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Sample records for stanford linear collider

  1. The Stanford Linear Collider

    SciTech Connect

    Rees, J.R.

    1989-10-01

    April, 1989, the first Z zero particle was observed at the Stanford Linear Collider (SLC). The SLC collides high-energy beams of electrons and positrons into each other. In break with tradition the SLC aims two linear beams at each other. Strong motives impelled the Stanford team to choose the route of innovation. One reason being that linear colliders promise to be less expensive to build and operate than storage ring colliders. An equally powerful motive was the desire to build an Z zero factory, a facility at which the Z zero particle can be studied in detail. More than 200 Z zero particles have been detected at the SLC and more continue to be churned out regularly. It is in measuring the properties of the Z zero that the SLC has a seminal contribution to make. One of the primary goals of the SLC experimental program is to determine the mass of the Z zero as precisely as possible.In the end, the SLC's greatest significance will be in having proved a new accelerator technology. 7 figs.

  2. New timing system for the Stanford Linear Collider

    SciTech Connect

    Paffrath, L.; Bernstein, D.; Kang, H.; Koontz, R.; Leger, G.; Ross, M.; Pierce, W.; Wilmunder, A.

    1984-11-01

    In order to be able to meet the goals of the Stanford Linear Collider, a much more precise timing system had to be implemented. This paper describes the specification and design of this system, and the results obtained from its use on 1/3 of the SLAC linac. The functions of various elements are described, and a programmable delay unit (PDU) is described in detail.

  3. Design and performance of the Stanford Linear Collider Control System

    SciTech Connect

    Melen, R.E.

    1984-10-01

    The success of the Stanford Linear Collider (SLC) will be dependent upon the implementation of a very large advanced computer-based instrumentation and control system. This paper describes the architectural design of this system as well as a critique of its performance. This critique is based on experience obtained from its use in the control and monitoring of 1/3 of the SLAC linac and in support of an expensive experimental machine physics experimental program. 11 references, 3 figures.

  4. Emittance calculations for the Stanford Linear Collider injector

    SciTech Connect

    Sheppard, J.C.; Clendenin, J.E.; Helm, R.H.; Lee, M.J.; Miller, R.H.; Blocker, C.A.

    1983-03-01

    A series of measurements have been performed to determine the emittance of the high intensity, single bunch beam that is to be injected into the Stanford Linear Collider. On-line computer programs were used to control the Linac for the purpose of data acquisition and to fit the data to a model in order to deduce the beam emittance. This paper will describe the method of emittance calculation and present some of the measurement results.

  5. Alignment of the Stanford Linear Collider Arcs: Concepts and results

    SciTech Connect

    Pitthan, R.; Bell, B.; Friedsam, H.; Pietryka, M.; Oren, W.; Ruland, R.

    1987-02-01

    The alignment of the Arcs for the Stanford Linear Collider at SLAC has posed problems in accelerator survey and alignment not encountered before. These problems come less from the tight tolerances of 0.1 mm, although reaching such a tight statistically defined accuracy in a controlled manner is difficult enough, but from the absence of a common reference plane for the Arcs. Traditional circular accelerators, including HERA and LEP, have been designed in one plane referenced to local gravity. For the SLC Arcs no such single plane exists. Methods and concepts developed to solve these and other problems, connected with the unique design of SLC, range from the first use of satellites for accelerator alignment, use of electronic laser theodolites for placement of components, computer control of the manual adjustment process, complete automation of the data flow incorporating the most advanced concepts of geodesy, strict separation of survey and alignment, to linear principal component analysis for the final statistical smoothing of the mechanical components.

  6. Fifty megawatt klystron for the Stanford Linear Collider

    SciTech Connect

    Lee, T.G.; Lebacqz, J.V.; Konrad, G.T.

    1983-09-01

    The proposed Stanford Linear Collider (SLC) has been designed to provide 50 on 50 GeV electron-positron collisions. The performance of the 240 klystrons driving the two-mile long linac must be upgraded to achieve at least 50 Megawatts of peak power output at a pulse of 5 ..mu..sec and a pulse repetition frequency of 180 pulses per second. The operating frequency of the upgraded linac will continue to be 2856 MHz. A klystron amplifier meeting these new requirements has been designed to operate at 315 kV, ..mu..k = 2, with a computed efficiency of slightly greater than 50%. Initial tests indicate the achievement of the basic power objectives; however, observed parasitic instabilities make beam focusing, RF drive frequency and drive level extremely critical. High electric fields in the electron gun, output gap and output window are all potential problems. Steps taken in the design to overcome these problems are discussed and test results are presented.

  7. Neutrino counting with the SLD at the Stanford Linear Collider

    SciTech Connect

    Band, H.; Bugg, W.; Chadwick, G.; Coyne, D.; Gyure, M.; Hertzbach, S.; Messner, R.; Mincer, A.; Mockett, P.; Nauenberg, U.

    1989-06-01

    One of the fundamental measurements to be made at the e/sup +/e/sup /minus// colliders, SLC and LEP, is the determination of the number of neutrino families produced in Z/sup 0/ boson decays. In the event that a fourth generation of light Dirac neutrinos exists, the experimental consequences at the Z/sup 0/ resonances are easily seen; the total width will be increased by 171 MeV over its three generation value, to be compared to the /approx/30 MeV precision that should be achievable once the systematic limit has been reached. A reasonable figure of merit for the precision of a neutrino counting measurement of 0.2 standard model generations corresponds to a Z/sup 0/ width measurement error of 35 MeV; close to the limit of anticipated experimental capability. In fact, it is highly desirable to achieve an even higher precision if possible, in order to distinguish potentially small effects due to exotic phenomena from beyond the Standard Model. This paper will address the issue of how to obtain the best measurement of the number of neutrino generations as a function of the size of the available sample of Z/sup 0/ decays. The results presented here were obtained by our study group in an attempt to understand the limitations of a realistic neutrino counting measurement with the SLD at the Stanford Linear Collider. However, many of our findings are general enough to be applicable to any e/sup +/e/sup /minus// detector designed to take data at the Z/sup 0/ resonance. 19 refs., 5 figs., 6 tabs.

  8. Accelerator physics of the Stanford Linear Collider and SLC accelerator experiments towards the Next Linear Collider

    SciTech Connect

    Seeman, J.T.

    1992-06-01

    The Stanford Linear Collider (SLC) was built to collide single bunches of electrons and positrons head-on at a single interaction point with single beam energies up to 55 GeV. The small beam sizes and high currents required for high luminosity operation have significantly pushed traditional beam quality limits. The Polarized Electron Source produces about 8 {times} 10{sup 10} electrons in each of two bunches with up to 28% polarization,. The Damping Rings provide coupled invariant emittances of 1.8 {times} 10{sup {minus}5} r-m with 4.5 {times} 10{sup 10} particles per bunch. The 57 GeV Linac has successfully accelerated over 3 {times} 10{sup 10} particles with design invariant emittances of 3 {times} 10{sup {minus}5} r-m. Both longitudinal and transverse wakefields affect strongly the trajectory and emittance corrections used for operations. The Arc systems routinely transport decoupled and betatron matched beams. In the Final Focus, the beams are chromatically corrected and demagnified producing spot sizes of 2 to 3 {mu}m at the focal point. Spot sizes below 2 {mu}m have been made during special tests. Instrumentation and feedback systems are well advanced, providing continuous beam monitoring and pulse-by-pulse control. A luminosity of 1.6 {times} 10{sup 29} cm{sup {minus}2}sec{sup {minus}1} has been produced. Several experimental tests for a Next Linear Collider (NLC) are being planned or constructed using the SLC accelerator as a test facility. The Final Focus Test Beam will demagnify a flat 50 GeV electron beam to dimensions near 60 nm vertically and 900 nm horizontally. A potential Emittance Dynamics Test Area has the capability to test the acceleration and transport of very low emittance beams, the compression of bunch lengths to 50 {mu}m, the acceleration and control of multiple bunches, and the properties of wakefields in the very short bunch length regime.

  9. Beam trajectory acquisition system for the arcs of the Stanford Linear Collider

    SciTech Connect

    Pellegrin, J.L.; Ross, M.C.; Scott, B.D.; Wilson, D.S.

    1987-02-01

    This report describes the beam position monitoring system of the collider arcs at the Stanford Linear Collider. This beam position monitoring system is different from others at SLAC in its large amount of hardware and its use of ungated, self-triggered electronics. All of the processing electronics are installed in the accelerator tunnel. (JDH)

  10. Construction and performance of a permanent earth anchor (tieback) system for the Stanford Linear Collider

    SciTech Connect

    Obergfell, M.N.

    1987-02-01

    The Stanford Linear Collider is the newest addition to the high-energy physics research complex at the Stanford Linear Accelerator Center. One of the many unique features of this project is the large, underground pit, where massive particle detectors will study the collision of subatomic particles. The large, open pit utilizes nearly 600 permanent earth anchors (tiebacks) for the support of the 56 ft (17 m) high walls, and is one of the largest applications of tiebacks for permanent support of a structure. This paper examines the use of tiebacks on this project with emphasis on their installation and performance.

  11. Optical tuning in the arcs and final focus sections of the Stanford Linear Collider

    SciTech Connect

    Bambade, P.S.

    1989-03-01

    In this thesis, we present the experimental tuning procedures developed for the Arcs and for the Final Focus Section of the Stanford Linear Collider (SLC). Such tuning is necessary to maximize the luminosity, by minimizing the beam size at the interaction point, and to reduce backgrounds in the experiment. In the final Focus Section, the correction strategy must result from the principles of the optical design, which is based on cancellations between second order aberrations, and on the ability to measure micron-size beams typical of the SLC. In the Arcs, the corrections were designed after the initial commissioning, to make the system more error-tolerant, through a modification in the optical design, and to enable adjustments of the beam phase-space a the injection to the Final Focus System, through a harmonic perturbation technique inspired from circular accelerators. Although the overall optimization of the SLC is not entirely finished, an almost optimal set-up has been achieved for the optics of the Arcs and of the Final Focus Section. Beams with transverse sizes close to the nominal ones, of a few microns, have been obtained at the interaction point. We present and discuss our results and the optical limits to the present performance. 24 refs., 25 figs., 2 tabs.

  12. Linear Colliders

    NASA Astrophysics Data System (ADS)

    Yamamoto, Akira; Yokoya, Kaoru

    2015-02-01

    An overview of linear collider programs is given. The history and technical challenges are described and the pioneering electron-positron linear collider, the SLC, is first introduced. For future energy frontier linear collider projects, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are introduced and their technical features are discussed. The ILC is based on superconducting RF technology and the CLIC is based on two-beam acceleration technology. The ILC collaboration completed the Technical Design Report in 2013, and has come to the stage of "Design to Reality." The CLIC collaboration published the Conceptual Design Report in 2012, and the key technology demonstration is in progress. The prospects for further advanced acceleration technology are briefly discussed for possible long-term future linear colliders.

  13. Linear Colliders

    NASA Astrophysics Data System (ADS)

    Yamamoto, Akira; Yokoya, Kaoru

    An overview of linear collider programs is given. The history and technical challenges are described and the pioneering electron-positron linear collider, the SLC, is first introduced. For future energy frontier linear collider projects, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are introduced and their technical features are discussed. The ILC is based on superconducting RF technology and the CLIC is based on two-beam acceleration technology. The ILC collaboration completed the Technical Design Report in 2013, and has come to the stage of "Design to Reality." The CLIC collaboration published the Conceptual Design Report in 2012, and the key technology demonstration is in progress. The prospects for further advanced acceleration technology are briefly discussed for possible long-term future linear colliders.

  14. Linear collider: a preview

    SciTech Connect

    Wiedemann, H.

    1981-11-01

    Since no linear colliders have been built yet it is difficult to know at what energy the linear cost scaling of linear colliders drops below the quadratic scaling of storage rings. There is, however, no doubt that a linear collider facility for a center of mass energy above say 500 GeV is significantly cheaper than an equivalent storage ring. In order to make the linear collider principle feasible at very high energies a number of problems have to be solved. There are two kinds of problems: one which is related to the feasibility of the principle and the other kind of problems is associated with minimizing the cost of constructing and operating such a facility. This lecture series describes the problems and possible solutions. Since the real test of a principle requires the construction of a prototype I will in the last chapter describe the SLC project at the Stanford Linear Accelerator Center.

  15. Linear collider development at SLAC

    SciTech Connect

    Irwin, J.

    1993-08-01

    Linear collider R&D at SLAC comprises work on the present Stanford Linear Collider (SLC) and work toward the next linear collider (NLC). Recent SLC developments are summarized. NLC studies are divided into hardware-based and theoretical. We report on the status of the NLC Test Accelerator (NLCTA) and the final focus test beam (FFTB), describe plans for ASSET, an installation to measure accelerator structure wakefields, and mention IR design developments. Finally we review recent NLC theoretical studies, ending with the author`s view of next linear collider parameter sets.

