International Nuclear Information System (INIS)

    Pankov, A.A.; Tsytrinov, A.V.; Paver, N.

    2006-01-01

    Numerous nonstandard dynamics dominated by very high mass exchanges are described at current and future accelerator energies by appropriate contactlike effective interactions among the standard model particles. Correspondingly, they can manifest themselves only through deviations of the cross sections from the standard model predictions. If one such deviation were observed, it would be important to definitely identify, to a given confidence level, the actual source among the various possible nonstandard interactions that, in principle, can explain it. Here we estimate the identification reach on different new physics effective interactions, obtainable from angular distributions of lepton pair production processes at the planned electron-positron International Linear Collider with polarized beams. For each nonstandard model, such an identification reach defines the range in the relevant heavy mass scale parameter where it can be unambiguously distinguished from the other nonstandard models as the source of corrections to the standard model cross sections, in case these are observed. The effective interactions for which we estimate the expected identification reach are the interactions based on gravity in large extra dimensions, in TeV -1 extra dimensions and the compositeness-inspired four-fermion contact interactions. The availability of both beams polarized at the International Linear Collider turns out, in many cases, to dramatically enhance the identification sensitivity

  20. Revealing the large extra dimension effective interaction at an e+e- collider with polarized beams

    International Nuclear Information System (INIS)

    Pankov, A. A.; Tsytrinov, A. V.; Paver, N.

    2007-01-01

    Several types of new physics scenarios are represented by contactlike effective interactions. An example is the exchange of nonstandard quanta of very large mass scales, beyond the kinematical limit for direct production set by the available collider energy. This kind of interactions can be revealed only through deviations of observables from the standard model predictions. If such deviations were observed, the relevant source should be identified among the possible models that could explain them. Here, we assess the expected 'identification reach' on the ADD model of gravity in large compactified extra dimensions, against the compositeness-inspired four-fermion contact interaction. As basic observables we take the differential cross sections for fermion-pair production at a 0.5-1 TeV electron-positron linear collider with both beams longitudinally polarized. For the four-fermion contact interaction, we assume a general linear combination of the individual models with definite chiralities, with arbitrary coupling constants. In this sense, the estimated identification reach on the ADD model can be considered as 'model independent'. In the analysis, we give estimates also for the expected ''discovery reaches'' on the various scenarios. We emphasize the substantial role of beams polarization in enhancing the sensitivity to the contactlike interactions under consideration

  1. Characterizing New Physics with Polarized Beams at High-Energy Hadron Colliders

    CERN Document Server

    Fuks, Benjamin; Rojo, Juan; Schienbein, Ingo

    2014-01-01

    The TeV energy region is currently being explored by both the ATLAS and CMS experiments of the Large Hadron Collider and phenomena beyond the Standard Model are extensively searched for. Large fractions of the parameter space of many models have already been excluded, and the ranges covered by the searches will certainly be increased by the upcoming energy and luminosity upgrades. If new physics has to be discovered in the forthcoming years, the ultimate goal of the high-energy physics program will consist of fully characterizing the newly-discovered degrees of freedom in terms of properties such as their masses, spins and couplings. The scope of this paper is to show how the availability of polarized beams at high-energy proton-proton colliders could yield a unique discriminating power between different beyond the Standard Model scenarios. We first discuss in a model-independent way how this discriminating power arises from the differences between polarized and unpolarized parton distribution functions. We t...

  2. Spin transport at the international linear collider and its impact on the measurement of polarization

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, Moritz

    2013-12-15

    At the planned International Linear Collider (ILC), the longitudinal beam polarization needs to be determined with an unprecedented precision. For that purpose, the beam delivery systems (BDS) are equipped with two laser Compton polarimeters each, which are foreseen to achieve a systematic uncertainty of {<=} 0.25 %. The polarimeters are located 1.6 km upstream and 150 m downstream of the e{sup +}e{sup -} interaction point (IP). The average luminosity-weighted longitudinal polarization P{sup lumi}{sub z}, which is the decisive quantity for the experiments, has to be determined from these measurements with the best possible precision. Therefore, a detailed understanding of the spin transport in the BDS is mandatory to estimate how precise the longitudinal polarization at the IP is known from the polarimeter measurements. The envisaged precision for the propagation of the measurement value is {<=} 0.1 %. This thesis scrutinizes the spin transport in view of the achievable precision. A detailed beamline simulation for the BDS has been developed, including the simulation of the beam-beam collisions at the IP. The following factors which might limit the achievable precision is investigated: a variation of the beam parameters, the beam alignment precision at the polarimeters and the IP, the bunch rotation at the IP, the detector magnets, the beam-beam collisions, the emission of synchrotron radiation and misalignments of the beamline elements. In absence of collisions, a precision of 0.085% on the propagation of the measured longitudinal polarization has been found achievable. This result however depends mainly on the presumed precisions for the parallel alignment of the beam at the polarimeters and for the alignment of polarization vector. In presence of collisions, the measurement at the downstream polarimeter depends strongly on the intensity of the collision and the size of the polarimeter laser spot. Therefore, a more detailed study of the laser-bunch interaction is

  3. Review on Recent Results from RHIC Polarized Collider; Unexpected Forward Neutron Asymmetry

    Science.gov (United States)

    Nakagawa, Itaru

    The polarized proton-proton collider at RHIC provides an unique opportunity to study the spin structure of the proton. The latest highlights from both transverse and longitudinal RHIC spin program are introduced in this document. For the transverse program, two asymmetry measurements are discussed here which are distinguished by the production mechanism either soft (diffractive) or hard perturbative QCD natures depending on the rapidity region of the hadron production. The former is the very forwardneutron asymmetry measurements which showed unexpectedly drastic dependence on the atomic mass. The latter is the forward pion production whose origin of the large asymmetry has been under debate for theoretical understanding over two decades. For longitudinal program, the latest highlights from the measurements on the gluon and the sea quark spin components of the proton spin are discussed.

  4. Polarization preservation and control in a figure-8 ring

    Energy Technology Data Exchange (ETDEWEB)

    Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Lin, Fanglei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Kondratenko, A. M. [GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058; Kondratenko, M. A. [GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058; Filatov, Yuri [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058

    2016-02-01

    We present a complete scheme for managing the polarization of ion beams in Jefferson Lab's proposed Medium-energy Electron-Ion Collider (MEIC). It provides preservation of the ion polarization during all stages of beam acceleration and polarization control in the collider's experimental straights. We discuss characteristic features of the spin motion in accelerators with Siberian snakes and in accelerators of figure-8 shape. We propose 3D spin rotators for polarization control in the MEIC ion collider ring. We provide polarization calculations in the collider with the 3D rotator for deuteron and proton beams. The main polarization control features of the figure-8 design are summarized.

  5. CERN: TeV Electron-Positron Linear Collider Studies; More polarization in LEP

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The world's highest energy electronpositron collider - CERN's LEP, with a circumference of 27 kilometres - will also be the last such machine to be built as a storage ring. With interest growing in electronpositron physics at energies beyond those attainable at LEP, the next generation of electron-positron colliders must be linear if prohibitive synchrotron radiation power losses are to be avoided. Very high energy linear colliders present many technical challenges but mastery of SLC at Stanford, the world's first electron-positron linear collider, is encouraging. The physics issues of a linear collider have been examined by the international community in ICFA workshops in Saariselka, Finland (September 1991) and most recently in Hawaii (April 1993). The emerging consensus is for a collider with an initial collision energy around 500 GeV, and which can be upgraded to over 1 TeV. A range of very different collider designs are being studied at Laboratories in Europe, the US, Japan and Russia. Following the report of the 1987 CERN Long Range Planning Committee chaired by Carlo Rubbia, studies for a 2 TeV linear collider have progressed at CERN alongside work towards the Laboratory's initial objective - the LHC high energy proton-proton collider in the LEP tunnel

  6. Design studies of high-luminoisty ring-ring- eletron-ion collider at CEBAF.

    Energy Technology Data Exchange (ETDEWEB)

    Bogacz, A.; Brindza, P.; Bruell, A.; Cardman, L.; Delayen, J.; Ostroumov, P.; Derbenev, Y.; Ent, R.; Evtushenko, P.; Grames, J.; Hutton, A.; Krafft, G.; Li, R.; Merminga, L.; Musson, J.; Poelker, M.; Thomas, A.; Wojteshowski, B.; Yunn, B.; Zhang, Y.; Fischer, W.; Montag, C.; Dudnikov, V.; Belov, A.; Derenchuk, V.; Physics; Jefferson Lab.; BNL; BTG; INR; IUCF

    2007-08-01

    Experimental studies of fundamental structure of nucleons require an electron-ion collider of a center-of-mass energy up to 90 GeV at luminosity up to 10{sup 35} cm{sup -2}s{sup -1} with both beams polarized. A CEBAF-based collider of 9 GeV electrons/positrons and 225 GeV ions is envisioned to meet this science need and as a next step for CEBAF after the planned 12 GeV energy upgrade of the fixed target program. A ring-ring scheme of this collider developed recently takes advantage of the existing polarized electron CW beam from the CEBAF and a green-field design of an ion complex with electron cooling. We present a conceptual design and report design studies of this high-luminosity collider.

  7. Spectroscopy of heavy few-electron ions

    International Nuclear Information System (INIS)

    Mokler, P.H.

    1986-07-01

    In this paper we ask first, why is it interesting to investigate heavy-few electron ions. Then the various accelerator-based methods to produce heavy few-electron ions are discussed. In the main part an overview on available heavy few-electron ion data and current experiments is given. The summary will end up with future aspects in this field. (orig.)

  8. Muon collider design

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, R.B.; Sessler, A.; Skrinsky, A.N.; Tollestrup, A.; Baltz, A.; Caspi, S.; Chen, P.; Cheng, W.-H.; Cho, Y.; Cline, D.B.; Courant, E.; Fernow, R.; Gallardo, J.C.; Garren, A.; Gordon, H.; Green, M.A.; Gupta, R.; Hershcovitch, A.; Johnstone, C.; Kahn, S.; Kirk, H.; Kycia, T.; Lee, Y.; Lissauer, D.; Luccio, A.; McInturff, A.; Mills, F.; Mokhov, N.V.; Morgan, G.; Neuffer, D.; Ng, K.-Y.; Noble, R.; Norem, J.; Norum, B.; Oide, K.; Parsa, Z.; Polychronakos, V.; Popovic, M.; Rehak, P.; Roser, T.; Rossmanith, R.; Scanlan, R.; Schachinger, L.; Silvestrov, G.; Stumer, I.; Summers, D.; Syphers, M.; Takahashi, H.; Torun, Y.; Trbojevic, D.; Turner, W.; Van Ginneken, A.; Vsevolozhskaya, T.; Weggel, R.; Willen, E.; Willis, W.; Winn, D.; Wurtele, J.; Zhao, Y. [Brookhaven Nat. Lab., Upton, NY (United States)]|[Stanford Linear Accelerator Center, Stanford, CA 94309 (United States)]|[Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)]|[BINP, 630090 Novosibirsk (Russian Federation)]|[Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)]|[Argonne National Laboratory, Argonne, IL 60439-4815 (United States)]|[Center for Advanced Accelerators, UCLA, Los Angeles, CA 90024-1547 (United States)]|[CEBAF, Newport News, VA 23606 (United States)]|[University of Virginia, Charlottesville, VA 22901 (United States)]|[KEK, Tsukuba-shi, Ibaraki-Ken 305 (Japan)]|[DESY, Hamburg (Germany)]|[University of Mississippi, Oxford, MS 38677 (United States)]|[SUNY, Stony Brook, NY 11974 (United States)]|[Francis Bitter National Magnet Laboratory, MIT, Cambridge, MA 02139 (United States)]|[Columbia University, New York, NY 10027 (United States)]|[Fairfield University, Fairfield, CT 06430-5195 (United States)]|[UC Berkele

    1996-11-01

    The construction principles of {mu}{sup +}{mu}{sup -}-colliders are discussed. After a presentation of the properties of some collider ring candidate designs, the methods for {mu}{sup {+-}} production are described. Then the principles of beam cooling for such colliders are considered. Finally the components of a collider storage rings are described, whereby also polarization is considered. (HSI).

  9. Update on the MEIC electron collider ring design

    International Nuclear Information System (INIS)

    The electron collider ring of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab is designed to accumulate and store a high-current polarized electron beam for collisions with an ion beam. We consider a design of the electron collider ring based on reusing PEP-II components, such as magnets, power supplies, vacuum system, etc. This has the potential to significantly reduce the cost and engineering effort needed to bring the project to fruition. This paper reports on an electron ring optics design considering the balance of PEP-II hardware parameters (such as dipole sagitta, magnet field strengths and acceptable synchrotron radiation power) and electron beam quality in terms of equilibrium emittances.

  10. Update on the MEIC electron collider ring design

    International Nuclear Information System (INIS)

    The electron collider ring of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab is designed to accumulate and store a high-current polarized electron beam for collisions with an ion beam. We consider a design of the electron collider ring based on reusing PEPII components, such as magnets, power supplies, vacuum system, etc. This has the potential to significantly reduce the cost and engineering effort needed to bring the project to fruition. This paper reports on an electron ring optics design considering the balance of PEP-II hardware parameters (such as dipole sagitta, magnet field strengths and acceptable synchrotron radiation power) and electron beam quality in terms of equilibrium emittances.

  11. Polarized single top quark production at leptonic colliders from broken R parity interactions incorporating CP violation

    CERN Document Server

    Chemtob, M

    2000-01-01

    The contribution from the R parity violating interaction lambda /sub ijk/'L/sub i/Q/sub j/D/sub k//sup c/ in the associated production of a top quark (antiquark) with a charm antiquark (quark) is examined for high energy leptonic colliders. We concentrate on the reaction l /sup -/+l/sup +/ to (tc)+(ct) to (bl nu c)+(bl nu c) associated with the semileptonic top quark decay. A set of characteristic dynamical distributions for the signal events is evaluated and the results contrasted against those from the standard model W-boson pair production background. The sensitivity to parameters (R parity violating coupling constants and down-squark mass) is studied at the energies of the CERN LEP-II collider and the future linear colliders. Next, we turn to a study of a CP-odd observable, associated with the top quark spin, which leads to an asymmetry in the energy distribution of the emitted charged leptons for the pair of CP- conjugate final states bl nu c and bl nu c. A nonvanishing asymmetry arises from a CP-odd pha...

  12. Ion Colliders

    CERN Document Server

    Fischer, W

    2014-01-01

    High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

  13. RHIC PERFORMANCE AND PLANS TOWARDS HIGHER LUMINOSITY AND HIGHER POLARIZATION.

    Energy Technology Data Exchange (ETDEWEB)

    SATOGATA,T.

    2004-07-05

    The Relativistic Heavy Ion Collider (RHIC), the first hadron accelerator and collider consisting of two independent rings, has completed its fourth year of operation since commissioning in 1999. RHIC is designed to provide luminosity over a wide range of beam energies and species, including heavy ions, polarized protons, and asymmetric beam collisions. RHIC has produced physics data at four experiments in runs that include gold-on-gold collisions at various beam energies (9.8, 31, 65, and 100 GeV/u), high-energy polarized proton-proton collisions (100 GeV), and deuteron-gold collisions (100 GeV/u). We review recent machine performance for high-luminosity gold-gold operations and polarized proton operations, including causes and solutions for known operational limits. Plans and progress for luminosity and polarization improvements, electron cooling, and the electron-ion collider eRHIC are discussed.

  14. Ion colliders

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions (77Asb1, 81Bou1). The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  15. Ion colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, W.

    2011-12-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions [77Asb1, 81Bou1]. The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  16. Numerical Simulation of Beam-Beam Effects in the Proposed Electron-Ion Colider at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Balsa Terzic, Yuhong Zhang

    2010-05-01

    One key limiting factor to a collider luminosity is beam-beam interactions which usually can cause serious emittance growth of colliding beams and fast reduction of luminosity. Such nonlinear collective beam effect can be a very serious design challenge when the machine parameters are pushed into a new regime. In this paper, we present simulation studies of the beam-beam effect for a medium energy ring-ring electron-ion collider based on CEBAF.

  17. Polarized Ion Beams in Figure-8 Rings of JLab's MEIC

    Energy Technology Data Exchange (ETDEWEB)

    Derbenev, Yaroslav; Lin, Fanglei; Morozov, Vasiliy; Zhang, Yuhong; Kondratenko, Anatoliy; Kondratenko, M A; Filatov, Yury

    2014-07-01

    The Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab is designed to provide high polarization of both colliding beams. One of the unique features of JLab's MEIC is figure-8 shape of its rings. It allows preservation and control of polarization of all ion species including small-anomalous-magnetic-moment deuterons during their acceleration and storage. The figure-8 design conceptually expands the capability of obtaining polarized high-energy beams in comparison to conventional designs because of its property of having no preferred periodic spin direction. This allows one to control effectively the beam polarization by means of magnetic insertions with small field integrals. We present a complete scheme for preserving the ion polarization during all stages of acceleration and its control in the collider's experimental straights.

  18. THE NEAR-INTEGER WORKING POINT FOR POLARIZED PROTONS IN THE RELATIVISTIC HEAVY ION COLLIDER

    Energy Technology Data Exchange (ETDEWEB)

    MONTAG,C.; BAI, M.; BEEBE-WANG, J.; CALAGA, R.; BLASKIEWICZ, M.; ET AL.

    2007-06-25

    To achieve the RHIC polarized proton enhanced luminosity goal of 150.10{sup 30} cm{sup -2}sec{sup -} on average in stores at 250 GeV, the luminosity needs to be increased by a factor of 3 compared to what was achieved in 2006. Since the number of bunches is already at its maximum of 1 1 1, limited by the injection kickers and the experiments' time resolution, the luminosity can only be increased by either increasing the bunch intensity and/or reducing the beam emittance. This leads to a larger beam-beam tuneshift parameter. Operations during 2006 has shown that the beam-beam interaction is already dominating the luminosity lifetime. To overcome this limitation, a near-integer working point is under study. We will present recent results of these studies.

  19. Probing Anomalous WW γ and WWZ Couplings with Polarized Electron Beam at the LHeC and FCC-Ep Collider

    CERN Document Server

    Turk Cakir, I; Tasci, A T; Cakir, O

    2016-01-01

    We study the anomalous WWγ and WWZ couplings by calculating total cross sections of two processes at the LHeC with electron beam energy Ee=140 GeV and the proton beam energy Ep=7 TeV, and at the FCC-ep collider with the polarized electron beam energy Ee=80 GeV and the proton beam energy Ep=50 TeV. At the LHeC with electron beam polarization, we obtain the results for the difference of upper and lower bounds as (0.975, 0.118) and (0.285, 0.009) for the anomalous (∆κγ, λγ) and (∆κz, λz) couplings, respectively. As for FCC-ep collider, these bounds are obtained as (1.101, 0.065) and (0.320, 0.002) at an integrated luminosity of Lint=100 fb-1.

  20. Opportunities for Polarized He-3 in RHIC and EIC

    Energy Technology Data Exchange (ETDEWEB)

    Aschenauer E.; Deshpande, A.; Fischer, W.; Derbenev, S.; Milner, R.; Roser, T.; Zelenski, A.

    2011-10-01

    The workshop on opportunities for polarized He-3 in RHIC and EIC was targeted at finding practical ways of implementing and using polarized He-3 beams. Polarized He-3 beams will provide the unique opportunity for first measurements, i.e, to a full quark flavor separation measuring single spin asymmetries for p{sup +}, p{sup -} and p{sup 0} in hadron-hadron collisions. In electron ion collisions the combination of data recorded with polarized electron proton/He-3 beams allows to determine the quark flavor separated helicity and transverse momentum distributions. The workshop had sessions on polarized He-3 sources, the physics of colliding polarized He-3 beams, polarimetry, and beam acceleration in the AGS Booster, AGS, RHIC, and ELIC. The material presented at the workshop will allow making plans for the implementation of polarized He-3 beams in RHIC.

  1. Indirect processes in electron-ion scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bottcher, C.; Griffin, D.C.; Pindzola, M.S.; Phaneuf, R.A.

    1983-10-01

    A summary is given of an informal workshop held at Oak Ridge National Laboratory on June 22-23, 1983, in which the current status of theoretical calculations of indirect processes in electron-ion scattering was reviewed. Processes of particular interest in astrophysical and fusion plasmas were emphasized. Topics discussed include atomic structure effects, electron-impact ionization, and dielectronic recombination.

  2. Muon Collider Design

    International Nuclear Information System (INIS)

    Chen, Pisin

    2003-01-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high luminosity μ + μ - colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Detector background, polarization, and nonstandard operating conditions are discussed

  3. Colliding nuclei

    International Nuclear Information System (INIS)

    Balian, Roger; Remaud, Bernard; Suraud, E.; Durand, Dominique; Tamain, Bernard; Gobbi, A.; Cugnon, J.; Drapier, Olivier; Govaerts, Jan; Prieels, Rene

    1995-09-01

    This 14. international school Joliot-Curie of nuclear physic deals with nuclei in collision at high energy. Nine lectures are included in the proceedings of this summer school: 1 - From statistical mechanics outside equilibrium to transport equations (Balian, R.); 2 - Modeling of heavy ions reactions (Remaud, B.); 3 - Kinetic equations in heavy ions physics (Suraud, E.); 4 - Colliding nuclei near the Fermi energy (Durand, D.; Tamain, B.); 5 - From the Fermi to the relativistic energy domain: which observable? For which physics? (Gobbi, A.); 6 - Collisions at relativistic and ultra relativistic energies, Theoretical aspects (Cugnon, J.); 7 - Quark-gluon plasma: experimental signatures (Drapier, O.); 8 - Electroweak interaction: a window on physics beyond the standard model (Govaerts, J.); 9 - Symmetry tests in β nuclear process: polarization techniques (Prieels, R.)

  4. Polarization developments

    International Nuclear Information System (INIS)

    Prescott, C.Y.

    1993-07-01

    Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist

  5. Muon colliders

    International Nuclear Information System (INIS)

    Cline, David

    1995-01-01

    The increasing interest in the possibility of positive-negative muon colliders was reflected in the second workshop on the Physics Potential and Development of Muon Colliders, held in Sausalito, California, from 16-19 November, with some 60 attendees. It began with an overview of the particle physics goals, detector constraints, the muon collider and mu cooling, and source issues. The major issue confronting muon development is the possible luminosity achievable. Two collider energies were considered: 200 + 200 GeV and 2 + 2 TeV. The major particle physics goals are the detection of the higgs boson(s) for the lower energy collider, together with WW scattering and supersymmetric particle discovery. At the first such workshop, held in Napa, California, in 1992, it was estimated that a luminosity of some 10 30 and 3 x 10 32 cm -2 s -1 for the low and high energy collider might be achieved (papers from this meeting were published in the October issue of NIM). This was considered a somewhat conservative estimate at the time. At the Sausalito workshop the goal was to see if a luminosity of 10 32 to 10 34 for the two colliders might be achievable and usable by a detector. There were five working groups - physics, 200 + 200 GeV collider, 2 + 2 TeV collider, detector design and backgrounds, and muon cooling and production methods. Considerable progress was made in all these areas at the workshop.

  6. Muon Colliders

    International Nuclear Information System (INIS)

    Robert B. Palmer; A. Sessler; A. Skrinsky; A. Tollestrup; A.J. Baltz; P. Chen; W-H. Cheng; Y. Cho; E. Courant; Richard C. Fernow; Juan C. Gallardo; A. Garren; M. Green; S. Kahn; H. Kirk; Y. Y. Lee; F. Mills; N. Mokhov; G. Morgan; David Neuffer; R. Noble; J. Norem; M. Popovic; L. Schachinger; G. Silvestrov; D. Summers; I. Stumer; M. Syphers; Yagmur Torun; D. Trbojevic; W. Turner; A. Van Ginneken; T. Vsevolozhskaya; R. Weggel; E. Willen; David Winn; J. Wurtele

    1994-01-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high luminosity(mu)(sup+)(mu)(sup -) colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Problems of detector background are also discussed

  7. The Stanford Linear Collider

    International Nuclear Information System (INIS)

    Emma, P.

    1995-01-01

    The Stanford Linear Collider (SLC) is the first and only high-energy e + e - linear collider in the world. Its most remarkable features are high intensity, submicron sized, polarized (e - ) beams at a single interaction point. The main challenges posed by these unique characteristics include machine-wide emittance preservation, consistent high intensity operation, polarized electron production and transport, and the achievement of a high degree of beam stability on all time scales. In addition to serving as an important machine for the study of Z 0 boson production and decay using polarized beams, the SLC is also an indispensable source of hands-on experience for future linear colliders. Each new year of operation has been highlighted with a marked improvement in performance. The most significant improvements for the 1994-95 run include new low impedance vacuum chambers for the damping rings, an upgrade to the optics and diagnostics of the final focus systems, and a higher degree of polarization from the electron source. As a result, the average luminosity has nearly doubled over the previous year with peaks approaching 10 30 cm -2 s -1 and an 80% electron polarization at the interaction point. These developments as well as the remaining identifiable performance limitations will be discussed

  8. Photon-photon colliders

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, A.M.

    1995-04-01

    Since the seminal work by Ginsburg, et at., the subject of giving the Next Linear Collider photon-photon capability, as well as electron-positron capability, has drawn much attention. A 1990 article by V.I. Teinov describes the situation at that time. In March 1994, the first workshop on this subject was held. This report briefly reviews the physics that can be achieved through the photon-photon channel and then focuses on the means of achieving such a collider. Also reviewed is the spectrum of backscattered Compton photons -- the best way of obtaining photons. We emphasize the spectrum actually obtained in a collider with both polarized electrons and photons (peaked at high energy and very different from a Compton spectrum). Luminosity is estimated for the presently considered colliders, and interaction and conversion-point geometries are described. Also specified are laser requirements (such as wavelength, peak power, and average power) and the lasers that might be employed. These include conventional and free-electron lasers. Finally, we describe the R&D necessary to make either of these approaches viable and explore the use of the SLC as a test bed for a photon-photon collider of very high energy.

  9. The SLAC linear collider

    International Nuclear Information System (INIS)

    Phinney, N.

    1992-01-01

    The SLAC Linear Collider has begun a new era of operation with the SLD detector. During 1991 there was a first engineering run for the SLD in parallel with machine improvements to increase luminosity and reliability. For the 1992 run, a polarized electron source was added and more than 10,000 Zs with an average of 23% polarization have been logged by the SLD. This paper discusses the performance of the SLC in 1991 and 1992 and the technical advances that have produced higher luminosity. Emphasis will be placed on issues relevant to future linear colliders such as producing and maintaining high current, low emittance beams and focusing the beams to the micron scale for collisions. (Author) tab., 2 figs., 18 refs

  10. ''Atomic'' Bremsstrahlung or polarizational radiation in collision of many-electron ions

    International Nuclear Information System (INIS)

    Amusia, M.Ya.; Solov'yov, A.V.

    1991-01-01

    In this work the so-called ''Atomic'' bremsstrahlung (AB) or polarizational radiation, created in collisions of atoms or ions, is discussed. This kind of radiation arises due to the polarization of the electron shell of colliding particles. It is created by the structured projectiles and targets if the constituents are electrically charged. 6 refs, 2 figs

  11. Asymmetric collider

    International Nuclear Information System (INIS)

    Bharadwaj, V.; Colestock, P.; Goderre, G.; Johnson, D.; Martin, P.; Holt, J.; Kaplan, D.

    1993-01-01

    The study of CP violation in beauty decay is one of the key challenges facing high energy physics. Much work has not yielded a definitive answer how this study might best be performed. However, one clear conclusion is that new accelerator facilities are needed. Proposals include experiments at asymmetric electron-positron colliders and in fixed-target and collider modes at LHC and SSC. Fixed-target and collider experiments at existing accelerators, while they might succeed in a first observation of the effect, will not be adequate to study it thoroughly. Giomataris has emphasized the potential of a new approach to the study of beauty CP violation: the asymmetric proton collider. Such a collider might be realized by the construction of a small storage ring intersecting an existing or soon-to-exist large synchrotron, or by arranging collisions between a large synchrotron and its injector. An experiment at such a collider can combine the advantages of fixed-target-like spectrometer geometry, facilitating triggering, particle identification and the instrumentation of a large acceptance, while the increased √s can provide a factor > 100 increase in beauty-production cross section compared to Tevatron or HERA fixed-target. Beams crossing at a non-zero angle can provide a small interaction region, permitting a first-level decay-vertex trigger to be implemented. To achieve large √s with a large Lorentz boost and high luminosity, the most favorable venue is the high-energy booster (HEB) at the SSC Laboratory, though the CERN SPS and Fermilab Tevatron are also worth considering

  12. Collider Physics

    Indian Academy of Sciences (India)

    This is summary of the activities of the working group on collider physics in the IXth Workshop on High Energy Physics Phenomenology (WHEPP-9) held at the Institute of Physics, Bhubaneswar, India in January 2006. Some of the work subsequently done on these problems by the subgroups formed during the workshop is ...

  13. Colliding muons

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Is a muon-muon collider really practical? That is the question being asked by Bob Palmer. Well known in particle physics, Palmer, with Nick Samios and Ralph Shutt, recently won the American Physical Society's Panofsky Prize for their 1964 discovery of the omega minus. As well as contributing to other major experiments, both at CERN and in the US, he has contributed ideas to stochastic cooling and novel acceleration schemes

  14. Wavelength dependent photoelectron circular dichroism of limonene studied by femtosecond multiphoton laser ionization and electron-ion coincidence imaging

    Science.gov (United States)

    Rafiee Fanood, Mohammad M.; Janssen, Maurice H. M.; Powis, Ivan

    2016-09-01

    Enantiomers of the monoterpene limonene have been investigated by (2 + 1) resonance enhanced multiphoton ionization and photoelectron circular dichroism employing tuneable, circularly polarized femtosecond laser pulses. Electron imaging detection provides 3D momentum measurement while electron-ion coincidence detection can be used to mass-tag individual electrons. Additional filtering, by accepting only parent ion tagged electrons, can be then used to provide discrimination against higher energy dissociative ionization mechanisms where more than three photons are absorbed to better delineate the two photon resonant, one photon ionization pathway. The promotion of different vibrational levels and, tentatively, different electronic ion core configurations in the intermediate Rydberg states can be achieved with different laser excitation wavelengths (420 nm, 412 nm, and 392 nm), in turn producing different state distributions in the resulting cations. Strong chiral asymmetries in the lab frame photoelectron angular distributions are quantified, and a comparison made with a single photon (synchrotron radiation) measurement at an equivalent photon energy.

  15. Electron-ion thermal equilibration after spherical shock collapse

    Energy Technology Data Exchange (ETDEWEB)

    Rygg, J R; Frenje, J A; Li, C K; Seguin, F H; Petrasso, R D; Meyerhofer, D D; Stoeckl, C

    2009-08-14

    A comprehensive set of dual nuclear product observations provides a snapshot of imploding inertial confinement fusion capsules at the time of shock collapse, shortly before the final stages of compression. The collapse of strong convergent shocks at the center of spherical capsules filled with D{sub 2} and {sup 3}He gas induces D-D and D-{sup 3}He nuclear production. Temporal and spectral diagnostics of products from both reactions are used to measure shock timing, temperature, and capsule areal density. The density and temperature inferred from these measurements are used to estimate the electron-ion thermal coupling, and demonstrate a lower electron-ion relaxation rate for capsules with lower initial gas density.

  16. Impact of the Tilted Detector Solenoid on the Ion Polarization at JLEIC

    Science.gov (United States)

    Kondratenko, A. M.; Kondratenko, M. A.; Filatov, Yu N.; Derbenev, Ya S.; Lin, F.; Morozov, V. S.; Zhang, Y.

    2017-12-01

    Jefferson Lab Electron Ion Collider (JLEIC) is a figure-8 collider “transparent” to the spin. This allows one to control the ion polarization using a universal 3D spin rotator based on weak solenoids. Besides the 3D spin rotator, a coherent effect on the spin is produced by a detector solenoid together with the dipole correctors and anti-solenoids compensating betatron oscillation coupling. The 4 m long detector solenoid is positioned along a straight section of the electron ring and makes a 50 mrad horizontal angle with a straight section of the ion ring. Such a large crossing angle is needed for a quick separation of the two colliding beams near the interaction point to make sufficient space for placement of interaction region magnets and to avoid parasitic collisions of shortly-spaced 476 MHz electron and ion bunches. We present a numerical analysis of the detector solenoid effect on the proton and deuteron polarizations. We demonstrate that the effect of the detector solenoid on the proton and deuteron polarizations can be compensated globally using an additional 3D rotator located anywhere in the ring. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contracts DE-AC05-06OR23177 and DE-AC02-06CH11357.

  17. ION BEAM POLARIZATION DYNAMICS IN THE 8 GEV BOOSTER OF THE JLEIC PROJECT AT JLAB

    Energy Technology Data Exchange (ETDEWEB)

    Kondratenko, A. M. [GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058, Russia; Kondratenko, M. A. [GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058, Russia; Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Lin, Fanglei; Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Filatov, Yuri [MIPT, Dolgoprudniy, Moscow Region, Russia

    2016-05-01

    In the Jefferson Lab’s Electron-Ion Collider (JLEIC) project, an injector of polarized ions into the collider ring is a superconducting 8 GeV booster. Both figure-8 and racetrack booster versions were considered. Our analysis showed that the figure-8 ring configuration allows one to preserve the polarization of any ion species during beam acceleration using only small longitudinal field with an integral less than 0.5 Tm. In the racetrack booster, to pre-serve the polarization of ions with the exception of deu-terons, it suffices to use a solenoidal Siberian snake with a maximum field integral of 30 Tm. To preserve deuteron polarization, we propose to use arc magnets for the race-track booster structure with a field ramp rate of the order of 1 T/s. We calculate deuteron and proton beam polari-zations in both the figure-8 and racetrack boosters includ-ing alignment errors of their magnetic elements using the Zgoubi code.

  18. Luminosity geometric reduction factor from colliding bunches with different lengths

    Energy Technology Data Exchange (ETDEWEB)

    Verdu-Andres, S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-09-29

    In the interaction point of the future electron-Ion collider eRHIC, the electron beam bunches are at least one order of magnitude shorter than the proton beam bunches. With the introduction of a crossing angle, the actual number of collisions resulting from the bunch collision gets reduced. Here we derive the expression for the luminosity geometric reduction factor when the bunches of the two incoming beams are not equal.

  19. Excitation and ionization contributions to sum-rule Born cross sections for collisions of one-electron ions with atoms

    International Nuclear Information System (INIS)

    Gillespie, G.H.

    1978-01-01

    The contributions of bound-state excitations and continuum ionizations to the total inelastic (sum-rule) cross section are examined in Born approximation. The results of an investigation of this problem for the case of one-electron ions colliding with neutral atoms are presented. Emphasis in this work is placed on the general features of these types of cross sections and on the relative contributions of excitation and ionization to the total Born cross section. In addition, extensive numerical results for the parameters which determine the cross sections for electron loss, and for excitation to bound states, are given for one-electron ions having atomic numbers up to 30 colliding with He, N, and Ar target atoms. It is shown that for the asymptotic (high-velocity) Born cross sections, excitation never contributes more than a certain fraction of the total sum-rule inelastic cross section, and this fraction has a bound which is determined by the dipole limit of the transition amplitudes for the incident ion. This bound is given by M/sub ex/ 2 /M/sub tot/ 2 , where M/sub tot/ 2 is the -1 energy moment of the dipole-oscillator-strength distribution and M/sub ex/ 2 is the contribution to this moment from transitions to bound excited states. This result is independent of the target atom involved in the collision. Since M/sub ex/ 2 /M/sub tot/ 2 does not depend on the atomic number for one-electron ions, this bound is also independent of the incident-ion atomic number in this case. As a consequence, ionization never contributes less to the sum-rule cross sections than the fraction (1-M/sub ex/ 2 /M/sub tot/ 2 ) = M/sub ion/ 2 /M/sub tot/ 2 . The more general problem, which involves multielectron ions (or atoms) colliding with atoms, is discussed from several viewpoints, and similar results are suggested for that case. In particular, separate upper bounds on the Born-excitation cross section, and lower bounds on the Born electron-loss cross section, are proposed

  20. Status of the MEIC ion collider ring design

    International Nuclear Information System (INIS)

    Morozov, Vasiliy; Derbenev, Yaroslav; Harwood, Leigh; Hutton, Andrew; Lin, Fanglei; Pilat, Fulvia; Zhang, Yuhong; Cai, Yunhai; Nosochkov, Y. M.; Sullivan, Michael; Wang, M.-H.; Wienands, Uli; Gerity, James; Mann, Thomas; McIntyre, Peter; Pogue, Nathaniel; Sattarov, Akhdiyor

    2015-09-01

    We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated super-conducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

  1. Status of the MEIC ion collider ring design

    International Nuclear Information System (INIS)

    Morozov, V. S.; Derbenev, Ya. S.; Harwood, L.; Hutton, A.; Lin, F.; Pilat, F.; Zhang, Y.; Cai, Y.; Nosochkov, Y. M.; Sullivan, M.; Wang, M-H; Wienands, U.; Gerity, J.; Mann, T.; McIntyre, P.; Pogue, N. J.; Satttarov, A.

    2015-01-01

    We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated superconducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

  2. Analytical Schwartz density applied to heavy two-electron ions

    Energy Technology Data Exchange (ETDEWEB)

    Romera, E.; Dehesa, J.S. [Universidad de Granada (Spain); Koga, Toshikatsu [Muroran Institute of Technology (Japan)

    1997-01-20

    An analytical expression of the electron density function p(r) due to Schwartz for two-electron atomic systems is applied to a detailed study of density-dependent properties of relatively heavy two-electron ions. Comparison of the Schwartz results with those from accurate Hartree-Fock and Hylleraas wave functions shows that despite its simple yet analytical form, the Schwartz density has a quantitative applicability in the density study of two-electron atoms within the nonrelativistic framework. 13 refs., 4 tabs.

  3. HIGH ENERGY MUON COLLIDERS

    International Nuclear Information System (INIS)

    KING, B.J.

    2001-01-01

    A plausible ''straw-man'' scenario and collider ring parameter sets are presented for future energy frontier muon colliders in symbiotic facilities with e + e - and hadron colliders: 1.6-10 TeV ''mu-linear colliders'' (mu-LC) where the muons are accelerated in the linacs of a TeV-scale linear e + e - collider, and a 100 TeV Very Large Muon Collider (VLMC) that shares a facility with a 200 TeV Very Large Hadron collider (VLHC) and a 140 TeV muon-proton collider

  4. Development of an electron electron ion coincidence analyzer for Auger photoelectron coincidence spectroscopy (APECS) and electron ion coincidence (EICO) spectroscopy

    International Nuclear Information System (INIS)

    Kakiuchi, Takuhiro; Kobayashi, Eiichi; Okada, Naoyuki; Oyamada, Ken; Okusawa, Makoto; Okudaira, Koji K.; Mase, Kazuhiko

    2007-01-01

    We have developed an electron electron ion coincidence (EEICO) analyzer for Auger photoelectron coincidence spectroscopy (APECS) and electron ion coincidence (EICO) spectroscopy. It consists of a coaxially symmetric mirror electron energy analyzer (coASMA), a miniature cylindrical mirror electron energy analyzer (CMA), a miniature time-of-flight ion mass spectrometer (TOF-MS), a xyz stage, a tilt-adjustment mechanism, and a conflat flange with an outer diameter of 203 mm. A sample surface is irradiated by synchrotron radiation, and emitted electrons are energy-analyzed and detected by the coASMA and the CMA, while desorbed ions are detected by the TOF-MS. The performance of the new EEICO analyzer was tested by measuring Si-LVV-Si-2p APECS data of clean Si(1 1 1)7 x 7 and Si(1 1 1)7 x 7 covered by dissociated H 2 O, and by measuring the Auger-electron photoion coincidence (AEPICO) spectra of condensed H 2 O at the 4a 1 <- O 1s resonance

  5. Muon Muon Collider: Feasibility Study

    International Nuclear Information System (INIS)

    2012-01-01

    how to shield the detector and reduce the background are addressed in the Detector Chapter. Polarization of the muons allows many very interesting measurements which are discussed in the Physics Chapter. Unlike the electron collider in which the electron beam is highly polarized and the positron beam unpolarized, both muon beams may be partially polarized. It is necessary to select forward moving muons from the pion's decay and thus reduce the available number of muons and hence the luminosity. The necessary machine technology needed to achieve such a collider is discussed in the Option Chapter; at the moment it is not part of our point design, although such capability would almost certainly be incorporated into an actual device.

  6. Muon Muon Collider: Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, J.C.; Palmer, R.B.; /Brookhaven; Tollestrup, A.V.; /Fermilab; Sessler, A.M.; /LBL, Berkeley; Skrinsky, A.N.; /Novosibirsk, IYF; Ankenbrandt, C.; Geer, S.; Griffin, J.; Johnstone, C.; Lebrun, P.; McInturff, A.; Mills, Frederick E.; Mokhov, N.; Moretti, A.; Neuffer, D.; Ng, K.Y.; Noble, R.; Novitski, I.; Popovic, M.; Qian, C.; Van Ginneken, A. /Fermilab /Brookhaven /Wisconsin U., Madison /Tel Aviv U. /Indiana U. /UCLA /LBL, Berkeley /SLAC /Argonne /Sobolev IM, Novosibirsk /UC, Davis /Munich, Tech. U. /Virginia U. /KEK, Tsukuba /DESY /Novosibirsk, IYF /Jefferson Lab /Mississippi U. /SUNY, Stony Brook /MIT /Columbia U. /Fairfield U. /UC, Berkeley

    2012-04-05

    e{sup +} - e{sup -} pair creation from {mu}{sup +} - {mu}{sup -} interaction. Studies of how to shield the detector and reduce the background are addressed in the Detector Chapter. Polarization of the muons allows many very interesting measurements which are discussed in the Physics Chapter. Unlike the electron collider in which the electron beam is highly polarized and the positron beam unpolarized, both muon beams may be partially polarized. It is necessary to select forward moving muons from the pion's decay and thus reduce the available number of muons and hence the luminosity. The necessary machine technology needed to achieve such a collider is discussed in the Option Chapter; at the moment it is not part of our point design, although such capability would almost certainly be incorporated into an actual device.