  16. SLC: The first linear collider

    NASA Astrophysics Data System (ADS)

    Phinney, Nan

    The Stanford Linear Collider (SLC) was built in the 1980s at the Stanford Linear Accelerator Center (SLAC) in California. Like LEP, it was designed to study the properties of the Z boson at a center-of-mass energy of about 91 GeV. The SLC was also a prototype for an entirely new approach to electron-positron colliders. The development of a new technology was motivated by the fact that in an electron storage ring, the electrons radiate synchrotron radiation as they are bent around the ring. To avoid excessive energy loss from this radiation, the circumference of the ring has to increase as the square of the desired energy, making very high energy rings prohibitively large and expensive. With a linear accelerator, the electrons do not need to bend and the tunnel length only grows linearly with energy...

  17. Rf-driver linear colliders

    SciTech Connect

    Wilson, P.B.

    1987-05-01

    The next generation of linear collider after the SLC (Stanford Linear Collider) will probably have an energy in the range 300 GeV-1 TeV per linac. A number of exotic accelerating schemes, such as laser and plasma acceleration, have been proposed for linear colliders of the far future. However, the technology which is most mature and which could lead to a collider in the above energy range in the relatively near future is the rf-driven linac, in which externally produced rf is fed into a more or less conventional metallic accelerating structure. Two basic technologies have been proposed for producing the required high peak rf power: discrete microwave power sources, and various two-beam acceleration schemes in which the rf is produced by a high current driving beam running parallel to the main accelerator. The current status of experimental and analytic work on both the discrete source and the two-beam methods for producing rf is discussed. The implications of beam-beam related effects (luminosity, disruption and beamstrahlung) for the design of rf-driven colliders are also considered.

  18. SLAC Linear Collider

    SciTech Connect

    Richter, B.

    1985-12-01

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

  19. Feedback Systems for Linear Colliders

    SciTech Connect

    1999-04-12

    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 integral part of the design. Feedback requirements 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 high bandwidth and fast response. To correct for the motion of individual bunches within a train, both feedforward and feedback systems are planned. SLC experience has shown that feedback systems are an invaluable operational tool for decoupling systems, allowing precision tuning, and providing pulse-to-pulse diagnostics. Feedback systems for the NLC will incorporate the key SLC features and the benefits of advancing technologies.

  20. Environmental Survey preliminary report, Stanford Linear Accelerator Center, Stanford, California

    SciTech Connect

    Not Available

    1988-07-01

    This report presents the preliminary findings from the first phase of the Survey of the US Department of Energy (DOE) Stanford Linear Accelerator Center (SLAC) at Stanford, California, conducted February 29 through March 4, 1988. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with the SLAC. The Survey covers all environmental media and all areas of environmental regulation and is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations at the SLAC, and interviews with site personnel. The Survey team is developing a Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during its on-site activities. The Sampling and Analysis Plan will be executed by a DOE National Laboratory or a support contractor. When completed, the results will be incorporated into the Environmental Survey Interim Report for the SLAC facility. The Interim Report will reflect the final determinations of the SLAC Survey. 95 refs., 25 figs., 25 tabs.

  1. Positrons for linear colliders

    SciTech Connect

    Ecklund, S.

    1987-11-01

    The requirements of a positron source for a linear collider are briefly reviewed, followed by methods of positron production and production of photons by electromagnetic cascade showers. Cross sections for the electromagnetic cascade shower processes of positron-electron pair production and Compton scattering are compared. A program used for Monte Carlo analysis of electromagnetic cascades is briefly discussed, and positron distributions obtained from several runs of the program are discussed. Photons from synchrotron radiation and from channeling are also mentioned briefly, as well as positron collection, transverse focusing techniques, and longitudinal capture. Computer ray tracing is then briefly discussed, followed by space-charge effects and thermal heating and stress due to showers. (LEW)

  2. LIONs at the Stanford Linear Accelerator Center

    SciTech Connect

    Constant, T.N.; Zdarko, R.W.; Simmons, R.H.; Bennett, B.M.

    1998-01-01

    The term LION is an acronym for Long Ionization Chamber. This is a distributed ion chamber which is used to monitor secondary ionization along the shield walls of a beam line resulting from incorrectly steered charged particle beams in lieu of the use of many discrete ion chambers. A cone of ionizing radiation emanating from a point source as a result of incorrect steering intercepts a portion of 1-5/8 inch Heliax cable (about 100 meters in length) filled with Argon gas at 20 psi and induces a pulsed current which is proportional to the ionizing charge. This signal is transmitted via the cable to an integrator circuit whose output is directed to an electronic comparators, which in turn is used to turn off the accelerated primary beam when preset limits are exceeded. This device is used in the Stanford Linear Accelerator Center (SLAC) Beam Containment System (BCS) to prevent potentially hazardous ionizing radiation resulting from incorrectly steered beams in areas that might be occupied by people. This paper describes the design parameters and experience in use in the Final Focus Test Beam (FFTB) area of the Stanford Linear Accelerator Center.

  3. Polarized Electrons for Linear Colliders

    NASA Astrophysics Data System (ADS)

    Clendenin, J. E.; Brachmann, A.; Garwin, E. L.; Kirby, R. E.; Luh, D.-A.; Maruyama, T.; Prescott, C. Y.; Sheppard, J. C.; Turner, J.; Prepost, R.

    2005-08-01

    Future electron-positron linear colliders require a highly polarized electron beam with a pulse structure that depends primarily on whether the acceleration utilizes warm or superconducting RF structures. The International Linear Collider (ILC) will use cold structures for the main linac. It is shown that a DC-biased polarized photoelectron source such as successfully used for the SLC can meet the charge requirements for the ILC micropulse with a polarization approaching 90%.

  4. Polarized Electrons for Linear Colliders

    SciTech Connect

    Clendenin, J.

    2004-11-19

    Future electron-positron linear colliders require a highly polarized electron beam with a pulse structure that depends primarily on whether the acceleration utilizes warm or superconducting rf structures. The International Linear Collider (ILC) will use cold structures for the main linac. It is shown that a dc-biased polarized photoelectron source such as successfully used for the SLC can meet the charge requirements for the ILC micropulse with a polarization approaching 90%.

  5. Vanilla technicolor at linear colliders

    NASA Astrophysics Data System (ADS)

    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.

  6. Challenges in future linear colliders

    SciTech Connect

    Swapan Chattopadhyay; Kaoru Yokoya

    2002-09-02

    For decades, electron-positron colliders have been complementing proton-proton colliders. But the circular LEP, the largest e-e+ collider, represented an energy limit beyond which energy losses to synchrotron radiation necessitate moving to e-e+ 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 socioeconomic and political challenges, likely necessitating continued development of international collaboration among parties involved in accelerator-based physics.

  7. Research and Development for an X-Band Linear Collider

    SciTech Connect

    Adolphsen, Chris

    1999-03-05

    At SLAC and KEK research is advancing toward a design for an electron-positron linear collider based on X-Band (11.4 GHz) rf accelerator technology. The nominal acceleration gradient in its main linacs will be about four times that in the Stanford Linear Collider (SLC). The design targets a 1.0 TeV center-of-mass energy but envisions initial operation at 0.5 TeV and allows for expansion to 1.5 TeV. A 1034 cm-2s-1 luminosity level will be achieved by colliding multiple bunches per pulse with bunch emittances about two orders of magnitude smaller than those in the SLC. The key components needed to realize such a collider are under development at SLAC and KEK. In this paper we review recent progress in the development of the linac rf system and discuss future R&D.

  8. The polarized electron source of the Stanford Linear Accelerator Center

    SciTech Connect

    Schultz, D.; Alley, R.; Clendenin, J.; Frisch, J.; Mulhollan, G.; Saez, P.; Tang, H.; Witte, K.

    1994-08-01

    The Stanford Linear Accelerator has been running with polarized electrons both in the collider (SLC) mode and in the fixed target mode. The accelerators polarized electron source is based on a thin, strained GaAs photocathode, which is held at a negative high voltage and illuminated by a Titanium Sapphire laser. The reliability of the source was better than 95% during the eight-month-long 1993 SLC run. A beam polarization of 63% was measured by the SLD experiment at the SLC interaction point in the 1993 data run. The fixed-target experiment E143 measured a beam polarization of 85% in its 1993--94 run. These polarization measurements, made at high energy, are in good agreement with measurements made at low energy on a calibrated Mott polarimeter. The higher beam polarization in the fixed target experiment is due to a thinner, more highly strained GaAs photocathode than had been used earlier, and to the experiment`s low beam current requirements. The SLC is now running with the high polarization photocathode. Details of the source, and experience with the high polarization strained GaAs photocathodes on the accelerator in the current SLC run, will be presented.

  9. Crab Cavities for Linear Colliders

    SciTech Connect

    Burt, G.; Ambattu, P.; Carter, R.; Dexter, A.; Tahir, I.; Beard, C.; Dykes, M.; Goudket, P.; Kalinin, A.; Ma, L.; McIntosh, P.; Shulte, D.; Jones, Roger M.; Bellantoni, L.; Chase, B.; Church, M.; Khabouline, T.; Latina, A.; Adolphsen, C.; Li, Z.; Seryi, Andrei; /SLAC

    2011-11-08

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  10. Intense beams at the micron level for the Next Linear Collider

    SciTech Connect

    Seeman, J.T.

    1991-08-01

    High brightness beams with sub-micron dimensions are needed to produce a high luminosity for electron-positron collisions in the Next Linear Collider (NLC). To generate these small beam sizes, a large number of issues dealing with intense beams have to be resolved. Over the past few years many have been successfully addressed but most need experimental verification. Some of these issues are beam dynamics, emittance control, instrumentation, collimation, and beam-beam interactions. Recently, the Stanford Linear Collider (SLC) has proven the viability of linear collider technology and is an excellent test facility for future linear collider studies.

  11. Fast feedback for linear colliders

    SciTech Connect

    Hendrickson, L.; Adolphsen, C.; Allison, S.; Gromme, T.; Grossberg, P.; Himel, T.; Krauter, K.; MacKenzie, R.; Minty, M.; Sass, R.

    1995-05-01

    A fast feedback system provides beam stabilization for the SLC. As the SLC is in some sense a prototype for future linear colliders, this system may be a prototype for future feedbacks. The SLC provides a good base of experience for feedback requirements and capabilities as well as a testing ground for performance characteristics. The feedback system controls a wide variety of machine parameters throughout the SLC and associated experiments, including regulation of beam position, angle, energy, intensity and timing parameters. The design and applications of the system are described, in addition to results of recent performance studies.

  12. Proceedings of the 2005 International Linear Collider Workshop (LCWS05)

    SciTech Connect

    Hewett, JoAnne,; /SLAC

    2006-12-18

    at Stanford University from 18 March through 22 March, 2005. This workshop was hosted by the Stanford Linear Accelerator Center and sponsored by the World Wide Study for future e+e- linear colliders. It was the eighth in a series of International Workshops (the first was held in Saariselka, Finland in 1991) devoted to the physics and detectors associated with high energy e+e- linear colliders. 397 physicists from 24 countries participated in the workshop. These proceedings represent the presentations and discussions which took place during the workshop. The contributions are comprised of physics studies, detector specifications, and accelerator design for the ILC. These proceedings are organized in two Volumes and include contributions from both the plenary and parallel sessions.

  13. Organizational cultural survey of the Stanford Linear Accelerator Center

    SciTech Connect

    Not Available

    1991-11-01

    At the request of the Department of Energy, an Organizational Survey (OS) was administered at the Stanford Linear Accelerator Center (SLAC). The OS measured employees' opinions on subjects such as organizational culture, communication, commitment, group cohesion, coordination, safety, environmental issues, and job satisfaction. The result of this work was a quantitative measure of the notion of culture at the SLAC site. This report presents these results and discusses their interpretation.

  14. Next-Generation Linear Collider Final Focus System Stability Tolerances

    SciTech Connect

    Roy, G.; Irwin, J.; /SLAC

    2007-04-25

    The design of final focus systems for the next generation of linear colliders has evolved largely from the experience gained with the design and operation of the Stanford Linear Collider (SLC) and with the design of the Final Focus Test Beam (FFTB). We will compare the tolerances for two typical designs for a next-generation linear collider final focus system. The chromaticity generated by strong focusing systems, like the final quadrupole doublet before the interaction point of a linear collider, can be canceled by the introduction of sextupoles in a dispersive region. These sextupoles must be inserted in pairs separated by a -I transformation (Chromatic Correction Section) in order to cancel the strong geometric aberrations generated by sextupoles. Designs proposed for both the JLC or NLC final focus systems have two separate chromatic correction sections, one for each transverse plane separated by a ''{beta}-exchanger'' to manipulate the {beta}-function between the two CCS. The introduction of sextupoles and bending magnets gives rise to higher order aberrations (long sextupole and chrome-geometries) and radiation induced aberrations (chromaticity unbalance and ''Oide effect'') and one must optimize the lattice accordingly.

  15. Depolarization due to beam-beam interaction in electron-positron linear colliders

    SciTech Connect

    Yokoya, Kaoru; Chen, Pisin

    1988-09-01

    We investigate two major mechanisms which induce depolarization of electron beams during beam-beam interaction in linear colliders. These are the classical spin precession under the collective field of the oncoming beam, and the spin-flip effect from beamstrahlung. Analytic formulas are derived for estimating these depolarization effects. As examples, we estimate the depolarization in the Stanford Linear Collider (SLC) and a possible future TeV linear collider (TLC). The effects are found to be negligibly small for SLC and not very large for TLC. 7 refs., 1 fig.