  7. Device for monitoring electron-ion ring parameters

    International Nuclear Information System (INIS)

    Tyutyunnikov, S.I.; Shalyapin, V.N.

    1982-01-01

    The invention is classified as the method of collective ion acceleration. The device for electron-ion ring parameters monitoring is described. The invention is aimed at increasing functional possibilities of the device at the expense of the enchance in the number of the ring controlled parameters. The device comprises three similar plane mirrors installed over accelerating tube circumference and a mirror manufactured in the form of prism and located in the tube centre, as well as the system of synchrotron radiation recording and processing. Two plane mirrors are installed at an angle of 45 deg to the vertical axis. The angle of the third plane mirror 3 α and that of prismatic mirror 2 α to the vertical axis depend on geometric parameters of the ring and accelerating tube and they are determined by the expression α=arc sin R K /2(R T -L), where R K - ring radius, R T - accelerating tube radius, L - the height of segment, formed by the mirror and inner surface of the accelerating tube. The device suggested permits to determine longitudinal dimensions of the ring, its velocity and the number of electrons and ions in the ring

  8. Measuring the electron-ion ring parameters by bremsstrahlung

    International Nuclear Information System (INIS)

    Inkin, V.D.; Mozelev, A.A.; Sarantsev, V.P.

    1982-01-01

    A system is described for measuring the number of electrons and ions in the electron-ion rings of a collective heavy ion accelerator. The system operation is based on detecting gamma quanta of bremsstrahlung following the ring electron interaction with the nuclei of neutral atoms and ions at different stages of filling the ring with ions. The radiation detector is a scintillation block - a photomultiplier operating for counting with NaI(Tl) crystal sized 30x30 mm and ensuring the detection efficiency close to unity. The system apparatus is made in the CAMAC standard and rems on-line with the TRA/i miniature computer. The block-diagrams of the system and algorithm of data processing are presented. A conclusion is drawn that the results of measuring the ring parameters with the use of the diagnostics system described are in good agreement within the range of measuring errors with those obtained by means of the diagnostics system employing synchrotron radiation and induction sensors

  9. A Spin-Light Polarimeter for Multi-GeV Longitudinally Polarized Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Mohanmurthy, Prajwal [Mississippi State University, Starkville, MS (United States); Dutta, Dipangkar [Mississippi State University, Starkville, MS (United States) and Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2014-02-01

    The physics program at the upgraded Jefferson Lab (JLab) and the physics program envisioned for the proposed electron-ion collider (EIC) include large efforts to search for interactions beyond the Standard Model (SM) using parity violation in electroweak interactions. These experiments require precision electron polarimetry with an uncertainty of < 0.5 %. The spin dependent Synchrotron radiation, called "spin-light," can be used to monitor the electron beam polarization. In this article we develop a conceptual design for a "spin-light" polarimeter that can be used at a high intensity, multi-GeV electron accelerator. We have also built a Geant4 based simulation for a prototype device and report some of the results from these simulations.

  10. Very high energy colliders

    International Nuclear Information System (INIS)

    Richter, B.

    1986-03-01

    The luminosity and energy requirements are considered for both proton colliders and electron-positron colliders. Some of the basic design equations for high energy linear electron colliders are summarized, as well as design constraints. A few examples are given of parameters for very high energy machines. 4 refs., 6 figs

  11. SETI and muon collider

    OpenAIRE

    Silagadze, Z. K.

    2008-01-01

    Intense neutrino beams that accompany muon colliders can be used for interstellar communications. The presence of multi-TeV extraterrestrial muon collider at several light-years distance can be detected after one year run of IceCube type neutrino telescopes, if the neutrino beam is directed towards the Earth. This opens a new avenue in SETI: search for extraterrestrial muon colliders.

  12. A Large Hadron Electron Collider at CERN

    CERN Document Server

    Abelleira Fernandez, J L; Adzic, P; Akay, A N; Aksakal, H; Albacete, J L; Allanach, B; Alekhin, S; Allport, P; Andreev, V; Appleby, R B; Arikan, E; Armesto, N; Azuelos, G; Bai, M; Barber, D; Bartels, J; Behnke, O; Behr, J; Belyaev, A S; Ben-Zvi, I; Bernard, N; Bertolucci, S; Bettoni, S; Biswal, S; Blumlein, J; Bottcher, H; Bogacz, A; Bracco, C; Bracinik, J; Brandt, G; Braun, H; Brodsky, S; Bruning, O; Bulyak, E; Buniatyan, A; Burkhardt, H; Cakir, I T; Cakir, O; Calaga, R; Caldwell, A; Cetinkaya, V; Chekelian, V; Ciapala, E; Ciftci, R; Ciftci, A K; Cole, B A; Collins, J C; Dadoun, O; Dainton, J; Roeck, A.De; d'Enterria, D; DiNezza, P; Dudarev, A; Eide, A; Enberg, R; Eroglu, E; Eskola, K J; Favart, L; Fitterer, M; Forte, S; Gaddi, A; Gambino, P; Garcia Morales, H; Gehrmann, T; Gladkikh, P; Glasman, C; Glazov, A; Godbole, R; Goddard, B; Greenshaw, T; Guffanti, A; Guzey, V; Gwenlan, C; Han, T; Hao, Y; Haug, F; Herr, W; Herve, A; Holzer, B J; Ishitsuka, M; Jacquet, M; Jeanneret, B; Jensen, E; Jimenez, J M; Jowett, J M; Jung, H; Karadeniz, H; Kayran, D; Kilic, A; Kimura, K; Klees, R; Klein, M; Klein, U; Kluge, T; Kocak, F; Korostelev, M; Kosmicki, A; Kostka, P; Kowalski, H; Kraemer, M; Kramer, G; Kuchler, D; Kuze, M; Lappi, T; Laycock, P; Levichev, E; Levonian, S; Litvinenko, V N; Lombardi, A; Maeda, J; Marquet, C; Mellado, B; Mess, K H; Milanese, A; Milhano, J G; Moch, S; Morozov, I I; Muttoni, Y; Myers, S; Nandi, S; Nergiz, Z; Newman, P R; Omori, T; Osborne, J; Paoloni, E; Papaphilippou, Y; Pascaud, C; Paukkunen, H; Perez, E; Pieloni, T; Pilicer, E; Pire, B; Placakyte, R; Polini, A; Ptitsyn, V; Pupkov, Y; Radescu, V; Raychaudhuri, S; Rinolfi, L; Rizvi, E; Rohini, R; Rojo, J; Russenschuck, S; Sahin, M; Salgado, C A; Sampei, K; Sassot, R; Sauvan, E; Schaefer, M; Schneekloth, U; Schorner-Sadenius, T; Schulte, D; Senol, A; Seryi, A; Sievers, P; Skrinsky, A N; Smith, W; South, D; Spiesberger, H; Stasto, A M; Strikman, M; Sullivan, M; Sultansoy, S; Sun, Y P; Surrow, B; Szymanowski, L; Taels, P; Tapan, I; Tasci, T; Tassi, E; Kate, H.Ten; Terron, J; Thiesen, H; Thompson, L; Thompson, P; Tokushuku, K; Tomas Garcia, R; Tommasini, D; Trbojevic, D; Tsoupas, N; Tuckmantel, J; Turkoz, S; Trinh, T N; Tywoniuk, K; Unel, G; Ullrich, T; Urakawa, J; VanMechelen, P; Variola, A; Veness, R; Vivoli, A; Vobly, P; Wagner, J; Wallny, R; Wallon, S; Watt, G; Weiss, C; Wiedemann, U A; Wienands, U; Willeke, F; Xiao, B W; Yakimenko, V; Zarnecki, A F; Zhang, Z; Zimmermann, F; Zlebcik, R; Zomer, F; CERN. Geneva. LHeC Department

    2012-01-01

    This document provides a brief overview of the recently published report on the design of the Large Hadron Electron Collider (LHeC), which comprises its physics programme, accelerator physics, technology and main detector concepts. The LHeC exploits and develops challenging, though principally existing, accelerator and detector technologies. This summary is complemented by brief illustrations of some of the highlights of the physics programme, which relies on a vastly extended kinematic range, luminosity and unprecedented precision in deep inelastic scattering. Illustrations are provided regarding high precision QCD, new physics (Higgs, SUSY) and electron-ion physics. The LHeC is designed to run synchronously with the LHC in the twenties and to achieve an integrated luminosity of O(100) fb$^{-1}$. It will become the cleanest high resolution microscope of mankind and will substantially extend as well as complement the investigation of the physics of the TeV energy scale, which has been enabled by the LHC.

  13. SLC and SLD: Experimental experience with a linear collider

    International Nuclear Information System (INIS)

    Breidenbach, M.

    1993-08-01

    The SLAC Linear Collider (SLC) is the prototype e + e - linear collider. This talk will consist of an introduction to SLC, a description of the strategy for luminosity, a description of the systems for the transport and measurement of the polarized electrons, and a description of the present performance of the SLC and planned upgrades. The detector, SLD, and the status of the polarization asymmetry measurement A LR will be described

  14. Correlated electron-ion collisions in a strong laser field

    International Nuclear Information System (INIS)

    Ristow, T.

    2007-01-01

    Electron-ion-collisions in plasmas in the presence of an ultra-short intensive laser pulse can cause high energy transfers to the electrons. During the collision the oscillation energy of the electron in the laser field is changed into drift energy. In this regime, multi-photon processes, known from the ionization of neutral atoms (Above-Threshold Ionization), and successive, so called correlated collisions, are important. The subject of the thesis is a study of binary Coulomb collisions in strong laser fields. The collisions are treated both in the context of classical Newtonian mechanics and in the quantum-mechanical framework by the Schroedinger equation. In the classical case a simplified instantaneous collision model and a complete dynamical treatment are discussed. Collisions can be treated instantaneously, if the ratio of the impact parameter to the quiver amplitude is small. The energy distributions calculated in this approximation show an elastic peak and a broad plateau due to rescattered electrons. At incident velocities smaller than the quiver velocity, correlated collisions are observed in the electron trajectories of the dynamical model. This effect leads to characteristic momentum distributions of the electrons, that are explicitly calculated and compared with the results of the instantaneous model. In addition, the time-dependence of the collisions is discussed in the framework of a singular perturbation theory. The complete description of the Coulomb scattering requires a quantum-mechanical description. A time-dependent method of wave-packet scattering is used and the corresponding time-dependent three-dimensional Schroedinger equation is solved by an implicit ADImethod on a spatial grid. The momentum and the energy distributions of the scattered electrons are calculated by the Fourier transformation of the wavefunction. A comparison of the scattering from a repulsive and an attractive potential is used to distinguish between simple collisions and

  15. Fireball as the result of self-organization of an ensemble of diamagnetic electron-ion nanoparticles in molecular gas

    Energy Technology Data Exchange (ETDEWEB)

    Lopasov, V. P., E-mail: lopas@iao.ru [Russian Academy of Sciences, Zuev Institute for Atmospheric Optics, Siberian Branch (Russian Federation)

    2011-12-15

    The conditions for dissipative self-organization of a fireball (FB) is a molecular gas by means of a regular correction of an elastic collision of water and nitrogen molecules by the field of a coherent bi-harmonic light wave (BLW) are presented. The BWL field is generated due to conversion of energy of a linear lightning discharge into light energy. A FB consists of two components: an ensemble of optically active diamagnetic electron-ion nanoparticles and a standing wave of elliptical polarization (SWEP). It is shown that the FB lifetime depends on the energies accumulated by nanoparticles and the SWEP field and on the stability of self-oscillations of the energy between nanoparticles and SWEP.

  16. Polarimetry at a Future Linear Collider - How Precise?

    International Nuclear Information System (INIS)

    Woods, Michael B

    2000-01-01

    At a future linear collider, a polarized electron beam will play an important role in interpreting new physics signals. Backgrounds to a new physics reaction can be reduced by choice of the electron polarization state. The origin of a new physics reaction can be clarified by measuring its polarization-dependence. This paper examines some options for polarimetry with an emphasis on physics issues that motivate how precise the polarization determination needs to be. In addition to Compton polarimetry, the possibility of using Standard Model asymmetries, such as the asymmetry in forward W-pairs, is considered as a possible polarimeter. Both e + e - and e + e - collider modes are considered

  17. Quantum theory of incoherent THz emission of an interacting electron-ion plasma

    Science.gov (United States)

    Richter, M.; Schaarschmidt, M.; Knorr, A.; Hoyer, W.; Moloney, J. V.; Wright, E. M.; Kira, M.; Koch, S. W.

    2005-05-01

    The THz spectrum of the spontaneous emission of an interacting electron-ion gas, recently observed in laser pulse ionized air, is theoretically analyzed. Using the correlation expansion of the involved many particle system, the contribution of electron-molecule and electron-ion collisions to the transitions in the free electron continuum are treated. Depending on the particle density and the ion distribution, electromagnetic emission is found from the terahertz range up to optical frequencies.

  18. Future Circular Collider Study FCC-he Baseline Parameters

    CERN Document Server

    Bruning, Oliver; Klein, Max; Pellegrini, Dario; Schulte, Daniel; Zimmermann, Frank

    2017-01-01

    Initial considerations are presented on the FCC-he, the electron-hadron collider con guration within the Future Circular Collider study. This note considers arguments for the choice of the electron beam energy based on physics, ep scattering kinematics and cost. The default con guration for the electron accelerator, as for the LHeC, is chosen to be a multi-turn energy recovery linac external to the proton beam tunnel. The main accelerator parameters of the FCC-he are discussed, assuming the concurrent operation of ep with the 100TeV cms energy pp collider. These are compared with the LHeC design concept, for increased performance as for a Higgs facility using the HL-LHC, and also the high energy HE-LHC ep collider configuration. Initial estimates are also provided for the luminosity performance of electron-ion colliders for the 60 GeV electron ERL when combined with the LHC, the HE-LHC and the FCC ion beams.

  19. ERL-BASED LEPTON-HADRON COLLIDERS: eRHIC AND LHeC

    CERN Document Server

    Zimmermann, F

    2013-01-01

    Two hadron-ERL colliders are being proposed. The Large Hadron electron Collider (LHeC) plans to collide the high-energy protons and heavy ions in the Large Hadron Collider (LHC) at CERN with 60-GeV polarized electrons or positrons. The baseline scheme for this facility adds to the LHC a separate recirculating superconducting (SC) lepton linac with energy recovery, delivering a lepton current of 6.4mA. The electron-hadron collider project eRHIC aims to collide polarized (and unpolarized) electrons with a current of 50 (220) mA and energies in the range 5–30 GeV with a variety of hadron beams— heavy ions as well as polarized light ions— stored in the existing Relativistic Heavy Ion Collider (RHIC) at BNL. The eRHIC electron beam will be generated in an energy recovery linac (ERL) installed inside the RHIC tunnel.

  20. Tevatron Collider physics

    International Nuclear Information System (INIS)

    Eichten, E.J.

    1990-02-01

    The physics of hadron colliders is briefly reviewed. Issues for further study are presented. Particular attention is given to the physics opportunities for a high luminosity (≥ 100 pb -1 /experiment/run) Upgrade of the Tevatron Collider. 25 refs., 10 figs., 2 tabs

  1. Stanford's linear collider

    International Nuclear Information System (INIS)

    Southworth, B.

    1985-01-01

    The peak of the construction phase of the Stanford Linear Collider, SLC, to achieve 50 GeV electron-positron collisions has now been passed. The work remains on schedule to attempt colliding beams, initially at comparatively low luminosity, early in 1987. (orig./HSI).

  2. The SLAC linear collider

    International Nuclear Information System (INIS)

    Richter, B.

    1985-01-01

    A report is given on the goals and progress of the SLAC Linear Collider. The author discusses the status of the machine and the detectors and give an overview of the physics which can be done at this new facility. He also gives some ideas on how (and why) large linear colliders of the future should be built

  3. Flow shear stabilization of hybrid electron-ion drift mode in tokamaks

    International Nuclear Information System (INIS)

    Bai, L.

    1999-01-01

    In this paper, a model of sheared flow stabilization on hybrid electron-ion drift mode is proposed. At first, in the presence of dissipative trapped electrons, there exists an intrinsic oscillation mode in tokamak plasmas, namely hybrid dissipative trapped electron-ion temperature gradient mode (hereafter, called as hybrid electron-ion drift mode). This conclusion is in agreement with the observations in the simulated tokamak experiment on the CLM. Then, it is found that the coupling between the sheared flows and dissipative trapped electrons is proposed as the stabilization mechanism of both toroidal sheared flow and poloidal sheared flow on the hybrid electron-ion drift mode, that is, similar to the stabilizing effect of poloidal sheared flow on edge plasmas in tokamaks, in the presence of both dissipative trapped electrons and toroidal sheared flow, large toroidal sheared flow is always a strong stabilizing effect on the hybrid electron-ion drift mode in internal transport barrier location, too. This result is consistent with the experimental observations in JT-60U. (author)

  4. Flow shear stabilization of hybrid electron-ion drift mode in tokamaks

    International Nuclear Information System (INIS)

    Bai, L.

    2001-01-01

    In this paper, a model of sheared flow stabilization on hybrid electron-ion drift mode is proposed. At first, in the presence of dissipative trapped electrons, there exists an intrinsic oscillation mode in tokamak plasmas, namely hybrid dissipative trapped electron-ion temperature gradient mode (hereafter, called as hybrid electron-ion drift mode). This conclusion is in agreement with the observations in the simulated tokamak experiment on the CLM. Then, it is found that the coupling between the sheared flows and dissipative trapped electrons is proposed as the stabilization mechanism of both toroidal sheared flow and poloidal sheared flow on the hybrid electron-ion drift mode, that is, similar to the stabilizing effect of poloidal sheared flow on edge plasmas in tokamaks, in the presence of both dissipative trapped electrons and toroidal sheared flow, large toroidal sheared flow is always a strong stabilizing effect on the hybrid electron-ion drift mode in internal transport barrier location, too. This result is consistent with the experimental observations in JT-60U. (author)

  5. Muon collider progress

    Energy Technology Data Exchange (ETDEWEB)

    Noble, Robert J. FNAL

    1998-08-01

    Recent progress in the study of muon colliders is presented. An international collaboration consisting of over 100 individuals is involved in calculations and experiments to demonstrate the feasibility of this new type of lepton collider. Theoretical efforts are now concentrated on low-energy colliders in the 100 to 500 GeV center-of-mass energy range. Credible machine designs are emerging for much of a hypothetical complex from proton source to the final collider. Ionization cooling has been the most difficult part of the concept, and more powerful simulation tools are now in place to develop workable schemes. A collaboration proposal for a muon cooling experiment has been presented to the Fermilab Physics Advisory Committee, and a proposal for a targetry and pion collection channel experiment at Brookhaven National Laboratory is in preparation. Initial proton bunching and space-charge compensation experiments at existing hadron facilities have occurred to demonstrate proton driver feasibility.

  6. FERMILAB: Collider detectors -2

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Last month's edition (April, page 12) included a status report on data collection and preliminary physics results from the 'newcomer' DO detector at Fermilab's Tevatron proton-antiproton collider. This time the spotlight falls in the Veteran' CDF detector, in action since 1985 and meanwhile significantly upgraded. Meanwhile the Tevatron collider continues to improve, with record collision rates

  7. Quantum ion acoustic solitary waves in electron-ion plasmas: A Sagdeev potential approach

    International Nuclear Information System (INIS)

    Mahmood, S.; Mushtaq, A.

    2008-01-01

    Linear and nonlinear ion acoustic waves are studied in unmagnetized electron-ion quantum plasmas. Sagdeev potential approach is employed to describe the nonlinear quantum ion acoustic waves. It is found that density dips structures are formed in the subsonic region in a electron-ion quantum plasma case. The amplitude of the nonlinear structures remains constant and the width is broadened with the increase in the quantization of the system. However, the nonlinear wave amplitude is reduced with the increase in the wave Mach number. The numerical results are also presented

  8. Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2015-01-01

    In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detector, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The internat...

  9. Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The interna...

  10. Towards a Muon Collider

    International Nuclear Information System (INIS)

    Eichten, E.

    2011-01-01

    A multi TeV Muon Collider is required for the full coverage of Terascale physics. The physics potential for a Muon Collider at ∼3 TeV and integrated luminosity of 1 ab -1 is outstanding. Particularly strong cases can be made if the new physics is SUSY or new strong dynamics. Furthermore, a staged Muon Collider can provide a Neutrino Factory to fully disentangle neutrino physics. If a narrow s-channel resonance state exists in the multi-TeV region, the physics program at a Muon Collider could begin with less than 10 31 cm -2 s -1 luminosity. Detailed studies of the physics case for a 1.5-4 TeV Muon Collider are just beginning. The goals of such studies are to: (1) identify benchmark physics processes; (2) study the physics dependence on beam parameters; (3) estimate detector backgrounds; and (4) compare the physics potential of a Muon Collider with those of the ILC, CLIC and upgrades to the LHC.

  11. Towards Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    The Large Hadron Collider (LHC) at CERN presently provides proton-proton collisions at a centre-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics programme will extend through the second half of the 2030’s. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ∼100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCC-ee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on $Nb_3Sn$ superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton c...

  12. Proceedings of the workshop on the PS-spin collider

    International Nuclear Information System (INIS)

    Mori, Yoshiharu

    1993-05-01

    This volume is a record of the PS-Spin Collider Workshop which was held at KEK, Jan. 31-Feb.1, 1992. As a future project of the KEK 12-GeV proton synchrotron (KEK-PS), the hadron collider (PS-Collider), has been under discussion. Originally, the PSC was designed for heavy ion beam collisions with the energy range of 5-7 GeV/u. If polarized protons are accelerated in PSC, 19 x 19 GeV collisions are possible. This workshop was proposed to bring together interested experimentalists and accelerator physicists to discuss the case that could be made for polarization physics and the technical feasibility at the PS Spin Collider. More than 30 physicists participated in the workshop and very interesting and useful discussions took place. (author)

  13. Polarized Proton Collisions at RHIC

    CERN Document Server

    Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

    2005-01-01

    The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...

  14. Tensor-polarized structure function b1 in the standard convolution description of the deuteron

    Science.gov (United States)

    Cosyn, W.; Dong, Yu-Bing; Kumano, S.; Sargsian, M.

    2017-04-01

    Tensor-polarized structure functions of a spin-1 hadron are additional observables, which do not exist for the spin-1 /2 nucleon. They could probe novel aspects of the internal hadron structure. Twist-2 tensor-polarized structure functions are b1 and b2, and they are related by the Callan-Gross-like relation in the Bjorken scaling limit. In this work, we theoretically calculate b1 in the standard convolution description for the deuteron. Two different theoretical models, a basic convolution description and a virtual nucleon approximation, are used for calculating b1, and their results are compared with the HERMES measurement. We found large differences between our theoretical results and the data. Although there is still room to improve by considering higher-twist effects and in the experimental extraction of b1 from the spin asymmetry Az z, there is a possibility that the large differences require physics beyond the standard deuteron model for their interpretation. Future b1 studies could shed light on a new field of hadron physics. In particular, detailed experimental studies of b1 will start soon at the Thomas Jefferson National Accelerator Facility. In addition, there are possibilities to investigate tensor-polarized parton distribution functions and b1 at Fermi National Accelerator Laboratory and a future electron-ion collider. Therefore, further theoretical studies are needed for understanding the tensor structure of the spin-1 deuteron, including a new mechanism to explain the large differences between the current data and our theoretical results.

  15. Gluons and the quark sea at high energies: distributions, polarization, tomography

    CERN Document Server

    Boer, D; Milner, Richard; Venugopalan, Raju; Vogelsang, Werner; Kaplan, David; Montgomery, Hugh; Vigdor, Steven; Accardi, A.; Aschenauer, E.C.; Burkardt, M.; Ent, R.; Guzey, V.; Hasch, D.; Kumar, K.; Lamont, M.A.C.; Li, Ying-chuan; Marciano, W.; Marquet, C.; Sabatie, F.; Stratmann, M.; Yuan, F.; Sassot, R.; Zurita, P.; Cherednikov, I.O.; Goncalves, V.P.; Sandapen, R.; Kopeliovich, B.Z.; Gao, J.-H.; Liang, Z.-T.; Passek-Kumericki, K.; Kumericki, K.; Lappi, T.; Wallon, S.; Pire, B.; Geraud, R.; Moutarde, H.; Gelis, F.; Soyez, G.; Meskauskas, M.; Mueller, Dieter; Stefanis, N.G.; Gallmeister, K.; Mosel, U.; Diehl, M.; Bartels, J.; Pirner, H.J.; Hagler, P.; Jager, B.; Spiesberger, H.; Lautenschlager, T.; Schafer, A.; Ringer, F.; Vogelsang, W.; Kroll, P.; Alekhin, S.; Blumlein, J; Moch, S.-O.; Pisano, C.; Rojo, J.; Bacchetta, A.; Pasquini, B.; Radici, M.; Ciofi degli Atti, C.; Mezzetti, C.B.; Kaptari, L.P.; Anselmino, M.; Tanaka, K.; Koike, Y.; Kumano, S.; Motyka, L.; Golec-Biernat, K.; Stasto, A.M.; Golec-Biernat, K.; Szymanowski, L.; Cherednikov, I.O.; Kaptari, L.P.; Radyushkin, A.; Alekhin, S.; Kondratenko, A.; Horowitz, W.A.; Schnell, G.; Chevtsov, P.; Mulders, P.J.; Rogers, T.C.; Boer, D.; Forshaw, J.R.; Cooper-Sarkar, A.; Chirilli, G.A.; Muller, D.; Wang, X.-N.; Yuan, F.; Qian, X.; Brodsky, S.J.; Schweitzer, P.; Horn, T.; Tuchin, K.; Dupre, R.; Erdelyi, B.; Manikonda, S.; Ostrumov, P.N.; Abeyratne, S.; Erdelyi, B.; Vossen, A.; Riordan, S.; Tsentalovich, E.; Goldstein, G.R.; Pozdeyev, E.; Huang, M.; Aidala, C.; Dumitru, A.; Dominguez, F.; Ben-Zvi, I.; Deshpande, A.; Faroughy, C.; Hammons, L.; Hao, Y.; Johnson, E.C.; Litvinenko, V.N.; Taneja, S.; Tsoupas, N.; Webb, S.; Beebe-Wang, J.; Belomestnykh, S.; Ben-Zvi, I.; Blaskiewicz, M.M.; Calaga, R.; Chang, X.; Fedotov, A.; Gassner, D.; Hahn, H.; Hammons, L.; Hao, Y.; He, P.; Jackson, W.; Jain, A.; Johnson, E.C.; Kayran, D.; Kewisch, J.; Litvinenko, V.N.; Luo, Y.; Mahler, G.; McIntyre, G.; Meng, W.; Minty, M.; Parker, B.; Pikin, A.; Ptitsyn, V.; Rao, T.; Roser, T.; Sheehy, B.; Skaritka, J.; Tepikian, S.; Than, Y.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Webb, S.; Wu, Q.; Xu, W.; Zelenski, A.; Beuf, G.; Burton, T.; Debbe, R.; Fazio, S.; Marciano, W.J.; Qiu, J.-W.; Toll, T.; Ullrich, T.; Deshpande, A.; Dumitru, A.; Kang, Z.-B.; Stasto, A.M.; Yuan, F.; Kovchegov, Y.V.; Majumder, A; Metz, A.; Zhou, J.; Gamberg, L.; Stasto, A.M.; Strikman, M.; Xiao, B.-W.; Guzzi, M.; Nadolsky, P.; Olness, F.; BC, H.; Liuti, S.; Ahmed, S.; Bogacz, A.; Derbenev, Ya.; Hutton, A.; Krafft, G.; Li, R.; Marhauser, F.; Morozov, V.; Pilat, F.; Rimmer, R.; Satogata, T.; Sullivan, M.; Spata, M.; Terzic, B.; Wang, H.; Yunn, B.; Zhang, Y.; Avakian, H.; Musch, B.; Nadel-Turonski, P.; Prokudin, A.; Radyushkin, A.; Weiss, C.; Krafft, G.; Radyushkin, A.; Sayed, H.; Gilfoyle, G.P.; Cloet, I.C.; Miller, G.; Gonderinger, M.

    2011-01-01

    This report is based on a ten-week program on "Gluons and the quark sea at high-energies", which took place at the Institute for Nuclear Theory in Seattle in Fall 2010. The principal aim of the program was to develop and sharpen the science case for an Electron-Ion Collider (EIC), a facility that will be able to collide electrons and positrons with polarized protons and with light to heavy nuclei at high energies, offering unprecedented possibilities for in-depth studies of quantum chromodynamics. This report is organized around four major themes: i) the spin and flavor structure of the proton, ii) three-dimensional structure of nucleons and nuclei in momentum and configuration space, iii) QCD matter in nuclei, and iv) Electroweak physics and the search for physics beyond the Standard Model. Beginning with an executive summary, the report contains tables of key measurements, chapter overviews for each of the major scientific themes, and detailed individual contributions on various aspects of the scientific op...

  16. Gluons and the quark sea at high energies: distributions, polarization, tomography

    Energy Technology Data Exchange (ETDEWEB)

    Boer, D.; Venugopalan, R.; Diehl, M.; Milner, R.; Vogelsang, W.; et al.

    2011-09-30

    This report is based on a ten-week program on Gluons and the quark sea at high-energies, which took place at the Institute for Nuclear Theory (INT) in Seattle in Fall 2010. The principal aim of the program was to develop and sharpen the science case for an Electron-Ion Collider (EIC), a facility that will be able to collide electrons and positrons with polarized protons and with light to heavy nuclei at high energies, offering unprecedented possibilities for in-depth studies of quantum chromodynamics (QCD). This report is organized around the following four major themes: (i) the spin and flavor structure of the proton, (ii) three dimensional structure of nucleons and nuclei in momentum and configuration space, (iii) QCD matter in nuclei, and (iv) Electroweak physics and the search for physics beyond the Standard Model. Beginning with an executive summary, the report contains tables of key measurements, chapter overviews for each of the major scientific themes, and detailed individual contributions on various aspects of the scientific opportunities presented by an EIC.

  17. Proton-Proton and Proton-Antiproton Colliders

    CERN Document Server

    Scandale, Walter

    2014-01-01

    In the last five decades, proton–proton and proton–antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion–ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  18. Projectile K-Auger-electron production by bare, one-, and two-electron ions

    International Nuclear Information System (INIS)

    Dillingham, T.R.; Newcomb, J.; Hall, J.; Pepmiller, P.L.; Richard, P.

    1984-01-01

    Projectile K-Auger-electron production measurements were performed for the bare, one-, and two-electron ions of C, N, O, and F incident on He, Ne, Ar, and Kr gases. The measurements were taken over an energy range of (1/4) to (2/3) MeV/amu using a cylindrical mirror analyzer. For the incident two-electron ions, single-electron capture to excited states of the (1s2s) 3 S metastable component of the incident beam was the principal mechanism giving rise to the observed K-Auger transitions. For the bare and one-electron ions, double electron capture to excited states was the dominant mechanism leading to K-Auger-electron production. In addition to Auger-spectroscopy measurements, total K-Auger production cross sections were determined as well as the partial cross sections for electron capture to specific n levels of the projectile. The n distributions were also measured for double electron capture to excited states of the bare and one-electron ions

  19. Systematics of projectile K-Auger electron production by bare, one, and two electron ions

    International Nuclear Information System (INIS)

    Dillingham, T.R.

    1983-01-01

    Projectile K-Auger electron production measurements were performed for the bare, one, and two electron ions of C, N, O, and F incident on He, Ne, Ar, and Kr gases. The measurements were taken over an energy range of 1/4 to 2/3 MeV/amu using a cylindrical mirror analyzer. For the incident two electron ions, single electron capture to excited states of the (1s2s) 3 S metastable component of the incident beam was the principal mechanism giving rise to the observed K-Auger transitions. For the bare and one electron ions, double electron capture to excited states was the dominant mechanism leading to K-Auger electron production. In addition to Auger spectroscopy measurements, total K-Auger production cross sections were determined as well as the partial cross sections for electron capture to specific n-levels of the projectile. The n-distribution for single electron capture was observed to follow a 1/n 3 dependence. The n-distributions were also measured for double electron capture to excited states of the bare and one electron ions

  20. ELECTRON-ION CORRELATION IN LIQUID-METALS FROM FIRST PRINCIPLES - LIQUID MG AND LIQUID PI

    NARCIS (Netherlands)

    DEWIJS, GA; PASTORE, G; SELLONI, A; VANDERLUGT, W

    1995-01-01

    We present a theoretical determination of electron-ion pair correlation functions g(ie) in liquid Mg and liquid Bi, two systems with widely different electronic and cohesive properties. Our calculations are based on first-principles molecular-dynamics simulations, which provide an accurate and

  1. Theoretical research of electron-ion direct impact excitation cross sections for hot dense plasma

    International Nuclear Information System (INIS)

    Tian Mingfeng

    2003-01-01

    An average-atom (AA) model, Younger formula and partial wave method are employed to study the electron- ion direct impact excitation cross sections for hot dense plasma. The phenomenon of electron resonance near the excitation threshold and its mechanism are discussed. (author)

  2. A new apparatus for electron-ion multiple coincidence momentum imaging spectroscopy

    International Nuclear Information System (INIS)

    Morishita, Y.; Kato, M.; Pruemper, G.; Liu, X.-J.; Lischke, T.; Ueda, K.; Tamenori, Y.; Oura, M.; Yamaoka, H.; Suzuki, I.H.; Saito, N.

    2006-01-01

    We have developed a new experimental apparatus for the electron-ion multiple coincidence momentum imaging spectroscopy in order to obtain the angular distributions of vibration-resolved photoelectrons from molecules fixed in space. The apparatus consists of a four-stage molecular supersonic jet and a spectrometer analyzing three-dimensional momenta of fragment ions and electrons in coincidence

  3. The development of colliders

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1993-02-01

    Don Kerst, Gersh Budker, and Bruno Touschek were the individuals, and the motivating force, which brought about the development of colliders, while the laboratories at which it happened were Stanford, MURA, the Cambridge Electron Accelerator, Orsay, Frascati, CERN, and Novosibirsk. These laboratories supported, during many years, this rather speculative activity. Of course, many hundreds of physicists contributed to the development of colliders but the men who started it, set it in the right direction, and forcefully made it happen, were Don, Gersh, and Bruno. Don was instrumental in the development of proton-proton colliders, while Bruno and Gersh spearheaded the development of electron-positron colliders. In this brief review of the history, I will sketch the development of the concepts, the experiments, and the technological developments which made possible the development of colliders. It may look as if the emphasis is on theoretical concepts, but that is really not the case, for in this field -- the physics of beams -- the theory and experiment go hand in hand; theoretical understanding and advances are almost always motivated by the need to explain experimental results or the desire to construct better experimental devices

  4. On the electron-ion temperature ratio established by collisionless shocks

    Science.gov (United States)

    Vink, Jacco; Broersen, Sjors; Bykov, Andrei; Gabici, Stefano

    2015-07-01

    Astrophysical shocks are often collisionless shocks, in which the changes in plasma flow and temperatures across the shock are established not through Coulomb interactions, but through electric and magnetic fields. An open question about collisionless shocks is whether electrons and ions each establish their own post-shock temperature (non-equilibration of temperatures), or whether they quickly equilibrate in the shock region. Here we provide a simple, thermodynamic, relation for the minimum electron-ion temperature ratios that should be expected as a function of Mach number. The basic assumption is that the enthalpy-flux of the electrons is conserved separately, but that all particle species should undergo the same density jump across the shock, in order for the plasma to remain charge neutral. The only form of additional electron heating that we allow for is adiabatic heating, caused by the compression of the electron gas. These assumptions result in an analytic treatment of expected electron-ion temperature ratio that agrees with observations of collisionless shocks: at low sonic Mach numbers, Ms ≲ 2, the electron-ion temperature ratio is close to unity, whereas for Mach numbers above Ms ≈ 60 the electron-ion temperature ratio asymptotically approaches a temperature ratio of Te/Ti = me/ ⟨ mi ⟩. In the intermediate Mach number range the electron-ion temperature ratio scales as Te/Ti ∝ Ms-2. In addition, we calculate the electron-ion temperature ratios under the assumption of adiabatic heating of the electrons only, which results in a higher electron-ion temperature ratio, but preserves the Te/Ti ∝ Ms-2 scaling. We also show that for magnetised shocks the electron-ion temperature ratio approaches the asymptotic value Te/Ti = me/ ⟨ mi ⟩ for lower magnetosonic Mach numbers (Mms), mainly because for a strongly magnetised shock the sonic Mach number is larger than the magnetosonic Mach number (Mms ≤ Ms). The predicted scaling of the electron-ion

  5. The SLAC polarized electron source

    International Nuclear Information System (INIS)

    Tang, H.; Alley, R.; Frisch, J.

    1995-06-01

    The SLAC polarized electron source employs a photocathode DC high voltage gun with a loadlock and a YAG pumped Ti:sapphire laser system for colliding beam experiments or a flash lamp pumped Ti:sapphire laser for fixed target experiments. It uses a thin, strained GaAs(100) photocathode, and is capable of producing a pulsed beam with a polarization of ≥80% and a peak current exceeding 10 A. Its operating efficiency has reached 99%. The physics and technology of producing high polarization electron beams from a GaAs photocathode will be reviewed. The prospects of realizing a polarized electron source for future linear colliders will also be discussed

  6. COLLIDE Pro Helvetia Award

    CERN Multimedia

    2016-01-01

    The COLLIDE Pro Helvetia Award is run in partnership with Pro Helvetia, giving the opportunity to Swiss artists to do research at CERN for three months.   From left to right: Laura Perrenoud, Marc Dubois and Simon de Diesbach. The photo shows their VR Project, +2199. Fragment.In are the winning artists of COLLIDE Pro Helvetia. They came to CERN for two months in 2015, and will now continue their last month in the laboratory. Fragment.In is a Swiss based interaction design studio. They create innovative projects, interactive installations, video and game design. Read more about COLLIDE here.

  7. The Large Hadron Collider

    CERN Document Server

    Evans, Lyndon

    2012-01-01

    The construction of the Large Hadron Collider (LHC) has been a massive endeavour spanning almost 30 years from conception to commissioning. Building the machine with the highest possible energy (7 TeV) in the existing large electron–positron (LEP) collider tunnel of 27 km circumference and with a tunnel diameter of only 3.8 m has required considerable innovation. The first was the development of a two-in-one magnet, where the two rings are integrated into a single magnetic structure. This compact two-in-one structure was essential for the LHC owing to the limited space available in the existing LEP collider tunnel and the cost. The second was a bold move to the use of superfluid helium cooling on a massive scale, which was imposed by the need to achieve a high (8.3 T) magnetic field using an affordable Nb-Ti superconductor.

  8. Superconducting super collider

    International Nuclear Information System (INIS)

    Limon, P.J.

    1987-01-01

    The Superconducting Super Collider is to be a 20 TeV per beam proton-proton accelerator and collider. Physically the SCC will be 52 miles in circumference and slightly oval in shape. The use of superconducting magnets instead of conventional cuts the circumference from 180 miles to the 52 miles. The operating cost of the SCC per year is estimated to be about $200-250 million. A detailed cost estimate of the project is roughly $3 billion in 1986 dollars. For the big collider ring, the technical cost are dominated by the magnet system. That is why one must focus on the cost and design of the magnets. Presently, the process of site selection is underway. The major R and D efforts concern superconducting dipoles. The magnets use niobium-titanium as a conductor stabilized in a copper matrix. 10 figures

  9. Collide@CERN Geneva

    CERN Multimedia

    CERN. Geneva; Kieffer, Robert; Blas Temino, Diego; Bertolucci, Sergio; Mr. Decelière, Rudy; Mr. Hänni, Vincent

    2014-01-01

    CERN, the Republic and Canton of Geneva, and the City of Geneva are delighted to invite you to “Collide@CERN Geneva Music”. Come to the public lecture about collisions between music and particle physics by the third winners of Collide@CERN Geneva, Vincent Hänni & Rudy Decelière, and their scientific inspiration partners, Diego Blas and Robert Kieffer. The event marks the beginning of their residency at CERN, and will be held at the CERN Globe of Science and Innovation on 16 October 2014 at 19.00. Doors will open at 18.30.

  10. The Colliding Beams Sequencer

    International Nuclear Information System (INIS)

    Johnson, D.E.; Johnson, R.P.

    1989-01-01

    The Colliding Beam Sequencer (CBS) is a computer program used to operate the pbar-p Collider by synchronizing the applications programs and simulating the activities of the accelerator operators during filling and storage. The Sequencer acts as a meta-program, running otherwise stand alone applications programs, to do the set-up, beam transfers, acceleration, low beta turn on, and diagnostics for the transfers and storage. The Sequencer and its operational performance will be described along with its special features which include a periodic scheduler and command logger. 14 refs., 3 figs

  11. Hadron collider luminosity limitations

    CERN Document Server

    Evans, Lyndon R

    1992-01-01

    The three colliders operated to date have taught us a great deal about the behaviour of both bunched and debunched beams in storage rings. The main luminosity limitations are now well enough understood that most of them can be stronglu attenuated or eliminated by approriate design precautions. Experience with the beam-beam interaction in both the SPS and the Tevatron allow us to predict the performance of the new generation of colliders with some degree of confidence. One of the main challenges that the accelerator physicist faces is the problem of the dynamic aperture limitations due to the lower field quality expected, imposed by economic and other constraints.

  12. The Muon Collider

    International Nuclear Information System (INIS)

    Zisman, Michael S.

    2011-01-01

    We describe the scientific motivation for a new type of accelerator, the muon collider. This accelerator would permit an energy-frontier scientific program and yet would fit on the site of an existing laboratory. Such a device is quite challenging, and requires a substantial R and D program. After describing the ingredients of the facility, the ongoing R and D activities of the Muon Accelerator Program are discussed. A possible U.S. scenario that could lead to a muon collider at Fermilab is briefly mentioned.

  13. Symmetric achromatic low-beta collider interaction region design concept

    Directory of Open Access Journals (Sweden)

    V. S. Morozov

    2013-01-01

    Full Text Available We present a new symmetry-based concept for an achromatic low-beta collider interaction region design. A specially designed symmetric chromaticity compensation block (CCB induces an angle spread in the passing beam such that it cancels the chromatic kick of the final focusing quadrupoles. Two such CCBs placed symmetrically around an interaction point allow simultaneous compensation of the 1st-order chromaticities and chromatic beam smear at the IP without inducing significant 2nd-order aberrations to the particle trajectory. We first develop an analytic description of this approach and explicitly formulate 2nd-order aberration compensation conditions at the interaction point. The concept is next applied to develop an interaction region design for the ion collider ring of an electron-ion collider. We numerically evaluate performance of the design in terms of momentum acceptance and dynamic aperture. The advantages of the new concept are illustrated by comparing it to the conventional distributed-sextupole chromaticity compensation scheme.

  14. Why Large Hadron Collider?

    Indian Academy of Sciences (India)

    or ¯pp collider is a synchrotron machine, where the particle and antiparticle beams are accelerated inside the same vacuum pipe (figure 1) using the same set of bending mag- nets and accelerating cavities (not shown). Thanks to their equal mass and opposite charge, the two beams go round in identical orbits on top of ...

  15. The Large Hadron Collider

    CERN Multimedia

    't Hooft, Gerardus; Llewellyn Smith, Christopher Hubert; Brüning, Oliver Sim; Collier, Paul; Stapnes, Steinar; Ellis, Jonathan Richard; Braun-Munzinger, Peter; Stachel, Johanna; Lederman, Leon Max

    2007-01-01

    Several articles about the LHC: The Making of the standard model; high-energy colliders and the rise of the standard model; How the LHC came to be; Building a behemoth; Detector challenges at the LHC; Beyond the standard model with the LHC; The quest for the quark-gluon plasma; The God particle et al. (42 pages

  16. Hadron collider physics

    Energy Technology Data Exchange (ETDEWEB)

    Pondrom, L.

    1991-10-03

    An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs.

  17. Diffraction at collider energies

    International Nuclear Information System (INIS)

    Frankfurt, L.L.

    1992-01-01

    Lessons with ''soft'' hadron physics to explain (a) feasibility to observe and to investigate color transparency, color opacity effects at colliders; (b) significant probability and specific features of hard diffractive processes; (c) feasibility to investigate components of parton wave functions of hadrons with minimal number of constituents. This new physics would be more important with increase of collision energy

  18. Large Hadron Collider

    CERN Multimedia

    2007-01-01

    "In the spring 2008, the Large Hadron Collider (LHC) machine at CERN (the European Particle Physics laboratory) will be switched on for the first time. The huge machine is housed in a circular tunnel, 27 km long, excavated deep under the French-Swiss border near Geneva." (1,5 page)

  19. Superconducting Super Collider project

    International Nuclear Information System (INIS)

    Perl, M.L.

    1986-04-01

    The scientific need for the Superconducting Super Collider (SSC) is outlined, along with the history of the development of the SSC concept. A brief technical description is given of each of the main points of the SSC conceptual design. The construction cost and construction schedule are discussed, followed by issues associated with the realization of the SSC. 8 refs., 3 figs., 3 tabs

  20. High luminosity particle colliders

    International Nuclear Information System (INIS)

    Palmer, R.B.; Gallardo, J.C.

    1997-03-01

    The authors consider the high energy physics advantages, disadvantages and luminosity requirements of hadron (pp, p anti p), lepton (e + e - , μ + μ - ) and photon-photon colliders. Technical problems in obtaining increased energy in each type of machine are presented. The machines relative size are also discussed

  1. LINEAR COLLIDERS: 1992 workshop

    International Nuclear Information System (INIS)

    Settles, Ron; Coignet, Guy

    1992-01-01

    As work on designs for future electron-positron linear colliders pushes ahead at major Laboratories throughout the world in a major international collaboration framework, the LC92 workshop held in Garmisch Partenkirchen this summer, attended by 200 machine and particle physicists, provided a timely focus

  2. Tevatron's complex collider cousins

    CERN Multimedia

    Fischer, W

    2004-01-01

    Letter referring to Schwarzschild's story "Disappointing performance and tight budgets confront Fermilab with tough decisions" and contesting that the Tevatron is not the most complex accelerator operating. They use the examples of CERN's SPS collider, HERA at DESY and the RHIC at Brookhaven (1/4 page)

  3. Hadron collider physics

    International Nuclear Information System (INIS)

    Pondrom, L.

    1991-01-01

    An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs

  4. B factory with hadron colliders

    International Nuclear Information System (INIS)

    Lockyer, N.S.

    1990-01-01

    The opportunities to study B physics in a hadron collider are discussed. Emphasis is placed on the technological developments necessary for these experiments. The R and D program of the Bottom Collider Detector group is reviewed. (author)

  5. Superconducting muon collider concepts

    International Nuclear Information System (INIS)

    Willen, E.

    1996-01-01

    High energy colliding beam machines for elementary particle research have grown so costly that funding for them has become problematical. The physics they would explore, however, remains compelling, so that new methods must be found to reach high energy if this physics is to be studied. One such new approach is the muon collider. This machine could reach multi-TeV collision energies with good luminosity at an affordable cost. The scenario for producing μ + μ - collisions is shown schematically in a figure. A high intensity proton synchrotron delivers protons in sharply defined bunches onto a stationary target with an energy of 30 GeV. Many pions are produced that decay into muons; both are collected in a solenoid magnet system with useful energies in the range 0.1--1.0 GeV. The muons are then cooled, i.e. their transverse momentum as well as the spread in their longitudinal momentum is reduced. In this way, a bunch of protons is turned into a bunch of positive or negative muons suitable for acceleration and collision. The energy of the muons at this stage is only 0.02 GeV. Acceleration is accomplished in a series of recirculating linac accelerators, similar to the approach used in CEBAF. Upon reaching 2,000 GeV (2 TeV) of energy, the muons are transferred into a ring where positive and negative muons, transferred in successive bunches, collide and the collisions studied in a suitable detector. About 25% of the muons originally collected survive into the collider ring, and here they live for an average of ∼ 1,000 revolutions. At this point, the surviving muons are dumped and new bunches are injected. This paper describes in abbreviated form the main features and parameters of the presently envisioned muon collider, most of it taken from the latter two reports

  6. Polarization at SLC

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1988-07-01

    The SLAC Linear Collider has been designed to readily accommodate polarized electron beams. Considerable effort has been made to implement a polarized source, a spin rotation system, and a system to monitor the beam polarization. Nearly all major components have been fabricated. At the current time, several source and polarimeter components have been installed. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. It is expected that a beam polarization of 45% will be achieved with no loss in luminosity. 13 refs., 15 figs

  7. The Photon Collider at Tesla

    Science.gov (United States)

    Badelek, B.; Blöchinger, C.; Blümlein, J.; Boos, E.; Brinkmann, R.; Burkhardt, H.; Bussey, P.; Carimalo, C.; Chyla, J.; Çiftçi, A. K.; Decking, W.; de Roeck, A.; Fadin, V.; Ferrario, M.; Finch, A.; Fraas, H.; Franke, F.; Galynskii, M.; Gamp, A.; Ginzburg, I.; Godbole, R.; Gorbunov, D. S.; Gounaris, G.; Hagiwara, K.; Han, L.; Heuer, R.-D.; Heusch, C.; Illana, J.; Ilyin, V.; Jankowski, P.; Jiang, Y.; Jikia, G.; Jönsson, L.; Kalachnikow, M.; Kapusta, F.; Klanner, R.; Klassen, M.; Kobayashi, K.; Kon, T.; Kotkin, G.; Krämer, M.; Krawczyk, M.; Kuang, Y. P.; Kuraev, E.; Kwiecinski, J.; Leenen, M.; Levchuk, M.; Ma, W. F.; Martyn, H.; Mayer, T.; Melles, M.; Miller, D. J.; Mtingwa, S.; Mühlleitner, M.; Muryn, B.; Nickles, P. V.; Orava, R.; Pancheri, G.; Penin, A.; Potylitsyn, A.; Poulose, P.; Quast, T.; Raimondi, P.; Redlin, H.; Richard, F.; Rindani, S. D.; Rizzo, T.; Saldin, E.; Sandner, W.; Schönnagel, H.; Schneidmiller, E.; Schreiber, H. J.; Schreiber, S.; Schüler, K. P.; Serbo, V.; Seryi, A.; Shanidze, R.; da Silva, W.; Söldner-Rembold, S.; Spira, M.; Stasto, A. M.; Sultansoy, S.; Takahashi, T.; Telnov, V.; Tkabladze, A.; Trines, D.; Undrus, A.; Wagner, A.; Walker, N.; Watanabe, I.; Wengler, T.; Will, I.; Wipf, S.; Yavaş, Ö.; Yokoya, K.; Yurkov, M.; Zarnecki, A. F.; Zerwas, P.; Zomer, F.

    High energy photon colliders (γγ,γe) are based on e-e- linear colliders where high energy photons are produced using Compton scattering of laser light on high energy electrons just before the interaction point. This paper is a part of the Technical Design Report of the linear collider TESLA.1 Physics program, possible parameters and some technical aspects of the photon collider at TESLA are discussed.

  8. Gluons and the quark sea at high energies : distributions, polarization, tomography

    NARCIS (Netherlands)

    Boer, D.; Diehl, M.; Milner, R.; Venugopalan, R.; Vogelsang, W.; Accardi, A.; Aschenauer, E.; Burkardt, M.; Ent, R.; Guzey, V.; Hasch, D.; Kumar, K.; Lamont, M. A. C.; Li, Y.; Marciano, W. J.; Marquet, C.; Sabatie, F.; Stratmann, M.; Yuan, F.; Abeyratne, S.; Ahmed, S.; Aidala, C.; Alekhin, S.; Anselmino, M.; Avakian, H.; Bacchetta, A.; Bartels, J.; H., BC; Beebe-Wang, J.; Belomestnykh, S.; Ben-Zvi, I.; Beuf, G.; Blumlein, J.; Blaskiewicz, M .; Bogacz, A.; Brodsky, S. J.; Burton, T.; Calaga, R.; Chang, X.; Cherednikov, I. O.; Chevtsov, P.; Chirilli, G. A.; Atti, C. Ciofi degli; Cloet, I. C.; Cooper-Sarkar, A.; Debbe, R.; Derbenev, Ya; Deshpande, A.; Dominguez, F.; Dumitru, A.; Dupre, R.; Erdelyi, B.; Faroughy, C.; Fazio, S.; Fedotov, A.; Forshaw, J. R.; Geraud, R.; Gallmeister, K.; Gamberg, L.; Gao, J. -H.; Gassner, D.; Gelis, F.; Gilfoyle, G. P.; Goldstein, G.; Golec-Biernat, K.; Goncalves, V. P.; Gonderinger, M.; Guzzi, M.; Hagler, P.; Hahn, H.; Hammons, L.; Hao, Y.; He, P.; Horn, T.; Horowitz, W. A.; Huang, M.; Hutton, A.; Jager, B.; Jackson, W.; Jain, A.; Johnson, E. C.; Kang, Z. -B.; Kaptari, L. P.; Kayran, D.; Kewisch, J.; Koike, Y.; Kondratenko, A.; Kopeliovich, B. Z.; Kovchegov, Y. V.; Krafft, G.; Kroll, P.; Kumano, S.; Kumericki, K.; Lappi, T.; Lautenschlager, T.; Li, R.; Liang, Z. -T.; Litvinenko, V. N.; Liuti, S.; Luo, Y.; Muller, D.; Mahler, G.; Majumder, A.; Manikonda, S.; Marhauser, F.; McIntyre, G.; Meskauskas, M.; Meng, W.; Metz, A.; Mezzetti, C. B.; Miller, G. A.; Minty, M.; Moch, S. -O.; Morozov, V.; Mosel, U.; Motyka, L.; Moutarde, H.; Mulders, P. J.; Musch, B.; Nadel-Turonski, P.; Nadolsky, P.; Olness, F.; Ostrumov, P. N.; Parker, B.; Pasquini, B.; Passek-Kumericki, K.; Pikin, A.; Pilat, F.; Pire, B.; Pirner, H.; Pisano, C.; Pozdeyev, E.; Prokudin, A.; Ptitsyn, V.; Qian, X.; Qiu, J. -W.; Radici, M.; Radyushkin, A.; Rao, T.; Rimmer, R.; Ringer, F.; Riordan, S.; Rogers, T.; Rojo, J.; Roser, T.; Sandapen, R.; Sassot, R.; Satogata, T.; Sayed, H.; Schafer, A.; Schnell, G.; Schweitzer, P.; Sheehy, B.; Skaritka, J.; Soyez, G.; Spata, M.; Spiesberger, H.; Stasto, A. M.; Stefanis, N. G.; Strikman, M.; Sullivan, M.; Szymanowski, L.; Tanaka, K.; Taneja, S.; Tepikian, S.; Terzic, B.; Than, Y.; Toll, T.; Trbojevic, D.; Tsentalovich, E.; Tsoupas, N.; Tuchin, K.; Tuozzolo, J.; Ullrich, T.; Vossen, A.; Wallon, S.; Wang, G.; Wang, H.; Wang, X. -N.; Webb, S.; Weiss, C.; Wu, Q.; Xiao, B. -W.; Xu, W.; Yunn, B.; Zelenski, A.; Zhang, Y.; Zhou, J.; Zurita, P.

    2011-01-01

    This report is based on a ten-week program on "Gluons and the quark sea at high-energies", which took place at the Institute for Nuclear Theory in Seattle in Fall 2010. The principal aim of the program was to develop and sharpen the science case for an Electron-Ion Collider (EIC), a facility that

  9. Effect of electron-ion equilibration on optical emission from a shock wave

    International Nuclear Information System (INIS)

    Chiu, G.; Ng, A.; Forsman, A.

    1997-01-01

    Optical emission from a shock wave emerging from a free surface is studied using numerical simulations taking into account the effect of temperature equilibration between electrons and ions. The results show significant variations depending on the equilibration rate. They also illustrate how measurements of the absolute intensity, relative spectral intensities, and temporal history of such emission can provide a new and important means for determining electron-ion equilibration rate in dense matter. copyright 1997 The American Physical Society

  10. A cold cathode of a gas-discharge electron-ion gun

    International Nuclear Information System (INIS)

    1974-01-01

    A cold cathode of a gas-discharge electron-ion gun is constructed in order to continuously replace the eroded material by feeding a wire or a set of coaxial cylinders in the spot where the ions hit the cathode. In this way, the form of the cathode and the electric-field configuration is preserved which guarantees the conservation of a sharp narrow electron beam profile

  11. Relativistic Shear Flow between Electron-Ion and Electron-Positron Plasmas and Astrophysical Applications

    Science.gov (United States)

    Liang, Edison; Fu, Wen; Böttcher, Markus

    2017-10-01

    We present particle-in-cell simulation results of relativistic shear boundary layers between electron-ion and electron-positron plasmas and discuss their potential applications to astrophysics. Specifically, we find that in the case of a fast electron-positron spine surrounded by a slow-moving or stationary electron-ion sheath, lepton acceleration proceeds in a highly anisotropic manner due to electromagnetic fields created at the shear interface. While the highest-energy leptons still produce a beaming pattern (as seen in the quasi-stationary frame of the sheath) of order 1/Γ, where Γ is the bulk Lorentz factor of the spine, for lower-energy particles, the beaming is much less pronounced. This is in stark contrast to the case of pure electron-ion shear layers, in which anisotropic particle acceleration leads to significantly narrower beaming patterns than 1/Γ for the highest-energy particles. In either case, shear-layer acceleration is expected to produce strongly angle-dependent lepton (hence, emanating radiation) spectra, with a significantly harder spectrum in the forward direction than viewed from larger off-axis angles, much beyond the regular Doppler boosting effect from a co-moving isotropic lepton distribution. This may solve the problem of the need for high (and apparently arbitrarily chosen) minimum Lorentz factors of radiating electrons, often plaguing current blazar and GRB jet modeling efforts.

  12. 6th International Conference on the Physics Opportunities at an ElecTron-Ion Collider

    CERN Document Server

    Sabatié, F; POETIC6

    2015-01-01

    POETIC6, the 6th edition of the International Conference on the "Physics Opportunities at an ElecTron-Ion Collider", will take place at Ecole Polytechnique in Palaiseau, France from Monday, September 7th to Friday, September 11th 2015, a few weeks before the National Science Advisory Committee recommends a new Long Range Plan to the United States' DOE and NSF. In the midst of this much-anticipated report, and following earlier workshops at Stellenbosch, Bloomington, Valparaiso, Jyvaskyla and Yale, it is timely for the POETIC series to become an international conference. The primary goal will remain to continue the advancement of the field of electron-ion collider physics. While the central theme of the conference will be the physics of a future electron-ion collider, the workshop will also cover strongly-related physics in the CEBAF, RHIC, and LHC experimental programs. The conference will aim primarily at developments on the theory/phenomenology side, but the latest accelerator and experimental developments ...

  13. High luminosity μ+ μ- collider: Report of a feasibility study

    International Nuclear Information System (INIS)

    Palmer, R.B.; Gallardo, J.C.; Tollestrup, A.; Sessler, A.

    1996-12-01

    Parameters are given of 4 TeV and 0.5 TeV (c-of-m) high luminosity μ + μ - colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Detector background, polarization, and nonstandard operating conditions are analyzed. Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. We briefly mention the luminosity requirements of hadrons and lepton machines and their high-energy-physics advantages and disadvantages in reference to their effective center of mass energy. Finally, we present an R ampersand D plan to determine whether such machines are practical

  14. Large Hadron Collider manual

    CERN Document Server

    Lavender, Gemma

    2018-01-01

    What is the universe made of? How did it start? This Manual tells the story of how physicists are seeking answers to these questions using the world’s largest particle smasher – the Large Hadron Collider – at the CERN laboratory on the Franco-Swiss border. Beginning with the first tentative steps taken to build the machine, the digestible text, supported by color photographs of the hardware involved, along with annotated schematic diagrams of the physics experiments, covers the particle accelerator’s greatest discoveries – from both the perspective of the writer and the scientists who work there. The Large Hadron Collider Manual is a full, comprehensive guide to the most famous, record-breaking physics experiment in the world, which continues to capture the public imagination as it provides new insight into the fundamental laws of nature.

  15. DESY: HERA polarization

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The new HERA electron-proton collider at DESY in Hamburg achieved the first luminosity for electron-proton collisions on 19 October last year. Only one month later, on 20 November, HERA passed another important milestone with the observation of transverse electron polarization

  16. The Large Hadron Collider

    CERN Document Server

    Juettner Fernandes, Bonnie

    2014-01-01

    What really happened during the Big Bang? Why did matter form? Why do particles have mass? To answer these questions, scientists and engineers have worked together to build the largest and most powerful particle accelerator in the world: the Large Hadron Collider. Includes glossary, websites, and bibliography for further reading. Perfect for STEM connections. Aligns to the Common Core State Standards for Language Arts. Teachers' Notes available online.

  17. QCD for Collider Physics

    OpenAIRE

    Skands, Peter

    2011-01-01

    These lectures are directed at a level suitable for graduate students in experimental and theoretical High Energy Physics. They are intended to give an introduction to the theory and phenomenology of quantum chromodynamics (QCD) as it is used in collider physics applications. The aim is to bring the reader to a level where informed decisions can be made concerning different approaches and their uncertainties. The material is divided into four main areas: 1) fundamentals, 2) perturbative QCD, ...

  18. Muon Collider Progress: Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Zisman, Michael S.

    2011-09-10

    A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 × 10{sup 34} cm{sup –2}s{sup –1}. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance (“cooling”). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program are described.

  19. Electron-electron luminosity in the Next Linear Collider -- a preliminary study

    International Nuclear Information System (INIS)

    Zimmermann, F.; Thompson, K.A.; Helm, R.H.

    1997-11-01

    In this paper, the authors discuss some operational aspects of electron-electron collisions at the Next Linear Collider (NLC) and estimate the luminosity attainable in such a machine. They also consider the use of two future technologies which could simplify the operation and improve the luminosity in an e - e - collider: polarized rf guns and plasma lenses

  20. Future Hadron Colliders

    CERN Document Server

    Keil, Eberhard

    1998-01-01

    Plans for future hadron colliders are presented, and accelerator physics and engineering aspects common to these machines are discussed. The Tevatron is presented first, starting with a summary of the achievements in Run IB which finished in 1995, followed by performance predictions for Run II which will start in 1999, and the TeV33 project, aiming for a peak luminosity $L ~ 1 (nbs)^-1$. The next machine is the Large Hadron Collider LHC at CERN, planned to come into operation in 2005. The last set of machines are Very Large Hadron Colliders which might be constructed after the LHC. Three variants are presented: Two machines with a beam energy of 50 TeV, and dipole fields of 1.8 and 12.6 T in the arcs, and a machine with 100 TeV and 12 T. The discussion of accelerator physics aspects includes the beam-beam effect, bunch spacing and parasitic collisions, and the crossing angle. The discussion of the engineering aspects covers synchrotron radiation and stored energy in the beams, the power in the debris of the p...

  1. Hadron Collider Detectors

    International Nuclear Information System (INIS)

    Incandela, J.R.

    2000-01-01

    Experiments are being prepared at the Fermilab Tevatron and the CERN Large Hadron Collider that promise to deliver extraordinary insights into the nature of spontaneous symmetry breaking, and the role of supersymmetry in the universe. This article reviews the goals, challenges, and designs of these experiments. The first hadron collider, the ISR at CERN, has to overcome two initial obstacles. The first was low luminosity, which steadily improved over time. The second was the broad angular spread of interesting events. In this regard Maurice Jacob noted (1): The answer is ... sophisticated detectors covering at least the whole central region (45 degree le θ le 135 degree) and full azimuth. This statement, while obvious today, reflects the major revelation of the ISR period that hadrons have partonic substructure. The result was an unexpectedly strong hadronic yield at large transverse momentum (p T ). Partly because of this, the ISR missed the discovery of the J/ψ and later missed the Υ. The ISR era was therefore somewhat less auspicious than it might have been. It did however make important contributions in areas such as jet production and charm excitation and it paved the way for the SPS collider, also at CERN

  2. Progress on optimization of the nonlinear beam dynamics in the MEIC collider rings

    International Nuclear Information System (INIS)

    Nosochkov, Y. M.; Cai, Y.; Sullivan, M.; Wang, M-H; Wienands, U.; Morozov, V. S.; Derbenev, Ya. S.; Lin, F.; Pilat, F.; Zhang, Y.

    2015-01-01

    One of the key design features of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab is a small beta function at the interaction point (IP) allowing one to achieve a high luminosity of up to 10 34 cm -2 s -1 . The required strong beam focusing unavoidably causes large chromatic effects such as chromatic tune spread and beam smear at the IP, which need to be compensated. This paper reports recent progress in our development of a chromaticity correction scheme for the ion ring including optimization of dynamic aperture and momentum acceptance.

  3. Progress on Optimization of the Nonlinear Beam Dynamics in the MEIC Collider Rings

    International Nuclear Information System (INIS)

    Morozov, Vasiliy S.; Derbenev, Yaroslav S.; Lin, Fanglei; Pilat, Fulvia; Zhang, Yuhong; Cai, Y.; Nosochkov, Y. M.; Sullivan, Michael; Wang, M.-H.; Wienands, Uli

    2015-09-01

    One of the key design features of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab is a small beta function at the interaction point (IP) allowing one to achieve a high luminosity of up to 10 34 cm -2 s -1 . The required strong beam focusing unavoidably causes large chromatic effects such as chromatic tune spread and beam smear at the IP, which need to be compensated. This paper reports recent progress in our development of a chromaticity correction scheme for the ion ring including optimization of dynamic aperture and momentum acceptance.

  4. Hadron-hadron colliders

    International Nuclear Information System (INIS)

    Month, M.; Weng, W.T.

    1983-01-01

    The objective is to investigate whether existing technology might be extrapolated to provide the conceptual framework for a major hadron-hadron collider facility for high energy physics experimentation for the remainder of this century. One contribution to this large effort is to formalize the methods and mathematical tools necessary. In this report, the main purpose is to introduce the student to basic design procedures. From these follow the fundamental characteristics of the facility: its performance capability, its size, and the nature and operating requirements on the accelerator components, and with this knowledge, we can determine the technology and resources needed to build the new facility

  5. Hadron collider physics at UCR

    International Nuclear Information System (INIS)

    Kernan, A.; Shen, B.C.

    1997-01-01

    This paper describes the research work in high energy physics by the group at the University of California, Riverside. Work has been divided between hadron collider physics and e + -e - collider physics, and theoretical work. The hadron effort has been heavily involved in the startup activities of the D-Zero detector, commissioning and ongoing redesign. The lepton collider work has included work on TPC/2γ at PEP and the OPAL detector at LEP, as well as efforts on hadron machines

  6. Ion-acoustic envelope modes in a degenerate relativistic electron-ion plasma

    Energy Technology Data Exchange (ETDEWEB)

    McKerr, M.; Kourakis, I. [Centre for Plasma Physics, School of Mathematics and Physics, Queen' s University Belfast, BT7 1NN Belfast, Northern Ireland (United Kingdom); Haas, F. [Instituto de Física, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, Porto Alegre, RS (Brazil)

    2016-05-15

    A self-consistent relativistic two-fluid model is proposed for one-dimensional electron-ion plasma dynamics. A multiple scales perturbation technique is employed, leading to an evolution equation for the wave envelope, in the form of a nonlinear Schrödinger type equation (NLSE). The inclusion of relativistic effects is shown to introduce density-dependent factors, not present in the non-relativistic case—in the conditions for modulational instability. The role of relativistic effects on the linear dispersion laws and on envelope soliton solutions of the NLSE is discussed.

  7. Electron-ion plasma dynamics in the presence of highly charged dust-clusters

    Energy Technology Data Exchange (ETDEWEB)

    Djebli, Mourad, E-mail: mdjebli@usthb.dz; Benkhelifa, El-Amine [USTHB, Faculty of Physics, Theoretical Physics Laboratory, B.P. 32 Bab-Ezzouar, 16079 Algiers (Algeria)

    2015-05-15

    Electron-ion plasma expansion is studied in the presence of positively (negatively) highly charged uniformly distributed dust particles, considered as impurities. For that purpose, a multi-fluid model is used, where the charged impurities characteristics are included in Poisson's equation. We found that ion acceleration is enhanced by the presence of positively charged dust. The latter leads to spiky structures in the ion front which have a higher amplitude as the charge increases. The charged impurities have a significant effect when the combination of their charge and density is greater than a critical value which depends on ion to electron temperature ratio.

  8. Directional modulation of electron-ion pairs recombination in liquid argon

    Science.gov (United States)

    Cataudella, V.; de Candia, A.; De Filippis, G.; Catalanotti, S.; Cadeddu, M.; Lissia, M.; Rossi, B.; Galbiati, C.; Fiorillo, G.

    2017-12-01

    Motivated by the ongoing study of a possible directional signal in liquid argon dark matter detectors, we introduce a new model describing the recombination of electron-ion pairs in ionizing tracks in liquid argon in the presence of a drift field. The emphasis is on the three-dimensional distribution of electrons and ions and on their orientation relative to that of the electric field. We successfully apply our model to describe the angular dependence of the ionization signal of protons recently reported in measurements performed by the ArgoNeuT Collaboration with a liquid argon time projection chamber.

  9. Proton-antiproton collider physics

    CERN Document Server

    Altarelli, Guido

    1989-01-01

    This volume reviews the physics studied at the CERN proton-antiproton collider during its first phase of operation, from the first physics run in 1981 to the last one at the end of 1985. The volume consists of a series of review articles written by physicists who are actively involved with the collider research program. The first article describes the proton-antiproton collider facility itself, including the antiproton source and its principle of operation based on stochastic cooling. The subsequent six articles deal with the various physics subjects studied at the collider. Each article descr

  10. Spin Transparency Mode in the NICA Collider with Solenoid Siberian Snakes for Proton and Deuteron Beam

    Science.gov (United States)

    Kovalenko, A. D.; Butenko, A. V.; Mikhaylov, V. A.; Kondratenko, M. A.; Kondratenko, A. M.; Filatov, Yu N.

    2017-12-01

    Two solenoid Siberian Snakes are required to obtain ion polarization in spin transparency mode of the NICA collider. The snake solenoids with a total field integral of 2×50 T·m are placed into the straight sections of the NICA collider. It allows one to control polarization of protons and deuterons up to 13.5 GeV/c and 4 GeV/c respectively. The snakes introduce a strong betatron oscillation coupling. The calculations of orbital parameters of proton and deuteron beams in the NICA collider with solenoid Snakes are presented.

  11. Majorana Higgses at colliders

    Science.gov (United States)

    Nemevšek, Miha; Nesti, Fabrizio; Vasquez, Juan Carlos

    2017-04-01

    Collider signals of heavy Majorana neutrino mass origin are studied in the minimal Left-Right symmetric model, where their mass is generated spontaneously together with the breaking of lepton number. The right-handed triplet Higgs boson Δ, responsible for such breaking, can be copiously produced at the LHC through the Higgs portal in the gluon fusion and less so in gauge mediated channels. At Δ masses below the opening of the V V decay channel, the two observable modes are pair-production of heavy neutrinos via the triplet gluon fusion gg → Δ → NN and pair production of triplets from the Higgs h → ΔΔ → 4 N decay. The latter features tri- and quad same-sign lepton final states that break lepton number by four units and have no significant background. In both cases up to four displaced vertices may be present and their displacement may serve as a discriminating variable. The backgrounds at the LHC, including the jet fake rate, are estimated and the resulting sensitivity to the Left-Right breaking scale extends well beyond 10 TeV. In addition, sub-dominant radiative modes are surveyed: the γγ, Zγ and lepton flavour violating ones. Finally, prospects for Δ signals at future e + e - colliders are presented.

  12. Polarized protons and parity violating asymmetries

    International Nuclear Information System (INIS)

    Trueman, T.L.

    1984-01-01

    The potential for utilizing parity violating effects, associated with polarized protons, to study the standard model, proton structure, and new physics at the SPS Collider is summarized. 24 references

  13. Polarization at the SLC

    Energy Technology Data Exchange (ETDEWEB)

    Moffeit, K.C.

    1988-10-01

    The Stanford Linear collider was designed to accommodate polarized electron beams. Longitudinally polarized electrons colliding with unpolarized positrons at a center of mass energy near the Z/sup 0/ mass can be used as novel and sensitive probes of the electroweak process. A gallium arsenide based photon emission source will provide a beam of longitudinally polarized electrons of about 45 percent polarization. A system of bend magnets and a superconducting solenoid will be used to rotate the spins so that the polarization is preserved while the 1.21 GeV electrons are stored in the damping ring. Another set of bend magnets and two superconducting solenoids orient the spin vectors so that longitudinal polarization of the electrons is achieved at the collision point with the unpolarized positrons. A system to monitor the polarization based on Moller and Compton scattering will be used. Nearly all major components have been fabricated and tested. Subsystems of the source and polarimeters have been installed, and studies are in progress. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. 8 refs., 16 figs., 1 tab.

  14. New family of exact solutions for colliding plane gravitational waves

    International Nuclear Information System (INIS)

    Yurtsever, U.

    1988-01-01

    We construct an infinite-parameter family of exact solutions to the vacuum Einstein field equations describing colliding gravitational plane waves with parallel polarizations. The interaction regions of the solutions in this family are locally isometric to the interiors of those static axisymmetric (Weyl) black-hole solutions which admit both a nonsingular horizon, and an analytic extension of the exterior metric to the interior of the horizon. As a member of this family of solutions we also obtain, for the first time, a colliding plane-wave solution where both of the two incoming plane waves are purely anastigmatic, i.e., where both incoming waves have equal focal lengths

  15. The photon collider at TESLA

    Czech Academy of Sciences Publication Activity Database

    Badelek, B.; Bloechinger, C.; Blümlein, J.; Boos, E.; Brinkman, R.; Burkhardt, H.; Bussey, P.; Carimalo, C.; Chýla, Jiří; Ciftci, A.K.

    2004-01-01

    Roč. 19, č. 30 (2004), s. 5097-5186 ISSN 0217-751X Institutional research plan: CEZ:AV0Z1010920 Keywords : photon collider * linear collider * gamma-gamma * photon-photon * photon electron * Compton scattering Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.054, year: 2004

  16. Test of QCD at colliders

    CERN Document Server

    Shimizu, Shima; The ATLAS collaboration

    2016-01-01

    The ATLAS and CMS collaborations measure QCD processes in a wide kinematic range using proton--proton colliding data at the Large Hadron Collider (LHC). A variety of recent results is presented. The results provide validation of the current understanding of QCD, such as the proton structure and interactions and radiations of partons.

  17. Vanilla Technicolor at Linear Colliders

    DEFF Research Database (Denmark)

    T. Frandsen, Mads; Jarvinen, Matti; Sannino, Francesco

    2011-01-01

    We analyze the reach of Linear Colliders (LC)s for models of dynamical electroweak symmetry breaking. We show that LCs can efficiently test the compositeness scale, identified with the mass of the new spin-one resonances, till the maximum energy in the center-of-mass of the colliding leptons...

  18. The Large Hadron Collider

    Science.gov (United States)

    Evans, Lyndon

    2011-11-01

    The Large Hadron Collider (LHC) is the most complex instrument ever built for particle physics research. It will, for the first time, provide access to the TeV-energy scale. Numerous technological innovations are necessary to achieve this goal. For example, two counterrotating proton beams are guided and focused by superconducting magnets whose novel two-in-one structure saves cost and allowed the machine to be installed in an existing tunnel. The very high (>8-T) field in the dipoles can be achieved only by cooling them below the transition temperature of liquid helium to the superfluid state. More than 80 tons of superfluid helium are needed to cool the whole machine. So far, the LHC has behaved reliably and predictably. Single-bunch currents 30% above the design value have been achieved, and the luminosity has increased by five orders of magnitude. In this review, I briefly describe the design principles of the major systems and discuss some initial results.

  19. Challenges in future linear colliders

    CERN Document Server

    Chattopadhyay, S

    2002-01-01

    For decades, electron-positron colliders have been complementing proton-proton colliders. But the circular LEP, the largest e/sup -/e /sup +/ collider, represented an energy limit beyond which energy losses to synchrotron radiation necessitate moving to e/sup -/e/sup + / linear colliders (LCs), thereby raising new challenges for accelerator builders. Japanese-American, German, and European collaborations have presented options for the "Future Linear Collider " (FLC). Key accelerator issues for any FLC option are the achievement of high enough energy and luminosity. Damping rings, taking advantage of the phenomenon of synchrotron radiation, have been developed as the means for decreasing beam size, which is crucial for ensuring a sufficiently high rate of particle-particle collisions. Related challenges are alignment and stability in an environment where even minute ground motion can disrupt performance, and the ability to monitor beam size. The technical challenges exist within a wider context of socioeconomi...

  20. CERN balances linear collider studies

    CERN Multimedia

    ILC Newsline

    2011-01-01

    The forces behind the two most mature proposals for a next-generation collider, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) study, have been steadily coming together, with scientists from both communities sharing ideas and information across the technology divide. In a support of cooperation between the two, CERN in Switzerland, where most CLIC research takes place, recently converted the project-specific position of CLIC Study Leader to the concept-based Linear Collider Study Leader.   The scientist who now holds this position, Steinar Stapnes, is charged with making the linear collider a viable option for CERN’s future, one that could include either CLIC or the ILC. The transition to more involve the ILC must be gradual, he said, and the redefinition of his post is a good start. Though not very much involved with superconducting radiofrequency (SRF) technology, where ILC researchers have made significant advances, CERN participates in many aspect...

  1. Probing electroweak symmetry breaking at multi-TeV colliders

    International Nuclear Information System (INIS)

    Chanowitz, M.S.

    1987-01-01

    Low energy theorems are derived for scattering of longitudinally polarized W and Z's, providing the basis for an estimate of the observable signal if electroweak symmetry breaking is due to new physics at the TeV scale. A pp collider with L, √s = 40 TeV, 10 33 cm. -2 s -1 is just sufficient to observe the signal while pp colliders with 40, 10 32 or 20, 10 33 are not. A collider that is sensitive to the TeV-scale signal provides valuable information about symmetry breaking whether the masses of the associated new particles are below, within, or above the 1-2 TeV region. 6 refs., 6 figs., 2 tabs

  2. Muon-muon and other high energy colliders

    International Nuclear Information System (INIS)

    Palmer, R.B.; Gallardo, J.C.

    1997-02-01

    The first section looks at the high energy physics advantages, disadvantages and luminosity requirements of hadron, of lepton and photon-photon colliders for comparison. The second section discusses the physics considerations for the muon collider. The third section covers muon collider components. The fourth section is about the intersection region and detectors. In the fifth section, the authors discuss modifications to enhance the muon polarization's operating parameters with very small momentum spreads, operations at energies other than the maximum for which the machine is designed, and designs of machines for different maximum energies. The final section discusses a Research and Development plan aimed at the operation of a 0.5 TeV demonstration machine by the year 2010, and of the 4 TeV machine by the year 2020

  3. Polarized electron beams at SLAC

    International Nuclear Information System (INIS)

    Moffeit, K.C.

    1992-11-01

    SLAC has successfully accelerated high energy polarized electrons for the Stanford Linear Collider and fixed polarized nuclear target experiments. The polarized electron beams at SLAC use a gallium arsenide (GaAlAs for E-142) photon emission source to provide the beam of polarized electrons with polarization of approximately 28% (41% for E-142). While the beam emittance is reduced in the damping ring for SLC operation a system of bend magnets and superconducting solenoids preserve and orient the spin direction for maximum longitudinal polarization at the collision point. The electron polarization is monitored with a Compton scattering polarimeter, and was typically 22% at the e+e- collision point for the 1992 run. Improvements are discussed to increase the source polarization and to reduce the depolarization effects between the source and the collision point

  4. Topics in Collider Physics

    Energy Technology Data Exchange (ETDEWEB)

    Petriello, Frank J

    2003-08-27

    It is an exciting time for high energy physics. Several experiments are currently exploring uncharted terrain; the next generation of colliders will begin operation in the coming decade. These experiments will together help us understand some of the most puzzling issues in particle physics: the mechanism of electroweak symmetry breaking and the generation of flavor physics. It is clear that the primary goal of theoretical particle physics in the near future is to support and guide this experimental program. These tasks can be accomplished in two ways: by developing experimental signatures for new models which address outstanding problems, and by improving Standard Model predictions for precision observables. We present here several results which advance both of these goals. We begin with a study of non-commutative field theories. It has been suggested that TeV-scale non-commutativity could explain the origin of CP violation in the SM. We identify several distinct signatures of non-commutativity in high energy processes. We also demonstrate the one-loop quantum consistency of a simple spontaneously broken non-commutative U(1) theory; this result is an important preface to any attempt to embed the SM within a non-commutative framework. We then investigate the phenomenology of extra-dimensional theories, which have been suggested recently as solutions to the hierarchy problem of particle physics. We first examine the implications of allowing SM fields to propagate in the full five-dimensional spacetime of the Randall-Sundrum model, which solves the hierarchy problem via an exponential ''warping'' of the Planck scale induced by a five-dimensional anti de-Sitter geometry. In an alternative extra-dimensional theory, in which all SM fields are permitted to propagate in flat extra dimensions, we show that properties of the Higgs boson are significantly modified. Finally, we discuss the next-to-next-to leading order QCD corrections to the dilepton

  5. Laboratory investigation of electric charging of dust particles by electrons, ions, and UV radiation

    Science.gov (United States)

    Svestka, Jiri; Pinter, S.; Gruen, E.

    1989-01-01

    In many cosmic environments electric charging of dust particles occurs by electrons, ions, and UV radiation. In case of interstellar dust particles the value of their electric charge can have, for instance, very important consequences for their destruction rate in supernova remnant's shock waves and can globally influence the overall life cycle of dust particles in galaxies. For experimental simulation of charging processes a vacuum chamber was used in which the particles fall through an electron or ion beam of energies up to 10 KeV. The aim of the experiments was to attain maximum charge of dust particles. Furthermore the influence of the rest gas was also determined because electrons and ions produced by collisional ionization of the rest gas can result in significant effects. For measurement particles from 1 to 100 microns from glass, carbon, Al, Fe, MgO, and very loosely bound conglomerates of Al2O3 were used.

  6. Study of device of electron-ion treatment of mother baking yeasts

    International Nuclear Information System (INIS)

    Ostapenkov, A.M.; Merinov, N.S.; Nazarov, V.N.; Balan, E.L.