  16. The principles and construction of linear colliders

    SciTech Connect

    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. (LEW)

  17. International Workshop on Linear Colliders 2010

    ScienceCinema

    None

    2016-07-12

    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

  18. The Status of the International Linear Collider

    NASA Astrophysics Data System (ADS)

    Harrison, Michael

    2016-03-01

    The International Linear Collider is under consideration in Japan as the next major global high energy physics facility. In this talk we shall describe the site and accelerator footprint together with the latest technical information on the superconducting RF technology.

  19. SLAC linear collider conceptual design report

    SciTech Connect

    Not Available

    1980-06-01

    The linear collider system is described in detail, including the transport system, the collider lattice, final focusing system, positron production, beam damping and compression, high current electron source, instrumentation and control, and the beam luminosity. The experimental facilities and the experimental uses are discussed along with the construction schedule and estimated costs. Appendices include a discussion of space charge effects in the linear accelerator, emittance growth in the collider, the final focus system, beam-beam instabilities and pinch effects, and detector backgrounds. (GHT)

  20. Beamstrahlung spectra in next generation linear colliders

    SciTech Connect

    Barklow, T.; Chen, P. ); Kozanecki, W. )

    1992-04-01

    For the next generation of linear colliders, the energy loss due to beamstrahlung during the collision of the e{sup +}e{sup {minus}} beams is expected to substantially influence the effective center-of-mass energy distribution of the colliding particles. In this paper, we first derive analytical formulae for the electron and photon energy spectra under multiple beamstrahlung processes, and for the e{sup +}e{sup {minus}} and {gamma}{gamma} differential luminosities. We then apply our formulation to various classes of 500 GeV e{sup +}e{sup {minus}} linear collider designs currently under study.

  1. Test facilities for future linear colliders

    SciTech Connect

    Ruth, R.D.

    1995-12-01

    During the past several years there has been a tremendous amount of progress on Linear Collider technology world wide. This research has led to the construction of the test facilities described in this report. Some of the facilities will be complete as early as the end of 1996, while others will be finishing up around the end 1997. Even now there are extensive tests ongoing for the enabling technologies for all of the test facilities. At the same time the Linear Collider designs are quite mature now and the SLC is providing the key experience base that can only come from a working collider. All this taken together indicates that the technology and accelerator physics will be ready for a future Linear Collider project to begin in the last half of the 1990s.

  2. Tiger Team Assessment of the Stanford Linear Accelerator Center

    SciTech Connect

    Not Available

    1991-11-01

    This report documents the Tiger Team Assessment of the buildings, facilities, and activities at the Stanford Linear Accelerator Center (SLAC) and the Stanford Synchrotron Radiation Laboratory (SSRL) near San Francisco, California. SLAC/SSRL is the twenty-eighth DOE site to be assessed by a Tiger Team. SLAC and SSRL are single-purpose laboratories. SLAC is dedicated to experimental and theoretical research in elementary particle physics and to the development of new techniques in high-energy accelerators and elementary particle detectors. SSRL is dedicated to research in atomic and solid-state physics, chemistry, biology, and medicine. The purpose of the SLAC/SSRL Tiger Team Assessment is to provide the Secretary of Energy with concise information on the following: current ES H compliance status at the site and the vulnerabilities associated with that compliance status; root causes for noncompliance; adequacy of DOE and SLAC/SSRL ES H management programs; response actions to address identified problem areas; and effectiveness of self-assessment.

  3. Tiger Team Assessment of the Stanford Linear Accelerator Center

    SciTech Connect

    Not Available

    1991-11-01

    This report documents the Tiger Team Assessment of the buildings, facilities, and activities at the Stanford Linear Accelerator Center (SLAC) and the Stanford Synchrotron Radiation Laboratory (SSRL) near San Francisco, California. SLAC/SSRL is the twenty-eighth DOE site to be assessed by a Tiger Team. SLAC and SSRL are single-purpose laboratories. SLAC is dedicated to experimental and theoretical research in elementary particle physics and to the development of new techniques in high-energy accelerators and elementary particle detectors. SSRL is dedicated to research in atomic and solid-state physics, chemistry, biology, and medicine. The purpose of the SLAC/SSRL Tiger Team Assessment is to provide the Secretary of Energy with concise information on the following: current ES&H compliance status at the site and the vulnerabilities associated with that compliance status; root causes for noncompliance; adequacy of DOE and SLAC/SSRL ES&H management programs; response actions to address identified problem areas; and effectiveness of self-assessment.

  4. World lays groundwork for future linear collider

    SciTech Connect

    Feder, Toni

    2010-07-15

    With the Large Hadron Collider at CERN finally working, the particle-physics community can now afford to divide its attention between achieving LHC results and preparing for the next machine on its wish list, an electron-positron linear collider. The preparations involve developing and deciding on the technology for such a machine, the mode of its governance, and how to balance regional and global particle- and accelerator-physics programs.

  5. [Experiment studies of electron-positron interactions at the Stanford Linear Accelerator Center]. Progress report, calendar year 1993

    SciTech Connect

    Hertzbach, S.S.; Kofler, R.R.

    1993-12-31

    The High Energy Physics group at the University of Massachusetts has continued its` program of experimental studies of electron-positron interactions at the Stanford Linear Accelerator Center (SLAC). The group activities have included: analysis of data taken between 1982 and 1990 with the TPC detector at the PEP facility, continuing data collection and data analysis using the SLC/SLD facility, planning for the newly approved B-factory at SLAC, and participation in design studies for future high energy linear colliders. This report will briefly summarize these activities.

  6. Wakefield effects in a linear collider

    SciTech Connect

    Bane, K.L.F.

    1986-12-01

    In this paper the wakefields for the Stanford Linear Accelerator Center (SLAC) accelerating structure are first discussed, and then some considerations dealing with the longitudinal wakefields are described. The main focus is on the effects of the transverse wakefield on the beam, including the case when there is an energy variation along the bunch. The use of an energy spread to inhibit emittance growth in a linac, indeed to damp the oscillations of the core of the bunch to below the unperturbed betatron oscillations, (in a process that is similar to Landau Damping) is qualitatively detailed. The example of the SLC, including errors, is also in detail.

  7. The Next Linear Collider: NLC2001

    SciTech Connect

    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.

  8. Beam dynamics issues for linear colliders

    SciTech Connect

    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.

  9. Linear Collider Accelerator Physics Issues Regarding Alignment

    SciTech Connect

    Seeman, J.T.; /SLAC

    2005-08-12

    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.

  10. Physics Case for the International Linear Collider

    SciTech Connect

    Fujii, Keisuke; Grojean, Christophe; Peskin, Michael E.; Barklow, Tim; Gao, Yuanning; Kanemura, Shinya; Kim, Hyungdo; List, Jenny; Nojiri, Mihoko; Perelstein, Maxim; Poeschl, Roman; Reuter, Juergen; Simon, Frank; Tanabe, Tomohiko; Yu, Jaehoon; Wells, James D.; Murayama, Hitoshi; 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.

  11. RF pulse compression for future linear colliders

    SciTech Connect

    Wilson, P.B.

    1995-05-01

    Future (nonsuperconducting) linear colliders will require very high values of peak rf power per meter of accelerating structure. The role of rf pulse compression in producing this power is examined within the context of overall rf system design for three future colliders at energies of 1.0--1.5 TeV, 5 TeV and 25 TeV. In order keep the average AC input power and the length of the accelerator within reasonable limits, a collider in the 1.0--1.5 TeV energy range will probably be built at an x-band rf frequency, and will require a peak power on the order of 150--200 MW per meter of accelerating structure. A 5 TeV collider at 34 GHz with a reasonable length (35 km) and AC input power (225 MW) would require about 550 MW per meter of structure. Two-beam accelerators can achieve peak powers of this order by applying dc pulse compression techniques (induction linac modules) to produce the drive beam. Klystron-driven colliders achieve high peak power by a combination of dc pulse compression (modulators) and rf pulse compression, with about the same overall rf system efficiency (30--40%) as a two-beam collider. A high gain (6.8) three-stage binary pulse compression system with high efficiency (80%) is described, which (compared to a SLED-11 system) can be used to reduce the klystron peak power by about a factor of two, or alternately, to cut the number of klystrons in half for a 1.0--1.5 TeV x-band collider. For a 5 TeV klystron-driven collider, a high gain, high efficiency rf pulse compression system is essential.

  12. RF pulse compression for future linear colliders

    NASA Astrophysics Data System (ADS)

    Wilson, Perry B.

    1995-07-01

    Future (nonsuperconducting) linear colliders will require very high values of peak rf power per meter of accelerating structure. The role of rf pulse compression in producing this power is examined within the context of overall rf system design for three future colliders at energies of 1.0-1.5 TeV, 5 TeV, and 25 TeV. In order to keep the average AC input power and the length of the accelerator within reasonable limits, a collider in the 1.0-1.5 TeV energy range will probably be built at an x-band rf frequency, and will require a peak power on the order of 150-200 MW per meter of accelerating structure. A 5 TeV collider at 34 GHz with a reasonable length (35 km) and AC input power (225 MW) would require about 550 MW per meter of structure. Two-beam accelerators can achieve peak powers of this order by applying dc pulse compression techniques (induction linac modules) to produce the drive beam. Klystron-driven colliders achieve high peak power by a combination of dc pulse compression (modulators) and rf pulse compression, with about the same overall rf system efficiency (30-40%) as a two-beam collider. A high gain (6.8) three-stage binary pulse compression system with high efficiency (80%) is described, which (compared to a SLED-II system) can be used to reduce the klystron peak power by about a factor of two, or alternatively, to cut the number of klystrons in half for a 1.0-1.5 TeV x-band collider. For a 5 TeV klystron-driven collider, a high gain, high efficiency rf pulse compression system is essential.

  13. Prospects for next-generation e sup + e sup minus linear colliders

    SciTech Connect

    Ruth, R.D.

    1990-02-01

    The purpose of this paper is to review progress in the US towards a next generation linear collider. During 1988, there were three workshops held on linear colliders: Physics of Linear Colliders,'' in Capri, Italy, June 14--18, 1988; Snowmass 88 (Linear Collider subsection) June 27--July 15, 1988; and SLAC International Workshop on Next Generation Linear Colliders, November 28--December 9, 1988. In this paper, I focus on reviewing the issues and progress on a next generation linear collider. The energy range is dictated by physics with a mass reach well beyond LEP, although somewhat short of SSC. The luminosity is that required to obtain 10{sup 3}--10{sup 4} units of R{sub 0} per year. The length is consistent with a site on Stanford land with collision occurring on the SLAC site; the power was determined by economic considerations. Finally, the technology as limited by the desire to have a next generation linear collider by the next century. 37 refs., 3 figs., 6 tabs.

  14. Progress report on the SLAC Linear Collider

    SciTech Connect

    Kozanecki, W.

    1987-11-01

    In this paper we report on the status of the SLAC Linear Collider (SLC), the prototype of a new generation of colliding beam accelerators. This novel type of machine holds the potential of extending electron-positron colliding beam studies to center-of-mass (c.m.) energies far in excess of what is economically achievable with colliding beam storage rings. If the technical challenges posed by linear colliders are solvable at a reasonable cost, this new approach would provide an attractive alternative to electron-positron rings, where, because of rapidly rising synchrotron radiation losses, the cost and size of the ring increases with the square of the c.m. energy. In addition to its role as a test vehicle for the linear collider principle, the SLC aims at providing an abundant source of Z/sup 0/ decays to high energy physics experiments. Accordingly, two major detectors, the upgraded Mark II, now installed on the SLC beam line, and the state-of-the-art SLD, currently under construction, are preparing to probe the Standard Model at the Z/sup 0/ pole. The SLC project was originally funded in 1983. Since the completion of construction, we have been commissioning the machine to bring it up to a performance level adequate for starting the high energy physics program. In the remainder of this paper, we will discuss the status, problems and performance of the major subsystems of the SLC. We will conclude with a brief outline of the physics program, and of the planned enhancements to the capabilities of the machine. 26 refs., 7 figs.

  15. Suppressing Electron Cloud in Future Linear Colliders

    SciTech Connect

    Pivi, M; Kirby, R.E.; Raubenheimer, T.O.; Le Pimpec, F.; /PSI, Villigen

    2005-05-27

    Any accelerator circulating positively charged beams can suffer from a build-up of an electron cloud (EC) in the beam pipe. The cloud develops through ionization of residual gases, synchrotron radiation and secondary electron emission and, when severe, can cause instability, emittance blow-up or loss of the circulating beam. The electron cloud is potentially a luminosity limiting effect for both the Large Hadron Collider (LHC) and the International Linear Collider (ILC). For the ILC positron damping ring, the development of the electron cloud must be suppressed. This paper discusses the state-of-the-art of the ongoing SLAC and international R&D program to study potential remedies.

  16. Progress in the Next Linear Collider Design

    NASA Astrophysics Data System (ADS)

    Raubenheimer, T. O.