    1980-01-01

    Devices for electron- ion treatment of mother baking yeasts are considered and classified by the way of aerions removal from the ionization zone: the first ones - by means of the electric field, the other - by air directed flux. Devices of the first type require high voltage - 20-60 kV. Electrodynamic ion generator has been applied as a device of the second type; considered is its construction, principal of operation, given are diagrams of ion flux dependence. The methods of process calculations in the generator and experimental results are presented. The main advantage of the generator of the second type is operation at low (3-5 kV) voltages. It is shown, that the yeast growth module can achieve 36% at essential increase of biomass when using these yeasts as sowing. The device can be used for biostimulation and antisepting of food raw materials

  7. High mass-resolution electron-ion-ion coincidence measurements on core-excited organic molecules

    CERN Document Server

    Tokushima, T; Senba, Y; Yoshida, H; Hiraya, A

    2001-01-01

    Total electron-ion-ion coincidence measurements on core excited organic molecules have been carried out with high mass resolution by using multimode (reflectron/linear) time-of-flight mass analyzer. From the ion correlation spectra of core excited CH sub 3 OH and CD sub 3 OH, the reaction pathway to form H sub 3 sup + (D sub 3 sup +) is identified as the elimination of three H (D) atoms from the methyl group, not as the inter-group (-CH sub 3 and -OH) interactions. In a PEPIPICO spectrum of acetylacetone (CH sub 3 COCH sub 2 COCH sub 3) measured by using a reflectron TOF, correlations between ions up to mass number 70 with one-mass resolution was recorded.

  8. RHIC Polarized proton performance in run-8

    International Nuclear Information System (INIS)

    Montag, C.; Bai, M.; MacKay, W.W.; Roser, T.; Abreu, N.; Ahrens, L.; Barton, D.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Bunce, G.; Calaga, R.; Cameron, P.; Connolly, R.; D'Ottavio, T.; Drees, A.; Fedotov, A.V.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.; Hayes, T.; Huang, H.; Ingrassia, P.; Kayran, D.A.; Kewisch, J.; Lee, R.C.; Lin, F.; Litvinenko, V.N.; Luccio, A.U.; Luo, Y.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Michnoff, R.; Morris, J.; Oerter, B.; Pilat, F.; Pile, P.; Robert-Demolaize, G.; Russo, T.; Satogata, T.; Schultheiss, C.; Sivertz, M.; Smith, K.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2008-01-01

    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Physics data were taken with vertical orientation of the beam polarization, which in the 'Yellow' RHIC ring was significantly lower than in previous years. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8, and we discuss possible causes of the not as high as previously achieved polarization performance of the 'Yellow' ring.

  9. The Strength of Chaos: Accurate Simulation of Resonant Electron Scattering by Many-Electron Ions and Atoms in the Presence of Quantum Chaos

    Science.gov (United States)

    2017-01-20

    AFRL-AFOSR-JP-TR-2017-0012 The Strength of Chaos: accurate simulation of resonant electron scattering by many-electron ions and atoms in the presence...SUBTITLE The Strength of Chaos: accurate simulation of resonant electron scattering by many- electron ions and atoms in the presence of quantum chaos...Strength of Chaos: accurate simulation of resonant electron scattering by many-electron ions and atoms in the presence of quantum chaos” Date 13

  10. The standard model and colliders

    International Nuclear Information System (INIS)

    Hinchliffe, I.

    1987-03-01

    Some topics in the standard model of strong and electroweak interactions are discussed, as well as how these topics are relevant for the high energy colliders which will become operational in the next few years. The radiative corrections in the Glashow-Weinberg-Salam model are discussed, stressing how these corrections may be measured at LEP and the SLC. CP violation is discussed briefly, followed by a discussion of the Higgs boson and the searches which are relevant to hadron colliders are then discussed. Some of the problems which the standard model does not solve are discussed, and the energy ranges accessible to the new colliders are indicated

  11. Vanilla technicolor at linear colliders

    Science.gov (United States)

    Frandsen, Mads T.; Järvinen, Matti; Sannino, Francesco

    2011-08-01

    We analyze the reach of linear colliders for models of dynamical electroweak symmetry breaking. We show that linear colliders can efficiently test the compositeness scale, identified with the mass of the new spin-one resonances, until the maximum energy in the center of mass of the colliding leptons. In particular we analyze the Drell-Yan processes involving spin-one intermediate heavy bosons decaying either leptonically or into two standard model gauge bosons. We also analyze the light Higgs production in association with a standard model gauge boson stemming also from an intermediate spin-one heavy vector.

  12. Physics at Future Hadron Colliders

    CERN Document Server

    Baur, U.; Parsons, J.; Albrow, M.; Denisov, D.; Han, T.; Kotwal, A.; Olness, F.; Qian, J.; Belyaev, S.; Bosman, M.; Brooijmans, G.; Gaines, I.; Godfrey, S.; Hansen, J.B.; Hauser, J.; Heintz, U.; Hinchliffe, I.; Kao, C.; Landsberg, G.; Maltoni, F.; Oleari, C.; Pagliarone, C.; Paige, F.; Plehn, T.; Rainwater, D.; Reina, L.; Rizzo, T.; Su, S.; Tait, T.; Wackeroth, D.; Vataga, E.; Zeppenfeld, D.

    2001-01-01

    We discuss the physics opportunities and detector challenges at future hadron colliders. As guidelines for energies and luminosities we use the proposed luminosity and/or energy upgrade of the LHC (SLHC), and the Fermilab design of a Very Large Hadron Collider (VLHC). We illustrate the physics capabilities of future hadron colliders for a variety of new physics scenarios (supersymmetry, strong electroweak symmetry breaking, new gauge bosons, compositeness and extra dimensions). We also investigate the prospects of doing precision Higgs physics studies at such a machine, and list selected Standard Model physics rates.

  13. Hadron collider physics at UCR

    Energy Technology Data Exchange (ETDEWEB)

    Kernan, A.; Shen, B.C.

    1997-07-01

    This paper describes the research work in high energy physics by the group at the University of California, Riverside. Work has been divided between hadron collider physics and e{sup +}-e{sup {minus}} collider physics, and theoretical work. The hadron effort has been heavily involved in the startup activities of the D-Zero detector, commissioning and ongoing redesign. The lepton collider work has included work on TPC/2{gamma} at PEP and the OPAL detector at LEP, as well as efforts on hadron machines.

  14. Tracing electron-ion recombination in nanoplasmas produced by extreme-ultraviolet irradiation of rare-gas clusters.

    Science.gov (United States)

    Schütte, B; Campi, F; Arbeiter, M; Fennel, Th; Vrakking, M J J; Rouzée, A

    2014-06-27

    We investigate electron-ion recombination in nanoplasmas produced by the ionization of rare-gas clusters with intense femtosecond extreme-ultraviolet (XUV) pulses. The relaxation dynamics following XUV irradiation is studied using time-delayed 790-nm pulses, revealing the generation of a large number of excited atoms resulting from electron-ion recombination. In medium-sized Ar-Xe clusters, these atoms are preferentially created in the Xe core within 10 ps after the cluster ionization. The ionization of excited atoms serves as a sensitive probe for monitoring the cluster expansion dynamics up to the ns time scale.

  15. When Black Holes Collide

    Science.gov (United States)

    Baker, John

    2010-01-01

    Among the fascinating phenomena predicted by General Relativity, Einstein's theory of gravity, black holes and gravitational waves, are particularly important in astronomy. Though once viewed as a mathematical oddity, black holes are now recognized as the central engines of many of astronomy's most energetic cataclysms. Gravitational waves, though weakly interacting with ordinary matter, may be observed with new gravitational wave telescopes, opening a new window to the universe. These observations promise a direct view of the strong gravitational dynamics involving dense, often dark objects, such as black holes. The most powerful of these events may be merger of two colliding black holes. Though dark, these mergers may briefly release more energy that all the stars in the visible universe, in gravitational waves. General relativity makes precise predictions for the gravitational-wave signatures of these events, predictions which we can now calculate with the aid of supercomputer simulations. These results provide a foundation for interpreting expect observations in the emerging field of gravitational wave astronomy.

  16. Collider Physics an Experimental Introduction

    International Nuclear Information System (INIS)

    Elvezio Pagliarone, Carmine

    2011-01-01

    This paper reviews shortly a small part of the contents of a set of lectures, presented at the XIV International School of Particles and Fields in Morelia, state of Michoacan, Mexico, during November 2010. The main goal of those lectures was to introduce students to some of the basic ideas and tools required for experimental and phenomenological analysis of collider data. In particular, after an introduction to the scientific motivations, that drives the construction of powerful accelerator complexes, and the need of reaching high center of mass energies and luminosities, some basic concept about collider particle detectors will be discussed. A status about the present running colliders and collider experiments as well as future plans and research and development is also given.

  17. Bottomonium production in hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Brenner Mariotto, C. [Universidade de Caxias do Sul, RS (Brazil). Centro de Ciencias Exatas e Tecnologia]. E-mail: mariotto@if.ufrgs.br; Gay Ducati, M.B. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica. Grupo de Fenomenologia de Particulas em Altas Energias; Ingelman, G. [Uppsala Univ. (Sweden). High Energy Physics

    2004-07-01

    Production of bottomonium in hadronic collisions is studied in the framework of the soft colour approach. We report some results for production of {upsilon} in the Tevatron and predictions for the future Large Hadron Collider (LHC). (author)

  18. US panel backs linear collider

    CERN Multimedia

    2001-01-01

    A draft report from a working group examining the future of American particle physics has stated that the US should give top priority to a high energy e-p collider, wherever it is built (2 paragraphs).

  19. Large Hadron Collider nears completion

    CERN Multimedia

    2008-01-01

    Installation of the final component of the Large Hadron Collider particle accelerator is under way along the Franco-Swiss border near Geneva, Switzerland. When completed this summer, the LHC will be the world's largest and most complex scientific instrument.

  20. Feedback systems for linear colliders

    CERN Document Server

    Hendrickson, L; Himel, Thomas M; Minty, Michiko G; Phinney, N; Raimondi, Pantaleo; Raubenheimer, T O; Shoaee, H; Tenenbaum, P G

    1999-01-01

    Feedback systems are essential for stable operation of a linear collider, providing a cost-effective method for relaxing tight tolerances. In the Stanford Linear Collider (SLC), feedback controls beam parameters such as trajectory, energy, and intensity throughout the accelerator. A novel dithering optimization system which adjusts final focus parameters to maximize luminosity contributed to achieving record performance in the 1997-98 run. Performance limitations of the steering feedback have been investigated, and improvements have been made. For the Next Linear Collider (NLC), extensive feedback systems are planned as an intregal part of the design. Feedback requiremetns for JLC (the Japanese Linear Collider) are essentially identical to NLC; some of the TESLA requirements are similar but there are significant differences. For NLC, algorithms which incorporate improvements upon the SLC implementation are being prototyped. Specialized systems for the damping rings, rf and interaction point will operate at hi...

  1. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  2. The rise of colliding beams

    International Nuclear Information System (INIS)

    Richter, B.

    1992-06-01

    It is a particular pleasure for me to have this opportunity to review for you the rise of colliding beams as the standard technology for high-energy-physics accelerators. My own career in science has been intimately tied up in the transition from the old fixed-target technique to colliding-beam work. I have led a kind of double life both as a machine builder and as an experimenter, taking part in building and using the first of the colliding-beam machines, the Princeton-Stanford Electron-Electron Collider, and building the most recent advance in the technology, the Stanford Linear Collider. The beginning was in 1958, and in the 34 years since there has been a succession of both electron and proton colliders that have increased the available center-of-mass energy for hard collisions by more than a factor of 1000. For the historians here, I regret to say that very little of this story can be found in the conventional literature. Standard operating procedure for the accelerator physics community has been publication in conference proceedings, which can be obtained with some difficulty, but even more of the critical papers are in internal laboratory reports that were circulated informally and that may not even have been preserved. In this presentation I shall review what happened based on my personal experiences and what literature is available. I can speak from considerable experience on the electron colliders, for that is the topic in which I was most intimately involved. On proton colliders my perspective is more than of an observer than of a participant, but I have dug into the literature and have been close to many of the participants

  3. Muon muon collider: Feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-18

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup {minus}2} s{sup {minus}1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice--the authors believe--to allow them to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring which has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design.

  4. When Moons Collide

    Science.gov (United States)

    Rufu, Raluca; Aharonson, Oded

    2017-10-01

    Impacts between two orbiting satellites is a natural consequence of Moon formation. Mergers between moonlets are especially important for the newly proposed multiple-impact hypothesis as these moonlets formed from different debris disks merge together to form the final Moon. However, this process is relevant also for the canonical giant impact, as previous work shows that multiple moonlets are formed from the same debris disk.The dynamics of impacts between two orbiting bodies is substantially different from previously heavily studied planetary-sized impacts. Firstly, the impact velocities are smaller and limited to, thus heating is limited. Secondly, both fragments have similar mass therefore, they would contribute similarly and substantially to the final satellite. Thirdly, this process can be more erosive than planetary impacts as the velocity of ejected material required to reach the mutual Hill sphere is smaller than the escape velocity, altering the merger efficiency. Previous simulations show that moonlets inherit different isotopic signatures from their primordial debris disk, depending on the parameters of the collision with the planet. We therefore, evaluate the degree of mixing in moonlet-moonlet collisions in the presence of a planetary gravitational field, using Smooth Particle Hydrodynamics (SPH). Preliminary results show that the initial thermal state of the colliding moonlets has only a minor influence on the amount of mixing, compared to the effects of velocity and impact angle over their likely ranges. For equal mass bodies in accretionary collisions, impact angular momentum enhances mixing. In the hit-and-run regime, only small amounts of material are transferred between the bodies therefore mixing is limited. Overall, these impacts can impart enough energy to melt ~15-30% of the mantle extending the magma ocean phase of the final Moon.

  5. Polarized protons at RHIC

    International Nuclear Information System (INIS)

    Tannenbaum, M.J.

    1990-12-01

    The Physics case is presented for the use of polarized protons at RHIC for one or two months each year. This would provide a facility with polarizations of approx-gt 50% high luminosity ∼2.0 x 10 32 cm -2 s -1 , the possibility of both longitudinal and transverse polarization at the interaction regions, and frequent polarization reversal for control of systematic errors. The annual integrated luminosity for such running (∼10 6 sec per year) would be ∫ Ldt = 2 x 10 38 cm -2 -- roughly 20 times the total luminosity integrated in ∼ 10 years of operation of the CERN Collider (∼10 inverse picobarns, 10 37 cm -2 ). This facility would be unique in the ability to perform parity-violating measurements and polarization test of QCD. Also, the existence of p-p collisions in a new energy range would permit the study of ''classical'' reactions like the total cross section and elastic scattering, etc., and serve as a complement to measurements from p-bar p colliders. 11 refs

  6. Light Higgs production at the Compton Collider

    International Nuclear Information System (INIS)

    Jikia, G.; Soeldner-Rembold, S.

    2000-01-01

    We have studied the production of a light Higgs boson with a mass of 120 GeV in photon-photon collisions at a Compton collider. The event generator for the backgrounds to a Higgs signal due to b-barb and c-barc heavy quark pair production in polarized γγ collisions is based on a complete next-to-leading order (NLO) perturbative QCD calculation. For J z = 0 the large double-logarithmic corrections up to four loops are also included. It is shown that the two-photon width of the Higgs boson can be measured with high statistical accuracy of about 2% for integrated γγ luminosity in the hard part of the spectrum of 40 fb -1 . As a result the total Higgs boson width can be calculated in a model independent way to an accuracy of about 14%

  7. Light Higgs production at a photon collider

    CERN Document Server

    Söldner-Rembold, S

    2001-01-01

    We present a preliminary study of the production of a light Higgs boson with a mass between 120 and 160 GeV in photon-photon collisions at a Compton collider. The event generator for the backgrounds to a Higgs signal due to b-barb and c-barc heavy quark pair production in polarized gamma gamma collisions is based on a complete next-to-leading order (NLO) perturbative QCD calculation. For J sub z =0 the large double-logarithmic corrections up to four loops are also included. It is shown that the two-photon width of the Higgs boson can be measured with high statistical accuracy of about 2-10% for integrated gamma gamma luminosity in the hard part of the spectrum of 43 fb sup - sup 1. From this result the total Higgs boson width can be derived in a model independent way.

  8. Electron-ion and ion-ion reaction rate coefficients at low altitudes during a PCA event

    NARCIS (Netherlands)

    Larsen, T.R.; Jespersen, M.; Murdin, J.; Bowling, T.S.; Beek, H.F. van; Stevens, G.A.

    Based on experimental data from several ESRO PCA rocket flights some considerations are presented regarding the mean values of the electron-ion dissociative recombination coefficient (αd) and the ion-ion neutralization coefficient (αi). The estimates yield values for αd = 10−5 cm3 sec−1 for heights

  9. The first ep collider run and future plans

    International Nuclear Information System (INIS)

    Desy, R.B.

    1993-01-01

    After successful machine commissioning in 1991, the new electron-proton collider HERA was ready to start the experimental program in spring last year. Data taking at the ZEUS and H1 experiments began on June 26. The energy of the colliding beams was E e =26.7 GeV and E p = 820 GeV, in accord with the design. The peak luminosity obtained so far was 2.2x10 29 cm -2 s -1 . Until the end of the experimental run in November 1992 an integrated luminosity of 33 nb -1 was delivered to the experiments. Future plans concerning ep operation focus on increasing the number of colliding bunches in order to approach the design goal for the luminosity of 1.5x10 31 cm -2 s -1 . In the electron ring, up to 60% transverse spin polarization have been achieved. It is planned to install a polarized gas target experiment (Hermes, approved as the 3rd HERA experiment) which will require an electron beam with about 50% longitudinal polarization. The machine modifications required for HERMES are scheduled for the 93/94 winter shut down. Furthermore, the possibilities of installing a fixed target experiment for b-quark physics in the proton ring are being studied

  10. Status report of a high luminosity muon collider and future research and development plans

    International Nuclear Information System (INIS)

    Palmer, R.B.; Tollestrup, A.; Sessler, A.

    1996-11-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV (c-of-m) high luminosity μ + μ - colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Detector background, polarization, and nonstandard operating conditions are analyzed. Finally, we present an R ampersand D plan to determine whether such machines are practical, and, if they are, lead to the construction of a 0.5 TeV demonstration by 2010, and to a 4 TeV collider by the year 2020

  11. Tau physics with polarized beams

    Energy Technology Data Exchange (ETDEWEB)

    Daoudi, M.

    1995-11-01

    We present the first results on tau physics using polarized beams. These include measurements of the {tau} Michel parameters {xi} and {xi}{delta} and the {tau} neutrino helicity h{sub {nu}}. The measurements were performed using the SLD detector at the Stanford Linear Collider (SLC).

  12. Polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

  13. Experimental prospects of hadron colliders

    International Nuclear Information System (INIS)

    Iwasaki, Hiroyuki

    1984-01-01

    The main subject of this report is to take a general view on the experiment with several tens of TeV hadron colliders. Intensive studies have been carried out about the physics and the detectors for such hadron machines. The experimental prospect of hadron colliders based on the studies and the view of the author are presented. To obtain a fundamental knowledge on the experiment with hadron colliders, the general properties of hadron scattering should be investigated. First, the total cross sections and charged particle multiplicity are estimated, and hard scattering process is reviewed. The cross sections for some interesting hard scattering process are summarized. The most serious problem for the experiment with hadron colliders is to pick out useful signals from enormous QCD back-ground processes, and a possibility of finding heavy Higgs bosons is discussed in detail as an example. On the basis of these studies, the requirement which general purpose detectors should satisfy is considered. Also the important machine parameters from experimental viewpoint are discussed. High energy hadron colliders have a potentiality to reveal new physics in TeV region, but the preparation for unexpected physics is necessary. (Kako, I.)

  14. Fluid aspects of electron streaming instability in electron-ion plasmas

    International Nuclear Information System (INIS)

    Jao, C.-S.; Hau, L.-N.

    2014-01-01

    Electrons streaming in a background electron and ion plasma may lead to the formation of electrostatic solitary wave (ESW) and hole structure which have been observed in various space plasma environments. Past studies on the formation of ESW are mostly based on the particle simulations due to the necessity of incorporating particle's trapping effects. In this study, the fluid aspects and thermodynamics of streaming instabilities in electron-ion plasmas including bi-streaming and bump-on-tail instabilities are addressed based on the comparison between fluid theory and the results from particle-in-cell simulations. The energy closure adopted in the fluid model is the polytropic law of d(pρ −γ )/dt=0 with γ being a free parameter. Two unstable modes are identified for the bump-on-tail instability and the growth rates as well as the dispersion relation of the streaming instabilities derived from the linear theory are found to be in good agreement with the particle simulations for both bi-streaming and bump-on-tail instabilities. At the nonlinear saturation, 70% of the electrons are trapped inside the potential well for the drift velocity being 20 times of the thermal velocity and the pρ −γ value is significantly increased. Effects of ion to electron mass ratio on the linear fluid theory and nonlinear simulations are also examined

  15. Molecular Dynamics Simulation of Electron-Ion Temperature Relaxation in Dense Hydrogen: Electronic Quantum Effects

    Science.gov (United States)

    Ma, Qian; Dai, Jiayu; Zhao, Zengxiu

    2016-10-01

    The electron-ion temperature relaxation is an important non-equilibrium process in the generation of dense plasmas, particularly in Inertial Confinement Fusion. Classical molecular dynamics considers electrons as point charges, ignoring important quantum processes. We use an Electron Force Field (EFF) method to study the temperature relaxation processes, considering the nuclei as semi-classical point charges and assume electrons as Gaussian wave packets which includes the influences of the size and the radial motion of electrons. At the same time, a Pauli potential is used to describe the electronic exchange effect. At this stage, quantum effects such as exchange, tunneling can be included in this model. We compare the results from EFF and classical molecular dynamics, and find that the relaxation time is much longer with including quantum effects, which can be explained directly by the deference of collision cross sections between quantum particles and classical particles. Further, the final thermal temperature of electron and ion is different compared with classical results that the electron quantum effects cannot be neglected.

  16. Siting the superconducting super collider

    International Nuclear Information System (INIS)

    Price, R.; Rooney, R.C.

    1988-01-01

    At the request of the Department of Energy, the National Academy of Sciences and the National Academy of Engineering established the Super Collider Site Evaluation Committee to evaluate the suitability of proposed sites for the Superconducting Super Collider. Thirty-six proposals were examined by the committee. Using the set of criteria announced by DOE in its Invitation for Site Proposals, the committee identified eight sites that merited inclusion on a ''best qualified list.'' The list represents the best collective judgment of 21 individuals, carefully chosen for their expertise and impartiality, after a detailed assessment of the proposals using 19 technical subcriteria and DOE's life cycle cost estimates. The sites, in alphabetical order, are: Arizona/Maricopa; Colorado; Illinois; Michigan/Stockbridge; New York/Rochester; North Carolina; Tennessee; and Texas/Dallas-Fort Worth. The evaluation of these sites and the Superconducting Super Collider are discussed in this book

  17. Muon Collider Task Force Report

    International Nuclear Information System (INIS)

    Ankenbrandt, C.; Alexahin, Y.; Balbekov, V.; Barzi, E.; Bhat, C.; Broemmelsiek, D.; Bross, A.; Burov, A.; Drozhdin, A.; Finley, D.; Geer, S.

    2007-01-01

    Muon Colliders offer a possible long term path to lepton-lepton collisions at center-of-mass energies √s (ge) 1 TeV. In October 2006 the Muon Collider Task Force (MCTF) proposed a program of advanced accelerator R and D aimed at developing the Muon Collider concept. The proposed R and D program was motivated by progress on Muon Collider design in general, and in particular, by new ideas that have emerged on muon cooling channel design. The scope of the proposed MCTF R and D program includes muon collider design studies, helical cooling channel design and simulation, high temperature superconducting solenoid studies, an experimental program using beams to test cooling channel RF cavities and a 6D cooling demonstration channel. The first year of MCTF activities are summarized in this report together with a brief description of the anticipated FY08 R and D activities. In its first year the MCTF has made progress on (1) Muon Collider ring studies, (2) 6D cooling channel design and simulation studies with an emphasis on the HCC scheme, (3) beam preparations for the first HPRF cavity beam test, (4) preparations for an HCC four-coil test, (5) further development of the MANX experiment ideas and studies of the muon beam possibilities at Fermilab, (6) studies of how to integrate RF into an HCC in preparation for a component development program, and (7) HTS conductor and magnet studies to prepare for an evaluation of the prospects for of an HTS high-field solenoid build for a muon cooling channel

  18. Accelerating and storing polarized hadron beams

    International Nuclear Information System (INIS)

    Teng, L.C.

    1990-10-01

    Polarization hadron experiments at high energies continue to generate surprises. Many questions remain unanswered or unanswerable within the frame work of QCD. These include such basic questions as to why at high energies the polarization analyzing power in pp elastic scattering remains high, why hyperons are produced with high polarizations etc. It is, therefore, interesting to investigate the possibilities of accelerating and storing polarized beams in high energy colliders. On the technical side the recent understanding and confirmation of the actions of partial and multiple Siberian snakes made it possible to contemplate accelerating and storing polarized hadron beams to multi-TeV energies. In this paper, we will examine the equipment, the operation and the procedure required to obtain colliding beams of polarized protons at TeV energies

  19. RHIC Polarized proton operation

    International Nuclear Information System (INIS)

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D'Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.E.; Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-01-01

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP 4 . A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above

  20. RHIC Polarized proton operation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D' Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R,; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; J.; Severino, F.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J. Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP{sup 4}. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above

  1. RHIC polarized proton performance in run-8.

    Energy Technology Data Exchange (ETDEWEB)

    Montag,C.; Abreu, N.; Ahrens, L.; Bai, M.; Barton, D.; et al.

    2008-06-23

    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Helical spin rotators at these two interaction regions were used to control the spin orientation of both beams at the collision points. Physics data were taken with different orientations of the beam polarization. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8.

  2. New electron-ion-plasma equipment for modification of materials and products surface

    International Nuclear Information System (INIS)

    Koval', N.N.

    2013-01-01

    Electron-ion-plasma treatment of materials and products, including surface clearing and activation, formation surface layers with changed chemical and phase structure, increased hardness and corrosion resistance; deposition of various functional coatings, has received a wide distribution in a science and industry. Widespread methods of ion-plasma modification of material and product surfaces are ion etching and activation, ion-plasma nitriding, arc or magnetron deposition of functional coatings, including nanostructured. The combination of above methods of surface modification allows essentially to improve exploitation properties of treated products and to optimize the characteristics of modified surfaces for concrete final requirements. For the purpose of a combination of various methods of ion-plasma treatment in a single work cycle at Institute of High Current Electronics of SB RAS (IHCE SB RAS) specialized technological equipment 'DUET', 'TRIO' and 'QUADRO' and 'KVINTA' have been developed. This equipment allow generating uniform low-temperature gas plasma at pressures of (0.1-1) Pa with concentration of (10 9 -10 11 ) cm -3 in volume of (0.1-1) m 3 . In the installations consistent realization of several various operations of materials and products treatment in a single work cycle is possible. The operations are preliminary heating and degassing, ion clearing, etching and activation of materials and products surface by plasma of arc discharges; chemicothermal treatment (nitriding) for formation of diffusion layer on a surface of treated sample using plasma of nonself-sustained low-pressure arc discharge; deposition of single- or multilayered superhard (≥40 GPa) nanocrystalline coatings on the basis of pure metals or their compounds (nitrides, carbides, carbonitrides) by the arc plasma-assisted method. For realization of the modes all installations are equipped by original sources of gas and metal plasma. Besides, in

  3. Unified first principles description from warm dense matter to ideal ionized gas plasma: electron-ion collisions induced friction.

    Science.gov (United States)

    Dai, Jiayu; Hou, Yong; Yuan, Jianmin

    2010-06-18

    Electron-ion interactions are central to numerous phenomena in the warm dense matter (WDM) regime and at higher temperature. The electron-ion collisions induced friction at high temperature is introduced in the procedure of ab initio molecular dynamics using the Langevin equation based on density functional theory. In this framework, as a test for Fe and H up to 1000 eV, the equation of state and the transition of electronic structures of the materials with very wide density and temperature can be described, which covers a full range of WDM up to high energy density physics. A unified first principles description from condensed matter to ideal ionized gas plasma is constructed.

  4. Coupled electron-ion Monte Carlo simulation of hydrogen molecular crystals

    Science.gov (United States)

    Rillo, Giovanni; Morales, Miguel A.; Ceperley, David M.; Pierleoni, Carlo

    2018-03-01

    We performed simulations for solid molecular hydrogen at high pressures (250 GPa ≤ P ≤ 500 GPa) along two isotherms at T = 200 K (phase III) and at T = 414 K (phase IV). At T = 200 K, we considered likely candidates for phase III, the C2c and Cmca12 structures, while at T = 414 K in phase IV, we studied the Pc48 structure. We employed both Coupled Electron-Ion Monte Carlo (CEIMC) and Path Integral Molecular Dynamics (PIMD). The latter is based on Density Functional Theory (DFT) with the van der Waals approximation (vdW-DF). The comparison between the two methods allows us to address the question of the accuracy of the exchange-correlation approximation of DFT for thermal and quantum protons without recurring to perturbation theories. In general, we find that atomic and molecular fluctuations in PIMD are larger than in CEIMC which suggests that the potential energy surface from vdW-DF is less structured than the one from quantum Monte Carlo. We find qualitatively different behaviors for systems prepared in the C2c structure for increasing pressure. Within PIMD, the C2c structure is dynamically partially stable for P ≤ 250 GPa only: it retains the symmetry of the molecular centers but not the molecular orientation; at intermediate pressures, it develops layered structures like Pbcn or Ibam and transforms to the metallic Cmca-4 structure at P ≥ 450 GPa. Instead, within CEIMC, the C2c structure is found to be dynamically stable at least up to 450 GPa; at increasing pressure, the molecular bond length increases and the nuclear correlation decreases. For the other two structures, the two methods are in qualitative agreement although quantitative differences remain. We discuss various structural properties and the electrical conductivity. We find that these structures become conducting around 350 GPa but the metallic Drude-like behavior is reached only at around 500 GPa, consistent with recent experimental claims.

  5. Working group report: Collider Physics

    Indian Academy of Sciences (India)

    journal of. October 2006 physics pp. 617–637. Working group report: Collider Physics. Coordinators: SUNANDA BANERJEE1, ROHINI M GODBOLE2 and ... and discussed, together with follow-up work, are summarized in this report. The .... Further studies are in progress, including a scan of the parameter space to see if.

  6. Top production at hadron colliders

    Indian Academy of Sciences (India)

    Introduction. Top quark studies are an important aspect of physics program at the Tevatron and the ..... Sin- gle top quark production at hadron colliders was first established in 2007 by the Tevatron experiments. Basically, there are three production processes: the s-channel, the t-channel ... So confronting the measurement.

  7. Linear collider systems and costs

    International Nuclear Information System (INIS)

    Loew, G.A.

    1993-05-01

    The purpose of this paper is to examine some of the systems and sub-systems involved in so-called ''conventional'' e + e - linear colliders and to study how their design affects the overall cost of these machines. There are presently a total of at least six 500 GeV c. of m. linear collider projects under study in the world. Aside from TESLA (superconducting linac at 1.3 GHz) and CLIC (two-beam accelerator with main linac at 30GHz), the other four proposed e + e - linear colliders can be considered ''conventional'' in that their main linacs use the proven technique of driving room temperature accelerator sections with pulsed klystrons and modulators. The centrally distinguishing feature between these projects is their main linac rf frequency: 3 GHz for the DESY machine, 11.424 GHz for the SLAC and JLC machines, and 14 GHz for the VLEPP machine. The other systems, namely the electron and positron sources, preaccelerators, compressors, damping rings and final foci, are fairly similar from project to project. Probably more than 80% of the cost of these linear colliders will be incurred in the two main linacs facing each other and it is therefore in their design and construction that major savings or extra costs may be found

  8. Fast Timing for Collider Detectors

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Advancements in fast timing particle detectors have opened up new possibilities to design collider detectors that fully reconstruct and separate event vertices and individual particles in the time domain. The applications of these techniques are considered for the physics at HL-LHC.

  9. Unraveling supersymmetry at future colliders

    Indian Academy of Sciences (India)

    Finally, we examine how we can proceed to establish whether or not any new physics discovered in the future is supersymmetry, and describe how we might zero in on the framework of SUSY breaking. In this connection, we review sparticle mass measurements at future colliders, and point out that some capabilities of ...

  10. Collider physics: A theorist's view

    International Nuclear Information System (INIS)

    Ellis, S.D.

    1986-06-01

    Recent experimental results from the CERN anti p p Collider are reviewed from a theorist's perspective. The conclusion is that the standard model is impressively verified and nothing else seems to be present. Some other relevant phenomenological and theoretical issues are also reviewed

  11. Working group report: Collider Physics

    Indian Academy of Sciences (India)

    This is summary of the activities of the working group on collider physics in the IXth Workshop on High Energy Physics Phenomenology (WHEPP-9) held at the Institute of Physics, Bhubaneswar, India in January 2006. Some of the work subsequently done on these problems by the subgroups formed during the workshop is ...

  12. Top production at hadron colliders

    Indian Academy of Sciences (India)

    New results on top quark production are presented from four hadron collider experiments: CDF and D0 at the Tevatron, and ATLAS and CMS at the LHC. Cross-sections for single top and top pair production are discussed, as well as results on the top–antitop production asymmetry and searches for new physics including ...

  13. CERN's Large Hadron Collider project

    Science.gov (United States)

    Fearnley, Tom A.

    1997-03-01

    The paper gives a brief overview of CERN's Large Hadron Collider (LHC) project. After an outline of the physics motivation, we describe the LHC machine, interaction rates, experimental challenges, and some important physics channels to be studied. Finally we discuss the four experiments planned at the LHC: ATLAS, CMS, ALICE and LHC-B.

  14. CERN's Large Hadron Collider project

    International Nuclear Information System (INIS)

    Fearnley, Tom A.

    1997-01-01

    The paper gives a brief overview of CERN's Large Hadron Collider (LHC) project. After an outline of the physics motivation, we describe the LHC machine, interaction rates, experimental challenges, and some important physics channels to be studied. Finally we discuss the four experiments planned at the LHC: ATLAS, CMS, ALICE and LHC-B

  15. The collider of the future?

    CERN Multimedia

    2009-01-01

    Why are two studies for one linear collider being conducted in parallel? This is far from a duplication of effort or a waste of resources, since the two studies reflect a complementary strategy aimed at providing the best technology for future physics. On Friday 12 June CERN hosted the first joint meeting between CLIC, ILC and the CERN management.

  16. Collider Scaling and Cost Estimation

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1986-01-01

    This paper deals with collider cost and scaling. The main points of the discussion are the following ones: 1) scaling laws and cost estimation: accelerating gradient requirements, total stored RF energy considerations, peak power consideration, average power consumption; 2) cost optimization; 3) Bremsstrahlung considerations; 4) Focusing optics: conventional, laser focusing or super disruption. 13 refs

  17. Relativistic, QED and nuclear effects in highly charged ions revealed by resonant electron-ion recombination in storage rings

    OpenAIRE

    Schippers, Stefan

    2008-01-01

    Dielectronic recombination (DR) of few-electron ions has evolved into a sensitive spectroscopic tool for highly charged ions. This is due to technological advances in electron-beam preparation and ion-beam cooling techniques at heavy-ion storage rings. Recent experiments prove unambiguously that DR collision spectroscopy has become sensitive to 2nd order QED and to nuclear effects. This review discusses the most recent developments in high-resolution spectroscopy of low-energy DR resonances, ...

  18. Tau physics at p bar p colliders

    International Nuclear Information System (INIS)

    Konigsberg, J.

    1993-01-01

    Tau detection techniques in hadron colliders are discussed together with the measurements and searches performed so far. We also underline the importance tau physics has in present and future collider experiments

  19. NOVOSIBIRSK/STANFORD: colliding linac beams

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Plans to use colliding beams from linear accelerators are being considered at Novosibirsk and Stanford. The VLEPP scheme proposed for Novosibirsk and the Stanford single pass collider scheme are described. (W.D.L.).

  20. World lays groundwork for future linear collider

    CERN Multimedia

    Feder, Toni

    2010-01-01

    "New physics from the Large Hadron Collider can best be explored with a large lepton collider; realizing one will require mobilizing accelerator and particle physicists, funding agencies, and politicians" (3 pages)

  1. New neutral current effects at e+e- linear colliders

    International Nuclear Information System (INIS)

    Pankov, A.A.

    2002-01-01

    Four fermion contact interaction effects in the processes e + e - → μ + μ - , b-barb and c-barc at the e + e - linear colliders with √ s = 0.5 TeV and longitudinally polarized initial beams have been studied. Presented analysis has been performed by means of new integrated observables expressed in terms of the forward (σ F ) and backward (σ B ) polarized cross sections such that they give information on individual helicity cross sections. The helicity cross sections allow to perform a general model-independent analysis of four-fermion contact interactions and obtain the corresponding constraints on their parameters. It is also shows that the sensitivity of the new polarized observables to contact interactions is quite larger than that of the conventional observables (σ, A FB , A LR , A LR,FB ) [ru

  2. Polarization Optics

    OpenAIRE

    Fressengeas, Nicolas

    2010-01-01

    The physics of polarization optics *Polarized light propagation *Partially polarized light; DEA; After a brief introduction to polarization optics, this lecture reviews the basic formalisms for dealing with it: Jones Calculus for totally polarized light and Stokes parameters associated to Mueller Calculus for partially polarized light.

  3. Effect of μe universality violation in muon pair production on colliding electron-positron beams

    International Nuclear Information System (INIS)

    Guliev, N.A.; Dzhafarov, I.G.; Mekhtiev, B.I.

    1981-01-01

    The muonic pair production in colliding electron-positron beams is treated assuming the electron and muon weak interaction constants to be different. General formulae for the differential and total cross sections applicable at arbitrary energies of the colliding beams are obtained taking simultaneously into account arbitrary polarizations of the incident particles and longitudinal polarization of the muon (μ - ). It is shown that study of some polarization characteristics of a given reaction allows to distinguish possible weak interaction μe universality breaking effects. The revealing effects are analysed in the framework of unified gauge SU(2)xU(1) models, of weak and electromagnetic interactions [ru

  4. Cross section for muon colliders in the MSSM with complex parameters

    International Nuclear Information System (INIS)

    Nguyen Chinh Cuong; Ha Huy Bang; Dao Thi Le Thuy

    2005-06-01

    The idea of a muon collider has already been brought up in the 1960s and 70s by Tinlot, Skrinsky, Neufer etc. However, major technical challenges have to be met in order to collect, accelerate, and collide muons and antimuons, which decay with a lifetime of 2.2μs. At present, the Muon Collider Collaboration carries out the R and D for a muon collider in the US. In Europe, a muon collider is discussed within the ECFA Prospective Study on Muon Colliders. Specific studies are done for O(100) GeV, 0.3 - 0.5 TeV, and multi-TeV machines with luminosities of 10 31 to 5 x 10 34 cm -- 2s -1 . In this paper, we consider the muon collider μ + μ - → q-tilde i q-bar-tilde j at the tree level with complex parameters and polarization of μ + , μ - beams. Numerical results are also performed and discussed. (author)

  5. Collision Technologies for Circular Colliders

    Science.gov (United States)

    Levichev, Eugene

    2015-02-01

    For several decades already, particle colliders have been essential tools for particle physics. From the very beginning, such accelerators have been among the most complicated scientific instruments ever built, including a number of innovative technological developments. Examples are ultrahigh vacuum systems, magnets with a very high magnetic field, and equipment for sub-ns synchronization and sub-mm precision alignment of equipment inside multi-km underground tunnels. Some key technologies are related to the focusing of the beam down to a scale of sub-μm at the collision point to obtain high luminosity. This review provides an overview of collision concepts and technologies for circular particle colliders, starting from the first ideas. In particular, it discusses such novel schemes and related technologies as crab waist collision and round beam collision.

  6. Measuring the contribution of low Bjorken-x gluons to the proton spin with polarized proton-proton collisions

    Science.gov (United States)

    Wolin, Scott Justin

    which arises from the determination of the relative luminosity. A precision ALLL measurement requires measuring the final state yield from the portions of the proton beams that collide like and unlike sign helicity protons separately. It also requires understanding the ratio of the collision rates of these two portions of the beam exquisitely well. This is a long standing problem and, until recently, had threatened to severely restrict the ability of PHENIX to utilize the large data sets that have been acquired in the last two years to improve the constraints on DeltaG. We will conclude this thesis with a comprehensive overview of the relative luminosity systematic uncertainty and present a new framework within which this uncertainty can be determined. The measurement of the gluon contribution to the proton spin at the PHENIX experiment is a multi- faceted problem which requires a multi-faceted solution. This thesis describes several aspects of the solution as the single- and di-hadron measurements from MPC data are likely to provide the best constraints to Delta G at low-x for the next decade. Eventually, an Electron-Ion Collider (EIC) will be designed and commissioned that will further extend the kinematic reach of the polarized DIS experiments that motivated the spin program at RHIC. In the meantime, the goal of PHENIX in general, and the MPC in particular, is to glean as much information about the gluon polarization as possible before the EIC era arrives. (Abstract shortened by UMI.)

  7. Top production at hadron colliders

    Indian Academy of Sciences (India)

    collisions at. √ s = 1.96 TeV and proton–proton collisions at. √ s = 7 TeV. The top quark is the heaviest known elementary particle with a mass of about 173 GeV and a short ... 2010 the LHC started its operation, producing pp collisions at 7 TeV CM system energy, ... essentially all physics objects at a collider experiment.

  8. A collider observable QCD axion

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, Savas; Hook, Anson; Huang, Junwu; Marques-Tavares, Gustavo [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94305 (United States)

    2016-11-09

    We present a model where the QCD axion is at the TeV scale and visible at a collider via its decays. Conformal dynamics and strong CP considerations account for the axion coupling strongly enough to the standard model to be produced as well as the coincidence between the weak scale and the axion mass. The model predicts additional pseudoscalar color octets whose properties are completely determined by the axion properties rendering the theory testable.

  9. Gluons and the Quark Sea at High Energies: Distributions, Polarization, Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Daniel; /Groningen U.; Diehl, Markus; /DESY; Milner, Richard; /MIT; Venugopalan, Raju; /Brookhaven; Vogelsang, Werner; /Tubingen U.; Kaplan, David; /Washington U., Seattle; Montgomery, Hugh; /Jefferson Lab; Vigdor, Steven; /Brookhaven; Accardi, A.; /Jefferson Lab; Aschenauer, E.C.; /Brookhaven; Burkardt, M.; /New Mexico State U.; Ent, R.; /Jefferson Lab; Guzey, V.; /Jefferson Lab; Hasch, D.; /Frascati; Kumar, K.; /Massachusetts U., Amherst; Lamont, M.A.C.; /Brookhaven; Li, Ying-chuan; /Brookhaven; Marciano, W.; /Brookhaven; Marquet, C.; /CERN; Sabatie, F.; /IRFU, SPhN, Saclay; Stratmann, M.; /Brookhaven /LBL, Berkeley /Buenos Aires U. /Antwerp U. /Pelotas U. /Moncton U. /Santa Maria U., Valparaiso /CCTVal, Valparaiso /Hefei, CUST /Shandong U., Weihai /Boskovic Inst., Zagreb /Zagreb U., Phys. Dept. /Jyvaskyla U. /Orsay, LPT /Paris U., VI-VII /Ecole Polytechnique, CPHT /IRFU, SPhN, Saclay /Saclay, SPhT /Ruhr U., Bochum /Giessen U. /DESY /Hamburg U., Inst. Theor. Phys. II /Heidelberg U. /Mainz U., Inst. Kernphys. /Mainz U., Inst. Phys. /Regensburg U. /Tubingen U. /Wuppertal U. /DESY /Cagliari U. /INFN, Cagliari /Frascati /Milan U. /INFN, Milan /INFN, Pavia /Pavia U. /INFN, Perugia /Perugia U.; /more authors..

    2012-06-07

    This report on the science case for an Electron-Ion Collider (EIC) is the result of a ten-week program at the Institute for Nuclear Theory (INT) in Seattle (from September 13-November 19, 2010), motivated by the need to develop a strong case for the continued study of the QCD description of hadron structure in the coming decades. Hadron structure in the valence quark region will be studied extensively with the Jefferson Lab 12 GeV science program, the subject of an INT program the previous year. The focus of the INT program was on understanding the role of gluons and sea quarks, the important dynamical degrees of freedom describing hadron structure at high energies. Experimentally, the most direct and precise way to access the dynamical structure of hadrons and nuclei at high energies is with a high luminosity lepton probe in collider mode. An EIC with optimized detectors offers enormous potential as the next generation accelerator to address many of the most important, open questions about the fundamental structure of matter. The goal of the INT program, as captured in the writeups in this report, was to articulate these questions and to identify golden experiments that have the greatest potential to provide definitive answers to these questions. At resolution scales where quarks and gluons become manifest as degrees of freedom, the structure of the nucleon and of nuclei is intimately connected with unique features of QCD dynamics, such as confinement and the self-coupling of gluons. Information on hadron sub-structure in DIS is obtained in the form of 'snapshots' by the 'lepton microscope' of the dynamical many-body hadron system, over different momentum resolutions and energy scales. These femtoscopic snapshots, at the simplest level, provide distribution functions which are extracted over the largest accessible kinematic range to assemble fundamental dynamical insight into hadron and nuclear sub-structure. For the proton, the EIC would be

  10. FUTURE CIRCULAR COLLIDER LOGISTICS STUDY

    CERN Document Server

    Beißert, Ulrike; Kuhlmann, Gerd; Nettsträter, Andreas; Prasse, Christian; Wohlfahrt, Andreas

    2018-01-01

    The Large Hadron Collider (LHC) at the European Organization for Nuclear Research CERN in Geneva is the largest and most powerful collider in the world. CERN and its research and experimental infrastructure is not only a focus for the science community but is also very much in the public eye. With the Future Circular Collider (FCC) Study, CERN has begun to examine the feasibility of a new underground accelerator ring with a length of approximately 100 kilometres. Logistics is of great importance for the construction, assembly and operation of the FCC. During the planning, construction and assembly of the LHC, logistics proved to be one of the key factors. As the FCC is even larger than the LHC, logistics will also become more and more significant. This report therefore shows new concepts, methods and analytics for logistics, supply chain and transport concepts as part of the FCC study. This report deals with three different logistics aspects for the planning and construction phase of FCC: 1. A discussion of d...

  11. Relativistic, QED and nuclear effects in highly charged ions revealed by resonant electron-ion recombination in storage rings

    International Nuclear Information System (INIS)

    Schippers, Stefan

    2009-01-01

    Dielectronic recombination (DR) of few-electron ions has evolved into a sensitive spectroscopic tool for highly charged ions. This is due to technological advances in electron-beam preparation and ion beam cooling techniques at heavy-ion storage rings. Recent experiments prove unambiguously that DR collision spectroscopy has become sensitive to 2nd order QED and to nuclear effects. This review discusses the most recent developments in high-resolution spectroscopy of low-energy DR resonances, experimental studies of KLL DR of very heavy hydrogen like ions, isotope shift measurements of DR resonances, and the experimental determination of hyperfine induced decay rates in divalent ions utilizing DR.

  12. Performance of the SLC polarized electron source with high polarization

    International Nuclear Information System (INIS)

    Clendenin, J.E.; Alley, R.K.; Aoyagi, H.

    1993-04-01

    For the 1992 operating cycle of the SLAC Linear Collider (SLC), the polarized electron source (PES) during its maiden run successfully met the pulse intensity and overall efficiency requirements of the SLC. However, the polarization of the bulk GaAs cathode was low (∼27%) and the pulse-to-pulse stability was marginal. We have shown that adequate charge for the SLC can be extracted from a strained layer cathode having P e ∼80% even though the quantum efficiency (QE) is - beam stability. The performance of the PES during the 1993 SLC operating cycle with these and other improvements is discussed

  13. RHIC Polarized proton performance in run-8

    Energy Technology Data Exchange (ETDEWEB)

    Montag,C.; Bai, M.; MacKay, W.W.; Roser, T.; Abreu, N.; Ahrens, L.; Barton, D.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Bunce, G.; Calaga, R.; Cameron, P.; Connolly, R.; D' Ottavio, T.; Drees, A.; Fedotov, A.V.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.; Hayes, T.; Huang, H.; Ingrassia, P.; Kayran, D.A.; Kewisch, J.; Lee, R.C.; Lin, F.; Litvinenko, V.N.; Luccio, A.U.; Luo, Y.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Michnoff, R.; Morris, J.; Oerter, B.; Pilat, F.; Pile, P.; Robert-Demolaize, G.; Russo, T.; Satogata, T.; Schultheiss, C.; Sivertz, M.; Smith, K.; Tepikian, S.; D. Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2008-10-06

    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Physics data were taken with vertical orientation of the beam polarization, which in the 'Yellow' RHIC ring was significantly lower than in previous years. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8, and we discuss possible causes of the not as high as previously achieved polarization performance of the 'Yellow' ring.

  14. Colliding with a crunching bubble

    Energy Technology Data Exchange (ETDEWEB)

    Freivogel, Ben; Freivogel, Ben; Horowitz, Gary T.; Shenker, Stephen

    2007-03-26

    In the context of eternal inflation we discuss the fate of Lambda = 0 bubbles when they collide with Lambda< 0 crunching bubbles. When the Lambda = 0 bubble is supersymmetric, it is not completely destroyed by collisions. If the domain wall separating the bubbles has higher tension than the BPS bound, it is expelled from the Lambda = 0 bubble and does not alter its long time behavior. If the domain wall saturates the BPS bound, then it stays inside the Lambda = 0 bubble and removes a finite fraction of future infinity. In this case, the crunch singularity is hidden behind the horizon of a stable hyperbolic black hole.

  15. Muon Colliders and Neutrino Factories

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Daniel M. [IIT, Chicago

    2015-05-29

    Muon colliders and neutrino factories are attractive options for future facilities aimed at achieving the highest lepton-antilepton collision energies and precision measurements of Higgs boson and neutrino mixing matrix parameters. The facility performance and cost depend on how well a beam of muons can be cooled. Recent progress in muon cooling design studies and prototype tests nourishes the hope that such facilities could be built starting in the coming decade. The status of the key technologies and their various demonstration experiments is summarized. Prospects "post-P5" are also discussed.

  16. Instrumentation for Colliding Beam Physics

    CERN Document Server

    2017-01-01

    INSTR17, the International Conference on Instrumentation for Colliding Beam Physics, will be held in the Budker Institute of Nuclear Physics, Novosibirsk, Russia, on 27 February – 4 March, 2017. The conference covers novel methods of particle detection used in various experiments at particle accelerators as well as in astrophysics. It is organized in close relationship with the Vienna Conference on Instrumentation (last held in 2016) and the Pisa Meeting on Advanced Detectors (last held in 2015). The deadline for registration and abstract submission is 15 January. For more details visit the conference website instr17.inp.nsk.su. Will be published in: JINST

  17. The proton-antiproton collider

    International Nuclear Information System (INIS)

    Evans, L.

    1988-01-01

    The subject of this lecture is the CERN Proton-Antiproton (panti p) Collider, in which John Adams was intimately involved at the design, development, and construction stages. Its history is traced from the original proposal in 1966, to the first panti p collisions in the Super Proton Synchrotron (SPS) in 1981, and to the present time with drastically improved performance. This project led to the discovery of the intermediate vector boson in 1983 and produced one of the most exciting and productive physics periods in CERN's history. (orig.)

  18. International Workshop on Linear Colliders 2010

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    IWLC2010 International Workshop on Linear Colliders 2010ECFA-CLIC-ILC joint meeting: Monday 18 October - Friday 22 October 2010Venue: CERN and CICG (International Conference Centre Geneva, Switzerland) This year, the International Workshop on Linear Colliders organized by the European Committee for Future Accelerators (ECFA) will study the physics, detectors and accelerator complex of a linear collider covering both CLIC and ILC options.Contact Workshop Secretariat  IWLC2010 is hosted by CERN

  19. Energy doubler for a linear collider

    Directory of Open Access Journals (Sweden)

    S. Lee

    2002-01-01

    Full Text Available The concept of using short plasma sections several meters in length to double the energy of a linear collider just before the collision point is proposed and modeled. In this scenario the beams from each side of a linear collider are split into pairs of microbunches with the first driving a plasma wake that accelerates the second. The luminosity of the doubled collider is maintained by employing plasma lenses to reduce the spot size before collision.

  20. Beam-beam observations in the Relativistic Heavy Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Laboratory (BNL), Upton, NY (United States); White, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2015-06-24

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

  1. Development of an Apparatus for High-Resolution Auger Photoelectron Coincidence Spectroscopy (APECS) and Electron Ion Coincidence (EICO) Spectroscopy

    Science.gov (United States)

    Kakiuchi, Takuhiro; Hashimoto, Shogo; Fujita, Narihiko; Mase, Kazuhiko; Tanaka, Masatoshi; Okusawa, Makoto

    We have developed an electron electron ion coincidence (EEICO) apparatus for high-resolution Auger photoelectron coincidence spectroscopy (APECS) and electron ion coincidence (EICO) spectroscopy. It consists of a coaxially symmetric mirror electron energy analyzer (ASMA), a miniature double-pass cylindrical mirror electron energy analyzer (DP-CMA), a miniature time-of-flight ion mass spectrometer (TOF-MS), a magnetic shield, an xyz stage, a tilt-adjustment mechanism, and a conflat flange with an outer diameter of 203 mm. A sample surface was irradiated by synchrotron radiation, and emitted electrons were energy-analyzed and detected by the ASMA and the DP-CMA, while desorbed ions were mass-analyzed and detected by the TOF-MS. The performance of the new EEICO analyzer was evaluated by measuring Si 2p photoelectron spectra of clean Si(001)-2×1 and Si(111)-7×7, and by measuring Si-L23VV-Si-2p Auger photoelectron coincidence spectra (Si-L23VV-Si-2p APECS) of clean Si(001)-2×1.

  2. FUTURE LEPTON COLLIDERS AND LASER ACCELERATION

    International Nuclear Information System (INIS)

    PARSA, Z.

    2000-01-01

    Future high energy colliders along with their physics potential, and relationship to new laser technology are discussed. Experimental approaches and requirements for New Physics exploration are also described

  3. Polarization at LEP. Vol. 2

    International Nuclear Information System (INIS)

    Alexander, G.; Altarelli, G.; Blondel, A.; Coignet, G.; Keil, E.; Plane, D.E.; Treille, D.

    1988-01-01

    This report contains a collection of papers covering the most important part of studies carried out by five study groups in view of a programme of experiments with polarized beams at LEP, the Large Electron-Positron collider under construction at CERN. The emphasis is on precision measurements at the Z peak. Such measurements are shown to be of considerable theoretical interest as well as very clean from the point of view of theoretical and experimental uncertainties. The measurement of the beam polarization can certainly be performed with sufficient accuracy, thanks to the availability of both e + and e - beam polarization. The normalization of the data taken with different beam helicities poses certain constraints that are described. Substantial progress has been made in understanding the possibility of providing longitudinally polarized beams in the LEP machine: The design of new wigglers and spin rotators, the study of correction procedures and results of numerical simulations are presented. (orig.)

  4. Very large hadron collider (VLHC)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    A VLHC informal study group started to come together at Fermilab in the fall of 1995 and at the 1996 Snowmass Study the parameters of this machine took form. The VLHC as now conceived would be a 100 TeV hadron collider. It would use the Fermilab Main Injector (now nearing completion) to inject protons at 150 GeV into a new 3 TeV Booster and then into a superconducting pp collider ring producing 100 TeV c.m. interactions. A luminosity of {approximately}10{sup 34} cm{sup -2}s{sup -1} is planned. Our plans were presented to the Subpanel on the Planning for the Future of US High- Energy Physics (the successor to the Drell committee) and in February 1998 their report stated ``The Subpanel recommends an expanded program of R&D on cost reduction strategies, enabling technologies, and accelerator physics issues for a VLHC. These efforts should be coordinated across laboratory and university groups with the aim of identifying design concepts for an economically and technically viable facility`` The coordination has been started with the inclusion of physicists from Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL), and Cornell University. Clearly, this collaboration must expanded internationally as well as nationally. The phrase ``economically and technically viable facility`` presents the real challenge.

  5. High Energy Hadron Colliders - Report of the Snowmass 2013 Frontier Capabilities Hadron Collider Study Group

    CERN Document Server

    Barletta, William; Battaglia, Marco; Klute, Markus; Mangano, Michelangelo; Prestemon, Soren; Rossi, Lucio; Skands, Peter

    2013-01-01

    High energy hadron colliders have been the tools for discovery at the highest mass scales of the energy frontier from the SppS, to the Tevatron and now the LHC. This report reviews future hadron collider projects from the high luminosity LHC upgrade to a 100 TeV hadron collider in a large tunnel, the underlying technology challenges and R&D directions and presents a series of recommendations for the future development of hadron collider research and technology.

  6. High luminosity electron-hadron collider eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Ptitsyn, V.; Aschenauer, E.; Bai, M.; Beebe-Wang, J.; Belomestnykh, S.; Ben-Zvi, I.; Blaskiewicz, M..; Calaga, R.; Chang, X.; Fedotov, A.; Gassner, D.; Hammons, L.; Hahn, H.; Hammons, L.; He, P.; Hao, Y.; Jackson, W.; Jain, A.; Johnson, E.C.; Kayran, D.; Kewisch, J.; Litvinenko, V.N.; Luo, Y.; Mahler, G.; McIntyre, G.; Meng, W.; Minty, M.; Parker, B.; Pikin, A.; Rao, T.; Roser, T.; Skaritka, J.; Sheehy, B.; Skaritka, J.; Tepikian, S.; Than, Y.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Webb, S.; Wu, Q.; Xu, W.; Pozdeyev, E.; Tsentalovich, E.

    2011-03-28

    We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10{sup 34} cm{sup -2} s{sup -1} can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling, ERL test facility and the compact magnets for recirculation passes. A natural staging scenario of step-by-step increases of the electron beam energy by building-up of eRHIC's SRF linacs is presented.

  7. Computing and data handling requirements for SSC [Superconducting Super Collider] and LHC [Large Hadron Collider] experiments

    International Nuclear Information System (INIS)

    Lankford, A.J.

    1990-05-01

    A number of issues for computing and data handling in the online in environment at future high-luminosity, high-energy colliders, such as the Superconducting Super Collider (SSC) and Large Hadron Collider (LHC), are outlined. Requirements for trigger processing, data acquisition, and online processing are discussed. Some aspects of possible solutions are sketched. 6 refs., 3 figs

  8. KEK/NAGOYA/SLAC: Highly polarized electrons

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    In the push by the Japanese KEK Laboratory, in collaboration with university groups and overseas laboratories, to develop new techniques for the future Japan electronpositron collider (JLC), a recent achievement is a significant increase in the efficient yield of highly polarized electrons

  9. RHIC FY15 pp Run RHIC and AGS polarization analysis

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Adams, P. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-20

    The polarization information is important for the spin physics program in Relativistic Heavy Ion Collider (RHIC). There are discrepancies between AGS and RHIC polarization measurements. First, the face value of AGS polarization is higher than RHIC ones in general. Second, the measured polarization profile (described by the profile ratio R) is stronger in AGS than in RHIC. This note analyzes the polarization data from FY15 pp run period. The results show that the differences between AGS and RHIC polarization measurements are reasonable, but the R value difference is puzzling. The difference between blue and yellow ring is worth of spin simulation to explain.

  10. Orbital parameters of proton and deuteron beams in the NICA collider with solenoid Siberian snakes

    International Nuclear Information System (INIS)

    Kovalenko, A D; Butenko, A V; Kekelidze, V D; Mikhaylov, V A; Kondratenko, M A; Filatov, Yu N; Kondratenko, A M

    2016-01-01

    Two solenoid Siberian snakes are required to obtain ion polarization in the “spin transparency” mode of the NICA collider. The field integrals of the solenoid snakes for protons and deuterons at maximum momentum of 13.5 GeV/c are equal to 2×50 T·m and 2×160 T·m respectively. The snakes introduce strong betatron oscillation coupling. The calculations of orbital parameters of proton and deuteron beams in NICA collider with solenoid snakes are presented. (paper)

  11. Polarized γ source based on Compton backscattering in a laser cavity

    Directory of Open Access Journals (Sweden)

    V. Yakimenko

    2006-09-01

    Full Text Available We propose a novel gamma source suitable for generating a polarized positron beam for the next generation of electron-positron colliders, such as the International Linear Collider (ILC, and the Compact Linear Collider (CLIC. This 30-MeV polarized gamma source is based on Compton scattering inside a picosecond CO_{2} laser cavity generated from electron bunches produced by a 4-GeV linac. We identified and experimentally verified the optimum conditions for obtaining at least one gamma photon per electron. After multiplication at several consecutive interaction points, the circularly polarized gamma rays are stopped on a target, thereby creating copious numbers of polarized positrons. We address the practicality of having an intracavity Compton-polarized positron source as the injector for these new colliders.

  12. Vertex Tracking at a Future Linear Collider

    CERN Document Server

    Battaglia, Marco

    2011-01-01

    The anticipated physics program at an high energy e+e- linear collider places special emphasis on the accuracy in extrapolating charged particle tracks to their production vertex to tag heavy quarks and leptons. This paper reviews physics motivations and performance requirements, sensor R&D directions and current results of the studies for a vertex tracker at a future linear collider.

  13. Higgs and SUSY searches at future colliders

    Indian Academy of Sciences (India)

    ... searches at future colliders, particularly comparing and contrasting the capabilities of LHC and next linear collider (NLC), including the aspects of Higgs searches in supersymmetric theories. I will also discuss how the search and study of sparticles other than the Higgs can be used to give information about the parameters ...

  14. Detector issues for a photon collider

    Indian Academy of Sciences (India)

    It has been proposed to collide a high power laser beam with the linear collider electron beams to create high ... At small angles the space in the γγ detector is taken by the laser pipes and the masking system. However ... of the interplay of the crossing angle and the detector solenoid the charge centre gets shifted where the ...

  15. Last magnet in place for colossal collider

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "Workers have installed the last magnet for the world's mew highest-energy particle smasher, the Large Hadron Collider (LHC). The installation marks an important milestone; however, researchers still may not get the collider completed in time to start it up in November as planned." (1 page)

  16. Working group report: Collider and B physics

    Indian Academy of Sciences (India)

    It is generally hoped that the Higgs boson, supersymmetric particles, existence of extra dimensions ..... may be discovered at the upcoming colliders. Bulk of the activities of the working group on collider and B physics revolved around these topics. Different aspects of. Higgs search were discussed by A Djouadi, R M ...

  17. ACCELERATION FOR A HIGH ENERGY MUON COLLIDER

    Energy Technology Data Exchange (ETDEWEB)

    BERG,J.S

    2000-04-07

    The authors describe a method for designing the acceleration systems for a muon collider, with particular application and examples for a high energy muon collider. This paper primarily concentrates on design considerations coming from longitudinal motion, but some transverse issues are briefly discussed.

  18. Multibillion-dolalr collider plans unveiled

    CERN Multimedia

    Cartlidge, Edwin

    2007-01-01

    "Particle physicists released an outline design for the proposed International Linear Collider (ILC) at a meeting in Beijing this morning. The design details the components needed to build the 31 km-long facility and comes with and initial estimate of the collider's cost: a cool $6.5bn for the core project. (1 page)

  19. Photon collider beam simulation with CAIN

    Indian Academy of Sciences (India)

    The CAIN simulation program was used to study the outgoing beam profile for the photon collider at ILC. The main aim of the analysis was to verify the feasibility of the photon linear collider running with 20 mrad electron beam crossing angle. The main problem is the distorted electron beam, which has to be removed from ...

  20. Anomalous VVH interactions at a linear collider

    Indian Academy of Sciences (India)

    We examine, in a model independent way, the sensitivity of a linear collider to the couplings of a light Higgs boson to a pair of gauge bosons, including the possibility of CP violation. We construct several observables that probe the various possible anomalous couplings. For an intermediate mass Higgs, a collider operating ...

  1. Physicist pins hopes on particle collider

    CERN Multimedia

    2007-01-01

    Physicist pins hopes on particle collider By Deseret Morning News Published: Monday, Dec. 31, 27 12:4 a.m. MST FONT Scott Thomas, a 187 State University graduate, is working at the frontiers of science. The theoretical physicist is crafting ways to extract fundamental secrets that seem certain to be uncovered by the Large Hadron Collider.

  2. Reggeon calculus at collider energies

    International Nuclear Information System (INIS)

    Pajares, C.; Varias, A.; Yepes, P.

    1983-01-01

    The phenomenology of the perturbative reggeon calculus at collider energies is studied. It is found that the graphs which were neglected at ISR energies are still negligeable at √s=540 GeV. The perturbative series for the total cross section still converges reasonably fast. The values of the different parameters which describe rightly the data up to ISR energies give rise to a total cross section of around 60 mb at √s=540 GeV. For these values, the corresponding low mass and high mass eikonal series converges much more slowly. The non perturbative reggeon calculus gives rise to a total cross section less than 60 mb. (orig.)

  3. Dark matter wants Linear Collider

    International Nuclear Information System (INIS)

    Matsumoto, S.; Asano, M.; Fujii, K.; Takubo, Y.; Honda, T.; Saito, T.; Yamamoto, H.; Humdi, R.S.; Ito, H.; Kanemura, S; Nabeshima, T.; Okada, N.; Suehara, T.

    2011-01-01

    One of the main purposes of physics at the International Linear Collider (ILC) is to study the property of dark matter such as its mass, spin, quantum numbers, and interactions with particles of the standard model. We discuss how the property can or cannot be investigated at the ILC using two typical cases of dark matter scenario: 1) most of new particles predicted in physics beyond the standard model are heavy and only dark matter is accessible at the ILC, and 2) not only dark matter but also other new particles are accessible at the ILC. We find that, as can be easily imagined, dark matter can be detected without any difficulties in the latter case. In the former case, it is still possible to detect dark matter when the mass of dark matter is less than a half mass of the Higgs boson.

  4. Collide@CERN: sharing inspiration

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    Late last year, Julius von Bismarck was appointed to be CERN's first "artist in residence" after winning the Collide@CERN Digital Arts award. He’ll be spending two months at CERN starting this March but, to get a flavour of what’s in store, he visited the Organization last week for a crash course in its inspiring activities.   Julius von Bismarck, taking a closer look... When we arrive to interview German artist Julius von Bismarck, he’s being given a presentation about antiprotons’ ability to kill cancer cells. The whiteboard in the room contains graphs and equations that might easily send a non-scientist running, yet as Julius puts it, “if I weren’t interested, I’d be asleep”. Given his numerous questions, he must have been fascinated. “This ‘introduction’ week has been exhilarating,” says Julius. “I’ve been able to interact ...

  5. Collide@CERN - public lecture

    CERN Multimedia

    2012-01-01

    CERN, the Republic and Canton of Geneva and the City of Geneva are delighted to invite you to a public lecture by Gilles Jobin, first winner of the Collide@CERN Geneva Dance and Performance Artist-in-residence Prize, and his CERN inspiration partner, Joao Pequenao. They will present their work in dance and science at the Globe of Science and Innovation on Wednesday, 23 May 2012 at 7 p.m. (doors open at 6.30 p.m.).   
                                                  Programme 19:00 Opening address by - Professor Rolf-Dieter Heuer, CERN Director-General, - Ariane Koek...

  6. POLARIZED NEUTRONS IN RHIC

    Energy Technology Data Exchange (ETDEWEB)

    COURANT,E.D.

    1998-04-27

    There does not appear to be any obvious way to accelerate neutrons, polarized or otherwise, to high energies by themselves. To investigate the behavior of polarized neutrons the authors therefore have to obtain them by accelerating them as components of heavier nuclei, and then sorting out the contribution of the neutrons in the analysis of the reactions produced by the heavy ion beams. The best neutron carriers for this purpose are probably {sup 3}He nuclei and deuterons. A polarized deuteron is primarily a combination of a proton and a neutron with their spins pointing in the same direction; in the {sup 3}He nucleus the spins of the two protons are opposite and the net spin (and magnetic moment) is almost the same as that of a free neutron. Polarized ions other than protons may be accelerated, stored and collided in a ring such as RHIC provided the techniques proposed for polarized proton operation can be adapted (or replaced by other strategies) for these ions. To accelerate polarized particles in a ring, one must make provisions for overcoming the depolarizing resonances that occur at certain energies. These resonances arise when the spin tune (ratio of spin precession frequency to orbit frequency) resonates with a component present in the horizontal field. The horizontal field oscillates with the vertical motion of the particles (due to vertical focusing); its frequency spectrum is dominated by the vertical oscillation frequency and its modulation by the periodic structure of the accelerator ring. In addition, the magnet imperfections that distort the closed orbit vertically contain all integral Fourier harmonics of the orbit frequency.

  7. The International Linear Collider Progress Report 2015

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Yamamoto, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-07-15

    The International Committee for Future Accelerators (ICFA) set up the Global Design Effort (GDE) for the design of the International Linear Collider (ILC) in 2005. Drawing on the resources of over 300 national laboratories, universities and institutes worldwide, the GDE produced a Reference Design Report in 2007, followed by a more detailed Technical Design Report (TDR) in 2013. Following this report, the GDE was disbanded. A compact core team, the Linear Collider Collaboration (LCC), replaced it. This is still under the auspices of ICFA and is directly overseen by the Linear Collider Board, which reports to ICFA. The LCC is charged with continuing the design effort on a much-reduced scale until the Project is approved for construction. An additional mandate of the LCC was to bring together all linear collider work, including the CERN-based Compact Linear Collider (CLIC) under one structure in order to exploit synergies between the two studies.

  8. The Smallest Drops of the Hottest Matter? New Investigations at the Relativistic Heavy Ion Collider (493rd Brookhaven Lecture)

    Energy Technology Data Exchange (ETDEWEB)

    Sickles, Anne [BNL Physics Department

    2014-03-19

    Pool sharks at the billiards hall know that sometimes you aim to rocket the cue ball for a head-on collision, and other times, a mere glance will do. Physicists need to know more than a thing or two about collision geometry too, as they sift through data from the billions of ions that smash together at the Relativistic Heavy Ion Collider (RHIC). Determining whether ions crash head-on or just glance is crucial for the physicists analyzing data to study quark-gluon plasma—the ultra-hot, "perfect" liquid of quarks and gluons that existed more than 13 billion years ago, before the first protons and neutrons formed. For these physicists, collision geometry data provides insights about quark-gluon plasma's extremely low viscosity and other unusual properties, which are essential for understanding more about the "strong force" that holds together the nucleus, protons, and neutrons of every atom in the universe. Dr. Sickles explains how physicists use data collected at house-sized detectors like PHENIX and STAR to determine what happens before, during, and after individual particle collisions among billions at RHIC. She also explains how the ability to collide different "species" of nuclei at RHIC—including protons and gold ions today and possibly more with a proposed future electron-ion collider upgrade (eRHIC)—enables physicists to probe deeper into the mysteries of quark-gluon plasma and the strong force.

  9. A Large Hadron Electron Collider at CERN: Report on the Physics and Design Concepts for Machine and Detector

    CERN Document Server

    Abelleira Fernandez, J.L.; Akay, A.N.; Aksakal, H.; Albacete, J.L.; Alekhin, S.; Allport, P.; Andreev, V.; Appleby, R.B.; Arikan, E.; Armesto, N.; Azuelos, G.; Bai, M.; Barber, D.; Bartels, J.; Behnke, O.; Behr, J.; Belyaev, A.S.; Ben-Zvi, I.; Bernard, N.; Bertolucci, S.; Bettoni, S.; Biswal, S.; Blumlein, J.; Bottcher, H.; Bogacz, A.; Bracco, C.; Brandt, G.; Braun, H.; Brodsky, S.; Buning, O.; Bulyak, E.; Buniatyan, A.; Burkhardt, H.; Cakir, I.T.; Cakir, O.; Calaga, R.; Cetinkaya, V.; Ciapala, E.; Ciftci, R.; Ciftci, A.K.; Cole, B.A.; Collins, J.C.; Dadoun, O.; Dainton, J.; De Roeck, A.; d'Enterria, D.; Dudarev, A.; Eide, A.; Enberg, R.; Eroglu, E.; Eskola, K.J.; Favart, L.; Fitterer, M.; Forte, S.; Gaddi, A.; Gambino, P.; Garcia Morales, H.; Gehrmann, T.; Gladkikh, P.; Glasman, C.; Godbole, R.; Goddard, B.; Greenshaw, T.; Guffanti, A.; Guzey, V.; Gwenlan, C.; Han, T.; Hao, Y.; Haug, F.; Herr, W.; Herve, A.; Holzer, B.J.; Ishitsuka, M.; Jacquet, M.; Jeanneret, B.; Jimenez, J.M.; Jowett, J.M.; Jung, H.; Karadeniz, H.; Kayran, D.; Kilic, A.; Kimura, K.; Klein, M.; Klein, U.; Kluge, T.; Kocak, F.; Korostelev, M.; Kosmicki, A.; Kostka, P.; Kowalski, H.; Kramer, G.; Kuchler, D.; Kuze, M.; Lappi, T.; Laycock, P.; Levichev, E.; Levonian, S.; Litvinenko, V.N.; Lombardi, A.; Maeda, J.; Marquet, C.; Mellado, B.; Mess, K.H.; Milanese, A.; Moch, S.; Morozov, I.I.; Muttoni, Y.; Myers, S.; Nandi, S.; Nergiz, Z.; Newman, P.R.; Omori, T.; Osborne, J.; Paoloni, E.; Papaphilippou, Y.; Pascaud, C.; Paukkunen, H.; Perez, E.; Pieloni, T.; Pilicer, E.; Pire, B.; Placakyte, R.; Polini, A.; Ptitsyn, V.; Pupkov, Y.; Radescu, V.; Raychaudhuri, S.; Rinol, L.; Rohini, R.; Rojo, J.; Russenschuck, S.; Sahin, M.; Salgado, C.A.; Sampei, K.; Sassot, R.; Sauvan, E.; Schneekloth, U.; Schorner-Sadenius, T.; Schulte, D.; Senol, A.; Seryi, A.; Sievers, P.; Skrinsky, A.N.; Smith, W.; Spiesberger, H.; Stasto, A.M.; Strikman, M.; Sullivan, M.; Sultansoy, S.; Sun, Y.P.; Surrow, B.; Szymanowski, L.; Taels, P.; Tapan, I.; Tasci, T.; Tassi, E.; Ten Kate, H.; Terron, J.; Thiesen, H.; Thompson, L.; Tokushuku, K.; Tomas Garcia, R.; Tommasini, D.; Trbojevic, D.; Tsoupas, N.; Tuckmantel, J.; Turkoz, S.; Trinh, T.N.; Tywoniuk, K.; Unel, G.; Urakawa, J.; VanMechelen, P.; Variola, A.; Veness, R.; Vivoli, A.; Vobly, P.; Wagner, J.; Wallny, R.; Wallon, S.; Watt, G.; Weiss, C.; Wiedemann, U.A.; Wienands, U.; Willeke, F.; Xiao, B.W.; Yakimenko, V.; Zarnecki, A.F.; Zhang, Z.; Zimmermann, F.; Zlebcik, R.; Zomer, F.

    2012-01-01

    The physics programme and the design are described of a new collider for particle and nuclear physics, the Large Hadron Electron Collider (LHeC), in which a newly built electron beam of 60 GeV, up to possibly 140 GeV, energy collides with the intense hadron beams of the LHC. Compared to HERA, the kinematic range covered is extended by a factor of twenty in the negative four-momentum squared, $Q^2$, and in the inverse Bjorken $x$, while with the design luminosity of $10^{33}$ cm$^{-2}$s$^{-1}$ the LHeC is projected to exceed the integrated HERA luminosity by two orders of magnitude. The physics programme is devoted to an exploration of the energy frontier, complementing the LHC and its discovery potential for physics beyond the Standard Model with high precision deep inelastic scattering measurements. These are designed to investigate a variety of fundamental questions in strong and electroweak interactions. The physics programme also includes electron-deuteron and electron-ion scattering in a $(Q^2, 1/x)$ ran...

  10. Comparison of electron-ion energy transfer in dense plasmas obtained from numerical simulations and quantum kinetic theory

    Science.gov (United States)

    Vorberger, J.; Gericke, D. O.

    2014-03-01

    We evaluate various analytical models for the electron-ion energy transfer and compare the results to data from molecular dynamics (MD) simulations. The models tested include energy transfer via strong binary collisions, Landau-Spitzer rates with different choices for the cut-off parameters in the Coulomb logarithm, rates based on Fermi's golden rule (FGR) and theories taking coupled collective modes (CM) into account. In search of a model easy to apply, we first analyze different approximations of the FGR energy transfer rate. Then, we investigate several numerical studies using MD simulations and try to uncover CM effects in the data obtained. Most MD data published so far, except one study by Murillo et al. [23], show no distinct CM effects and, thus, can be interpreted within a FGR or binary collision approach. We show that this finding is related to the parameter regime, in particular the initial temperature difference, considered in these investigations.

  11. Electron-ion attachment induced instability of dust acoustic waves in the presence of ionization in a charge varying collisional dusty plasma

    International Nuclear Information System (INIS)

    Ghosh, Samiran; Khan, Manoranjan

    2006-01-01

    Low frequency electrostatic dust acoustic wave (DAW) instability with a significant background pressure of neutrals has been investigated in a collisional dusty plasma incorporating the dust charge relaxation and electron-ion attachment (recombination) onto dust grains using a self consistent theory. A long wavelength mode is found to be unstable due to electron-ion attachment on to the dust grains. Applications to experimental observations of low frequency fluctuation and the relevance of these results to 'void' in a laboratory gas discharge dusty plasma are briefly discussed

  12. Optimizing integrated luminosity of future hadron colliders

    Science.gov (United States)

    Benedikt, Michael; Schulte, Daniel; Zimmermann, Frank

    2015-10-01

    The integrated luminosity, a key figure of merit for any particle-physics collider, is closely linked to the peak luminosity and to the beam lifetime. The instantaneous peak luminosity of a collider is constrained by a number of boundary conditions, such as the available beam current, the maximum beam-beam tune shift with acceptable beam stability and reasonable luminosity lifetime (i.e., the empirical "beam-beam limit"), or the event pileup in the physics detectors. The beam lifetime at high-luminosity hadron colliders is largely determined by particle burn off in the collisions. In future highest-energy circular colliders synchrotron radiation provides a natural damping mechanism, which can be exploited for maximizing the integrated luminosity. In this article, we derive analytical expressions describing the optimized integrated luminosity, the corresponding optimum store length, and the time evolution of relevant beam parameters, without or with radiation damping, while respecting a fixed maximum value for the total beam-beam tune shift or for the event pileup in the detector. Our results are illustrated by examples for the proton-proton luminosity of the existing Large Hadron Collider (LHC) at its design parameters, of the High-Luminosity Large Hadron Collider (HL-LHC), and of the Future Circular Collider (FCC-hh).

  13. Optimizing integrated luminosity of future hadron colliders

    Directory of Open Access Journals (Sweden)

    Michael Benedikt

    2015-10-01

    Full Text Available The integrated luminosity, a key figure of merit for any particle-physics collider, is closely linked to the peak luminosity and to the beam lifetime. The instantaneous peak luminosity of a collider is constrained by a number of boundary conditions, such as the available beam current, the maximum beam-beam tune shift with acceptable beam stability and reasonable luminosity lifetime (i.e., the empirical “beam-beam limit”, or the event pileup in the physics detectors. The beam lifetime at high-luminosity hadron colliders is largely determined by particle burn off in the collisions. In future highest-energy circular colliders synchrotron radiation provides a natural damping mechanism, which can be exploited for maximizing the integrated luminosity. In this article, we derive analytical expressions describing the optimized integrated luminosity, the corresponding optimum store length, and the time evolution of relevant beam parameters, without or with radiation damping, while respecting a fixed maximum value for the total beam-beam tune shift or for the event pileup in the detector. Our results are illustrated by examples for the proton-proton luminosity of the existing Large Hadron Collider (LHC at its design parameters, of the High-Luminosity Large Hadron Collider (HL-LHC, and of the Future Circular Collider (FCC-hh.

  14. The principles and construction of linear colliders

    International Nuclear Information System (INIS)

    Rees, J.

    1986-09-01

    The problems posed to the designers and builders of high-energy linear colliders are discussed. Scaling laws of linear colliders are considered. The problem of attainment of small interaction areas is addressed. The physics of damping rings, which are designed to condense beam bunches in phase space, is discussed. The effect of wake fields on a particle bunch in a linac, particularly the conventional disk-loaded microwave linac structures, are discussed, as well as ways of dealing with those effects. Finally, the SLAC Linear Collider is described. 18 refs., 17 figs

  15. Self colliding beams ('migma') and controlled fusion

    CERN Document Server

    Maglic, Bogdan C; Mazarakis, M; Miller, R A; Nering, J; Powell, C; Treglio, J

    1975-01-01

    While much of the early work on colliding beams was done in the US, the lead on the development of this technique is now held by Europe. The most spectacular being the only colliding of nuclei in the intersecting storage rings at CERN. The idea of using colliding beams for fusion is nearly as old as is the interest in fusion as a source of power, but the problems of low reaction rate and high Coulomb scattering initially seemed insurmountable. The authors describe recent work done at the Fusion Energy Corporation which attempts to overcome these problems. (9 refs).

  16. Compensatable muon collider calorimeter with manageable backgrounds

    Science.gov (United States)

    Raja, Rajendran

    2015-02-17

    A method and system for reducing background noise in a particle collider, comprises identifying an interaction point among a plurality of particles within a particle collider associated with a detector element, defining a trigger start time for each of the pixels as the time taken for light to travel from the interaction point to the pixel and a trigger stop time as a selected time after the trigger start time, and collecting only detections that occur between the start trigger time and the stop trigger time in order to thereafter compensate the result from the particle collider to reduce unwanted background detection.

  17. String Resonances at Hadron Colliders

    CERN Document Server

    Anchordoqui, Luis A; Dai, De-Chang; Feng, Wan-Zhe; Goldberg, Haim; Huang, Xing; Lust, Dieter; Stojkovic, Dejan; Taylor, Tomasz R

    2014-01-01

    [Abridged] We consider extensions of the standard model based on open strings ending on D-branes. Assuming that the fundamental string mass scale M_s is in the TeV range and that the theory is weakly coupled, we discuss possible signals of string physics at the upcoming HL-LHC run (3000 fb^{-1}) with \\sqrt{s} = 14 TeV, and at potential future pp colliders, HE-LHC and VLHC, operating at \\sqrt{s} = 33 and 100 TeV, respectively. In such D-brane constructions, the dominant contributions to full-fledged string amplitudes for all the common QCD parton subprocesses leading to dijets and \\gamma + jet are completely independent of the details of compactification, and can be evaluated in a parameter-free manner. We make use of these amplitudes evaluated near the first (n=1) and second (n=2) resonant poles to determine the discovery potential for Regge excitations of the quark, the gluon, and the color singlet living on the QCD stack. We show that for string scales as large as 7.1 TeV (6.1 TeV), lowest massive Regge exc...

  18. On a possibility to construct a high luminosity 2 x 5 GeV photon collider at SLC

    International Nuclear Information System (INIS)

    Sarantsev, V.P.; Yurkov, M.V.; Saldin, E.L.; Schneidmiller, E.A.