    2001-07-01

    An electron/positron linear collider with a center-of-mass energy between 0.5 and 1 TeV would be an important complement to the physics program of the LHC. The Next Linear Collider (NLC) is being designed by a US collaboration (FNAL, LBNL, LLNL, and SLAC) which is working closely with the Japanese collaboration that is designing the Japanese Linear Collider (JLC). The NLC main linacs are based on normal conducting 11 GHz rf. This paper will discuss the technical difficulties encountered as well as the many changes that have been made to the NLC design over the last year. These changes include improvements to the X-band rf system as well as modifications to the injector and the beam delivery system. They are based on new conceptual solutions as well as results from the R&D programs which have exceeded initial specifications. The net effect has been to reduce the length of the collider from about 32 km to 25 km and to reduce the number of klystrons and modulators by a factor of two. Together these lead to significant cost savings.

  17. Towards a Future Linear Collider and The Linear Collider Studies at CERN

    ScienceCinema

    None

    2016-07-12

    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.

  18. Linear Collider Physics Resource Book Snowmass 2001

    SciTech Connect

    Ronan , 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

  19. International linear collider reference design report

    SciTech Connect

    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.

  20. Progress report on the SLAC Linear Collider

    SciTech Connect

    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. (LEW)

  1. Linear collider IR and final focus introduction

    SciTech Connect

    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{sup 33} to 10{sup 34} cm{sup {minus}2}s{sup {minus}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.

  2. Improving reliability in the SLC (Stanford Linear Collider) control system

    SciTech Connect

    Heinen, N.; Spencer, N.; Tinsman, J.

    1989-10-01

    During the past year, considerable emphasis has been placed on improving the overall reliability of the SLC control system. The Errorlog Facility has proven a useful tool to diagnose hardware and software problems. By analyzing the various error messages and their correlations, one can usually determine the software component or hardware module causing faults. Daily summaries help to identify problems so that they can be remedied before they become catastrophic; thereby bringing about a considerable increase in performance. We discuss the various tools we use and our operational experience with them. 3 refs., 6 figs.

  3. 2001 Report on the Next Linear Collider

    SciTech Connect

    Gronnberg, J; Breidenbach; Burke, D; Corlett, J; Dombeck, T; Markiewicz, T

    2001-08-28

    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.

  4. X-Band klystron development at the Stanford Linear Accelerator Center

    SciTech Connect

    Sprehn, D.W.

    2000-03-24

    X-band klystrons capable of 75 MW and utilizing either solenoidal or Periodic Permanent Magnet (PPM) focusing are undergoing design, fabrication and testing at the Stanford Linear Accelerator Center (SLAC). The klystron development is part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). SLAC has completed a solenoidal-focused X-band klystron development effort to study the design and operation of tubes with beam microperveances of 1.2. As of early 2000, nine 1.2{micro}K klystrons have been tested to 50 MW at 1.5{micro}s. The first 50 MW PPM klystron, constructed in 1996, was designed with a 0.6 {micro}K beam at 465 kV and uses a 5-cell traveling-wave output structure. Recent testing of this tube at wider pulsewidths has reached 50 MW at 55% efficiency, 2.4{micro}s and 60 Hz. A 75 MW PPM klystron prototype was constructed in 1998 and has reached the NLC design target of 75 MW at 1.5 {micro}s. A new 75 MW PPM klystron design, which is aimed at reducing the cost and increasing the reliability of multi-megawatt PPM klystrons, is under investigation. The tube is scheduled for testing during early 2001.

  5. X-band klystron development at the Stanford Linear Accelerator Center

    NASA Astrophysics Data System (ADS)

    Sprehn, Daryl; Caryotakis, George; Jongewaard, Erik N.; Phillips, Robert M.; Vlieks, A.

    2000-07-01

    X-band klystrons capable of 75 MW and utilizing either solenoidal or Periodic Permanent Magnet (PPM) focusing are undergoing design, fabrication and testing at the Stanford Linear Accelerator Center (SLAC). The klystron development is part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). SLAC has completed a solenoidal-focused X-band klystron development effort to study the design and operation of tubes with beam microperveances of 1.2. As of early 2000, nine 1.2 (mu) K klystrons have been tested to 50 MW at 1.5 microsecond(s) . The first 50 MW PPM klystron, constructed in 1996, was designed with a 0.6 (mu) K beam at 465 kV and uses a 5-cell traveling-wave output structure. Recent testing of this tube at wider pulsewidths has reached 50 MW at 55% efficiency, 2.4 microsecond(s) and 60 Hz. A 75 MW PPM klystron prototype was constructed in 1998 and has reached the NLC design target of 75 MW at 1.5 microsecond(s) . A new 75 MW PPM klystron design, which is aimed at reducing the cost and increasing the reliability of multi- megawatt PPM klystrons, is under investigation. The tube is scheduled for testing during early 2001.

  6. Electron Cloud Effect in the Linear Colliders

    SciTech Connect

    Pivi, M

    2004-09-13

    Beam induced multipacting, driven by the electric field of successive positively charged bunches, may arise from a resonant motion of electrons, generated by secondary emission, bouncing back and forth between opposite walls of the vacuum chamber. The electron-cloud effect (ECE) has been observed or is expected at many storage rings [1]. In the beam pipe of the Damping Ring (DR) of a linear collider, an electron cloud is produced initially by ionization of the residual gas and photoelectrons from the synchrotron radiation. The cloud is then sustained by secondary electron emission. This electron cloud can reach equilibrium after the passage of only a few bunches. The electron-cloud effect may be responsible for collective effects as fast coupled-bunch and single-bunch instability, emittance blow-up or incoherent tune shift when the bunch current exceeds a certain threshold, accompanied by a large number of electrons in the vacuum chamber. The ECE was identified as one of the most important R&D topics in the International Linear Collider Report [2]. Systematic studies on the possible electron-cloud effect have been initiated at SLAC for the GLC/NLC and TESLA linear colliders, with particular attention to the effect in the positron main damping ring (MDR) and the positron Low Emittance Transport which includes the bunch compressor system (BCS), the main linac, and the beam delivery system (BDS). We present recent computer simulation results for the main features of the electron cloud generation in both machine designs. Thus, single and coupled-bunch instability thresholds are estimated for the GLC/NLC design.

  7. Broader Impacts of the International Linear Collider

    SciTech Connect

    Bardeen, M.; Ruchti, R.

    2005-08-01

    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.

  8. Next linear collider test accelerator injector upgrade

    SciTech Connect

    Yeremian, A.D.; Miller, R.H.

    1995-12-31

    The Next Linear Collider Test Accelerator (NLCTA) is being constructed at SLAC to demonstrate multibunch beam loading compensation, suppression of higher order deflecting modes and measure transverse components of the accelerating fields in X-band accelerating structures. Currently a simple injector which provides the average current necessary for the beam loading compensations studies is under construction. An injector upgrade is planned to produce bunch trains similar to that of the NLC with microbunch intensity, separation and energy spread, identical to that of NLC. We discuss the design of the NLCTA injector upgrade.

  9. Nonlinear resonant collimation for future linear colliders

    NASA Astrophysics Data System (ADS)

    Emma, P.; Helm, R.; Nosochkov, Y.; Pitthan, R.; Raubenheimer, T.; Thompson, K.; Zimmermann, F.

    1999-04-01

    We present a scheme for collimating large amplitude particles in the main linacs of a linear collider, by adding octupoles to the FODO lattice of the linac. With this scheme the requirements on downstream collimation can be greatly reduced or perhaps even eliminated. An analytic estimate of the amplitude at which particles are lost is made by calculating the separatrix of the fourth order resonance, and is in good agreement with the results of simulations. Simulations of particle distributions in the beam core and halo are presented, as well as alignment tolerances for the octupoles.

  10. Relativistic klystron research for linear colliders

    SciTech Connect

    Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Higo, T.; Hoag, H.A.; Koontz, R.F.

    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.

  11. Rf power sources for linear colliders

    SciTech Connect

    Allen, M.A.; Callin, R.S.; Caryotakis, G.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Farkas, Z.D.; Fowkes, W.R.; Hoag, H.A.; Feinstein, J.; Ko, K.; Koontz, R.F.; Kroll, N.M.; Lavine, T.L.; Lee, T.G.; Loew, G.A.; Miller, R.H.; Nelson, E.M.; Ruth, R.D.; Vlieks, A.E.; Wang, J.W.; Wilson, P.B. ); Boyd, J.K.; Houk, T.; Ryne, R.D.; Westenskow, G.A.; Yu, S.S. (Lawrence Live

    1990-06-01

    The next generation of linear colliders requires peak power sources of over 200 MW per meter at frequencies above 10 GHz at pulse widths of less than 100 nsec. Several power sources are under active development, including a conventional klystron with rf pulse compression, a relativistic klystron (RK) and a crossed-field amplifier. Power from one of these has energized a 0.5 meter two- section High Gradient Accelerator (HGA) and accelerated a beam at over 80 MeV meter. Results of tests with these experimental devices are presented here.

  12. An organizational survey of the Stanford Linear Accelerator Center

    SciTech Connect

    Shurberg, D.A.; Haber, S.B.

    1991-11-01

    At the request of the Department of Energy, an Organizational Survey (OS) was administered at the Stanford Accelerator Center (SLAC). The OS measured employees' opinions on subjects such as organizational culture, communication, commitment, group cohesion, coordination, safety, environmental issues, and job satisfaction. The result of this work was a quantitative measure of the notion of culture at the SLAC site. This report presents these results and discusses their interpretation.

  13. Organizational cultural survey of the Stanford Linear Accelerator Center

    SciTech Connect

    Not Available

    1991-11-01

    At the request of the Department of Energy, an Organizational Survey (OS) was administered at the Stanford Accelerator Center (SLAC). The OS measured employees' opinions on subjects such as organizational culture, communication, commitment, group cohesion, coordination, safety, environmental issues, and job satisfaction. The result of this work was a quantitative measure of the notion of culture at the SLAC site. This report presents these results and discusses their interpretation.

  14. An organizational survey of the Stanford Linear Accelerator Center

    SciTech Connect

    Shurberg, D.A.; Haber, S.B.

    1991-11-01

    At the request of the Department of Energy, an Organizational Survey (OS) was administered at the Stanford Accelerator Center (SLAC). The OS measured employees` opinions on subjects such as organizational culture, communication, commitment, group cohesion, coordination, safety, environmental issues, and job satisfaction. The result of this work was a quantitative measure of the notion of culture at the SLAC site. This report presents these results and discusses their interpretation.

  15. Frequency scaling of linear super-colliders

    SciTech Connect

    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.

  16. Development work for a superconducting linear collider

    NASA Technical Reports Server (NTRS)

    Matheisen, Axel

    1995-01-01

    For future linear e(+)e(-) colliders in the TeV range several alternatives are under discussion. The TESLA approach is based on the advantages of superconductivity. High Q values of the accelerator structures give high efficiency for converting RF power into beam power. A low resonance frequency for the RF structures can be chosen to obtain a large number of electrons (positrons) per bunch. For a given luminosity the beam dimensions can be chosen conservatively which leads to relaxed beam emittance and tolerances at the final focus. Each individual superconducting accelerator component (resonator cavity) of this linear collider has to deliver an energy gain of 25 MeV/m to the beam. Today s.c. resonators are in use at CEBAF/USA, at DESY/Germany, Darmstadt/Germany KEK/Japan and CERN/Geneva. They show acceleration gradients between 5 MV/m and 10 MV/m. Encouraging experiments at CEA Saclay and Cornell University showed acceleration gradients of 20 MV/m and 25 MV/m in single and multicell structures. In an activity centered at DESY in Hamburg/Germany the TESLA collaboration is constructing a 500 MeV superconducting accelerator test facility (TTF) to demonstrate that a linear collider based on this technique can be built in a cost effective manner and that the necessary acceleration gradients of more than 15 MeV/m can be reached reproducibly. The test facility built at DESY covers an area of 3.000 m2 and is divided into 3 major activity areas: (1) The testlinac, where the performance ofthe modular components with an electron beam passing the 40 m long acceleration section can be demonstrated. (2) The test area, where all individual resonators are tested before installation into a module. (3) The preparation and assembly area, where assembly of cavities and modules take place. We report here on the design work to reach a reduction of costs compared to actual existing superconducting accelerator structures and on the facility set up to reach high acceleration gradients in

  17. The next linear collider damping ring complex

    SciTech Connect

    Corlett,J.; Atkinson,D.; De Santis,S.; Hartman, N.; Kennedy, K.; Li, D.; Marks, S.; Minamihara, Y.; Nishimura, H.; Pivi, M.; Reavill, D.; Rimmer, R.; Schlueter, R.; Wolski, A.; Anderson,S.; McKee,B.; Raubenheimer, T.; Ross, M.; Sheppard, J.C.

    2001-06-12

    We report progress on the design of the Next Linear Collider (NLC) Damping Rings complexes. The purpose of the damping rings is to provide low emittance electron and positron bunch trains to the NLC linacs, at a rate of 120 Hz. As an option to operate at the higher rate of 180 Hz, two 1.98 GeV main damping rings per beam are proposed, and one positron pre-damping ring. The main damping rings store up to 0.8 amp in 3 trains of 190 bunches each and have normalized extracted beam emittances {gamma}{var_epsilon}x = 3 mm-mrad and {gamma}{var_epsilon}y = 0.02 mm-mrad. The optical designs, based on a theoretical minimum emittance lattice (TME), are described, with an analysis of dynamic aperture and non-linear effects. Key subsystems and components are described, including the wiggler, the vacuum systems and photon stop design, and the higher-order-mode damped RF cavities. Impedance and instabilities are discussed.

  18. Linear collider approach to a B anti B factory

    SciTech Connect

    Wilson, P.B.

    1987-06-01

    In this paper we consider the basic design expression and principal design constraints for a linear collider suitable for a B anti-B factory: Energy approx. =10 GeV, luminosity 10/sup 33/-10/sup 34/ cm/sup -2/s/sup -1/, energy resolution approx. =10/sup -2/. The design of room temperature linear colliders for a B factory is discussed. In such colliders, the rf energy stored in the linac structure is thrown away after each linac pulse. Linear colliders using superconducting rf cavities are considered. Some brief conclusions are presented.

  19. Governance of the International Linear Collider Project

    SciTech Connect

    Foster, B.; Barish, B.; Delahaye, J.P.; Dosselli, U.; Elsen, E.; Harrison, M.; Mnich, J.; Paterson, J.M.; Richard, F.; Stapnes, S.; Suzuki, A.; Wormser, G.; Yamada, S.; /KEK, Tsukuba

    2012-05-31

    Governance models for the International Linear Collider Project are examined in the light of experience from similar international projects around the world. Recommendations for one path which could be followed to realize the ILC successfully are outlined. The International Linear Collider (ILC) is a unique endeavour in particle physics; fully international from the outset, it has no 'host laboratory' to provide infrastructure and support. The realization of this project therefore presents unique challenges, in scientific, technical and political arenas. This document outlines the main questions that need to be answered if the ILC is to become a reality. It describes the methodology used to harness the wisdom displayed and lessons learned from current and previous large international projects. From this basis, it suggests both general principles and outlines a specific model to realize the ILC. It recognizes that there is no unique model for such a laboratory and that there are often several solutions to a particular problem. Nevertheless it proposes concrete solutions that the authors believe are currently the best choices in order to stimulate discussion and catalyze proposals as to how to bring the ILC project to fruition. The ILC Laboratory would be set up by international treaty and be governed by a strong Council to whom a Director General and an associated Directorate would report. Council would empower the Director General to give strong management to the project. It would take its decisions in a timely manner, giving appropriate weight to the financial contributions of the member states. The ILC Laboratory would be set up for a fixed term, capable of extension by agreement of all the partners. The construction of the machine would be based on a Work Breakdown Structure and value engineering and would have a common cash fund sufficiently large to allow the management flexibility to optimize the project's construction. Appropriate contingency, clearly

  20. Physics prospects: Why do we want a linear collider?

    SciTech Connect

    Murayama, Hitoshi |

    1995-12-01

    The need to understand physics of electroweak symmetry breaking is reviewed. An electron positron linear collider will play crucial roles in that respect. It is discussed how the LHC and a linear collider need each other to understand symmetry breaking mechanism unambiguously. Two popular scenarios, supersymmetry and technicolor- like models, are used to demonstrate this point.

  1. Multimegawatt rf power sources for linear colliders

    SciTech Connect

    Caryotakis, G.

    1991-04-01

    Conceptual designs for a future linear collider operating at 11.4 GHz call for peak rf power as high as 240 MW per meter, with an accelerator length of 14 km. This is an extremely high total power, which results in requirements for microwave sources that cannot be met with existing microwave tubes. While some new tube concepts are being considered, work is proceeding at several laboratories in the US and abroad on conventional 100 MW klystrons for this application. The electron beam necessary for this power to be generated, unless carefully controlled, can easily cause intrapulse melting at the klystron output circuit. This, coupled to the need for good efficiency, high production yield, and long life, poses some difficult problems to the klystron designer. Experimental klystrons at SLAC and other laboratories are approaching the goal of 100 MW in 800 nsec pulses, but much work remains to be done before a design is available which is suitable for manufacturing thousands of these tubes. 4 figs., 1 tab.

  2. (Stanford Linear Accelerator Center) annual environmental monitoring report, January--December 1989

    SciTech Connect

    Not Available

    1990-05-01

    This progress report discusses environmental monitoring activities at the Stanford Linear Accelerator Center for 1989. Topics include climate, site geology, site water usage, land use, demography, unusual events or releases, radioactive and nonradioactive releases, compliance summary, environmental nonradiological program information, environmental radiological program information, groundwater protection monitoring ad quality assurance. 5 figs., 7 tabs. (KJD)

  3. Run scenarios for the linear collider

    SciTech Connect

    M. Battaglia et al.

    2002-12-23

    We have examined how a Linear Collider program of 1000 fb{sup -1} could be constructed in the case that a very rich program of new physics is accessible at {radical}s {le} 500 GeV. We have examined possible run plans that would allow the measurement of the parameters of a 120 GeV Higgs boson, the top quark, and could give information on the sparticle masses in SUSY scenarios in which many states are accessible. We find that the construction of the run plan (the specific energies for collider operation, the mix of initial state electron polarization states, and the use of special e{sup -}e{sup -} runs) will depend quite sensitively on the specifics of the supersymmetry model, as the decay channels open to particular sparticles vary drastically and discontinuously as the underlying SUSY model parameters are varied. We have explored this dependence somewhat by considering two rather closely related SUSY model points. We have called for operation at a high energy to study kinematic end points, followed by runs in the vicinity of several two body production thresholds once their location is determined by the end point studies. For our benchmarks, the end point runs are capable of disentangling most sparticle states through the use of specific final states and beam polarizations. The estimated sparticle mass precisions, combined from end point and scan data, are given in Table VIII and the corresponding estimates for the mSUGRA parameters are in Table IX. The precision for the Higgs boson mass, width, cross-sections, branching ratios and couplings are given in Table X. The errors on the top quark mass and width are expected to be dominated by the systematic limits imposed by QCD non-perturbative effects. The run plan devotes at least two thirds of the accumulated luminosity near the maximum LC energy, so that the program would be sensitive to unexpected new phenomena at high mass scales. We conclude that with a 1 ab{sup -1} program, expected to take the first 6-7 years

  4. Klystron switching power supplies for the Internation Linear Collider

    SciTech Connect

    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.

  5. Design considerations for a laser-plasma linear collider

    SciTech Connect

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

    2009-01-22

    Design considerations for a next-generation electron-positron linear collider based on laser-plasma-accelerators are discussed. Several of the advantages and challenges of laser-plasma-based accelerator technology are addressed. An example of the parameters for a 1 TeV laser-plasma-based collider is presented.

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

    SciTech Connect

    Breidenbach, M.; SLD and SLC Collaborations

    1993-08-01

    The SLAC Linear Collider (SLC) is the prototype e{sup +}e{sup {minus}} 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{sub LR} will be described.

  7. Next linear collider test accelerator injector design and status

    SciTech Connect

    Yeremian, A.D.; Miller, R.H.; Wang, J.W.

    1994-08-01

    The Next Linear Collider Test Accelerator (NLCTA) being built at SLAC will integrate the new technologies of X-band accelerator structures and RF systems for the Next Linear Collider, demonstrate multibunch beam-loading energy compensation and suppression of higher-order deflecting modes, measure transverse components of the accelerating field, and measure the dark current generated by RF field emission in the accelerator Injector design and simulation results for the NLCTA injector are discussed.

  8. Beamstrahlung spectra in next generation linear colliders. Revision

    SciTech Connect

    Barklow, T.; Chen, P.; Kozanecki, W.

    1992-04-01

    For the next generation of linear colliders, the energy loss due to beamstrahlung during the collision of the e{sup +}e{sup {minus}} beams is expected to substantially influence the effective center-of-mass energy distribution of the colliding particles. In this paper, we first derive analytical formulae for the electron and photon energy spectra under multiple beamstrahlung processes, and for the e{sup +}e{sup {minus}} and {gamma}{gamma} differential luminosities. We then apply our formulation to various classes of 500 GeV e{sup +}e{sup {minus}} linear collider designs currently under study.

  9. Scaling linear colliders to 5 TeV and above

    SciTech Connect

    Wilson, P.B.

    1997-04-01

    Detailed designs exist at present for linear colliders in the 0.5-1.0 TeV center-of-mass energy range. For linear colliders driven by discrete rf sources (klystrons), the rf operating frequencies range from 1.3 GHz to 14 GHz, and the unloaded accelerating gradients from 21 MV/m to 100 MV/m. Except for the collider design at 1.3 GHz (TESLA) which uses superconducting accelerating structures, the accelerating gradients vary roughly linearly with the rf frequency. This correlation between gradient and frequency follows from the necessity to keep the ac {open_quotes}wall plug{close_quotes} power within reasonable bounds. For linear colliders at energies of 5 TeV and above, even higher accelerating gradients and rf operating frequencies will be required if both the total machine length and ac power are to be kept within reasonable limits. An rf system for a 5 TeV collider operating at 34 GHz is outlined, and it is shown that there are reasonable candidates for microwave tube sources which, together with rf pulse compression, are capable of supplying the required rf power. Some possibilities for a 15 TeV collider at 91 GHz are briefly discussed.

  10. Alternate approaches to future electron-positron linear colliders

    SciTech Connect

    Loew, G.A.

    1998-07-01

    The purpose of this article is two-fold: to review the current international status of various design approaches to the next generation of e{sup +}e{sup {minus}} linear colliders, and on the occasion of his 80th birthday, to celebrate Richard B. Neal`s many contributions to the field of linear accelerators. As it turns out, combining these two tasks is a rather natural enterprise because of Neal`s long professional involvement and insight into many of the problems and options which the international e{sup +}e{sup {minus}} linear collider community is currently studying to achieve a practical design for a future machine.

  11. Laser cooling of electron beams for linear colliders

    SciTech Connect

    Telnov, V.

    1996-10-01

    A novel method of electron beam cooling is considered which can be used for linear colliders. The electron beam is cooled during collision with focused powerful laser pulse. With reasonable laser parameters (laser flash energy about 10 J) one can decrease transverse beam emittances by a factor about 10 per one stage. The ultimate transverse emittances are much below that given by other methods. Depolarization of a beam during the cooling is about 5--15% for one stage. This method is especially useful for photon colliders and open new possibilities for e{sup +}e{sup {minus}} colliders and x-ray FEL based on high energy linacs.

  12. A Photon Collider Experiment based on SLC

    SciTech Connect

    Gronberg, J

    2003-11-01

    Technology for a photon collider experiment at a future TeV-scale linear collider has been under development for many years. The laser and optics technology has reached the point where a GeV-scale photon collider experiment is now feasible. We report on the photon-photon luminosities that would be achievable at a photon collider experiment based on a refurbished Stanford Linear Collider.

  13. Laser-plasma-based linear collider using hollow plasma channels

    NASA Astrophysics Data System (ADS)

    Schroeder, C. B.; Benedetti, C.; Esarey, E.; Leemans, W. P.

    2016-09-01

    A linear electron-positron collider based on laser-plasma accelerators using hollow plasma channels is considered. Laser propagation and energy depletion in the hollow channel is discussed, as well as the overall efficiency of the laser-plasma accelerator. Example parameters are presented for a 1-TeV and 3-TeV center-of-mass collider based on laser-plasma accelerators.

  14. The first colliders: AdA, VEP-1 and Princeton-Stanford

    NASA Astrophysics Data System (ADS)

    Shiltsev, Vladimir

    The idea of exploring collisions in the center-of-mass system to fully exploit the energy of the accelerated particles had been given serious consideration by the Norwegian engineer and inventor Rolf Wideröe, who applied for a patent on the idea in 1943 (and got the patent in 1953 [1]) after considering the kinematic advantage of keeping the center of mass at rest to produce larger momentum transfers. Describing this advantage, G. K. O'Neill, one of the collider pioneers, wrote in 1956 [2]: "... as accelerators of higher and higher energy are built, their usefulness is limited by the fact that the energy available for creating new particles is measured in the center-of-mass system of the target nucleon and the bombarding particle. In the relativistic limit, this energy rises only as the square root of the accelerator energy. However, if two particles of equal energy traveling in opposite directions could be made to collide, the available energy would be twice the whole energy of one particle ... " Therefore, no kinetic energy is wasted by the motion of the center of mass of the system, and the available reaction energy ER = 2Ebeam (while a particle with the same energy Ebeam colliding with another particle of the mass m at rest produces only ER = (2Ebeamm)1/2 in the extreme relativistic case). One can also add that the colliders are "cleaner" machines with respect to the fixed-target ones since the colliding beams do not interact with the target materials. The other advantage is that it is much easier to organize collisions of beams composed of matter-antimatter particles, like in electron-positron and proton-antiproton colliders...