    1993-01-01

    Physical principles of operation of the high energy photon linear colliders (PLC) based on the Compton backscattering of laser photons on high energy electrons are discussed. The main emphasis is put on the analysis of a possibility to construct the PLC with the centre of mass energy 3-10 GeV at the Stanford Linear Collider (SLC) facility. It is shown that such a collider providing luminosity of colliding γγ beams L γ γ ∼ 10 3 4 cm - 2 s - 1, may be constructed at the present level of acceleration technique R D (research and development) with moderate modifications of the existing SLC facility by installation of new injector, kicker magnet and two-stage free electron laser (FEL) consisting of a FEL oscillator (λ ∼ 10-30 μm, output power ∼ 10 MW) with subsequent amplification of the master signal in a FEL amplifier up to the power ∼ 3·10 1 1 W. It is emphasized that such a collider will be a unique instrument for precision study of the charmonium and bottomonium physics as well as τ-lepton physics providing ∼ 10 2 polarized τ-leptons per second. At the same time the Photon Linear Collider at SLC will serve as a reliable test base for constructing future TeV range photon linear colliders

  19. Identifying the nature of dark matter at e-e+ colliders

    Science.gov (United States)

    Baouche, Nabil; Ahriche, Amine

    2017-09-01

    In this work, we consider the process e++e-→b b ¯ + ET, at the future electron-positron colliders such as the International Linear Collider and Compact Linear Collider, to look for the dark matter (DM) effect and identify its nature at two different center-of-mass energies Ec .m .=500 GeV and 1 TeV. For this purpose, we take two extensions of the standard model, in which the DM could be a real scalar or a heavy right-handed neutrino (RHN) similar to many models motivated by neutrino mass. In the latter extension, the charged leptons are coupled to the RHNs via a lepton flavor violating interaction that involves a charged singlet scalar. After discussing different constraints, we define a set of kinematical cuts that suppress the background and generate different distributions that are useful in identifying the DM nature. The use of polarized beams (like the polarization P (e-,e+)=[+0.8 ,-0.3 ] at the International Linear Collider) makes the signal detection easier and the DM identification more clear, where the statistical significance gets enhanced by twice (five times) for scalar (RHN) DM.

  20. Facts about real antimatter collide with fiction

    CERN Multimedia

    Siegfried, Tom

    2004-01-01

    When science collides with fiction, sometimes a best seller emerges from the debris. Take Dan Brown's Angels & Demons, for instance, a murder mystery based on science at CERN, the European nuclear research laboratory outside Geneva

  1. Decoupling schemes for the SSC Collider

    International Nuclear Information System (INIS)

    Cai, Y.; Bourianoff, G.; Cole, B.; Meinke, R.; Peterson, J.; Pilat, F.; Stampke, S.; Syphers, M.; Talman, R.

    1993-05-01

    A decoupling system is designed for the SSC Collider. This system can accommodate three decoupling schemes by using 44 skew quadrupoles in the different configurations. Several decoupling schemes are studied and compared in this paper

  2. Decoupling schemes for the SCC Collider

    International Nuclear Information System (INIS)

    Cai, Y.; Bourianoff, G.; Cole, B.; Meinke, R.; Peterson, J.; Pilat, F.; Stampke, S.; Syphers, M.; Talman, R.

    1993-01-01

    A decoupling system is designed for the SSC Collider. This system can accommodate three decoupling schemes by using 44 skew quadrupoles in the different configurations. Several decoupling schemes are studied and compared in this paper

  3. Topcolor and the First Muon Collider

    Energy Technology Data Exchange (ETDEWEB)

    Hill, C.T. [Fermi National Accelerator Lab., Batavia, IL (United States)][Chicago Univ., IL (United States)

    1998-04-01

    We describe a class of models of electroweak symmetry breaking that involve strong dynamics and top quark condensation. A new scheme based upon a seesaw mechanism appears particularly promising. Various implications for the first-stage muon collider are discussed.

  4. Physics prospects at a linear -collider

    Indian Academy of Sciences (India)

    The talk described the prospects of studying standard model parameters as well as scenarios beyond the standard model, like the minimal supersymmetric standard model, theories with extra dimensions and theories with extra neutral gauge bosons, at a future linear + - collider.

  5. Super High Energy Colliding Beam Accelerators

    International Nuclear Information System (INIS)

    Abdelaziz, M.E.

    2009-01-01

    This lecture presents a review of cyclic accelerators and their energy limitations. A description is given of the phase stability principle and evolution of the synchrotron, an accelerator without energy limitation. Then the concept of colliding beams emerged to yield doubling of the beam energy as in the Tevatron 2 trillion electron volts (TeV) proton collider at Fermilab and the Large Hadron Collider (LHC) which is now planned as a 14-TeV machine in the 27 kilometer tunnel of the Large Electron Positron (LEP) collider at CERN. Then presentation is given of the Superconducting Supercollider (SSC), a giant accelerator complex with energy 40-TeV in a tunnel 87 kilometers in circumference under the country surrounding Waxahachie in Texas, U.S.A. These superhigh energy accelerators are intended to smash protons against protons at energy sufficient to reveal the nature of matter and to consolidate the prevailing general theory of elementary particle.

  6. The collider calamity, publ. by Scientific American

    CERN Multimedia

    2006-01-01

    "For decades, the big guns of American science have been the U.S. Department of Energy's particle collider, which investigate the nature of matter by accelerating subatomic particles and smashing them together." (1 page)

  7. Optimizing integrated luminosity of future hadron colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Schulte, Daniel; Zimmermann, Frank

    2015-01-01

    The integrated luminosity, a key figure of merit for any particle-physics collider, is closely linked to the peak luminosity and to the beam lifetime. The instantaneous peak luminosity of a collider is constrained by a number of boundary conditions, such as the available beam current, the maximum beam-beam tune shift with acceptable beam stability and reasonable luminosity lifetime (i.e., the empirical “beam-beam limit”), or the event pileup in the physics detectors. The beam lifetime at high-luminosity hadron colliders is largely determined by particle burn off in the collisions. In future highest-energy circular colliders synchrotron radiation provides a natural damping mechanism, which can be exploited for maximizing the integrated luminosity. In this article, we derive analytical expressions describing the optimized integrated luminosity, the corresponding optimum store length, and the time evolution of relevant beam parameters, without or with radiation damping, while respecting a fixed maximum value...

  8. New Stanford collider starts at Z

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    On 11 April the new SLC Stanford Linear Collider created its first Z particle, inaugurating high energy physics research at this novel machine based on the two-mile linac at the Stanford Linear Accelerator Centre, SLAC. (orig./HSI).

  9. Prospects of measuring general Higgs couplings at e{sup +}e{sup -} linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, K. [KEK, Ibaraki (Japan). Theory Group; Ishihara, S. [KEK, Ibaraki (Japan). Theory Group; Department of Physics, Hyogo University of Education, 941-1 Shimokume, Yashiro, Kato, Hyogo 673-1494 (Japan); Kamoshita, J. [Department of Physics, Ochanomizu University, 2-1-1 Otsuka, Bunkyo, Tokyo 112-8610 (Japan); Kniehl, B.A. [II. Institut fuer Theoretische Physik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)

    2000-06-01

    We examine how accurately the general HZV couplings, with V=Z{gamma}, may be determined by studying e{sup +}e{sup -}{yields}Hf anti f processes at future e{sup +}e{sup -} linear colliders. By using the optimal-observable method, which makes use of all available experimental information, we find out which combinations of the various HZV coupling terms may be constrained most efficiently with high luminosity. We also assess the benefits of measuring the tau-lepton helicities, identifying the bottom-hadron charges, polarizing the electron beam and running at two different collider energies. The HZZ couplings are generally found to be well constrained, even without these options, while the HZ{gamma} couplings are not. The constraints on the latter may be significantly improved by beam polarization. (orig.)

  10. Positron sources for electron-positron colliders application to the ILC and CLIC

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    The increased demanding qualities for positron sources dedicated to e+e- colliders pushed on investigations oriented on new kinds of e+ sources. The different kinds of positron sources polarized and no polarized are considered. Their main features (intensity, emittance) are described and analysed. Comparison between the different sources is worked out. The characteristics of the positron beam available in the collision point are greatly depending on the capture device and on the positron accelerator. Different kinds of capture systems are considered and their qualities, compared. Intense positron sources which are necessary for the colliders require intense incident beams (electrons or photons). The large number of pairs created in the targets leads to important energy deposition and so, thermal heating, which associated to temperature gradients provoke mechanical stresses often destructive. Moreover, the important Coulomb collisions, can affect the atomic structure in crystal targets and the radiation resist...

  11. Photon Linear Collider Gamma-Gamma Summary

    International Nuclear Information System (INIS)

    Gronberg, J.

    2012-01-01

    High energy photon - photon collisions can be achieved by adding high average power short-pulse lasers to the Linear Collider, enabling an expanded physics program for the facility. The technology required to realize a photon linear collider continues to mature. Compton back-scattering technology is being developed around the world for low energy light source applications and high average power lasers are being developed for Inertial Confinement Fusion.

  12. Dedicating Fermilab's Collider

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    It was a bold move to have a fullscale dedication ceremony for the new proton-antiproton Collider at the Fermilab Tevatron on 13 October, two days before the first collisions were seen. However the particles dutifully behaved as required, and over the following weekend the Collider delivered its goods at a total energy of 1600 GeV, significantly boosting the world record for laboratory collisions

  13. Nuclear collisions at the Future Circular Collider

    Energy Technology Data Exchange (ETDEWEB)

    Armesto, N., E-mail: nestor.armesto@usc.es [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia-Spain (Spain); Dainese, A. [INFN – Sezione di Padova, 35131 Padova (Italy); D' Enterria, D. [Physics Department, CERN, CH-1211 Genéve 23 (Switzerland); Masciocchi, S. [EMMI and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Roland, C. [Massachusetts Institute of Technology, Cambridge, MA 02139-4307 (United States); Salgado, C.A. [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia-Spain (Spain); Leeuwen, M. van [Nikhef, National Institute for Subatomic Physics, Amsterdam (Netherlands); Institute for Subatomic Physics of Utrecht University, Utrecht (Netherlands); Wiedemann, U.A. [Physics Department, CERN, CH-1211 Genéve 23 (Switzerland)

    2016-12-15

    The Future Circular Collider is a new proposed collider at CERN with centre-of-mass energies around 100 TeV in the pp mode. Ongoing studies aim at assessing its physics potential and technical feasibility. Here we focus on updates in physics opportunities accessible in pA and AA collisions not covered in previous Quark Matter contributions, including Quark-Gluon Plasma and gluon saturation studies, novel hard probes of QCD matter, and photon-induced collisions.

  14. Nuclear collisions at the Future Circular Collider

    CERN Document Server

    Armesto, N.; d'Enterria, D.; Masciocchi, S.; Roland, C.; Salgado, C.A.; van Leeuwen, M.; Wiedemann, U.A.

    2016-01-01

    The Future Circular Collider is a new proposed collider at CERN with centre-of-mass energies around 100 TeV in the pp mode. Ongoing studies aim at assessing its physics potential and technical feasibility. Here we focus on updates in physics opportunities accessible in pA and AA collisions not covered in previous Quark Matter contributions, including Quark-Gluon Plasma and gluon saturation studies, novel hard probes of QCD matter, and photon-induced collisions.

  15. Considerations on Energy Frontier Colliders after LHC

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir [Fermilab

    2016-11-15

    Since 1960’s, particle colliders have been in the forefront of particle physics, 29 total have been built and operated, 7 are in operation now. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). The future of the world-wide HEP community critically depends on the feasibility of possible post-LHC colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity and feasibility of cost. Here we overview all current options for post-LHC colliders from such perspective (ILC, CLIC, Muon Collider, plasma colliders, CEPC, FCC, HE-LHC) and discuss major challenges and accelerator R&D required to demonstrate feasibility of an energy frontier accelerator facility following the LHC. We conclude by taking a look into ultimate energy reach accelerators based on plasmas and crystals, and discussion on the perspectives for the far future of the accelerator-based particle physics. This paper largely follows previous study [1] and the presenta ion given at the ICHEP’2016 conference in Chicago [2].

  16. Brilliant positron sources for CLIC and other collider projects

    CERN Document Server

    Rinolfi, Louis; Dadoun, Olivier; Kamitani, Takuya; Strakhovenko, Vladimir; Variola, Alessandro

    2013-01-01

    The CLIC (Compact Linear Collider), as future linear collider, requires an intense positron source. A brief history is given up to the present baseline configuration which assumes unpolarized beams. A conventional scheme, with a single tungsten target as source of e-e+ pairs, has been studied several years ago. But, in order to reduce the beam energy deposition on the e+ target converter, a double-target system has been studied and proposed as baseline for CLIC. With this ‘‘hybrid target’’, the positron production scheme is based on the channeling process. A 5 GeV electron beam impinges on a thin crystal tungsten target aligned along its axis, enhancing the photon production by channeling radiation. A large number of photons are sent to a thick amorphous tungsten target, generating large number of e-e+ pairs, while the charged particles are bent away, reducing the deposited energy and the PEDD (Peak Energy Deposition Density). The targets parameters are optimized for the positron production. Polarize...

  17. Initial value problem for colliding gravitational plane waves. III

    International Nuclear Information System (INIS)

    Hauser, I.; Ernst, F.J.

    1990-01-01

    The development of a homogeneous Hilbert problem (HHP) approach to the initial value problem (IVP) for colliding gravitational plane waves with noncollinear polarization that began in two earlier papers [I. Hauser and F. J. Ernst, J. Math. Phys. 30, 872 (1989) and 30, 2322 (1989)] is continued. After formulating the HHP, the description of how one can apply it to generate a new family of solutions of the colliding wave problem that generalizes a three-parameter family constructed by Ernst, Garcia, and Hauser [J. Math. Phys. 29, 681 (1988)] using a double-Harrison transformation is given. Then the proof that the solution of the new HHP indeed solves the IVP that is posed is presented. A matrix Fredholm equation of the second kind that is equivalent to the HHP is also deduced. This will be used in a sequel to complete the proof of existence of solutions of the HHP and the proof that certain assumed differentiability hypotheses are in fact valid

  18. Physics at high luminosity muon colliders and a facility overview

    International Nuclear Information System (INIS)

    Parsa, Z.

    2001-01-01

    Physics potentials at future colliders including high luminosity μ + μ - colliders are discussed. Luminosity requirement, estimates for Muon collider energies of interest (0.1 TeV to 100 TeV) are calculated. Schematics and an overview of Muon Collider facility concept are also included

  19. A novel cell-scale bio-nanogenerator based on electron-ion interaction for fast light power conversion.

    Science.gov (United States)

    Li, Yu-Tao; Tian, He; Zhao, Hai-Ming; Jian, Mu-Qiang; Lv, Yu-Jia; Tian, Ye; Wang, Qian; Yang, Yi; Xiang, Yan; Zhang, Yingying; Ren, Tian-Ling

    2018-01-03

    Natural energy haversting devices serve as an alternative candidate for power supply in many micro-/nano-systems. However, traditional nanogenerators based on piezoelectricity or triboelectric power generation face challenges in terms of biocompatibility and stability in various biological systems. The bacteriorhodopsin (bR) protein in Halobacterium halobium is an ideal biocompatible material for photoelectric conversion. Conventional bR systems based on ion transport or enhanced light absorption layers have a limited light power conversion speed. On the other hand, bR-based biohybrid devices have a great potential for sensitive light power conversion as compared to conventional nanogenerators. Herein, we present a biohybrid nanogenerator made of bR and horizontally aligned-long carbon nanotubes (CNTs) with electron-ion interaction for the first time for sensitive light power conversion. The bR layer serves as the proton pump, whereas CNTs are utilized to enhance the photocurrent; thus, the photocurrent frequency response improves significantly because of the effect of the electron-ion interaction. The photocurrent shows a linear relationship with the intensity of light and can still obtain a stable signal at a light intensity of 0.03 mW cm -2 . With regard to the influence of the light on-off period, the photocurrent initially increases and then decreases with an increase in flickering frequency up to 360 Hz; this can be ascribed to the combinational influence of light switch speed and photocycle decay time. The photocurrent shows highest value (99 nA cm -2 ) at a frequency of about 50 Hz at a light intensity of 0.43 mW cm -2 , which matches well with the frequency standard of the electrical power supply system. Moreover, we found that a higher density of CNTs contributed to improve performance of the nanogenerators. Furthermore, a H + ion releasing model was proposed to interpret the operating mechanism of the biohybrid nanogenerator. The biohybrid nanogenerator

  20. Final Report for the UNIVERSITY-BASED DETECTOR RESEARCH AND DEVELOPMENT FOR THE INTERNATIONAL LINEAR COLLIDER

    Energy Technology Data Exchange (ETDEWEB)

    Brau, James E [Univ. of Oregon

    2013-04-22

    The U.S Linear Collider Detector R&D program, supported by the DOE and NSF umbrella grants to the University of Oregon, made significant advances on many critical aspects of the ILC detector program. Progress advanced on vertex detector sensor development, silicon and TPC tracking, calorimetry on candidate technologies, and muon detection, as well as on beamline measurements of luminosity, energy, and polarization.

  1. Molecular dynamics studies of electron-ion temperature equilibration in hydrogen plasmas within the coupled-mode regime.

    Science.gov (United States)

    Benedict, Lorin X; Surh, Michael P; Stanton, Liam G; Scullard, Christian R; Correa, Alfredo A; Castor, John I; Graziani, Frank R; Collins, Lee A; Čertík, Ondřej; Kress, Joel D; Murillo, Michael S

    2017-04-01

    We use classical molecular dynamics (MD) to study electron-ion temperature equilibration in two-component plasmas in regimes for which the presence of coupled collective modes has been predicted to substantively reduce the equilibration rate. Guided by previous kinetic theory work, we examine hydrogen plasmas at a density of n=10^{26}cm^{-3}, T_{i}=10^{5}K, and 10^{7}K

  2. Results from the magnetic electron ion spectrometer (MagEIS) instruments aboard the Van Allen Probes spacecraft

    Science.gov (United States)

    Fennell, Joseph; O'Brien, Paul; Roeder, James; Reeves, Geoffrey; Claudepierre, Seth; Clemmons, James; Spence, Harlan; Blake, Bernard

    The Magnetic Electron Ion Spectrometer (MagEIS) instruments aboard the Van Allen Probes Spacecraft (formerly RBSP) measure electrons and ions in the Earth's inner and outer radiation belts. The MagEIS instruments are part of the Energetic Particle, Composition, and Thermal Plasma Suite (ECT), which also includes the Relativistic Electron Proton Telescope (REPT) and the Helium Oxygen Proton Electron (HOPE) analyzer. MagEIS consists of four magnetic electron spectrometers aboard each of the two Van Allen Probes spacecraft that measure the differential fluxes, energies, and angular distributions of electrons from 20 keV to 4 MeV. The MagEIS suite also contains a silicon-detector telescope that measures the differential fluxes, energies, and angular distributions of protons from 60 keV to 20 MeV, and helium and oxygen ions above a hundred keV/AMU. We briefly describe the instrument design and measurement technique and present a set of results from the MagEIS observations, including ultra-low frequency (ULF) modulations of energetic electron flux, and observations of electron flux enhancements associated with the recent BARREL x-ray observations.

  3. Initial Results from the Magnetic Electron Ion Spectrometer (MagEIS) Instruments Aboard the Van Allen Probes Spacecraft

    Science.gov (United States)

    Claudepierre, S. G.; Blake, J. B.; Fennell, J. F.; Clemmons, J. H.; Roeder, J. L.; Spence, H. E.; Reeves, G. D.; Van Allen Probes ECT Team

    2013-05-01

    The Magnetic Electron Ion Spectrometer (MagEIS) instruments aboard the Van Allen Probes Spacecraft (formerly RBSP) measure electrons and ions in the Earth's inner and outer radiation belts. The MagEIS instruments are part of the Energetic Particle, Composition, and Thermal Plasma Suite (ECT), which also includes the Relativistic Electron Proton Telescope (REPT) and the Helium Oxygen Proton Electron (HOPE) analyzer. MagEIS consists of four magnetic electron spectrometers aboard each of the two Van Allen Probes spacecraft that measure the differential fluxes, energies, and angular distributions of electrons from 20 keV to 4 MeV. The MagEIS suite also contains a silicon-detector telescope that measures the differential fluxes, energies, and angular distributions of protons from 60 keV to 20 MeV, and helium and oxygen ions above a hundred keV/AMU. We briefly describe the instrument design and measurement technique and present a set of initial results from the MagEIS observations, including ultra-low frequency (ULF) modulations of energetic electron flux, and observations of electron flux enhancements associated with the recent BARREL x-ray observations.

  4. Validity of the independent-processes approximation for resonance structures in electron-ion scattering cross sections

    International Nuclear Information System (INIS)

    Badnell, N.R.; Pindzola, M.S.; Griffin, D.C.

    1991-01-01

    The total inelastic cross section for electron-ion scattering may be found in the independent-processes approximation by adding the resonant cross section to the nonresonant background cross section. We study the validity of this approximation for electron excitation of multiply charged ions. The resonant-excitation cross section is calculated independently using distorted waves for various Li-like and Na-like ions using (N+1)-electron atomic-structure methods previously developed for the calculation of dielectronic-recombination cross sections. To check the effects of interference between the two scattering processes, we also carry out detailed close-coupling calculations for the same atomic ions using the R-matrix method. For low ionization stages, interference effects manifest themselves sometimes as strong window features in the close-coupling cross section, which are not present in the independent-processes cross section. For higher ionization stages, however, the resonance features found in the independent-processes approximation are found to be in good agreement with the close-coupling results

  5. Structure of very heavy few-electron ions - new results from the heavy ion storage ring, ESR

    International Nuclear Information System (INIS)

    Mokler, P.H.; Stoehlker, T.; Kozhuharov, C.; Moshammer, R.; Rymuza, P.; Bosch, F.; Kandler, T.

    1993-08-01

    The heavy ion synchrotron/storage ring facility at GSI, SIS/ESR, provides intense beams of cooled, highly-charged ions up to naked uranium (U 92+ ). By electron capture during ion-atom collisions in the gas target of the ESR or by recombination at ion-electron encounters in the ''electron cooler'' excited states are populated. The detailed structure of very heavy one-, two- and three-electron ions is studied. The different mechanisms leading to the excited states are described, as well as the new experimental tools now available for a detailed spectroscopy of these interesting systems. Special emphasis is given to X-ray transitions to the groundstates in H- and He-like systems. For the heaviest species the groundstate Lambshift can now be probed on an accuracy level of better than 10% using solid-state X-ray detectors. Applying dispersive X-ray analyzing techniques, this accuracy will certainly be improved in future. However, utilizing the dielectronic resonances for a spectroscopy, the structure in Li-like heavy ions can already be probed now on the sub eV level. (orig.)

  6. Status of the Future Circular Collider Study

    Science.gov (United States)

    Benedikt, Michael

    2016-03-01

    Following the 2013 update of the European Strategy for Particle Physics, the international Future Circular Collider (FCC) Study has been launched by CERN as host institute, to design an energy frontier hadron collider (FCC-hh) in a new 80-100 km tunnel with a centre-of-mass energy of about 100 TeV, an order of magnitude beyond the LHC's, as a long-term goal. The FCC study also includes the design of a 90-350 GeV high-luminosity lepton collider (FCC-ee) installed in the same tunnel, serving as Higgs, top and Z factory, as a potential intermediate step, as well as an electron-proton collider option (FCC-he). The physics cases for such machines will be assessed and concepts for experiments will be developed in time for the next update of the European Strategy for Particle Physics by the end of 2018. The presentation will summarize the status of machine designs and parameters and discuss the essential technical components to be developed in the frame of the FCC study. Key elements are superconducting accelerator-dipole magnets with a field of 16 T for the hadron collider and high-power, high-efficiency RF systems for the lepton collider. In addition the unprecedented beam power presents special challenges for the hadron collider for all aspects of beam handling and machine protection. First conclusions of geological investigations and implementation studies will be presented. The status of the FCC collaboration and the further planning for the study will be outlined.

  7. The lay-out of the photon collider at the international linear collider

    Indian Academy of Sciences (India)

    Logo of the Indian Academy of Sciences. Indian Academy of Sciences. Home · About IASc · History · Memorandum ... Home; Journals; Pramana – Journal of Physics; Volume 69; Issue 6. The lay-out of the photon collider at the international linear collider. V I Telnov. Machine Detector Interface Volume 69 Issue 6 December ...

  8. PROSPECTS FOR COLLIDERS AND COLLIDER PHYSICS TO THE 1 PEV ENERGY SCALE

    International Nuclear Information System (INIS)

    KING, B.J.

    2000-01-01

    A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing the authors progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC--one each of e + e - and hadron colliders and three μ + μ - colliders--and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R and D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory

  9. PROSPECTS FOR COLLIDERS AND COLLIDER PHYSICS TO THE 1 PEV ENERGY SCALE

    Energy Technology Data Exchange (ETDEWEB)

    KING,B.J.

    2000-05-05

    A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing the authors progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC--one each of e{sup +}e{sup {minus}} and hadron colliders and three {mu}{sup +}{mu}{sup {minus}} colliders--and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R and D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory.

  10. Progress on $e^{+}e^{-}$ linear colliders

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit; Siemann, Peter

    2002-01-01

    Physics issues. The physics program will be reviewed for e+e- linear colliders in the TeV energy range. At these prospective facilities central issues of particle physics can be addressed, the problem of mass, unification and structure of space-time. In this context the two lectures will focus on analyses of the Higgs mechanism, supersymmetry and extra space dimensions. Moreover, high-precision studies of the top-quark and the gauge boson sector will be discussed. Combined with LHC results, a comprehensive picture can be developed of physics at the electroweak scale and beyond. Designs and technologies (R. Siemann - 29, 30, 31 May) The physics and technologies of high energy linear colliders will be reviewed. Fundamental concepts of linear colliders will be introduced. They will be discussed in: the context of the Stanford Linear Collider where many ideas changed and new ones were developed in response to operational experience. the requirements for future linear colliders. The different approaches for reac...

  11. Polarization, political

    NARCIS (Netherlands)

    Wojcieszak, M.; Mazzoleni, G.; Barnhurst, K.G.; Ikeda, K.; Maia, R.C.M.; Wessler, H.

    2015-01-01

    Polarization has been studied in three different forms: on a social, group, and individual level. This entry first focuses on the undisputed phenomenon of elite polarization (i.e., increasing adherence of policy positions among the elites) and also outlines different approaches to assessing mass

  12. Polarization holography

    DEFF Research Database (Denmark)

    Nikolova, L.; Ramanujam, P.S.

    Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

  13. The Tevatron Hadron Collider: A short history

    International Nuclear Information System (INIS)

    Tollestrup, A.V.

    1994-11-01

    The subject of this presentation was intended to cover the history of hadron colliders. However this broad topic is probably better left to historians. I will cover a much smaller portion of this subject and specialize my subject to the history of the Tevatron. As we will see, the Tevatron project is tightly entwined with the progress in collider technology. It occupies a unique place among accelerators in that it was the first to make use of superconducting magnets and indeed the basic design now forms a template for all machines using this technology. It was spawned in an incredibly productive era when new ideas were being generated almost monthly and it has matured into our highest energy collider complete with two large detectors that provide the major facility in the US for probing high Pt physics for the coming decade

  14. Calorimetry at a Future Linear Collider

    CERN Document Server

    AUTHOR|(CDS)2090195; Marshall, John

    This thesis describes the optimisation of the calorimeter design for collider experiments at the future Compact LInear Collider (CLIC) and the International Linear Collider (ILC). The detector design of these experiments is built around high-granularity Particle Flow Calorimetry that, in contrast to traditional calorimetry, uses the energy measurements for charged particles from the tracking detectors. This can only be realised if calorimetric energy deposits from charged particles can be separated from those of neutral particles. This is made possible with fine granularity calorimeters and sophisticated pattern recognition software, which is provided by the PandoraPFA algorithm. This thesis presents results on Particle Flow calorimetry performance for a number of detector configurations. To obtain these results a new calibration procedure was developed and applied to the detector simulation and reconstruction to ensure optimal performance was achieved for each detector configuration considered. This thesis a...

  15. SUPERCONDUCTING SOLENOIDS FOR THE MUON COLLIDER

    Energy Technology Data Exchange (ETDEWEB)

    GREEN,M.A.; EYSSA,Y.; KENNY,S.; MILLER,J.R.; PRESTEMON,S.; WEGGEL,R.J.

    2000-06-12

    The muon collider is a new idea for lepton colliders. The ultimate energy of an electron ring is limited by synchrotron radiation. Muons, which have a rest mass that is 200 times that of an electron can be stored at much higher energies before synchrotron radiation limits ring performance. The problem with muons is their short life time (2.1 {micro}s at rest). In order to operate a muon storage ring large numbers of muon must be collected, cooled and accelerated before they decay to an electron and two neutrinos. As the authors see it now, high field superconducting solenoids are an integral part of a muon collider muon production and cooling systems. This report describes the design parameters for superconducting and hybrid solenoids that are used for pion production and collection, RF phase rotations of the pions as they decay into muons and the muon cooling (reduction of the muon emittance) before acceleration.

  16. Multiplicities and minijets at Tevatron Collider energies

    International Nuclear Information System (INIS)

    Sarcevic, I.

    1989-01-01

    We show that in the parton branching model, the probability distribution does not obey KNO scaling. As energy increases, gluon contribution to multiplicities increases, resulting in the widening of the probability distribution, in agreement with experimental data. We predict that the widening of the distribution will stop at Tevatron Collider energies due to the dominant role of gluons at these energies. We also find that the gluon contribution to the 'minijet' cross section increases with energy and becomes dominant at the Tevatron Collider. We calculate QCD minijet cross sections for a variety of structure functions, QCD scales and p T min . We compare our theoretical results with the experimental data and find that some of the structure functions and choices of scale are preferred by the experimental data. We give theoretical predictions for the minijet cross section at the Tevatron Collider, indicating the possibility of distinguishing between different sets of structure functions and choices of scale. (orig.)

  17. Collider and detector protection at beam accidents

    International Nuclear Information System (INIS)

    Rakhno, I.L.; Mokhov, N.V.; Drozhdin, A.I.

    2003-01-01

    Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occurred at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section

  18. Collider and Detector Protection at Beam Accidents

    International Nuclear Information System (INIS)

    Rakhno, I.L.; Mokhov, N.V.; Drozhdin, A.I.

    2003-01-01

    Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occurred at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section

  19. Superconducting Solenoids for the Muon Collider

    International Nuclear Information System (INIS)

    Green, M.A.; Eyssa, Y.; Kenny, S.; Miller, J.R.; Prestemon, S.; Weggel, R.J.

    2000-01-01

    The muon collider is a new idea for lepton colliders. The ultimate energy of an electron ring is limited by synchrotron radiation. Muons, which have a rest mass that is 200 times that of an electron can be stored at much higher energies before synchrotron radiation limits ring performance. The problem with muons is their short life time (2.1 micros at rest). In order to operate a muon storage ring large numbers of muon must be collected, cooled and accelerated before they decay to an electron and two neutrinos. As the authors see it now, high field superconducting solenoids are an integral part of a muon collider muon production and cooling systems. This report describes the design parameters for superconducting and hybrid solenoids that are used for pion production and collection, RF phase rotations of the pions as they decay into muons and the muon cooling (reduction of the muon emittance) before acceleration

  20. Final Cooling for a Muon Collider

    Energy Technology Data Exchange (ETDEWEB)

    Acosta Castillo, John Gabriel [Univ. of Mississippi, Oxford, MS (United States)

    2017-05-01

    To explore the new energy frontier, a new generation of particle accelerators is needed. Muon colliders are a promising alternative, if muon cooling can be made to work. Muons are 200 times heavier than electrons, so they produce less synchrotron radiation, and they behave like point particles. However, they have a short lifetime of 2.2 $\\mathrm{\\mu s}$ and the beam is more difficult to cool than an electron beam. The Muon Accelerator Program (MAP) was created to develop concepts and technologies required by a muon collider. An important effort has been made in the program to design and optimize a muon beam cooling system. The goal is to achieve the small beam emittance required by a muon collider. This work explores a final ionization cooling system using magnetic quadrupole lattices with a low enough $\\beta^{\\star} $ region to cool the beam to the required limit with available low Z absorbers.

  1. Electron lenses for super-colliders

    CERN Document Server

    Shiltsev, Vladimir D

    2016-01-01

    This book provides a comprehensive overview of the operating principles and technology of electron lenses in supercolliders.  Electron lenses are a novel instrument for high energy particle accelerators, particularly for the energy-frontier superconducting hadron colliders, including the Tevatron, RHIC, LHC and future very large hadron colliders.  After reviewing the issues surrounding beam dynamics in supercolliders, the book offers an introduction to the electron lens method and its application.  Further chapters describe the technology behind the electron lenses which have recently been proposed, built and employed for compensation of beam-beam effects and for collimation of high-energy high-intensity beams, for compensation of space-charge effects and several other applications in accelerators. The book will be an invaluable resource for those involved in the design, construction and operation of the next generation of hadron colliders.

  2. Final focus systems for linear colliders

    International Nuclear Information System (INIS)

    Helm, R.; Irwing, J.

    1992-01-01

    Final focus systems for linear colliders present many exacting challenges in beam optics, component design, and beam quality. Efforts to resolve these problems as they relate to a new generation of linear colliders are under way at several laboratories around the world. We outline criteria for final focus systems and discuss the current state of understanding and resolution of the outstanding problems. We discuss tolerances on alignment, field quality and stability for optical elements, and the implications for beam parameters such as emittance, energy spread , bunch length, and stability in position and energy. Beam-based correction procedures, which in principle can alleviate many of the tolerances, are described. Preliminary results from the Final Focus Test Beam (FFTB) under construction at SLAC are given. Finally, we mention conclusions from operating experience at the Stanford Linear Collider (SLC). (Author) 16 refs., 4 tabs., 6 figs

  3. Final focus systems for linear colliders

    International Nuclear Information System (INIS)

    Helm, R.; Irwin, J.

    1992-08-01

    Final focus systems for linear colliders present many exacting challenges in beam optics, component design, and beam quality. Efforts to resolve these problems as they relate to a new generation of linear colliders are under way at several laboratories around the world. We will outline criteria for final focus systems and discuss the current state of understanding and resolution of the outstanding problems. We will discuss tolerances on alignment, field quality and stability for optical elements, and the implications for beam parameters such as emittance, energy spread, bunch length, and stability in position and energy. Beam-based correction procedures, which in principle can alleviate many of the tolerances, will be described. Preliminary results from the Final Focus Test Beam (FFTB) under construction at SLAC will be given. Finally, we mention conclusions from operating experience at the Stanford Linear Collider (SLC)

  4. International linear collider reference design report 2007

    International Nuclear Information System (INIS)

    Aarons, G.

    2007-01-01

    The International Linear Collider will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. A proposed electron-positron collider, the ILC will complement the Large Hadron Collider, a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, together unlocking some of the deepest mysteries in the universe. With LHC discoveries pointing the way, the ILC -- a true precision machine -- will provide the missing pieces of the puzzle. Consisting of two linear accelerators that face each other, the ILC will hurl some 10 billion electrons and their anti-particles, positrons, toward each other at nearly the speed of light. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they smash in a blazing crossfire at the centre of the machine. Stretching approximately 35 kilometres in length, the beams collide 14,000 times every second at extremely high energies -- 500 billion-electron-volts (GeV). Each spectacular collision creates an array of new particles that could answer some of the most fundamental questions of all time. The current baseline design allows for an upgrade to a 50-kilometre, 1 trillion-electron-volt (TeV) machine during the second stage of the project. This reference design provides the first detailed technical snapshot of the proposed future electron-positron collider, defining in detail the technical parameters and components that make up each section of the 31-kilometer long accelerator. The report will guide the development of the worldwide R and D program, motivate international industrial studies and serve as the basis for the final engineering design needed to make an official project proposal later this decade

  5. International linear collider reference design report

    Energy Technology Data Exchange (ETDEWEB)

    Aarons, G.

    2007-06-22

    The International Linear Collider will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. A proposed electron-positron collider, the ILC will complement the Large Hadron Collider, a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, together unlocking some of the deepest mysteries in the universe. With LHC discoveries pointing the way, the ILC -- a true precision machine -- will provide the missing pieces of the puzzle. Consisting of two linear accelerators that face each other, the ILC will hurl some 10 billion electrons and their anti-particles, positrons, toward each other at nearly the speed of light. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they smash in a blazing crossfire at the centre of the machine. Stretching approximately 35 kilometres in length, the beams collide 14,000 times every second at extremely high energies -- 500 billion-electron-volts (GeV). Each spectacular collision creates an array of new particles that could answer some of the most fundamental questions of all time. The current baseline design allows for an upgrade to a 50-kilometre, 1 trillion-electron-volt (TeV) machine during the second stage of the project. This reference design provides the first detailed technical snapshot of the proposed future electron-positron collider, defining in detail the technical parameters and components that make up each section of the 31-kilometer long accelerator. The report will guide the development of the worldwide R&D program, motivate international industrial studies and serve as the basis for the final engineering design needed to make an official project proposal later this decade.

  6. The Next Linear Collider: NLC2001

    Energy Technology Data Exchange (ETDEWEB)

    D. Burke et al.

    2002-01-14

    Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider. A first Zeroth-Order Design Report (ZDR) [2] for a second-generation electron-positron linear collider, the Next Linear Collider (NLC), was published five years ago. The NLC design is based on a high-frequency room-temperature rf accelerator. Its goal is exploration of elementary particle physics at the TeV center-of-mass energy, while learning how to design and build colliders at still higher energies. Many advances in accelerator technologies and improvements in the design of the NLC have been made since 1996. This Report is a brief update of the ZDR.

  7. The ILC polarized electron source

    CERN Document Server

    Brachmann, Axel; Garwin, Edward; Kirby, Robert; Luh Dah An; Maruyama, Takashi; Prepost, Richard; Schultz, David; Sheppard, John

    2005-01-01

    The SLC polarized electron source (PES) can meet the expected requirements of the International Linear Collider (ILC) for polarization, charge and lifetime. However, experience with newer and successful PES designs at JLAB, Mainz and elsewhere can be incorporated into a first-generation ILC source that will emphasize reliability and stability without compromising the photocathode performance. The long pulse train for the ILC may introduce new challenges for the PES, and in addition more reliable and stable operation of the PES may be achievable if appropriate R&D is carried out for higher voltage operation and for a simpler load-lock system. The outline of the R&D program currently taking shape at SLAC and elsewhere is discussed. The principal components of the proposed ILC PES, including the laser system necessary for operational tests, are described.

  8. Collider physics for the late 1980's

    International Nuclear Information System (INIS)

    Hinchliffe, I.

    1987-01-01

    Topics in the Standard Model of strong and electroweak interactions and how these topics are relevant for the high energy colliders are discussed. Radiative corrections in the Glashow-Weinberg-Salam model are discussed, stressing how these corrections may be measured at LEP and the SLC. CP violation is discussed, followed by a discussion of the Higgs boson and the searches which can be carried out for it. Some features of quantum chromodynamics are discussed which are relevant to hadron colliders. Some of the problems which the Standard Model does not solve are discussed. 115 refs., 53 figs

  9. Final focus designs for crab waist colliders

    CERN Document Server

    AUTHOR|(CDS)2084369; Levichev, Evgeny; Piminov, Pavel

    2016-01-01

    The crab waist collision scheme promises significant luminosity gain. The successful upgrade of the DA$\\Phi$NE collider proved the principle of crab waist collision and increased luminosity 3 times. Therefore, several new projects try to implement the scheme. The paper reviews interaction region designs with the crab waist collision scheme for already existent collider DA$\\Phi$NE and SuperKEKB, presently undergoing commissioning, for the projects of SuperB in Italy, CTau in Novosibirsk and FCC-ee at CERN.

  10. Final focus designs for crab waist colliders

    Directory of Open Access Journals (Sweden)

    A. Bogomyagkov

    2016-12-01

    Full Text Available The crab waist collision scheme promises significant luminosity gain. The successful upgrade of the DAΦNE collider proved the principle of crab waist collision and increased luminosity 3 times. Therefore, several new projects try to implement the scheme. The paper reviews interaction region designs with the crab waist collision scheme for already existent collider DAΦNE and SuperKEKB, presently undergoing commissioning, for the projects of SuperB in Italy, CTau in Novosibirsk and FCC-ee at CERN.

  11. Sixth international workshop on linear colliders. Proceedings

    International Nuclear Information System (INIS)

    Urakawa, Junji

    1995-08-01

    The sixth international workshop on linear colliders (LC95) was held by KEK at Tsukuba Center for Institute. In the workshop 8 parallel working group were organized: WG1 (beam sources and injection linacs), WG2 (damping rings and bunch compressors), WG3 (a: RF sources and structures, b: superconducting cavities, c: two beam accelerators), WG4 (beam dynamics in main linacs), WG5 (final focus and integration regions), WG6 (beam instrumentation), WG7 (overall parameters and construction techniques), WG8 (gamma-gamma collider and miscellaneous). This issue compiles materials which were used in the workshop. (J.P.N.)

  12. Sixth international workshop on linear colliders. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Urakawa, Junji [ed.

    1995-08-01

    The sixth international workshop on linear colliders (LC95) was held by KEK at Tsukuba Center for Institute. In the workshop 8 parallel working group were organized: WG1 (beam sources and injection linacs), WG2 (damping rings and bunch compressors), WG3 (a: RF sources and structures, b: superconducting cavities, c: two beam accelerators), WG4 (beam dynamics in main linacs), WG5 (final focus and integration regions), WG6 (beam instrumentation), WG7 (overall parameters and construction techniques), WG8 (gamma-gamma collider and miscellaneous). This issue compiles materials which were used in the workshop. (J.P.N.).

  13. Optimizing integrated luminosity of future hadron colliders

    OpenAIRE

    Benedikt, Michael; Schulte, Daniel; Zimmermann, Frank

    2015-01-01

    The integrated luminosity, a key figure of merit for any particle-physics collider, is closely linked to the peak luminosity and to the beam lifetime. The instantaneous peak luminosity of a collider is constrained by a number of boundary conditions, such as the available beam current, the maximum beam-beam tune shift with acceptable beam stability and reasonable luminosity lifetime (i.e., the empirical “beam-beam limit”), or the event pileup in the physics detectors. The beam lifetime at high...