  15. Novel final focus design for future linear colliders.

    PubMed

    Raimondi, P; Seryi, A

    2001-04-23

    The length, complexity, and cost of the present final focus designs for linear colliders grow very quickly with the beam energy. In this Letter, a novel final focus system is presented and compared with the one proposed for the Next Linear Collider (NLC Zeroth-Order Design Report, edited by T. O. Raubenheimer, SLAC Report No. 474, 1996). This new design has fewer optical elements and is much shorter, nonetheless achieving better chromatic properties. Moreover, the new system is more suitable for operation over a larger energy range.

  16. BEAM-BASED NON-LINEAR OPTICS CORRECTIONS IN COLLIDERS.

    SciTech Connect

    PILAT, R.; LUO, Y.; MALITSKY, N.; PTITSYN, V.

    2005-05-16

    A method has been developed to measure and correct operationally the non-linear effects of the final focusing magnets in colliders, that gives access to the effects of multi-pole errors by applying closed orbit bumps, and analyzing the resulting tune and orbit shifts. This technique has been tested and used during 4 years of RHIC (the Relativistic Heavy Ion Collider at BNL) operations. I will discuss here the theoretical basis of the method, the experimental set-up, the correction results, the present understanding of the machine model, the potential and limitations of the method itself as compared with other non-linear correction techniques.

  17. Beam dynamics verification in linacs of linear colliders

    SciTech Connect

    Seeman, J.T.

    1989-01-01

    The SLAC two-mile linac has been upgraded to accelerate high current, low emittance electron and positron beams to be used in the SLAC Linear Collider (SLC). After the upgrade was completed, extensive beam studies were made to verify that the design criteria have been met. These tests involved the measurement of emittance, beam phase space orientation, energy dispersion, trajectory oscillations, bunch length, energy spectrum and wakefields. The methods, the systems and the data cross checks are compared for the various measurements. Implications for the next linear collider are discussed. 12 refs., 13 figs., 2 tabs.

  18. Characterization of an Electromagnetic Calorimeter for the Proposed International Linear Collider

    SciTech Connect

    Frey, Merideth; /Wellesley Coll. /SLAC

    2006-09-11

    The International Linear Collider (ILC) is part of a new generation of accelerators enabling physicists to gain a deeper understanding of the fundamental components of the universe. The proposed ILC will accelerate positrons and electrons towards each other with two facing linear colliders, each twenty kilometers long. Designing and planning for the future accelerator has been undertaken as a global collaboration, with groups working on several possible detectors to be used at the ILC. The following research at the Stanford Linear Accelerator Center (SLAC) pertained to the design of an electromagnetic calorimeter. The energy and spatial resolution of the calorimeter was tested by using computer simulations for proposed detectors. In order to optimize this accuracy, different designs of the electromagnetic calorimeter were investigated along with various methods to analyze the data from the simulated detector. A low-cost calorimeter design was found to provide energy resolution comparable to more expensive designs, and new clustering algorithms offered better spatial resolution. Energy distribution and shape characteristics of electromagnetic showers were also identified to differentiate various showers in the calorimeter. With further research, a well-designed detector will enable the ILC to observe new realms of physics.

  19. Power Saving Optimization for Linear Collider Interaction Region Parameters

    SciTech Connect

    Seryi, Andrei; /SLAC

    2009-10-30

    Optimization of Interaction Region parameters of a TeV energy scale linear collider has to take into account constraints defined by phenomena such as beam-beam focusing forces, beamstrahlung radiation, and hour-glass effect. With those constraints, achieving a desired luminosity of about 2E34 would require use of e{sup +}e{sup -} beams with about 10 MW average power. Application of the 'travelling focus' regime may allow the required beam power to be reduced by at least a factor of two, helping reduce the cost of the collider, while keeping the beamstrahlung energy loss reasonably low. The technique is illustrated for the 500 GeV CM parameters of the International Linear Collider. This technique may also in principle allow recycling the e{sup +}e{sup -} beams and/or recuperation of their energy.

  20. Where do we stand on the SLC (SLAC Linear Collider)

    SciTech Connect

    Kozanecki, W.

    1989-02-01

    This paper reviews the current performance of the SLAC Linear Collider, as well as the issues, problems and prospects facing the project. A few of the original accelerator physics results achieved in the last year are described in detail. 36 refs., 12 figs., 1 tab.

  1. SLAC linear collider: the machine, the physics, and the future

    SciTech Connect

    Richter, B.

    1981-11-01

    The SLAC linear collider, in which beams of electrons and positrons are accelerated simultaneously, is described. Specifications of the proposed system are given, with calculated preditions of performance. New areas of research made possible by energies in the TeV range are discussed. (GHT)

  2. The generation and acceleration of low emittance flat beams for future linear colliders

    SciTech Connect

    Raubenheimer, T.O.

    1991-11-01

    Many future linear collider designs call for electron and positron beams with normalized rms horizontal and vertical emittances of {gamma}{epsilon}{sub x} = 3{times}10{sup {minus}6} m-rad and {gamma}{epsilon}{sub y} = 3{times}10{sup {minus}8} m-rad; these are a factor of 10 to 100 below those observed in the Stanford Linear Collider. In this dissertation, we examine the feasibility of achieving beams with these very small vertical emittances. We examine the limitations encountered during both the generation and the subsequent acceleration of such low emittance beams. We consider collective limitations, such as wakefields, space charge effects, scattering processes, and ion trapping; and also how intensity limitations, such as anomalous dispersion, betatron coupling, and pulse-to-pulse beam jitter. In general, the minimum emittance in both the generation and the acceleration stages is limited by the transverse misalignments of the accelerator components. We describe a few techniques of correcting the effect of these errors, thereby easing the alignment tolerances by over an order of magnitude. Finally, we also calculate ``fundamental`` limitations on the minimum vertical emittance; these do not constrain the current designs but may prove important in the future.

  3. The generation and acceleration of low emittance flat beams for future linear colliders

    SciTech Connect

    Raubenheimer, T.O.

    1991-11-01

    Many future linear collider designs call for electron and positron beams with normalized rms horizontal and vertical emittances of {gamma}{epsilon}{sub x} = 3{times}10{sup {minus}6} m-rad and {gamma}{epsilon}{sub y} = 3{times}10{sup {minus}8} m-rad; these are a factor of 10 to 100 below those observed in the Stanford Linear Collider. In this dissertation, we examine the feasibility of achieving beams with these very small vertical emittances. We examine the limitations encountered during both the generation and the subsequent acceleration of such low emittance beams. We consider collective limitations, such as wakefields, space charge effects, scattering processes, and ion trapping; and also how intensity limitations, such as anomalous dispersion, betatron coupling, and pulse-to-pulse beam jitter. In general, the minimum emittance in both the generation and the acceleration stages is limited by the transverse misalignments of the accelerator components. We describe a few techniques of correcting the effect of these errors, thereby easing the alignment tolerances by over an order of magnitude. Finally, we also calculate fundamental'' limitations on the minimum vertical emittance; these do not constrain the current designs but may prove important in the future.

  4. Physics considerations for laser-plasma linear colliders

    SciTech Connect

    Schroeder, Carl; Esarey, Eric; Geddes, Cameron; Benedetti, Carlo; Leemans, Wim

    2010-06-11

    Physics considerations for a next-generation linear collider based on laser-plasma accelerators are discussed. The ultra-high accelerating gradient of a laser-plasma accelerator and short laser coupling distance between accelerator stages allows for a compact linac. Two regimes of laser-plasma acceleration are discussed. The highly nonlinear regime has the advantages of higher accelerating fields and uniform focusing forces, whereas the quasi-linear regime has the advantage of symmetric accelerating properties for electrons and positrons. Scaling of various accelerator and collider parameters with respect to plasma density and laser wavelength are derived. Reduction of beamstrahlung effects implies the use of ultra-short bunches of moderate charge. The total linac length scales inversely with the square root of the plasma density, whereas the total power scales proportional to the square root of the density. A 1 TeV center-of-mass collider based on stages using a plasma density of 10{sup 17} cm{sup -3} requires tens of J of laser energy per stage (using 1 {micro}m wavelength lasers) with tens of kHz repetition rate. Coulomb scattering and synchrotron radiation are examined and found not to significantly degrade beam quality. A photon collider based on laser-plasma accelerated beams is also considered. The requirements for the scattering laser energy are comparable to those of a single laser-plasma accelerator stage.

  5. A damping ring design for the SLAC Next Linear Collider

    SciTech Connect

    Raubenheimer, T.O.; Byrd, J.; Corlett, J.

    1995-05-01

    In this paper, we describe the design of the main damping rings and the positron pre-damping ring for the SLAC Next Linear Collider, a future linear collider with a center-of-mass energy of 0.5 to 1.5 TeV. The rings will operate at an energy of 2 GeV with a maximum repetition rate of 180 Hz. The normalized extracted beam emittances are {gamma}{epsilon}{sub x} = 3 mm-mrad and {gamma}{epsilon}{sub y} = 0.03 mm-mrad. To provide the necessary damping, the rings must damp multiple trains of bunches. Thus, the beam current is large, roughly 1 A. We will present the optical layout, magnet designs, and RF systems, along with the dynamic aperture and required alignment tolerances; collective effects will be discussed in another paper.

  6. Some Alignment Considerations for the Next Linear Collider

    SciTech Connect

    Ruland, R

    2004-06-08

    Next Linear Collider type accelerators require a new level of alignment quality. The relative alignment of these machines is to be maintained in an error envelope dimensioned in micrometers and for certain parts in nanometers. In the nanometer domain our terra firma cannot be considered monolithic but compares closer to jelly. Since conventional optical alignment methods cannot deal with the dynamics and cannot approach the level of accuracy, special alignment and monitoring techniques must be pursued.

  7. Single bunch beam measurements for the proposed SLAC linear collider

    SciTech Connect

    Clendenin, J.E.; Loew, G.A.; Miller, R.H.; Pellegrin, J.L.; Truher, J.B.

    1981-02-01

    Single S-band bunches of approx. 10/sup 9/ electrons have been used to study the characteristics of the SLAC linac in anticipation of its operation as a linear collider. Emittance measurements have been made, the longitudinal charge distribution within single bunches has been determined and transverse emittance growth has been produced by deliberately missteering the beam. New equipment is being installed and checked out, and the sensitivity of new traveling-wave beam position monitors has been measured.

  8. Radiation Safety System of the B-Factory at the Stanford Linear Accelerator Center

    SciTech Connect

    Liu, James C.

    1998-10-12

    The radiation safety system (RSS) of the B-Factory accelerator facility at the Stanford Linear Accelerator Center (SLAC) is described. The RSS, which is designed to protect people from prompt radiation exposure due to beam operation, consists of the access control system (ACS) and the radiation containment system (RCS). The ACS prevents people from being exposed to the very high radiation levels inside a beamline shielding housing. The ACS consists of barriers, a standard entry module at every entrance, and beam stoppers. The RCS prevents people from being exposed to the radiation outside a shielding housing, due to either normal or abnormal operation. The RCS consists of power limiting devices, shielding, dump/collimator, and an active radiation monitor system. The inter-related system elements for the ACS and RCS, as well as the associated interlock network, are described. The policies and practices in setting up the RSS are also compared with the regulatory requirements.

  9. LINEAR COLLIDER PHYSICS RESOURCE BOOK FOR SNOWMASS 2001.

    SciTech Connect

    ABE,T.; DAWSON,S.; HEINEMEYER,S.; MARCIANO,W.; PAIGE,F.; TURCOT,A.S.; ET AL

    2001-05-03

    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 {minus}} 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 {minus}} 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 {minus}} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup {minus}} experiments can provide.

  10. Physics and technology of the next linear collider

    SciTech Connect

    1996-06-01

    The authors present the prospects for the next generation of high-energy physics experiments with electron-positron colliding beams. This report summarizes the current status of the design and technological basis of a linear collider of center-of-mass energy 0.5--1.5 TeV, and the opportunities for high-energy physics experiments that this machine is expected to open. The physics goals discussed here are: Standard Model processes and simulation; top quark physics; Higgs boson searches and properties; supersymmetry; anomalous gauge boson couplings; strong WW scattering; new gauge bosons and exotic particles; e{sup {minus}}e{sup {minus}}, e{sup {minus}}{gamma}, and {gamma}{gamma} interactions; and precision tests of QCD.

  11. RF properties of periodic accelerating structures for linear colliders

    SciTech Connect

    Wang, J.W.

    1989-07-01

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

  12. Approaches to Beam Stabilization in X-Band Linear Colliders

    SciTech Connect

    Frisch, Josef; Hendrickson, Linda; Himel, Thomas; Markiewicz, Thomas; Raubenheimer, Tor; Seryi, Andrei; Burrow, Philip; Molloy, Stephen; White, Glen; /Queen Mary U. of London

    2006-09-05

    In order to stabilize the beams at the interaction point, the X-band linear collider proposes to use a combination of techniques: inter-train and intra-train beam-beam feedback, passive vibration isolation, and active vibration stabilization based on either accelerometers or laser interferometers. These systems operate in a technologically redundant fashion: simulations indicate that if one technique proves unusable in the final machine, the others will still support adequate luminosity. Experiments underway for all of these technologies have already demonstrated adequate performance.

  13. GARLIC: GAmma Reconstruction at a LInear Collider experiment

    NASA Astrophysics Data System (ADS)

    Jeans, D.; Brient, J.-C.; Reinhard, M.

    2012-06-01

    The precise measurement of hadronic jet energy is crucial to maximise the physics reach of a future Linear Collider. An important ingredient required to achieve this is the efficient identification of photons within hadronic showers. One configuration of the ILD detector concept employs a highly granular silicon-tungsten sampling calorimeter to identify and measure photons, and the GARLIC algorithm described in this paper has been developed to identify photons in such a calorimeter. We describe the algorithm and characterise its performance using events fully simulated in a model of the ILD detector.

  14. A RECIPE FOR LINEAR COLLIDER FINAL FOCUS SYSTEM DESIGN

    SciTech Connect

    Seryi, Andrei

    2003-05-27

    The design of Final Focus systems for linear colliders is challenging because of the large demagnifications needed to produce nanometer-sized beams at the interaction point. Simple first- and second-order matrix matching have proven insufficient for this task, and minimization of third- and higher-order aberrations is essential. An appropriate strategy is required for the latter to be successful. A recipe for Final Focus design, and a set of computational tools used to implement this approach, are described herein. An example of the use of this procedure is given.

  15. Staging optics considerations for a plasma wakefield acceleration linear collider

    NASA Astrophysics Data System (ADS)

    Lindstrøm, C. A.; Adli, E.; Allen, J. M.; Delahaye, J. P.; Hogan, M. J.; Joshi, C.; Muggli, P.; Raubenheimer, T. O.; Yakimenko, V.

    2016-09-01

    Plasma wakefield acceleration offers acceleration gradients of several GeV/m, ideal for a next-generation linear collider. The beam optics requirements between plasma cells include injection and extraction of drive beams, matching the main beam beta functions into the next cell, canceling dispersion as well as constraining bunch lengthening and chromaticity. To maintain a high effective acceleration gradient, this must be accomplished in the shortest distance possible. A working example is presented, using novel methods to correct chromaticity, as well as scaling laws for a high energy regime.

  16. Tests of anomalous quartic couplings at the Next Linear Collider

    NASA Astrophysics Data System (ADS)

    Éboli, O. J. P.; Gonzalez-Garcia, M. C.; Mizukoshi, J. K.

    1998-08-01

    We analyze the potential of the Next Linear e+e- Collider to study anomalous quartic vector-boson interactions through the processes e+e--->W+W-Z and ZZZ. In the framework of SU(2)L⊗U(1)Y chiral Lagrangians, we examine all effective operators of order p4 that lead to four-gauge-boson interactions but do not induce anomalous trilinear vertices. In our analysis, we take into account the decay of the vector bosons to fermions and evaluate the efficiency in their reconstruction. We obtain the bounds that can be placed on the anomalous quartic interactions and we study the strategies to distinguish the possible couplings.

  17. Physics at the e⁺e⁻ linear collider

    SciTech Connect

    Moortgat-Picka, G.; Kronfeld, A. S.

    2015-08-14

    A comprehensive review of physics at an e⁺e⁻ linear collider in the energy range of √s = 92 GeV–3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focuses in particular on Higgs-boson, top-quark and electroweak precision physics, but also discusses several models of beyond the standard model physics such as supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analysed as well.

  18. Comparison of Tracking Codes for the International Linear Collider

    SciTech Connect

    Latina, A.; Schulte, D.; Smith, J.C.; Poirier, F.; Walker, N.J.; Lebrun, P.; Ranjan, K.; Kubo, K.; Tenenbaum, Peter Gregory; Eliasson, P.; /Uppsala U.

    2008-01-23

    In an effort to compare beam dynamics and create a ''benchmark'' for Dispersion Free Steering (DFS) a comparison was made between different International Linear Collider (ILC) simulation programs while performing DFS. This study consisted of three parts. Firstly, a simple betatron oscillation was tracked through each code. Secondly, a set of component misalignments and corrector settings generated from one program was read into the others to confirm similar emittance dilution. Thirdly, given the same set of component misalignments, DFS was performed independently in each program and the resulting emittance dilution was compared. Performance was found to agree exceptionally well in all three studies.

  19. Tracking studies of the Compact Linear Collider collimation system

    SciTech Connect

    Agapov, I.; Burkhardt, H.; Schulte, D.; Latina, A.; Blair, G.A.; Malton, S.; Resta-Lopez, J.; /Oxford U., JAI

    2009-08-01

    A collimation system performance study includes several types of computations performed by different codes. Optics calculations are performed with codes such as MADX, tracking studies including additional effects such as wakefields, halo and tail generation, and dynamical machine alignment are done with codes such as PLACET, and energy deposition can be studied with BDSIM. More detailed studies of hadron production in the beam halo interaction with collimators are better performed with GEANT4 and FLUKA. A procedure has been developed that allows one to perform a single tracking study using several codes simultaneously. In this paper we study the performance of the Compact Linear Collider collimation system using such a procedure.

  20. The Optimized Bunch Compressor for the International Linear Collider

    SciTech Connect

    Seletskiy, S.; Tenenbaum, P.; /SLAC

    2007-07-06

    The International Linear Collider (ILC) utilizes a two stage Bunch Compressor (BC) that compresses the RMS bunch length from 9 mm to 200 to 300 micrometers before sending the electron beam to the Main Linac. This paper reports on the new design of the optimized BC wiggler. It was reduced in length by more than 30%. The introduction of nonzero dispersion slope in the BC wigglers enabled them to generate the required compression while having a small SR emittance growth, a tunability range of over a factor of 2 in each wiggler, and less than 3% RMS energy spread throughout the entire system.

  1. Multi-Stage Bunch Compressors for the International Linear Collider

    SciTech Connect

    Tenenbaum, P.; Raubenheimer, T.O.; Wolski, A.; /LBL, Berkeley

    2005-05-27

    We present bunch compressor designs for the International Linear Collider (ILC) which achieve a reduction in RMS bunch length from 6 mm to 0.3 mm via multiple stages of compression, with stages of acceleration inserted between the stages of compression. The key advantage of multi-stage compression is that the maximum RMS energy spread is reduced to approximately 1%, compared to over 3% for a single-stage design. Analytic and simulation studies of the multi-stage bunch compressors are presented, along with performance comparisons to a single-stage system. Parameters for extending the systems to a larger total compression factor are discussed.

  2. Linear accelerators for TeV colliders. Revision

    SciTech Connect

    Wilson, P.B.

    1985-10-01

    The basic scaling relations for important linear collider design parameters are introduced. Some of the basic concepts concerning the design of accelerating structures are presented, and breakdown limitations are discussed. Rf power sources are considered. Some of the key concepts of wakefield accelerators are discussed, and some examples of wake fields for typical linac structures are presented. Some general concepts concerning emittance, and the limitations on the emittance that can be obtained from linac guns and damping rings are discussed. 49 refs., 15 figs. (LEW)

  3. Periodic permanent magnet development for linear collider X-band klystrons

    NASA Astrophysics Data System (ADS)

    Sprehn, D.; Caryotakis, G.; Jongewaard, E.; Phillips, R.

    1999-05-01

    The Stanford Linear Accelerator Center (SLAC) klystron group is currently designing, fabricating and testing 11.424 GHz klystrons with peak output powers from 50 to 75 MW at 1 to 2 μs rf pulsewidths as part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). In order to eliminate the projected operational-year energy bill for klystron solenoids, Periodic Permanent Magnet (PPM) focusing has been employed on our latest X-band klystron designs. A PPM beam tester has operated at the same repetition rate, voltage and average beam power required for a 75-MW NLC klystron. Prototype 50 and 75-MW PPM klystrons were built and tested during 1996 and 1997 which operate from 50 to 70 MW at efficiencies greater than 55%. Construction and testing of 75-MW research klystrons will continue while the design and reliability is perfected. This paper will discuss the design of these PPM klystrons and the results of testing to date along with future plans for the development of a low-cost Design for Manufacture (DFM) 75-MW klystron and invitation for industry participation.

  4. Periodic permanent magnet development for linear collider x-band klystrons

    SciTech Connect

    Sprehn, D.; Caryotakis, G.; Jongewaard, E.; Phillips, R.M.

    1998-09-01

    The Stanford Linear Accelerator Center (SLAC) klystron group is currently designing, fabricating and testing 11.424 GHz klystrons with peak output powers from 50 to 75 MW at 1 to 2 {micro}s rf pulsewidths as part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). In order to eliminate the projected operational-year energy bill for klystron solenoids, Periodic Permanent Magnet (PPM) focusing has been employed on the latest X-band klystron designs. A PPM beam tester has operated at the same repetition rate, voltage and average beam power required for a 75 MW NLC klystron. Prototype 50 and 75 MW PPM klystrons were built and tested during 1996 and 1997 which operate from 50 to 70 MW at efficiencies greater than 55%. Construction and testing of 75 MW research klystrons will continue while the design and reliability is perfected. This paper discusses the design of these PPM klystrons and the results of testing to date along with future plans for the development of a low-cost Design for Manufacture (DFM) 75 MW klystron and invitation for industry participation.

  5. Fourth standard model family neutrino at future linear colliders

    SciTech Connect

    Ciftci, A.K.; Ciftci, R.; Sultansoy, S.

    2005-09-01

    It is known that flavor democracy favors the existence of the fourth standard model (SM) family. In order to give nonzero masses for the first three-family fermions flavor democracy has to be slightly broken. A parametrization for democracy breaking, which gives the correct values for fundamental fermion masses and, at the same time, predicts quark and lepton Cabibbo-Kobayashi-Maskawa (CKM) matrices in a good agreement with the experimental data, is proposed. The pair productions of the fourth SM family Dirac ({nu}{sub 4}) and Majorana (N{sub 1}) neutrinos at future linear colliders with {radical}(s)=500 GeV, 1 TeV, and 3 TeV are considered. The cross section for the process e{sup +}e{sup -}{yields}{nu}{sub 4}{nu}{sub 4}(N{sub 1}N{sub 1}) and the branching ratios for possible decay modes of the both neutrinos are determined. The decays of the fourth family neutrinos into muon channels ({nu}{sub 4}(N{sub 1}){yields}{mu}{sup {+-}}W{sup {+-}}) provide cleanest signature at e{sup +}e{sup -} colliders. Meanwhile, in our parametrization this channel is dominant. W bosons produced in decays of the fourth family neutrinos will be seen in detector as either di-jets or isolated leptons. As an example, we consider the production of 200 GeV mass fourth family neutrinos at {radical}(s)=500 GeV linear colliders by taking into account di-muon plus four jet events as signatures.

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

    SciTech Connect

    Pisano, Cristian; Boer, Daniël; Brodsky, Stanley J.; Buffing, Maarten G. A.; Mulders, Piet J.

    2013-10-01

    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 by positivity, for both charm and bottom quark pair production. The upper bounds on the asymmetries are shown to be very large depending on the transverse momentum of the heavy quarks, which is promising especially for their measurements at a possible future Electron-Ion Collider or a Large Hadron electron Collider. We also study the analogous processes and asymmetries in muon pair production as a means to probe linearly polarized photons inside unpolarized protons. For increasing invariant mass of the muon pair the asymmetries become very similar to the heavy quark pair ones. Finally, we discuss the process dependence of the results that arises due to differences in color flow and address the problem with factorization in case of proton-proton collisions.

  7. Ingot Nb based SRF technology for the International Linear Collider

    SciTech Connect

    Yamamoto, Akira; Yamanaka, Masashi; Myneni, Ganapati

    2015-12-04

    The International Linear Collider (ILC) is anticipated to be built as the next energy-frontier electron-positron colliding accelerator with a global effort in particle physics. Niobium based Superconducting Radio-Frequency (SRF) technology is required to provide beam-accelerating structure with elliptical cavity strings to linearly accelerate the electron and positron beams up to 250 GeV and to realize a center-of-mass energy of 500 GeV in collisions. The accelerator design and R&D efforts progressed, and the ILC Technical Design Report (ILC-TDR) was published in 2013. Niobium will take a critical role to generate electric field gradient with a frequency of 1.3 GHz, for accelerating the beam with the best efficiency, in energy balance, using RF superconductivity. This paper discusses a technical approach to provide Nb material (ingot) and thin disks for producing the elliptical cavity structure, with direct slicing from Nb ingot having sufficiently optimized purity and residual resistance ration (RRR) necessary for the ILC SRF cavities.

  8. The development of seismic guidelines for the Stanford Linear Accelerator Center

    SciTech Connect

    Huggins, R.

    1996-08-01

    This paper describes the development of Seismic Guidelines for the Stanford Linear Accelerator Center (SLAC). Although structures have always been built conservatively, SLAC management decided to review and update their seismic guidelines. SLAC is about mid-way between the epicenters of the 8.3 Richter magnitude 1906 San Francisco and the 7.2 Loma Prieta Earthquakes. The west end of the two mile long electron/positron particle accelerator lies a half mile from the large San Andreas Fault. Suggestions for seismic planning processes were solicited from local computer manufacturing firms, universities, and federal laboratories. A Committee of the various stakeholders in SLAC`s seismic planning retained an internationally known Seismic Planning Consultant and reviewed relevant standards and drafted Guidelines. A panel of seismic experts was convened to help define the hazard, site response spectra, probabilistic analysis of shaking, and near field effects. The Facility`s structures were assigned to seismic classes of importance, and an initial assessment of a sample of a dozen buildings conducted. This assessment resulted in emergency repairs to one structure, and provided a {open_quotes}reality basis{close_quotes} for establishing the final Guidelines and Administrative Procedures, and a program to evaluate remaining buildings, shielding walls, tunnels, and other special structures.