  14. Top quark studies at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Sinervo, P.K. [Univ. of Toronto, Ontario (Canada)

    1997-01-01

    The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and DO Collaborations are reviewed, including the top quark cross section, mass, branching fractions, and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.

  15. Polar Bears

    Science.gov (United States)

    Amstrup, Steven C.; Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.

    2002-01-01

    Polar bears (Ursus maritimus) are hunted throughout most of their range. In addition to hunting polar bears of the Beaufort Sea region are exposed to mineral and petroleum extraction and related human activities such as shipping road-building, and seismic testing (Stirling 1990).Little was known at the start of this project about how polar bears move about in their environment, and although it was understood that many bears travel across political borders, the boundaries of populations had not been delineated (Amstrup 1986, Amstrup et al. 1986, Amstrup and DeMaster 1988, Garner et al. 1994, Amstrup 1995, Amstrup et al. 1995, Amstrup 2000).As human populations increase and demands for polar bears and other arctic resources escalate, managers must know the sizes and distributions of the polar bear populations. Resource managers also need reliable estimates of breeding rates, reproductive intervals, litter sizes, and survival of young and adults.Our objectives for this research were 1) to determine the seasonal and annual movements of polar bears in the Beaufort Sea, 2) to define the boundaries of the population(s) using this region, 3) to determine the size and status of the Beaufort Sea polar bear population, and 4) to establish reproduction and survival rates (Amstrup 2000).

  16. High luminosity polarized proton collisions at RHIC

    International Nuclear Information System (INIS)

    Roser, T.

    2001-01-01

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) provides the unique opportunity to collide polarized proton beams at a center-of-mass energy of up to 500 GeV and luminosities of up to 2 x 10 32 cm -2 s -1 . Such high luminosity and high energy polarized proton collisions will open up the possibility of studying spin effects in hard processes. However, the acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial Siberian snake and a rf dipole that ensure stable adiabatic spin motion during acceleration has made it possible to accelerate polarized protons to 25 GeV at the Brookhaven AGS. After successful operation of RHIC with gold beams polarized protons from the AGS have been successfully injected into RHIC and accelerated using a full Siberian snakes built from four superconducting helical dipoles. A new high energy proton polarimeter was also successfully commissioned. Operation with two snakes per RHIC ring is planned for next year

  17. Theoretical implications of recent collider results

    International Nuclear Information System (INIS)

    Peccei, R.D.

    1984-10-01

    After discussing the comparison of the properties of the W and Z bosons found at the CERN collider with what is expected in the standard model, I critically overview various theoretical speculations concerning some recently reported exotic events, like radiative Z decays, monojets, hot photons, and jet activity. No overwhelmingly favored theoretical explanation appears to spring forth for all the existing exotica. (orig.)

  18. Anomalous VVH interactions at a linear collider

    Indian Academy of Sciences (India)

    the SM Higgs boson it will be therefore, necessary to establish its properties such as hypercharge, CP parity etc. At an e+e− collider the dominant Higgs production processes are e+e− → f ¯fH, which proceed via the VVH coupling with V = W, Z and f any light fermion. Demanding Lorentz invariance, the VVH couplings can.

  19. Black Holes and the Large Hadron Collider

    Science.gov (United States)

    Roy, Arunava

    2011-01-01

    The European Center for Nuclear Research or CERN's Large Hadron Collider (LHC) has caught our attention partly due to the film "Angels and Demons." In the movie, an antimatter bomb attack on the Vatican is foiled by the protagonist. Perhaps just as controversial is the formation of mini black holes (BHs). Recently, the American Physical Society…

  20. Physics Case for the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Keisuke; /KEK, Tsukuba; Grojean, Christophe; /DESY /ICREA, Barcelona; Peskin, Michael E.; Barklow, Tim; /SLAC; Gao, Yuanning; /Tsinghua U., Beijing, CHEP; Kanemura, Shinya; /Toyama U.; Kim, Hyungdo; /Seoul Natl U.; List, Jenny; /DESY; Nojiri, Mihoko; /KEK, Tsukuba; Perelstein, Maxim; /Cornell U., LEPP; Poeschl, Roman; /LAL, Orsay; Reuter, Juergen; /DESY; Simon, Frank; /Munich, Max Planck Inst.; Tanabe, Tomohiko; /Tokyo U., ICEPP; Yu, Jaehoon; /Texas U., Arlington; Wells, James D.; /Michigan U., MCTP; Murayama, Hitoshi; /UC, Berkeley /LBNL /Tokyo U., IPMU; Yamamoto, Hitoshi; /Tohoku U.

    2015-06-23

    We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.

  1. Particle collider magnet self-destructs

    CERN Multimedia

    Higgins, Alexander G

    2007-01-01

    "A 43-foot-long magnet for the world's largest particle collider broke "with a loud band and a cloud of dust" during a high-pressure test, and officils said Tuesday they are working to find a replacement part." (1 page)

  2. Higgs physics at the Large Hadron Collider

    Indian Academy of Sciences (India)

    addition to this, the dark matter in the Universe, seems to also not consist of any of the known particles in the SM. Interestingly, almost all the extensions of the SM .... mental constraints on the Higgs mass from the collider experiments, taken from the web pages of the LEPEWWG and the Gfitter group. Both the panels show χ2 ...

  3. From the LHC to Future Colliders

    Energy Technology Data Exchange (ETDEWEB)

    De Roeck, A.; Ellis, J.; /CERN; Grojean, C.; Heinemeyer, S.; /Cantabria Inst. of Phys.; Jakobs, K.; /Freiburg U.; Weiglein, G.; /Durham U., IPPP; Azuelos, G.; /TRIUMF; Dawson, S.; /Brookhaven; Gripaios, B.; /CERN; Han, T.; /Wisconsin U., Madison; Hewett, J.; /SLAC; Lancaster, M.; /University Coll. London; Mariotti, C.; /INFN, Turin; Moortgat, F.; /Zurich, ETH; Moortgat-Pick, G.; /Durham U., IPPP; Polesello, G.; /INFN, Pavia; Riemann, S.; /DESY; Assamagan, K.; /Brookhaven; Bechtle, P.; /DESY; Carena, M.; /Fermilab; Chachamis, G.; /PSI, Villigen /Taiwan, Natl. Taiwan U. /INFN, Florence /Bonn U. /CERN /Bonn U. /Freiburg U. /Oxford U. /Louvain U., CP3 /Bangalore, Indian Inst. Sci. /INFN, Milan Bicocca /Munich, Max Planck Inst. /Taiwan, Natl. Taiwan U. /Frascati /Fermilab /Warsaw U. /Florida U. /Orsay, LAL /LPSC, Grenoble /Warsaw U. /Yale U. /Stockholm U., Math. Dept. /Durham U., IPPP /DESY /Rome U. /University Coll. London /UC, San Diego /Heidelberg U. /Florida State U. /SLAC /Durham U., IPPP /Southern Denmark U., CP3-Origins /McGill U. /Durham U., IPPP; /more authors..

    2010-06-11

    Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300 fb{sup -1} of integrated luminosity, of the proposed sLHC luminosity upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10 fb{sup -1} of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, theWorking Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discovered by the LHC. Their reports provide the particle physics community with some tools for reviewing the scientific priorities for future colliders after the LHC produces its first harvest of new physics from multi-TeV collisions.

  4. The Story of Large Electron Positron Collider

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 11. The Story of Large Electron Positron Collider - Experiments done at LEP. S N Ganguli. General Article Volume 7 Issue 11 November 2002 pp 18-34. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Linear Collider partners woo newly opened India

    CERN Multimedia

    Bagla, Pallava

    2006-01-01

    "With the wheels of Air Force One barely off the tarmac following U.S. President George W. Bush's visit, which ended India's 3 decades as a nuclear pariah state, a delegation of U.S. and European physicists arrived here last week to discuss India's involvement in the International Linear Collider."

  6. The Fermilab proton-antiproton collider upgrades

    International Nuclear Information System (INIS)

    Marriner, J.P.

    1996-10-01

    The plans for increases in the Tevatron proton-antiproton collider luminosity in the near future (Run II) and the more distant future (TeV33) are described. While there are many important issues, the fundamental requirement is to produce more antiprotons and to use them more efficiently

  7. and collider physics: Working group report

    Indian Academy of Sciences (India)

    physics pp. 335–345 and collider physics: Working group report. DEBAJYOTI CHOUDHURY. ¾ and RAHUL SINHA. Ѕї. Working Group members: S Arunagiri. ½. , Gautam .... cross-section for gluino pair production for our choice of С . As the production occurs primarily .... The final state В Г* has multiple partial waves [7] ...

  8. The Story of Large Electron Positron Collider

    Indian Academy of Sciences (India)

    The Story of Large Electron Positron Collider. 2. Experiments done at LEP. S N Ganguli is at the Tata. Institute of Fundamental. Research, Mumbai. He is ...... team of engineers and technicians of CERN. The preci- sion measurements at LEP left no one in doubt that the understanding of physics through the standard model is.

  9. Beam dynamics issues for linear colliders

    International Nuclear Information System (INIS)

    Ruth, R.D.

    1987-09-01

    In this paper we discuss various beam dynamics issues for linear colliders. The emphasis is to explore beam dynamics effects which lead to an effective dilution of the emittance of the beam and thus to a loss of luminosity. These considerations lead to various tolerances which are evaluated for a particular parameter set

  10. Status of the Future Circular Collider Study

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    Following the 2013 update of the European Strategy for Particle Physics, the international Future Circular Collider (FCC) Study has been launched by CERN as host institute. Its main purpose and long-term goal is to design an energyfrontier hadron collider (FCC-hh) with a centre-of-mass energy of about 100 TeV in a new 80–100 km tunnel. The FCC study also includes the design of a 90–350 GeV highluminosity lepton collider (FCC-ee) installed in the same tunnel, serving as Higgs, top and Z factory, as a potential intermediate step, as well as an electron-proton collider option (FCC-he). The physics cases for such machines are being assessed and concepts for experiments will be developed by the end of 2018, in time for the next update of the European Strategy for Particle Physics. This overview summarizes the status of machine designs and parameters, and it discusses the essential technical components being developed in the frame of the FCC study. Key elements are superconducting accelerator-dipole magnets wit...

  11. Working group report: Collider and flavour physics

    Indian Academy of Sciences (India)

    Working group report: Collider and flavour physics. Coordinators: DEBAJYOTI CHOUDHURY1, ASESH K DATTA2 and ANIRBAN KUNDU3,∗. 1Department of Physics and Astrophysics, University of Delhi, New Delhi 110 007, India. 2Regional Centre for Accelerator-based Particle Physics, Harish-Chandra Research.

  12. Higgs physics at the Large Hadron Collider

    Indian Academy of Sciences (India)

    In this talk I shall begin by summarizing the importance of the Higgs physics studies at the Large Hadron Collider (LHC). I shall then give a short description of the pre-LHC constraints on the Higgs mass and the theoretical predictions for the LHC along with a discussion of the current experimental results, ending with ...

  13. Working group report: Collider and flavour physics

    Indian Academy of Sciences (India)

    Abstract. The activities of the working group took place under two broad subgroups: Collider Physics subgroup and Flavour Physics subgroup. Reports on some of the projects undertaken are included. Also, some of the leading discussions organized by the working group are summarized.

  14. Meeting the demands of future colliders

    International Nuclear Information System (INIS)

    Blanar, George

    1990-01-01

    Physicists are very aware of the challenge of developing and building detectors and instrumentation for the next generation of proton colliders - the US Superconducting Supercollider (SSC) and CERN's LHC. The accompanying articles highlight special problems in electronics and in computing, but the effort underway extends over a wider front

  15. Dreams collide with reality for international experiment

    CERN Document Server

    Cho, Adrian

    2007-01-01

    "Three weeks ago, an international team released a design and cost estimate for the International Linear Collider (ILC). American physicists want to build the ILC at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, and researchers had hoped to break ground in 2012 and fire up the ILC's beams of electrons and positrons in 2019." (1 page)

  16. Measuring supersymmetry at the large hadron collider

    Indian Academy of Sciences (India)

    The large hadron collider (LHC) should have the ability to detect supersymmetric particles if low-energy supersymmetry solves the hierarchy problem. Studies of the LHC detection reach, and the ability to measure properties of supersymmetric particles are currently underway. We highlight some of these, such as the reach ...

  17. Working group report: Collider and B physics

    Indian Academy of Sciences (India)

    60, No. 2. — journal of. February 2003 physics pp. 383–394. Working group report: Collider and B physics. Coordinators: AMITAVA DATTA and K SRIDHAR. Working Group Members: K Abe, K Agashe, ..... different from +1) will be a smoking gun signal for this model. Pramana – J. Phys., Vol. 60, No. 2, February 2003. 393 ...

  18. International linear collider simulations using BDSIM

    Indian Academy of Sciences (India)

    BDSIM is a Geant4 [1] extension toolkit for the simulation of particle transport in accelerator beamlines. It is a code that combines accelerator-style particle tracking with traditional Geant-style tracking based on Runga–Kutta techniques. A more detailed description of the code can be found in [2]. In an e+e− linear collider ...

  19. Physics with $e^{+}e^{-}$ linear colliders

    CERN Document Server

    Behnke, T; Zerwas, Peter M

    2002-01-01

    The physics programme is summarized for future e/sup +/e/sup -/ linear colliders. These machines will allow us to perform precision studies of the top quark and the electroweak gauge bosons in a complementary way to the proton collider LHC. The Higgs boson can be discovered at the LHC within the entire range of canonical mass values. Lepton colliders are ideal instruments to investigate the properties of the Higgs boson and to establish essential elements of the Higgs mechanism as the fundamental mechanism for breaking the electroweak symmetries. In the area beyond the Standard Model, new particles and their interactions can be discovered and explored comprehensively. Supersymmetric particles can be searched for at the LHC with masses up to 2-3 TeV. Their properties can be determined at lepton colliders with very high precision so that the mechanism of supersymmetry breaking can be investigated experimentally and the underlying unified theory can be reconstructed. Stable extrapolations are possible up to scal...

  20. Linear collider accelerator physics issues regarding alignment

    International Nuclear Information System (INIS)

    Seeman, J.T.

    1990-01-01

    The next generation of linear colliders will require more stringent alignment tolerances than those for the SLC with regard to the accelerating structures, quadrupoles, and beam position monitors. New techniques must be developed to achieve these tolerances. A combination of mechanical-electrical and beam-based methods will likely be needed

  1. Fundamentally new physics at the Tevatron Collider?

    International Nuclear Information System (INIS)

    Chan Hongmo; Nellen, L.; Tsou Sheungtsun

    1989-02-01

    A new dispersion relation analysis of present pp-bar scattering data suggests the existence by Tevatron Collider energies of a threshold, of such nature, as is unlikely to be explainable in terms of known physics or any of its standard projections. (author)

  2. The analysis of colliding-shock experiments

    International Nuclear Information System (INIS)

    Bradley, D.K.; Hares, J.; Rankin, A.; Rose, S.J.

    1985-03-01

    X-ray radiographic and photoabsorption measurements are described of material which has been highly compressed and strongly heated by laser-driven colliding shocks. Theoretical work which attempts to interpret the data is also presented. The experimental data appears to favour one particular formulation of the continuum lowering. (author)

  3. Emotions run high in race for collider

    CERN Multimedia

    Cartlidge, E

    2001-01-01

    The head of KEK expressed his dismay that SLAC has entered into a collaboration with 3 other US labs and proposes to build the next linear collider at Fermilab, Ilinois. KEK wants the next accelerator to be built somewhere in the Asian Pacific region (1 page).

  4. From the LHC to Future Colliders

    DEFF Research Database (Denmark)

    De Roeck, A.; Ellis, J.; Grojean, C.

    2010-01-01

    upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10/fb of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because...

  5. Linear collider RF: Introduction and summary

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1995-01-01

    The relation of acceleration gradient with RF frequency is examined, and approximate general RF power requirements are derived. Considerations of efficiency and cost are discussed. RF Sources, presented at the conference, are reviewed. Overall efficiencies of the linear collider proposals are compared. copyright 1995 American Institute of Physics

  6. Higgs physics at the Large Hadron Collider

    Indian Academy of Sciences (India)

    and on inclusion of the direct limits from the collider searches, one gets MH < 185 GeV, at 95% CL. The closeness of this bound with the theoretical analysis presented in figure 2 in fact raises the hairy prospect that we might find only a light Higgs and nothing else at the LHC. It should be mentioned here however, that some ...

  7. New physics with the Compact Linear Collider

    CERN Multimedia

    Ellis, Jonathan Richard

    2001-01-01

    Investigating the 'strong' interactions between particles would be best investigated using a lepton-antilepton collider of energy 2 TeV or more. Plans for an accelerator of this type, called CLIC, have been underway at CERN for many years in collaboration with other accelerator laboratories (5 pages).

  8. Progress report on the SLAC Linear Collider

    International Nuclear Information System (INIS)

    Rees, J.

    1986-06-01

    The SLAC Linear Collider project (SLC) is reported as being near completion. The performance specifications are tabulated both for the initial form and for eventual goals. Various parts of the SLC are described and the status of their construction is reported, including the front end electron gun and booster, the linac, damping ring, positron source, SLC arcs, and conventional facilities. 5 refs., 12 figs

  9. Microwave Feeding System Devices Of Linear Collider

    CERN Document Server

    Bogdanovich, B Yu; Kaminsky, V I; Lalayan, M V; Sobenin, N P; Zavadtsev, D A

    2004-01-01

    The simulations, manufacturing and experimental results for two devices of linear collider RF power distribution system are presented. One of these devices is magic tee with movable choke plungers in E- and H-arms for the tuning the coupling-factor and RF phase of highpower accelerating cavities. The QEXT

  10. Collider Tests of (Composite) Diphoton Resonances

    DEFF Research Database (Denmark)

    Molinaro, Emiliano; Sannino, Francesco; Vignaroli, Natascia

    2016-01-01

    We analyze the Large Hadron Collider sensitivity to new pseudoscalar resonances decaying into diphoton with masses up to scales of few TeVs. We focus on minimal scenarios where the production mechanisms involve either photon or top-mediated gluon fusion, partially motivated by the tantalizing...

  11. Muon polarization in e+e- → μ+μ-

    International Nuclear Information System (INIS)

    Gary, J.W.

    1978-01-01

    A calculation of the cross section for e + e - → μ + μ - interactions is performed assuming colliding beam conditions and propagation of a neutral intermediate vector boson. From this a derivation of the expression for the longitudinal polarization of the final state μ - is made. The calculation, using relativistic, weak interaction, and field theory, demonstrates the connection between the polarization and the weak force parameters explicity

  12. Linear Collider Physics Resource Book Snowmass 2001

    International Nuclear Information System (INIS)

    Ronan, M.T.

    2001-01-01

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e + e - linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e + e - linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e + e - linear collider; in any scenario that is now discussed, physics will benefit from the new information that e + e - experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and built in a few years, it would make

  13. Linear Collider Physics Resource Book Snowmass 2001

    Energy Technology Data Exchange (ETDEWEB)

    Ronan (Editor), M.T.

    2001-06-01

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and

  14. "Towards a Future Linear Collider" and "The Linear Collider Studies at CERN"

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    During the week 18-22 October, more than 400 physicists will meet at CERN and in the CICG (International Conference Centre Geneva) to review the global progress towards a future linear collider. The 2010 International Workshop on Linear Colliders will study the physics, detectors and accelerator complex of a linear collider covering both the CLIC and ILC options. Among the topics presented and discussed will be the progress towards the CLIC Conceptual Design Report in 2011, the ILC Technical Design Report in 2012, physics and detector studies linked to these reports, and an increasing numbers of common working group activities. The seminar will give an overview of these topics and also CERN’s linear collider studies, focusing on current activities and initial plans for the period 2011-16. n.b: The Council Chamber is also reserved for this colloquium with a live transmission from the Main Auditorium.

  15. SLAC linear collider and a few ideas on future linear colliders

    International Nuclear Information System (INIS)

    Loew, G.A.

    1984-04-01

    This paper comes in two parts. The first part is a progress report on the SLAC Linear Collider (SLC) with emphasis on those systems which are of special interest to linear accelerator designers; it sets the stage for a number of contributed papers on specific topics which are also presented at this conference. The second part presents some ideas which are of interest to the design of future linear colliders of higher energies

  16. The lay-out of the photon collider at the international linear collider

    Indian Academy of Sciences (India)

    The photon collider (γγ, γe) is being considered as an 'option' in the international linear collider (ILC) project [1–3], while e+e− collisions are 'baseline'. In reality, this means that at the beginning of its operation, the ILC will run in the e+e− mode, and then one of the interaction regions (IPs) and the detector will be upgraded ...

  17. Druid, displaying root module used for linear collider detectors

    International Nuclear Information System (INIS)

    Ruan, M

    2012-01-01

    Based on the ROOT TEve/TGeo classes and the standard linear collider data structure, a dedicated linear collider event display has been developed. It supports the latest detector models for both International Linear Collider and Compact Linear Collider as well as the CALICE test beam prototypes. It can be used to visualise event information at the generation, simulation and reconstruction levels. Many options are provided in an intuitive interface. It has been heavily employed in a variety of analyses.

  18. Correlated electron-ion collisions in a strong laser field; Korrelierte Elektron-Ion-Stoesse in starken Laserfeldern

    Energy Technology Data Exchange (ETDEWEB)

    Ristow, T.

    2007-12-17

    Electron-ion-collisions in plasmas in the presence of an ultra-short intensive laser pulse can cause high energy transfers to the electrons. During the collision the oscillation energy of the electron in the laser field is changed into drift energy. In this regime, multi-photon processes, known from the ionization of neutral atoms (Above-Threshold Ionization), and successive, so called correlated collisions, are important. The subject of the thesis is a study of binary Coulomb collisions in strong laser fields. The collisions are treated both in the context of classical Newtonian mechanics and in the quantum-mechanical framework by the Schroedinger equation. In the classical case a simplified instantaneous collision model and a complete dynamical treatment are discussed. Collisions can be treated instantaneously, if the ratio of the impact parameter to the quiver amplitude is small. The energy distributions calculated in this approximation show an elastic peak and a broad plateau due to rescattered electrons. At incident velocities smaller than the quiver velocity, correlated collisions are observed in the electron trajectories of the dynamical model. This effect leads to characteristic momentum distributions of the electrons, that are explicitly calculated and compared with the results of the instantaneous model. In addition, the time-dependence of the collisions is discussed in the framework of a singular perturbation theory. The complete description of the Coulomb scattering requires a quantum-mechanical description. A time-dependent method of wave-packet scattering is used and the corresponding time-dependent three-dimensional Schroedinger equation is solved by an implicit ADImethod on a spatial grid. The momentum and the energy distributions of the scattered electrons are calculated by the Fourier transformation of the wavefunction. A comparison of the scattering from a repulsive and an attractive potential is used to distinguish between simple collisions and

  19. Magnetic Field Generation through Angular Momentum Exchange between Circularly Polarized Radiation and Charged Particles

    CERN Document Server

    Shvets, G

    2002-01-01

    The interaction between circularly polarized (CP) radiation and charged particles can lead to generation of magnetic field through an inverse Faraday effect. The spin of the circularly polarized electromagnetic wave can be converted into the angular momentum of the charged particles so long as there is dissipation. We demonstrate this by considering two mechanisms of angular momentum absorption relevant for laser-plasma interactions: electron-ion collisions and ionization. The precise dissipative mechanism, however, plays a role in determining the efficiency of the magnetic field generation.

  20. Magnetic Field Generation through Angular Momentum Exchange between Circularly Polarized Radiation and Charged Particles

    International Nuclear Information System (INIS)

    G. Shvets; N.J. Fisch; J.-M. Rax

    2002-01-01

    The interaction between circularly polarized (CP) radiation and charged particles can lead to generation of magnetic field through an inverse Faraday effect. The spin of the circularly polarized electromagnetic wave can be converted into the angular momentum of the charged particles so long as there is dissipation. We demonstrate this by considering two mechanisms of angular momentum absorption relevant for laser-plasma interactions: electron-ion collisions and ionization. The precise dissipative mechanism, however, plays a role in determining the efficiency of the magnetic field generation

  1. Helical dipole magnets for polarized protons in RHIC

    International Nuclear Information System (INIS)

    Syphers, M.; Courant, E.; Fischer, W.

    1997-01-01

    Superconducting helical dipole magnets will be used in the Brookhaven Relativistic Heavy Ion Collider (RHIC) to maintain polarization of proton beams and to perform localized spin rotations at the two major experimental detector regions. Requirements for the helical dipole system are discussed, and magnet prototype work is reported

  2. Circular polarization in the optical afterglow of GRB 121024A

    DEFF Research Database (Denmark)

    Wiersema, K.; Covino, S.; Toma, K.

    2014-01-01

    Gamma-ray bursts (GRBs) are most probably powered by collimated relativistic outflows (jets) from accreting black holes at cosmological distances. Bright afterglows are produced when the outflow collides with the ambient medium. Afterglow polarization directly probes the magnetic properties of th...

  3. New neutral current effects at e sup + e sup - linear colliders

    CERN Document Server

    Pankov, A A

    2002-01-01

    Four fermion contact interaction effects in the processes e sup + e sup - -> mu sup +mu sup - , b-barb and c-barc at the e sup + e sup - linear colliders with sq root s = 0.5 TeV and longitudinally polarized initial beams have been studied. Presented analysis has been performed by means of new integrated observables expressed in terms of the forward (sigma sub F) and backward (sigma sub B) polarized cross sections such that they give information on individual helicity cross sections. The helicity cross sections allow to perform a general model-independent analysis of four-fermion contact interactions and obtain the corresponding constraints on their parameters. It is also shows that the sensitivity of the new polarized observables to contact interactions is quite larger than that of the conventional observables (sigma, A sub F sub B , A sub L sub R , A sub L sub R sub , sub F sub B)

  4. Radiative corrections for the LHC and linear collider era

    NARCIS (Netherlands)

    Laenen, E.; Wackeroth, D.

    2009-01-01

    We emphasize the importance of including radiative corrections when extracting physics from colliders such as the Tevatron Run II at Fermilab, the Large Hadron Collider (LHC) at CERN, and a future linear collider (LC). We review both well-tested methods and recent advances for calculating these

  5. Highlights of the SLD Physics Program at the SLAC Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Willocq, Stephane

    2001-09-07

    Starting in 1989, and continuing through the 1990s, high-energy physics witnessed a flowering of precision measurements in general and tests of the standard model in particular, led by e{sup +}e{sup -} collider experiments operating at the Z{sup 0} resonance. Key contributions to this work came from the SLD collaboration at the SLAC Linear Collider. By exploiting the unique capabilities of this pioneering accelerator and the SLD detector, including a polarized electron beam, exceptionally small beam dimensions, and a CCD pixel vertex detector, SLD produced a broad array of electroweak, heavy-flavor, and QCD measurements. Many of these results are one of a kind or represent the world's standard in precision. This article reviews the highlights of the SLD physics program, with an eye toward associated advances in experimental technique, and the contribution of these measurements to our dramatically improved present understanding of the standard model and its possible extensions.

  6. Polarization Bremsstrahlung

    CERN Document Server

    Korol, Andrey V

    2014-01-01

    This book introduces and reviews both theory and applications of polarizational bremsstrahlung, i.e. the electromagnetic radiation emitted during collisions of charged particles with structured, thus polarizable targets, such as atoms, molecules and clusters.   The subject, following the first experimental evidence a few decades ago, has gained importance through a number of modern applications.  Thus, the study of several radiative mechanisms is expected to lead to the design of novel light sources, operating in various parts of the electromagnetic spectrum. Conversely, the analysis of the spectral and angular distribution of the photon emission constitutes a new tool for extracting information on the interaction of the colliding particles, and on their internal structure and dynamical properties.   Last but not least, accurate quantitative descriptions of the photon emission processes determine the radiative energy losses of particles in various media, thereby providing essential  information required f...

  7. Luminosity Spectrum Reconstruction at Linear Colliders

    CERN Document Server

    Poss, Stéphane

    2014-04-11

    A good knowledge of the luminosity spectrum is mandatory for many measurements at future e+e- colliders. As the beam-parameters determining the luminosity spectrum cannot be measured precisely, the luminosity spectrum has to be measured through a gauge process with the detector. The measured distributions, used to reconstruct the spectrum, depend on Initial State Radiation, cross-section, and Final State Radiation. To extract the basic luminosity spectrum, a parametric model of the luminosity spectrum is created, in this case the spectrum at the 3 TeV Compact Linear Collider (CLIC). The model is used within a reweighting technique to extract the luminosity spectrum from measured Bhabha event observables, taking all relevant effects into account. The centre-of-mass energy spectrum is reconstructed within 5% over the full validity range of the model. The reconstructed spectrum does not result in a significant bias or systematic uncertainty in the exemplary physics benchmark process of smuon pair production.

  8. Imaging hadron calorimetry for future Lepton Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Repond, José, E-mail: repond@hep.anl.gov

    2013-12-21

    To fully exploit the physics potential of a future Lepton Collider requires detectors with unprecedented jet energy and dijet-mass resolution. To meet these challenges, detectors optimized for the application of Particle Flow Algorithms (PFAs) are being designed and developed. The application of PFAs, in turn, requires calorimeters with very fine segmentation of the readout, so-called imaging calorimeters. This talk reviews progress in imaging hadron calorimetry as it is being developed for implementation in a detector at a future Lepton Collider. Recent results from the large prototypes built by the CALICE Collaboration, such as the Scintillator Analog Hadron Calorimeter (AHCAL) and the Digital Hadron Calorimeters (DHCAL and SDHCAL) are being presented. In addition, various R and D efforts beyond the present prototypes are being discussed.

  9. Collider detector at Fermilab - CDF. Progress report

    International Nuclear Information System (INIS)

    Theriot, D.

    1985-06-01

    CDF, the Collider Detector at Fermilab, is a collaboration of almost 180 physicists from ten US universities (University of Chicago, Brandeis University, Harvard University, University of Illinois, University of Pennsylvania, Purdue University, Rockefeller University, Rutgers University, Texas A and M University, and University of Wisconsin), three US DOE supported national laboratories (Fermilab, Argonne National Laboratory, and Lawrence Berkeley Laboratory), Italy (Frascati National Laboratory and University of Pisa), and Japan (KEK National Laboratory and University of Tsukuba). The primary physics goal for CDF is to study the general features of proton-antiproton collisions at 2 TeV center-of-mass energy. On general grounds, we expect that parton subenergies in the range 50 to 500 GeV will provide the most interesting physics at this energy. Work at the present CERN Collider has already demonstrated the richness of the 100 GeV scale in parton subenergies. 7 refs., 14 figs

  10. Progress on muon+muon- colliders

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1997-05-01

    Advantages and disadvantages of muon colliders are discussed. Recent results of calculations of the radiation hazard from muon decay neutrinos are presented. This is a significant problem for machines with center of mass energy of 4 TeV, but of no consequence for lower energies. Plans are outlined for future theoretical and experimental studies. Besides continued work on the parameters of a 4 TeV collider, studies are now starting on a machine near 100 GeV that could be a factory for the s-channel production of Higgs particles. Proposals are also presented for a demonstration of ionization cooling and of the required targeting, pion capture, and phase rotation rf

  11. arXiv Proton Colliders at the Energy Frontier

    CERN Document Server

    Benedikt, Michael

    Since the CERN ISR, hadron colliders have defined the energy frontier. Noteworthy are the conversion of the Super Proton Synchrotron (SPS) into a proton-antiproton collider, the Tevatron collider, as well as the abandoned SSC in the United States. Hadron colliders are likely to determine the pace of particle-physics progress also during the next hundred years. Discoveries at past hadron colliders were essential for establishing the so-called Standard Model of particle physics. The world's present flagship collider, the LHC, including its high-luminosity upgrade HL-LHC, is set to operate through the second half of the 2030's. Further increases of the energy reach during the 21st century require another, still more powerful hadron collider. Three options for a next hadron collider are presently under investigation. The Future Circular Collider (FCC) study, hosted by CERN, is designing a 100 TeV collider, to be installed inside a new 100 km tunnel in the Lake Geneva basin. A similar 100 km collider, called SppC,...

  12. Hadroproduction of heavy flavors at collider energies

    International Nuclear Information System (INIS)

    Scott, D.M.

    1979-11-01

    The possibility of detecting the top quark in hadron interactions at collider energies is investigated. The production of bound and naked t-quarks for m/sub t/ = 15 - 100 GeV, and the experimental signatures from their leptonic and semileptonic decay modes are studied. The background to any leptonic signature is expected to be severe, suggesting the requirement of simultaneous detection of hadrons

  13. The RHIC [Relativistic Heavy Ion Collider] lattice

    International Nuclear Information System (INIS)

    Lee, S.Y.; Claus, J.; Courant, E.D.; Dell, G.F.; Hahn, H.; Parzen, G.; Ruggiero, A.G.

    1988-01-01

    An antisymmetric lattice for the proposed Relativistic Heavy Ion Collider at Brookhaven National Laboratory is presented. It has been designed to have an energy range from 7 GeV/amu up to 100 GeV/amu; a good tunability of Β* and betatron tune; capability of operating unequal species, for example, proton on gold. Suppression of structure resonances is achieved by proper choice of the phase advances across the insertions and the arc cells. 9 refs., 6 figs., 1 tab

  14. Large Hadron Collider The Discovery Machine

    CERN Multimedia

    2008-01-01

    The mammoth machine, after a nine-year construction period, is scheduled (touch wood) to begin producing its beams of particles later this year. The commissioning process is planned to proceed from one beam to two beams to colliding beams; from lower energies to the terascale; from weaker test intensities to stronger ones suitable for producing data at useful rates but more difficult to control.

  15. German lab wins linear collider contest

    CERN Multimedia

    Cartlidge, Edwin

    2004-01-01

    Particle physicists have chosen to base the proposed International Linear Collider on superconducting technology developed by an international collaboration centred on the DESY lab in Germany. The superconducting approach was chosen by an internatinal panel ahead of a rival technology developed at Stanford in the US and the KEK lab in Japan. The eagerly-awaited decision was announced at the International Conference on High Energy Physics in Beijing today (½ page)

  16. Collimation systems in the next linear collider

    International Nuclear Information System (INIS)

    Merminga, N.; Irwin, J.; Helm, R.; Ruth, R.D.

    1991-02-01

    Experience indicates that beam collimation will be an essential element of the next generation e + E - linear colliders. A proposal for using nonlinear lenses to drive beam tails to large amplitudes was presented in a previous paper. Here we study the optimization of such systems including effects of wakefields and optical aberrations. Protection and design of the scrapers in these systems are discussed. 9 refs., 7 figs

  17. Status of the Relativistic Heavy Ion Collider

    International Nuclear Information System (INIS)

    Lee, S.Y.

    1990-01-01

    Accelerator Physics issues, such as the dynamical aperture, the beam lifetime and the current--intensity limitation are carefully studied for the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The single layer superconducting magnets, of 8 cm coil inner diameter, satisfying the beam stability requirements have also been successfully tested. The proposal has generated wide spread interest in the particle and nuclear physics. 1 ref., 4 figs., 3 tabs

  18. Longitudinal damping in the Tevatron collider

    Energy Technology Data Exchange (ETDEWEB)

    Kerns, Q.A.; Jackson, G.; Kerns, C.R.; Miller, H.; Reid, J.; Siemann, R.; Wildman, D.

    1989-03-01

    This paper describes the damper design for 6 proton on 6 pbar bunches in the Tevatron collider. Signal pickup, transient phase detection, derivative networks, and phase correction via the high-level rf are covered. Each rf station is controlled by a slow feedback loop. In addition, global feedback loops control each set of four cavities, one set for protons and one set for antiprotons. Operational experience with these systems is discussed. 7 refs., 9 figs.

  19. Muon Colliders: the Ultimate Neutrino Beamlines

    International Nuclear Information System (INIS)

    King, Bruce J.

    1999-01-01

    It is shown that muon decays in straight sections of muon collider rings will naturally produce highly collimated neutrino beams that can be several orders of magnitude stronger than the beams at existing accelerators. We discuss possible experimental setups and give a very brief overview of the physics potential from such beamlines. Formulae are given for the neutrino event rates at both short and long baseline neutrino experiments in these beams

  20. Longitudinal damping in the Tevatron collider

    International Nuclear Information System (INIS)

    Kerns, Q.A.; Jackson, G.; Kerns, C.R.; Miller, H.; Reid, J.; Siemann, R.; Wildman, D.

    1989-03-01

    This paper describes the damper design for 6 proton on 6 pbar bunches in the Tevatron collider. Signal pickup, transient phase detection, derivative networks, and phase correction via the high-level rf are covered. Each rf station is controlled by a slow feedback loop. In addition, global feedback loops control each set of four cavities, one set for protons and one set for antiprotons. Operational experience with these systems is discussed. 7 refs., 9 figs

  1. Top Quark Production at Hadron Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Phaf, Lukas Kaj [Univ. of Amsterdam (Netherlands)

    2004-03-01

    This thesis describes both theoretical and experimental research into top quark production. The theoretical part contains a calculation of the single-top quark production cross section at hadron colliders, at Next to Leading Order (NLO) accuracy. The experimental part describes a measurement of the top quark pair production cross section in proton-antiproton collisions, at a center of mass energy of 1.96 TeV.

  2. Luminosity Tuning at the Large Hadron Collider

    CERN Document Server

    Wittmer, W

    2006-01-01

    By measuring and adjusting the beta-functions at the interaction point (IP the luminosity is being optimized. In LEP (Large Electron Positron Collider) this was done with the two closest doublet magnets. This approach is not applicable for the LHC (Large Hadron Collider) and RHIC (Relativistic Heavy Ion Collider) due to the asymmetric lattice. In addition in the LHC both beams share a common beam pipe through the inner triplet magnets (in these region changes of the magnetic field act on both beams). To control and adjust the beta-functions without perturbation of other optics functions, quadrupole groups situated on both sides further away from the IP have to be used where the two beams are already separated. The quadrupoles are excited in specific linear combinations, forming the so-called "tuning knobs" for the IP beta-functions. For a specific correction one of these knobs is scaled by a common multiplier. The different methods which were used to compute such knobs are discussed: (1) matching in MAD, (2)i...

  3. The Next Linear Collider Design: NLC 2001

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Alberta

    2001-08-21

    Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider.

  4. Seventh International Accelerator School for Linear Colliders

    CERN Multimedia

    Organizers of the Seventh International Accelerator School for Linear Colliders

    2012-01-01

    We are pleased to announce the Seventh International Accelerator School for Linear Colliders. This school is a continuation of the series of schools which began six years ago.  The first school was held in 2006 in Sokendai, Japan, the second in 2007 in Erice, Italy, the third in 2008 in Oakbrook Hills, USA, the fourth in 2009 in Huairou, China, the fifth in 2010 in Villars-sur-Ollon, Switzerland, and the sixth in 2011 in Pacific Grove, USA.   The school is organized by the International Linear Collider (ILC) Global Design Effort (GDE), the Compact Linear Collider (CLIC) and the International Committee for Future Accelerators (ICFA) Beam Dynamics Panel. The school this year will take place at the Radisson Blu Hotel, Indore, India from November 27 to December 8, 2012. It is hosted by the Raja Ramanna Center for Advanced Technology (RRCAT) and sponsored by a number of funding agencies and institutions around the world including the U.S. Department of Energy (DOE), the U.S. National Science...

  5. Muon Collider Machine-Detector Interface

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, Nikolai V.; /Fermilab

    2011-08-01

    In order to realize the high physics potential of a Muon Collider (MC) a high luminosity of {mu}{sup +}{mu}{sup -}-collisions at the Interaction Point (IP) in the TeV range must be achieved ({approx}10{sup 34} cm{sup -2}s{sup -1}). To reach this goal, a number of demanding requirements on the collider optics and the IR hardware - arising from the short muon lifetime and from relatively large values of the transverse emittance and momentum spread in muon beams that can realistically be obtained with ionization cooling should be satisfied. These requirements are aggravated by limitations on the quadrupole gradients as well as by the necessity to protect superconducting magnets and collider detectors from muon decay products. The overall detector performance in this domain is strongly dependent on the background particle rates in various sub-detectors. The deleterious effects of the background and radiation environment produced by the beam in the ring are very important issues in the Interaction Region (IR), detector and Machine-Detector Interface (MDI) designs. This report is based on studies presented very recently.

  6. Linear collider IR and final focus introduction

    International Nuclear Information System (INIS)

    Irwin, J.; Burke, D.

    1991-09-01

    The Linear Collider subgroup of the Accelerator Physics working group concerned itself with all aspects of the Next Linear Collider (NLC) design from the end of the accelerating structure to and through the interaction region. Within this region are: (1) a collimation section, (2) muon protection (of the detector from the collimator), (3) final focus system, (4) interaction point physics, and (5) detector masking from synchrotron radiation and beam-beam pair production. These areas of study are indicated schematically in Fig. 1. The parameters for the Next Linear Collider are still in motion, but attention has settled on a handful of parameter sets. Energies under consideration vary from 0.5 to 1.5 TeV in the center of mass, and luminosities vary from 10 33 to 10 34 cm -2 s -1 . To be concrete we chose as a guide for our studies the parameter sets labeled F and G, Table 1 from Palmer. These cover large and small crossing angle cases and 0.4 m to 1.8 m of free length at the interaction point

  7. Progress on the CLIC Linear Collider Study

    CERN Document Server

    Guignard, Gilbert

    2001-01-01

    The CLIC study aims at a multi-TeV, high luminosity e+e- linear collider design. Beam acceleration uses high frequency (30 GHz), normal conducting structures operating at high accelerating gradients, in order to reduce the length and, in consequence, the cost of the linac. The cost-effective RF power production scheme, based on the so-called Two-beam Acceleration method, enables electrons and positrons to be collided at energies ranging from ~ 0.1 TeV up to a maximum of 5 TeV, in stages. A road map has been drawn up to indicate the research and development necessary to demonstrate the technical feasibility of a 3 TeV centre-of-mass collider with a luminosity of 1035 cm-2s-1. Considerable progress has been made in meeting the challenges associated with the CLIC technology and the present paper briefly reviews some of them. In particular, the status is given of the studies on the CLIC high-gradient structures, the dynamic time-dependent effects, the stabilisation of the vibration and the beam delivery system. T...

  8. Political polarization

    OpenAIRE

    Dixit, Avinash K.; Weibull, Jörgen W.

    2007-01-01

    Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality.

  9. Political polarization.

    Science.gov (United States)

    Dixit, Avinash K; Weibull, Jörgen W

    2007-05-01

    Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality.

  10. Physics at a future collider beyond the LHC and a TeV class linear collider

    CERN Multimedia

    CERN. Geneva

    2003-01-01

    After the LHC will have probed the physics at the TeV frontier, new generations of colliders capable of reaching into the multi-TeV energy domain will need to be considered. Concepts for both high energy e+e- linear colliders and muon storage rings have been proposed as well as hadron colliders. Highly challenging R&D programs are presently pursued to demonstrate their principles. The definition of a physics programme in the multi-TeV range still requires essential data that is likely to become available only after the first years of LHC operation and, possibly, also the results from a TeV-class linear collider. At present we have to envisage several possible scenarios for the fundamental questions to be addressed by collider experiments in the next decade, to guide the choices in the accelerator designs and parameters. After a brief review of the main accelerator projects and the present status of their R&D, I shall discuss the main signatures of the physics of possible relevance in relation to the e...

  11. ColliderBit. A GAMBIT module for the calculation of high-energy collider observables and likelihoods

    Energy Technology Data Exchange (ETDEWEB)

    Balazs, Csaba [Monash University, School of Physics and Astronomy, Melbourne, VIC (Australia); Australian Research Council Centre of Excellence for Particle Physics at the Tera-scale (Australia); Buckley, Andy [University of Glasgow, SUPA, School of Physics and Astronomy, Glasgow (United Kingdom); Dal, Lars A.; Krislock, Abram; Raklev, Are [University of Oslo, Department of Physics, Oslo (Norway); Farmer, Ben [AlbaNova University Centre, Oskar Klein Centre for Cosmoparticle Physics, Stockholm (Sweden); Jackson, Paul; Murnane, Daniel; White, Martin [Australian Research Council Centre of Excellence for Particle Physics at the Tera-scale (Australia); University of Adelaide, Department of Physics, Adelaide, SA (Australia); Kvellestad, Anders [NORDITA, Stockholm (Sweden); Putze, Antje [Universite de Savoie, LAPTh, Annecy-le-Vieux (France); Rogan, Christopher [Harvard University, Department of Physics, Cambridge, MA (United States); Saavedra, Aldo [Australian Research Council Centre of Excellence for Particle Physics at the Tera-scale (Australia); The University of Sydney, Faculty of Engineering and Information Technologies, Centre for Translational Data Science, School of Physics, Sydney, NSW (Australia); Scott, Pat [Imperial College London, Blackett Laboratory, Department of Physics, London (United Kingdom); Weniger, Christoph [University of Amsterdam, GRAPPA, Institute of Physics, Amsterdam (Netherlands); Collaboration: The GAMBIT Scanner Workgroup

    2017-11-15

    We describe ColliderBit, a new code for the calculation of high energy collider observables in theories of physics beyond the Standard Model (BSM). ColliderBit features a generic interface to BSM models, a unique parallelised Monte Carlo event generation scheme suitable for large-scale supercomputer applications, and a number of LHC analyses, covering a reasonable range of the BSM signatures currently sought by ATLAS and CMS. ColliderBit also calculates likelihoods for Higgs sector observables, and LEP searches for BSM particles. These features are provided by a combination of new code unique toColliderBit, and interfaces to existing state-of-the-art public codes. ColliderBit is both an important part of the GAMBIT framework for BSM inference, and a standalone tool for efficiently applying collider constraints to theories of new physics. (orig.)

  12. Characteristics of leptonic signals for Z boson pairs at hadron colliders

    International Nuclear Information System (INIS)

    Matsura, T.; Bij, J.J. van der

    1991-02-01

    We study the production of Z boson pairs at hadron colliders followed by their subsequent decay into muons or electrons. We take into account the processes qanti q → ZZ and gg → ZZ. The calculation incorporates all effects of the polarization of the Z bosons. Particular emphasis is put on the Higgs-signal where we study the angular distribution of the decay leptons, in order to determine the longitudinal polarisation fraction of the Z bosons. We also study the correlation of the decay planes of the leptons from the two Z bosons. This correlation may be significant for light Higgs bosons. (orig.)

  13. Upgrading the AGS polarized beam facility

    International Nuclear Information System (INIS)

    Ratner, L.G.

    1991-01-01

    Although present techniques for crossing depolarizing resonances in circular accelerators work, they are very time-consuming to implement and were only able to provide about a 40% polarized beam at 22 GeV in the Alternating Gradient Synchrotron (AGS). We propose to install a partial ''Siberian Snake'' solenoid in the AGS to eliminate the need to correct imperfection resonances and to make other modifications in our intrinsic resonance correctors. This will allow us to reach an energy of 25 GeV with 70% polarization and will enable the AGS to be an efficient injector of polarized protons into the Relativistic Heavy Ion Collider (RHIC), as well as being able to carry on a fixed-target program with minimum set-up time. 3 refs., 5 figs., 1 tab

  14. Physics with e+e- linear colliders

    Science.gov (United States)

    Accomando, E.; Andreazza, A.; Anlauf, H.; Ballestrero, A.; Barklow, T.; Bartels, J.; Bartl, A.; Battaglia, M.; Beenakker, W.; Bélanger, G.; Bernreuther, W.; Biebel, J.; Binnewies, J.; Blümlein, J.; Boos, E.; Borzumati, F.; Boudjema, F.; Brandenburg, A.; Bussey, P. J.; Cacciari, M.; Casalbuoni, R.; Corsetti, A.; De Curtis, S.; Cuypers, F.; Daskalakis, G.; Deandrea, A.; Denner, A.; Diehl, M.; Dittmaier, S.; Djouadi, A.; Dominici, D.; Dreiner, H.; Eberl, H.; Ellwanger, U.; Engel, R.; Flöttmann, K.; Franz, H.; Gajdosik, T.; Gatto, R.; Genten, H.; Godbole, R.; Gounaris, G.; Greco, M.; Grivaz, J.-F.; Guetta, D.; Haidt, D.; Harlander, R.; He, H. J.; Hollik, W.; Huitu, K.; Igo-Kemenes, P.; Ilyin, V.; Janot, P.; Jegerlehner, F.; Jez&dot,; abek, M.; Jim, B.; Kalinowski, J.; Kilian, W.; Kim, B. R.; Kleinwort, T.; Kniehl, B. A.; Krämer, M.; Kramer, G.; Kraml, S.; Krause, A.; Krawczyk, M.; Kryukov, A.; Kühn, J. H.; Kyriakis, A.; Leike, A.; Lotter, H.; Maalampi, J.; Majerotto, W.; Markou, C.; Martinez, M.; Martyn, U.; Mele, B.; Miller, D. J.; Miquel, R.; Nippe, A.; Nowak, H.; Ohl, T.; Osland, P.; Overmann, P.; Pancheri, G.; Pankov, A. A.; Papadopoulos, C. G.; Paver, N.; Pietila, A.; Peter, M.; Pizzio, M.; Plehn, T.; Pohl, M.; Polonsky, N.; Porod, W.; Pukhov, A.; Raidal, M.; Riemann, S.; Riemann, T.; Riesselmann, K.; Riu, I.; De Roeck, A.; Rosiek, J.; Rückl, R.; Schreiber, H. J.; Schulte, D.; Settles, R.; Shanidze, R.; Shichanin, S.; Simopoulou, E.; Sjöstrand, T.; Smith, J.; Sopczak, A.; Spiesberger, H.; Teubner, T.; Troncon, C.; Vander Velde, C.; Vogt, A.; Vuopionper, R.; Wagner, A.; Ward, J.; Weber, M.; Wiik, B. H.; Wilson, G. W.; Zerwas, P. M.

    1998-06-01

    The physics potential of e+e- linear colliders is summarized in this report. These machines are planned to operate in the first phase at a center-of-mass energy of 500 GeV, before being scaled up to about 1 TeV. In the second phase of the operation, a final energy of about 2 TeV is expected. The machines will allow us to perform precision tests of the heavy particles in the Standard Model, the top quark and the electroweak bosons. They are ideal facilities for exploring the properties of Higgs particles, in particular in the intermediate mass range. New vector bosons and novel matter particles in extended gauge theories can be searched for and studied thoroughly. The machines provide unique opportunities for the discovery of particles in supersymmetric extensions of the Standard Model, the spectrum of Higgs particles, the supersymmetric partners of the electroweak gauge and Higgs bosons, and of the matter particles. High precision analyses of their properties and interactions will allow for extrapolations to energy scales close to the Planck scale where gravity becomes significant. In alternative scenarios, i.e. compositeness models, novel matter particles and interactions can be discovered and investigated in the energy range above the existing colliders up to the TeV scale. Whatever scenario is realized in Nature, the discovery potential of e+e- linear colliders and the high precision with which the properties of particles and their interactions can be analyzed, define an exciting physics program complementary to hadron machines.

  15. Calibrating the energy of a 50x50 GeV muon collider using spin precession

    International Nuclear Information System (INIS)

    Raja, Rajendran; Tollestrup, Alvin

    1998-01-01

    The neutral Higgs boson is expected to have a mass in the region 90-150 GeV/c 2 in various schemes within the Minimal Supersymmetric extension to the Standard Model. A first generation Muon Collider is uniquely suited to investigate the mass, width and decay modes of the Higgs boson, since the coupling of the Higgs to muons is expected to be strong enough for it to be produced in the s channel mode in the muon collider. Due to the narrow width of the Higgs, it is necessary to measure and control the energy of the individual muon bunches to a precision of a few parts in a million. We investigate the feasibility of determining the energy scale of a muon collider ring with circulating muon beams of 50 GeV energy by measuring the turn by turn variation of the energy deposited by electrons produced by the decay of the muons. This variation is caused by the existence of an average initial polarization of the muon beam and a non-zero value of g-2 for the muon. We demonstrate that it is feasible to determine the energy scale of the machine with this method to a few parts per million using data collected during 1000 turns

  16. Calibrating the energy of a 50x50 GeV muon collider using spin precession

    International Nuclear Information System (INIS)

    Raja, R.; Tollestrup, A.

    1998-01-01

    The neutral Higgs boson is expected to have a mass in the region 90 endash 150thinspGeV /c 2 in various schemes within the minimal supersymmetric extension of the standard model. A first generation muon collider is uniquely suited to investigate the mass, width, and decay modes of the Higgs boson, since the coupling of the Higgs boson to muons is expected to be strong enough for it to be produced in the s channel mode in the muon collider. Because of the narrow width of the Higgs boson, it is necessary to measure and control the energy of the individual muon bunches to a precision of a few parts in a million. We investigate the feasibility of determining the energy scale of a muon collider ring with circulating muon beams of 50thinspGeV energy by measuring the turn by turn variation of the energy deposited by electrons produced by the decay of the muons. This variation is caused by the existence of an average initial polarization of the muon beam and a nonzero value of g-2 for the muon. We demonstrate that it is feasible to determine the energy scale of the machine with this method to a few parts per million using data collected during 1000 turns. copyright 1998 The American Physical Society

  17. TRISTAN, electron-positron colliding beam project

    International Nuclear Information System (INIS)

    1987-03-01

    In this report e + e - colliding beam program which is now referred to as TRISTAN Project will be described. A brief chronology and outline of TRISTAN Project is given in Chapter 1. Chapter 2 of this article gives a discussion of physics objectives at TRISTAN. Chapter 3 treats the overall description of the accelerators. Chapter 4 describes design of each of the accelerator systems. In Chapter 5, detector facilities are discussed in some detail. A description of accelerator tunnels, experimental areas, and utilities are given in Chapter 6. In the Appendix, the publications on the TRISTAN Project are listed. (author)

  18. Relativistic klystron research for linear colliders

    International Nuclear Information System (INIS)

    Allen, M.A.; Callin, R.S.; Deruyter, H.

    1988-09-01

    Relativistic klystrons are being developed as a power source for high gradient accelerator applications which include large linear electron-positron colliders, compact accelerators, and FEL sources. We have attained 200 MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We report here on the design of our relativistic klystrons, the results of our experiments so far, and some of our plans for the near future. 5 refs., 9 figs., 1 tab

  19. The Large Hadron Collider and Grid computing.

    Science.gov (United States)

    Geddes, Neil

    2012-02-28

    We present a brief history of the beginnings, development and achievements of the worldwide Large Hadron Collider Computing Grid (wLCG). The wLCG is a huge international endeavour, which is itself embedded within, and directly influences, a much broader computing and information technology landscape. It is often impossible to identify true cause and effect, and they may appear very different from the different perspectives (e.g. information technology industry or academic researcher). This account is no different. It represents a personal view of the developments over the last two decades and is therefore inevitably biased towards those things in which the author has been personally involved.

  20. Broader Impacts of the International Linear Collider

    International Nuclear Information System (INIS)

    Bardeen, M.; Fermilab; Ruchti, R.; NSF, Wash., D.C.; Notre Dame U.

    2005-01-01

    Large-scale scientific endeavors such as the International Linear Collider Project can have a lasting impact on education and outreach to our society. The ILC will provide a discovery platform for frontier physical science and it will also provide a discovery platform for broader impacts and social science. The importance of Broader Impacts of Science in general and the ILC in particular are described. Additionally, a synopsis of education and outreach activities carried out as an integral part of the Snowmass ILC Workshop is provided

  1. Electroweak physics at the Tevatron collider

    International Nuclear Information System (INIS)

    Aihara, H.

    1993-08-01

    Preliminary results on electroweak physics from the 1992--1993 run with the CDF and D0 detectors at the Tevatron collider are presented. New measurements of the ratio of the W and Z production cross sections times the branching fractions for subsequent decay into leptons are shown. The W width, Γ(W), and a limit on the top-quark mass independent of decay mode are extracted. The status of a measurement of the charge asymmetry of electrons from W decay is given. Also shown are a study of diboson (Wγ, Zγ and WZ) production and a search for a new neutral gauge boson (Z')

  2. Advanced silicon sensors for future collider experiments

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00437143; Moll, Michael; Mannelli, Marcello

    In this thesis, we address two key technological challenges: the radiation tolerance assessment and timing performance studies of thin planar diodes to be used as sensing technology in the recently approved CMS forward sampling calorimeter for the HL-LHC operation, the High Granularity Calorimeter (HGCAL); and, complementary, we carried out a detailed study of a novel kind of position sensitive microstrip sensors for ionising particles which implements the well established charge-division method to determine the particle impinging position along the microstrip electrode direction; this technology could become an interesting low-material budget solution for the new generation of tracking detectors to be operated in the future lepton collider experiments.

  3. Calorimetry at the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Repond, Jose [Argonne National Laboratory, Argonne, IL (United States)]. E-mail: respond@hep.anl.gov

    2007-03-01

    The physics potential of the International Linear Collider depends critically on the jet energy resolution of its detector. Detector concepts are being developed which optimize the jet energy resolution, with the aim of achieving {sigma}{sub jet}=30%/E{sub jet}. Under the assumption that Particle Flow Algorithms (PFAs), which combine tracking and calorimeter information to reconstruct the energy of hadronic jets, can provide this unprecedented jet energy resolution, calorimeters with very fine granularity are being developed. After a brief introduction outlining the principles of PFAs, the current status of various calorimeter prototype construction projects and their plans for the next few years will be reviewed.

  4. [New technology for linear colliders.] Progress report

    International Nuclear Information System (INIS)

    McIntyre, P.M.

    1986-01-01

    The purpose of the contract is to devise and analyze new technologies appropriate for future linear colliders. The focus of our research during 1986 has been the coaxial pulse line (CPL) accelerating structure. It is similar to a wake field structure, except that it replaces the annular ring beam driver by an annular TEM wave. The driver wave can be launched using a capacitor discharge arrangement similar to induction linacs. The structure has the combined advantages of high gradient (∼200 MeV/m) and high efficiency (perhaps ∼50%). A high-power lasertron based on a ribbon electron beam is proposed

  5. LHC - Large Hadon Collider Exhibition LEPFest 2000

    CERN Multimedia

    2000-01-01

    The Large Hadron Collider (LHC) will accelerate two proton beams to an energy corresponding to about 7,000 times their mass (7000 GeV). The collision of the two beams reproduces the conditions in the Universe when it was about 10 -1 2 sec old. Many innovative techniques - such as cooling with superfluid helium, the extensive use of high temperature superconducting cables, the two-in-one design for super-conducting dipole magnets, and new ultra-high vacuum technologies - had to be developed to make its construc-tion possible.

  6. Reducing risk where tectonic plates collide

    Science.gov (United States)

    Gomberg, Joan S.; Ludwig, Kristin A.

    2017-06-19

    Most of the world’s earthquakes, tsunamis, landslides, and volcanic eruptions are caused by the continuous motions of the many tectonic plates that make up the Earth’s outer shell. The most powerful of these natural hazards occur in subduction zones, where two plates collide and one is thrust beneath another. The U.S. Geological Survey’s (USGS) “Reducing Risk Where Tectonic Plates Collide—A USGS Plan to Advance Subduction Zone Science” is a blueprint for building the crucial scientific foundation needed to inform the policies and practices that can make our Nation more resilient to subduction zone-related hazards.

  7. SSC collider dipole magnet end mechanical design

    Energy Technology Data Exchange (ETDEWEB)

    Delchamps, S.W.; Bossert, R.C.; Carson, J.; Ewald, K.; Fulton, H.; Kerby, J.; Koska, W.; Strait, J.; Wake, S.M. (Fermi National Accelerator Lab., Batavia, IL (USA)); Leung, K.K. (Superconducting Super Collider Lab., Dallas, TX (USA))

    1991-05-01

    This paper describes the mechanical design of the ends of Superconducting Super Collider dipole magnets to be constructed and tested at Fermilab. Coil end clamps, end yoke configuration, and end plate design are discussed. Loading of the end plate by axial Lorentz forces is discussed. Relevant data from 40 mm and 50 mm aperture model dipole magnets built and tested at Fermilab are presented. In particular, the apparent influence of end clamp design on the quench behavior of model SSC dipoles is described. 8 refs., 3 figs.

  8. A high brilliance source for muon colliders

    International Nuclear Information System (INIS)

    Gastaldi, Ugo

    2001-01-01

    A scheme of muon production for debugging and test of a muon collider is outlined. μ + and μ - microbunches are generated simultaneously, at high energy, with high brilliance and pointing to the same direction, by annihilation of e + and e - stored in two rings located in the same tunnel and running at the same energy E. e + and e - bunches cross each other repeatedly along the muon beam line, that they traverse respectively at angles ±α, chosen so that the total muon energy in the lab is E-m μ

  9. SUSY Without Prejudice at Linear Colliders

    International Nuclear Information System (INIS)

    Rizzo, T.

    2008-01-01

    We explore the physics of the general CP-conserving MSSM with Minimal Flavor Violation, the pMSSM. The 19 soft SUSY breaking parameters are chosen so to satisfy all existing experimental and theoretical constraints assuming that the WIMP is the lightest neutralino. We scan this parameter space twice using both flat and log priors and compare the results which yield similar conclusions. Constraints from both LEP and the Tevatron play an important role in obtaining our final model samples. Implications for future TeV-scale e + e - linear colliders (LC) are discussed

  10. Beam Dynamics Challenges for Future Circular Colliders

    CERN Multimedia

    Zimmermann, Frank

    2004-01-01

    The luminosity of hadron colliders rises with the beam intensity, until some limit is encountered, mostly due to head-on and long-range beam-beam interaction, due to electron cloud, or due to conventional impedance sources. Also beam losses caused by various mechanisms may affect the performance. The limitations can be alleviated, if not overcome, by a proper choice of beam parameters and by dedicated compensation schemes. Examples include alternating crossing at several interaction points, electromagnetic wires, super-bunches, electron lenses, clearing electrodes, and nonlinear collimation. I discuss such mitigating measures and related research efforts, with special emphasis on the LHC and its upgrade.

  11. Future high energy colliders. Formal report

    International Nuclear Information System (INIS)

    Parsa, Z.

    1996-01-01

    This Report includes copies of transparencies and notes from the presentations made at the Symposium on Future High Energy Colliders, October 21-25, 1996 at the Institute for Theoretical Physics, University of California, Santa Barbara California, that was made available by the authors. Editing, reduction and changes to the authors contributions were made only to fulfill the printing and publication requirements. We would like to take this opportunity and thank the speakers for their informative presentations and for providing copies of their transparencies and notes for inclusion in this Report

  12. Beam loss mechanisms in relativistic heavy-ion colliders

    CERN Document Server

    Bruce, Roderik; Gilardoni, S; Wallén, E

    2009-01-01

    The Large Hadron Collider (LHC), the largest particle accelerator ever built, is presently under commissioning at the European Organization for Nuclear Research (CERN). It will collide beams of protons, and later Pb82+ ions, at ultrarelativistic energies. Because of its unprecedented energy, the operation of the LHC with heavy ions will present beam physics challenges not encountered in previous colliders. Beam loss processes that are harmless in the presently largest operational heavy-ion collider, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, risk to cause quenches of superconducting magnets in the LHC. Interactions between colliding beams of ultrarelativistic heavy ions, or between beam ions and collimators, give rise to nuclear fragmentation. The resulting isotopes could have a charge-to-mass ratio different from the main beam and therefore follow dispersive orbits until they are lost. Depending on the machine conditions and the ion species, these losses could occur in loca...

  13. Radiation Field in the Vicinity of the Collider Center

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, A. J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    1994-10-26

    The Collider Center and the adjoining cryogenic support building are unique among the buildings close to the collider tunnel because these are locations where the occupancy by non-radiation workers is high. This note describes calculations of the dose equivalent from local beam loss at both the nearest point of these buildings to the collider ring and on the berm in the vicinity of these buildings.

  14. Anomalous Higgs couplings at an eγ collider

    International Nuclear Information System (INIS)

    Choudhury, Debajyoti; Mamta

    2006-01-01

    We examine the sensitivity of eγ colliders (based on e + e - linear colliders of c.m. energy 500 GeV) to the anomalous couplings of the Higgs to W-boson via the process e - γ→νWH. This has the advantage over e + e - collider in being able to dissociate WWH vertex from ZZH. We are able to construct several dynamical variables which may be used to constrain the various couplings in the WWH vertex

  15. Beyond the Large Hadron Collider: a first look at cryogenics for CERN future circular colliders

    CERN Document Server

    Lebrun, Ph

    2015-01-01

    Following the first experimental discoveries at the Large Hadron Collider (LHC) and the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. The study, conducted with the collaborative participation of interested institutes world-wide, considers several options for very high energy hadron-hadron, electron-positron and hadron-electron colliders to be installed in a quasi-circular underground tunnel in the Geneva basin, with a circumference of 80 km to 100 km. All these machines would make intensive use of advanced superconducting devices, i.e. high-field bending and focusing magnets and/or accelerating RF cavities, thus requiring large helium cryogenic systems operating at 4.5 K or below. Based on preliminary sets of parameters and layouts for the particle colliders under study, we discuss the main challenges of their cryogenic systems and present first estimates of the cryogenic refrigeration capacities req...

  16. Muon colliders, frictional cooling and universal extra dimensions

    International Nuclear Information System (INIS)

    Greenwald, Daniel E.

    2011-01-01

    A muon collider combines the advantages of proton-proton and electron-positron colliders, sidestepping many of their disadvantages, and has the potential to make discoveries and precision measurements at high energies. However, muons bring their own technical challenges, largely relating to their instability. We present a summary of the motivations and R and D efforts for a muon collider. We detail a scheme for preparing high-luminosity muon beams on timescales shorter than the muon lifetime, and an experiment to demonstrate aspects of this scheme at the Max Planck Institute for Physics. We also investigate the potentials to discover physics beyond the standard model at a muon collider. (orig.)

  17. Klystron switching power supplies for the Internation Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Fraioli, Andrea; /Cassino U. /INFN, Pisa

    2009-12-01

    The International Linear Collider is a majestic High Energy Physics particle accelerator that will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. ILC will complement the Large Hadron Collider (LHC), a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, by producing electron-positron collisions at center of mass energy of about 500 GeV. In particular, the subject of this dissertation is the R&D for a solid state Marx Modulator and relative switching power supply for the International Linear Collider Main LINAC Radio Frequency stations.

  18. Muon colliders, frictional cooling and universal extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Greenwald, Daniel E.

    2011-07-20

    A muon collider combines the advantages of proton-proton and electron-positron colliders, sidestepping many of their disadvantages, and has the potential to make discoveries and precision measurements at high energies. However, muons bring their own technical challenges, largely relating to their instability. We present a summary of the motivations and R and D efforts for a muon collider. We detail a scheme for preparing high-luminosity muon beams on timescales shorter than the muon lifetime, and an experiment to demonstrate aspects of this scheme at the Max Planck Institute for Physics. We also investigate the potentials to discover physics beyond the standard model at a muon collider. (orig.)

  19. eγ and γγ colliders

    International Nuclear Information System (INIS)

    Watanabe, Isamu

    1994-01-01

    The results that can be expected by eγ and γγ colliders in future are summarized. eγ and γγ colliders have many fine possibilities, and are the economical selection for utilizing future e + e - colliders more effectively. eγ and γγ colliders were proposed by former USSR researchers at the beginning of 1980s, but recently, the prospect of realizing future e + e - collision type linear accelerator projects has become high, they have become to be considered seriously as the option of remodeling them. The high energy photon beam of eγ and γγ colliders is obtained by causing Compton reverse scattering, irradiating laser beam to the electron beam of e + e - accelerators. The production of γ-beam is explained. As for the physics noteworthy in eγ colliders, abnormal gauge coupling, the formation of Higgs particles, excited leptons, lepto-quark, supersymmetric particles and top quark are explained. As the physics noteworthy in γγ colliders, the formation of Higgs particles which is most interesting in γγ colliders, abnormal gauge coupling, top quark, Yukawa coupling, Higgs pair formation and other particles are enumerated. The linear e + e - accelerators of TeV range including JLC have the performance to be remodeled to eγ and γγ colliders, and the prospect of realizing them has become high. Their possibility of realization is discussed. (K.I.)

  20. Transverse mode coupling instability of colliding beams

    Directory of Open Access Journals (Sweden)

    S. White

    2014-04-01

    Full Text Available In high brightness circular colliders, coherent and incoherent beam dynamics are dominated by beam-beam interactions. It is generally assumed that the incoherent tune spread introduced by the beam-beam interactions is sufficiently large to cure any instabilities originating from impedance. However, as the two counterrotating beams interact they can give rise to coherent dipole modes and therefore modify the coherent beam dynamics and stability conditions. In this case, coherent beam-beam effects and impedance cannot be treated independently and their interplay should be taken into account in any realistic attempt to study the beam stability of colliding beams. Due to the complexity of these physics processes, numerical simulations become an important tool for the analysis of this system. Two approaches are proposed in this paper: a fully self-consistent multiparticle tracking including particle-in-cell Poisson solver for the beam-beam interactions and a linearized model taking into account finite bunch length effects. To ensure the validity of the results a detailed benchmarking of these models was performed. It will be shown that under certain conditions coherent beam-beam dipole modes can couple with higher order headtail modes and lead to strong instabilities with characteristics similar to the classical transverse mode coupling instability originating from impedance alone. Possible cures for this instability are explored both for single bunch and multibunch interactions. Simulation results and experimental evidences of the existence of this instability at the LHC will be presented for the specific case of offset collisions.

  1. 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

  2. Physics at the Large Hadron Collider

    CERN Document Server

    Mukhopadhyaya, Biswarup; Raychaudhari, Amitava

    2009-01-01

    In an epoch when particle physics is awaiting a major step forward, the Large Hydron Collider (LHC) at CERN, Geneva will soon be operational. It will collide a beam of high energy protons with another similar beam circulation in the same 27 km tunnel but in the opposite direction, resulting in the production of many elementary particles some never created in the laboratory before. It is widely expected that the LHC will discover the Higgs boson, the particle which supposedly lends masses to all other fundamental particles. In addition, the question as to whether there is some new law of physics at such high energy is likely to be answered through this experiment. The present volume contains a collection of articles written by international experts, both theoreticians and experimentalists, from India and abroad, which aims to acquaint a non-specialist with some basic issues related to the LHC. At the same time, it is expected to be a useful, rudimentary companion of introductory exposition and technical expert...

  3. Ntuples for NLO Events at Hadron Colliders

    CERN Document Server

    Bern, Z.; Febres Cordero, F.; Höche, S.; Ita, H.; Kosower, D.A.; Maitre, D.

    2014-01-01

    We present an event-file format for the dissemination of next-to-leading-order (NLO) predictions for QCD processes at hadron colliders. The files contain all information required to compute generic jet-based infrared-safe observables at fixed order (without showering or hadronization), and to recompute observables with different factorization and renormalization scales. The files also make it possible to evaluate cross sections and distributions with different parton distribution functions. This in turn makes it possible to estimate uncertainties in NLO predictions of a wide variety of observables without recomputing the short-distance matrix elements. The event files allow a user to choose among a wide range of commonly-used jet algorithms and jet-size parameters. We provide event files for a $W$ or $Z$ boson accompanied by up to four jets, and for pure-jet events with up to four jets. The files are for the Large Hadron Collider with a center of mass energy of 7 or 8 TeV. A C++ library along with a Python in...

  4. The Large Hadron Collider, a personal recollection

    CERN Document Server

    Evans, L

    2014-01-01

    The construction of the Large Hadron Collider (LHC) has been a massive endeavor spanning almost 30 years from conception to commissioning. Building the machine with the highest possible energy (7 TeV) in the existing LEP tunnel of 27 km circumference and with a tunnel diameter of only 3.8m has required considerable innovation. The first was the development of an idea first proposed by Bob Palmer at Brookhaven National Laboratory in 1978, where the two rings are integrated into a single magnetic structure. This compact 2-in-1 structure was essential for the LHC due to both the limited space available in the existing Large Electron-Positron collider tunnel and the cost. The second innovation was the bold move to use superfluid helium cooling on a massive scale, which was imposed by the need to achieve a high (8.3 T) magnetic field using an affordable Nb-Ti superconductor. In this article, no attempt is made to give a comprehensive review of the machine design. This can be found in the LHC Design Report {[}1], w...

  5. Frequency scaling of linear super-colliders

    International Nuclear Information System (INIS)

    Mondelli, A.; Chernin, D.; Drobot, A.; Reiser, M.; Granatstein, V.

    1986-06-01

    The development of electron-positron linear colliders in the TeV energy range will be facilitated by the development of high-power rf sources at frequencies above 2856 MHz. Present S-band technology, represented by the SLC, would require a length in excess of 50 km per linac to accelerate particles to energies above 1 TeV. By raising the rf driving frequency, the rf breakdown limit is increased, thereby allowing the length of the accelerators to be reduced. Currently available rf power sources set the realizable gradient limit in an rf linac at frequencies above S-band. This paper presents a model for the frequency scaling of linear colliders, with luminosity scaled in proportion to the square of the center-of-mass energy. Since wakefield effects are the dominant deleterious effect, a separate single-bunch simulation model is described which calculates the evolution of the beam bunch with specified wakefields, including the effects of using programmed phase positioning and Landau damping. The results presented here have been obtained for a SLAC structure, scaled in proportion to wavelength

  6. Large hadron collider workshop. Proceedings. Vol. 2

    International Nuclear Information System (INIS)

    Jarlskog, G.; Rein, D.

    1990-01-01

    The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol.1 of these proceedings contains the papers presented at the plenary sessions, Vol.2 the individual contributions to the physics sessions, and Vol.3 those to the instrumentation sessions. (orig.)

  7. Large hadron collider workshop. Proceedings. Vol. 3

    International Nuclear Information System (INIS)

    Jarlskog, G.; Rein, D.

    1990-01-01

    The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentaiton and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

  8. Large hadron collider workshop. Proceedings. Vol. 1

    International Nuclear Information System (INIS)

    Jarlskog, G.; Rein, D.

    1990-01-01

    The aim of the LCH workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

  9. Alignment Challenges for a Future Linear Collider

    CERN Document Server

    Durand, H; Stern, G

    2013-01-01

    The preservation of ultra-low emittances in the main linac and Beam Delivery System area is one of the main challenges for linear colliders. This requires alignment tolerances never achieved before at that scale, down to the micrometre level. As a matter of fact, in the LHC, the goal for the smoothing of the components was to obtain a 1σ deviation with respect to a smooth curve of 0.15 mm over a 150 m long sliding window, while for the CLIC project for example, it corresponds to 10 μm over a sliding window of 200 m in the Beam Delivery System area. Two complementary strategies are being studied to fulfil these requirements: the development and validation of long range alignment systems over a few hundreds of metres and short range alignment systems over a few metres. The studies undertaken, with associated tests setups and the latest results will be detailed, as well as their application for the alignment of both CLIC and ILC colliders.

  10. Scaling Laws for $e^+ e^-$ Linear Colliders

    CERN Document Server

    Delahaye, J P; Raubenheimer, T O; Wilson, Ian H

    1999-01-01

    Design studies of a future TeV e+e- Linear Collider (TLC) are presently being made by five major laboratories within the framework of a world-wide collaboration. A figure of merit is defined which enables an objective comparison of these different designs. This figure of merit is shown to depend only on a small number of parameters. General scaling laws for the main beam parameters and linac parameters are derived and prove to be very effective when used as guidelines to optimize the linear collider design. By adopting appropriate parameters for beam stability, the figure of merit becomes nearly independent of accelerating gradient and RF frequency of the accelerating structures. In spite of the strong dependence of the wake-fields with frequency, the single bunch emittance preservation during acceleration along the linac is also shown to be independent of the RF frequency when using equivalent trajectory correction schemes. In this situation, beam acceleration using high frequency structures becomes very adv...

  11. Optics measurement and correction during beam acceleration in the Relativistic Heavy Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-09-09

    To minimize operational complexities, setup of collisions in high energy circular colliders typically involves acceleration with near constant β-functions followed by application of strong focusing quadrupoles at the interaction points (IPs) for the final beta-squeeze. At the Relativistic Heavy Ion Collider (RHIC) beam acceleration and optics squeeze are performed simultaneously. In the past, beam optics correction at RHIC has taken place at injection and at final energy with some interpolation of corrections into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats which if corrected could minimize undesirable emittance dilutions and maximize the spin polarization of polarized proton beams by avoidance of higher-order multipole fields sampled by particles within the bunch. In this report the methodology now operational at RHIC for beam optics corrections during acceleration with simultaneous beta-squeeze will be presented together with measurements which conclusively demonstrate the superior beam control. As a valuable by-product, the corrections have minimized the beta-beat at the profile monitors so reducing the dominant error in and providing more precise measurements of the evolution of the beam emittances during acceleration.

  12. Strategic Polarization.

    Science.gov (United States)

    Kalai, Adam; Kalai, Ehud

    2001-08-01

    In joint decision making, similarly minded people may take opposite positions. Consider the example of a marriage in which one spouse gives generously to charity while the other donates nothing. Such "polarization" may misrepresent what is, in actuality, a small discrepancy in preferences. It may be that the donating spouse would like to see 10% of their combined income go to charity each year, while the apparently frugal spouse would like to see 8% donated. A simple game-theoretic analysis suggests that the spouses will end up donating 10% and 0%, respectively. By generalizing this argument to a larger class of games, we provide strategic justification for polarization in many situations such as debates, shared living accommodations, and disciplining children. In some of these examples, an arbitrarily small disagreement in preferences leads to an arbitrarily large loss in utility for all participants. Such small disagreements may also destabilize what, from game-theoretic point of view, is a very stable equilibrium. Copyright 2001 Academic Press.

  13. STAR FORMATION IN TURBULENT MOLECULAR CLOUDS WITH COLLIDING FLOW

    International Nuclear Information System (INIS)

    Matsumoto, Tomoaki; Dobashi, Kazuhito; Shimoikura, Tomomi

    2015-01-01

    Using self-gravitational hydrodynamical numerical simulations, we investigated the evolution of high-density turbulent molecular clouds swept by a colliding flow. The interaction of shock waves due to turbulence produces networks of thin filamentary clouds with a sub-parsec width. The colliding flow accumulates the filamentary clouds into a sheet cloud and promotes active star formation for initially high-density clouds. Clouds with a colliding flow exhibit a finer filamentary network than clouds without a colliding flow. The probability distribution functions (PDFs) for the density and column density can be fitted by lognormal functions for clouds without colliding flow. When the initial turbulence is weak, the column density PDF has a power-law wing at high column densities. The colliding flow considerably deforms the PDF, such that the PDF exhibits a double peak. The stellar mass distributions reproduced here are consistent with the classical initial mass function with a power-law index of –1.35 when the initial clouds have a high density. The distribution of stellar velocities agrees with the gas velocity distribution, which can be fitted by Gaussian functions for clouds without colliding flow. For clouds with colliding flow, the velocity dispersion of gas tends to be larger than the stellar velocity dispersion. The signatures of colliding flows and turbulence appear in channel maps reconstructed from the simulation data. Clouds without colliding flow exhibit a cloud-scale velocity shear due to the turbulence. In contrast, clouds with colliding flow show a prominent anti-correlated distribution of thin filaments between the different velocity channels, suggesting collisions between the filamentary clouds

  14. High Energy Colliders and Hidden Sectors

    Science.gov (United States)

    Dror, Asaf Jeff

    This thesis explores two dominant frontiers of theoretical physics, high energy colliders and hidden sectors. The Large Hadron Collider (LHC) is just starting to reach its maximum operational capabilities. However, already with the current data, large classes of models are being put under significant pressure. It is crucial to understand whether the (thus far) null results are a consequence of a lack of solution to the hierarchy problem around the weak scale or requires expanding the search strategy employed at the LHC. It is the duty of the current generation of physicists to design new searches to ensure that no stone is left unturned. To this end, we study the sensitivity of the LHC to the couplings in the Standard Model top sector. We find it can significantly improve the measurements on ZtRtR coupling by a novel search strategy, making use of an implied unitarity violation in such models. Analogously, we show that other couplings in the top sector can also be measured with the same technique. Furthermore, we critically analyze a set of anomalies in the LHC data and how they may appear from consistent UV completions. We also propose a technique to measure lifetimes of new colored particles with non-trivial spin. While the high energy frontier will continue to take data, it is likely the only collider of its kind for the next couple decades. On the other hand, low-energy experiments have a promising future with many new proposed experiments to probe the existence of particles well below the weak scale but with small couplings to the Standard Model. In this work we survey the different possibilities, focusingon the constraints as well as possible new hidden sector dynamics. In particular, we show that vector portals which couple to an anomalous current, e.g., baryon number, are significantly constrained from flavor changing meson decays and rare Z decays. Furthermore, we present a new mechanism for dark matter freezeout which depletes the dark sector through an

  15. Theoretical analysis of the multiple resonances for many-level spin systems. The four-level spin system of s electron ions subjected to strong microwave fields

    International Nuclear Information System (INIS)

    Popescu, F.F.; Marica, F.

    1994-01-01

    The analytic steady state solutions of master equation for the density matrix of a multilevel spin system in dilute paramagnetic crystals at high temperature, subjected to strong microwave fields, are discussed. These solutions enable to obtain the populations of the levels, and the microwave powers absorbed or emitted by the crystal, in the presence of one, two or more microwave fields. A detailed theoretical study of the maser effects for s electron ions with nuclear spin one-half is carried out. In the case of three frequency correlated strong fields, when 'the spectroscopic' bridge conditions are fulfilled, sensitive detections, or high efficient generations of microwaves of frequency higher than those of the pumping fields are predicted. (author) 16 figs., 16 refs

  16. Ultimate parameters of the photon collider at the international linear ...

    Indian Academy of Sciences (India)

    At linear colliders, the + - luminosity is limited by beam-collision effects, which determine the required emittances of beams in damping rings (DRs). In collisions at the photon collider, these effects are absent, and so smaller emittances are desirable. In the present damping ring designs, nominal DR parameters ...

  17. Monolithic CMOS pixel detector for international linear collider ...

    Indian Academy of Sciences (India)

    Toggle navigation. Logo of the Indian Academy of Sciences. Indian Academy of Sciences. Home · About ... Home; Journals; Pramana – Journal of Physics; Volume 69; Issue 6. Monolithic CMOS pixel detector for international linear ... Keywords. Vertex detector; international linear collider; linear collider; high energy physics.

  18. Working group report: High energy and collider physics

    Indian Academy of Sciences (India)

    journal of. December 2004 physics pp. 1331–1353. Working group report: High energy and collider physics. Coordinators: NABA K MONDAL1 and SAURABH D ... The projects undertaken in the working group I on high energy and collider physics ..... A recent summary of the progress in the area can be found in [20,21] and.

  19. German lab unveils plan to build physicists' next collider

    CERN Multimedia

    Abott, A

    2001-01-01

    An international team of physicists are to propose the construction of a major collider. 'TESLA' - the 'Tera electron volt Energy Superconducting Linear Accelerator' will be a linear electron-positron collider based on superconducting resonators. It will be based at DESY and cost around three billion US dollars (2 pages).

  20. Linear Collider Flavour Identification status report: Sensors for the ...

    Indian Academy of Sciences (India)

    The Linear Collider Flavour Identification (LCFI) collaboration is continuing the work to develop column-parallel CCDs (CPCCD) and CMOS readout chips to be used in the vertex detector at the international linear collider (ILC). The CPCCD achieves several orders of magnitude faster readout than conventional CCDs ...