  9. Top Quark Anomalous Couplings at the International Linear Collider

    SciTech Connect

    Devetak, Erik; Nomerotski, Andrei; Peskin, Michael; /SLAC

    2011-08-15

    We present a study of the experimental determination of the forward-backward asymmetry in the process e{sup +}e{sup -} {yields} t{bar t} and in the subsequent t {yields} Wb decay, studied in the context of the International Linear Collider. This process probes the elementary couplings of the top quark to the photon, the Z and the W bosons at a level of precision that is difficult to achieve at hadron colliders. Measurement of the forward-backward asymmetry requires excellent b quark identification and determination of the quark charge. The study reported here is performed in the most challenging all-hadronic channel e{sup +}e{sup -} {yields} b{bar b}q{bar q}q{bar q}. It includes realistic details of the experimental environment, a full Monte Carlo simulation of the detector, based on the Silicon Detector concept, and realistic event reconstruction. The forward-backward asymmetries are determined to a precision of approximately 1% for each of two choices of beam polarization. We analyze the implications for the determination of the t{bar t}Z and Wt{bar b} couplings.

  10. The Physics Program at the International Linear Collider

    NASA Astrophysics Data System (ADS)

    Strube, Jan; International Linear Collider Physics; Detector study groups Team

    2016-03-01

    The precise exploration of all aspects of the Higgs sector is one of the key goals for future colliders at the Energy Frontier. The International Linear Collider (ILC) provides the capability for model-independent measurements of all relevant couplings of the Higgs boson to fermions and gauge bosons, including direct measurements of the Top Yukawa coupling as well as of the Higgs self-coupling. In addition, it has a discovery potential for physics beyond the Standard Model that is complementary to the LHC. This contribution will review the highlights of ILC physics in the context of a 20-year-long program. This program covers different collision energies up to 500 GeV with various beam polarizations, each contributing important aspects to the exploration of this new sector of particle physics. Beyond this initial scope of the ILC, we will also discuss the prospects of a 1 TeV upgrade, which offers complementary capabilities for the measurement of double Higgs production and the Higgs self-coupling and increases the reach of direct and indirect searches. This work is presented on behalf of the groups contributing to ILC physics and detector studies in Asia, Europe and the US.

  11. Super Strong Permanent Magnet Quadrupole for a Linear Collider

    SciTech Connect

    Mihara, Takanori

    2004-02-19

    The field strength generated by permanent magnets has been further extended by the introduction of saturated iron. A permanent magnet quadrupole (PMQ) lens with such saturated iron is one of the candidates for the final focus lens for an e{sup +}e{sup -} Linear Collider accelerator, because of its compactness and low power consumption. The first prototype of the PMQ has been fabricated and demonstrated to have an integrated strength of 28.5T with an overall length of 10 cm and a 7mm bore radius. Two drawbacks should be considered: its negative temperature coefficient of field strength and its fixed strength. A thermal compensation material is being tested to cure the first problem. The other problem may be solved by rotating sectioned magnet bricks, but that may lead to movement of the magnetic center and introduction of multipoles beyond some strict requirements.

  12. International Linear Collider-A Technical Progress Report

    SciTech Connect

    Elsen, Eckhard; Harrison, Mike; Hesla, Leah; Ross, Marc; Royole-Degieux, Perrine; Takahashi, Rika; Walker, Nicholas; Warmbein, Barbara; Yamamoto, Akira; Yokoya, Kaoru; Zhang, Min; /Beijing, Inst. High Energy Phys.

    2011-11-04

    The International Linear Collider: A Technical Progress Report marks the halfway point towards the Global Design Effort fulfilling its mandate to follow up the ILC Reference Design Report with a more optimised Technical Design Report (TDR) by the end of 2012. The TDR will be based on much of the work reported here and will contain all the elements needed to propose the ILC to collaborating governments, including a technical design and implementation plan that are realistic and have been better optimised for performance, cost and risk. We are on track to develop detailed plans for the ILC, such that once results from the Large Hadron Collider (LHC) at CERN establish the main science goals and parameters of the next machine, we will be in good position to make a strong proposal for this new major global project in particle physics. The two overriding issues for the ILC R&D programme are to demonstrate that the technical requirements for the accelerator are achievable with practical technologies, and that the ambitious physics goals can be addressed by realistic ILC detectors. This GDE interim report documents the impressive progress on the accelerator technologies that can make the ILC a reality. It highlights results of the technological demonstrations that are giving the community increased confidence that we will be ready to proceed with an ILC project following the TDR. The companion detector and physics report document likewise demonstrates how detector designs can meet the ambitious and detailed physics goals set out by the ILC Steering Committee. LHC results will likely affect the requirements for the machine design and the detectors, and we are monitoring that very closely, intending to adapt our design as those results become available.

  13. Relative Humidity in Limited Streamer Tubes for Stanford Linear Accelerator Center's BaBar Detector

    SciTech Connect

    Lang, M.I.; Convery, M.; Menges, W.; /Queen Mary, U. of London

    2005-12-15

    The BABAR Detector at the Stanford Linear Accelerator Center studies the decay of B mesons created in e{sup +}e{sup -} collisions. The outermost layer of the detector, used to detect muons and neutral hadrons created during this process, is being upgraded from Resistive Plate Chambers (RPCs) to Limited Streamer Tubes (LSTs). The standard-size LST tube consists of eight cells, where a silver-plated wire runs down the center of each. A large potential difference is placed between the wires and ground. Gas flows through a series of modules connected with tubing, typically four. LSTs must be carefully tested before installation, as it will be extremely difficult to repair any damage once installed in the detector. In the testing process, the count rate in most modules showed was stable and consistent with cosmic ray rate over an approximately 500 V operating range between 5400 to 5900 V. The count in some modules, however, was shown to unexpectedly spike near the operation point. In general, the modules through which the gas first flows did not show this problem, but those further along the gas chain were much more likely to do so. The suggestion was that this spike was due to higher humidity in the modules furthest from the fresh, dry inflowing gas, and that the water molecules in more humid modules were adversely affecting the modules' performance. This project studied the effect of humidity in the modules, using a small capacitive humidity sensor (Honeywell). The sensor provided a humidity-dependent output voltage, as well as a temperature measurement from a thermistor. A full-size hygrometer (Panametrics) was used for testing and calibrating the Honeywell sensors. First the relative humidity of the air was measured. For the full calibration, a special gas-mixing setup was used, where relative humidity of the LST gas mixture could be varied from almost dry to almost fully saturated. With the sensor calibrated, a set of sensors was used to measure humidity vs. time

  14. A CDU-based data acquisition system for the energy spectrometer at the Stanford Linear Collider

    SciTech Connect

    Briggs, D.D.; Tinsman, J.E.; Rouse, F.; von Zanthier, C.

    1988-10-01

    We describe a system using the Calorimetry Data Unit (a 32-channel multisample analog integrated circuit) to read out the charge ejected by secondary emission of a synchrotron beam from wires lying in its path. The wires comprise the Wire-Imaging Synchrotron Radiation Detector (WISRD) in the SLC Extraction-Line Spectrometer. The primary module in the system is a board containing 24 channels of charge sensitive amplification, shaping, sampling, multiplexing and digitization. This board also provides a fast analog measure of the charge distribution across the wires. We discuss the design and performance of this system. 4 refs., 5 figs.

  15. Saw-tooth instability studies in the Stanford Linear Collider damping rings

    SciTech Connect

    Podobedov, B.V.; Siemann, R.H.

    1997-05-01

    Experimental results of the instability studies are being reported. The system built gives a BPM-derived single bunch `instability signal`. The signal was recorded simultaneously with the longitudinal density bunch profiles obtained from the synchrotron light with the high resolution Hamamatsu streak camera. Correlation of the instability signal with the streak camera profiles has been found. For the strongly developed instability state the dominant mode structure was obtained.

  16. General, database-driven fast-feedback system for the Stanford Linear Collider

    SciTech Connect

    Rouse, F.; Allison, S.; Castillo, S.; Gromme, T.; Hall, B.; Hendrickson, L.; Himel, T.; Krauter, K.; Sass, B.' Shoaee, H.

    1991-05-01

    A new feedback system has been developed for stabilizing the SLC beams at many locations. The feedback loops are designed to sample and correct at the 60 Hz repetition rate of the accelerator. Each loop can be distributed across several of the standard 80386 microprocessors which control the SLC hardware. A new communications system, KISNet, has been implemented to pass signals between the microprocessors at this rate. The software is written in a general fashion using the state space formalism of digital control theory. This allows a new loop to be implemented by just setting up the online database and perhaps installing a communications link. 3 refs., 4 figs.

  17. Beam parametr measurements for the SLAC linear collider

    SciTech Connect

    Clendenin, J.E.; Blocker, C.; Breidenbach, M.

    1981-01-01

    A stable, closely-controlled, high-intensity, single-bunch beam will be required for the SLAC Linear Collider. The characteristics of short-pulse, low-intensity beams in the SLAC linac have been studied. A new, high-intensity thermionic gun, subharmonic buncher and S-band buncher/accelerator section were installed recently at SLAC. With these components, up to 10/sup 11/ electrons in a single S-band bunch are available for injection into the linac. the first 100-m accelerator sector has been modified to allow control of short-pulse beams by a model-driven computer program. Additional instrumentation, including a computerized energy analyzer and emittance monitor have been added at the end of the 100-m sector. The beam intensity, energy spectrum, emittance, charge distribution and the effect of wake fields in the first accelerator sector have been measured. The new source and beam control system are described and the most recent results of the beam parameter measurements are discussed.

  18. Adjustable permanent quadrupoles for the next linear collider

    SciTech Connect

    James T. Volk et al.

    2001-06-22

    The proposed Next Linear Collider (NLC) will require over 1400 adjustable quadrupoles between the main linacs' accelerator structures. These 12.7 mm bore quadrupoles will have a range of integrated strength from 0.6 to 138 Tesla, with a maximum gradient of 141 Tesla per meter, an adjustment range of +0 to {minus}20% and effective lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micron during the 20% adjustment. In an effort to reduce costs and increase reliability, several designs using hybrid permanent magnets have been developed. Four different prototypes have been built. All magnets have iron poles and use Samarium Cobalt to provide the magnetic fields. Two use rotating permanent magnetic material to vary the gradient, one uses a sliding shunt to vary the gradient and the fourth uses counter rotating magnets. Preliminary data on gradient strength, temperature stability, and magnetic center position stability are presented. These data are compared to an equivalent electromagnetic prototype.

  19. The SLC as a second generation linear collider

    SciTech Connect

    Spencer, J.E.

    1995-05-01

    With enough luminosity, the SLC could contribute to most of the high energy physics of current interest such as new hadrons, quark molecules, gluebaus and studies of the Standard Model and Minimal Supersymmetric SM in the form of particle searches for the lowest mass Higgs or selectron or tests of the point-like predictions for the W, Z or {tilde e}{sub R}. Some experiments require alternative incident channels such as e{gamma} and {gamma}{gamma} but only modest increases in energy. Just as the SLC was a prototype for the NLC, it could also be a prototype for a general or {gamma} linear collider -- a GLC. Because the main problem is luminosity, we give a scaling relation based on multiple bunches per R-F pulse. We then ask what is possible for the SLC in terms of bunch and train current, emittance and energy at the IP. The results suggest a phased development with the Higgs as a possible last step requiring a luminosity L{ge}10{sup 32}.

  20. Characterization of the International Linear Collider damping ring optics

    NASA Astrophysics Data System (ADS)

    Shanks, J.; Rubin, D. L.; Sagan, D.

    2014-10-01

    A method is presented for characterizing the emittance dilution and dynamic aperture for an arbitrary closed lattice that includes guide field magnet errors, multipole errors and misalignments. This method, developed and tested at the Cornell Electron Storage Ring Test Accelerator (CesrTA), has been applied to the damping ring lattice for the International Linear Collider (ILC). The effectiveness of beam based emittance tuning is limited by beam position monitor (BPM) measurement errors, number of corrector magnets and their placement, and correction algorithm. The specifications for damping ring magnet alignment, multipole errors, number of BPMs, and precision in BPM measurements are shown to be consistent with the required emittances and dynamic aperture. The methodology is then used to determine the minimum number of position monitors that is required to achieve the emittance targets, and how that minimum depends on the location of the BPMs. Similarly, the maximum tolerable multipole errors are evaluated. Finally, the robustness of each BPM configuration with respect to random failures is explored.

  1. Acclerator R&D for a Linear Collider

    SciTech Connect

    Rubin, D.L.; Dugan, G.; Gibbons, L.; Palmer, M.; Patterson, R.; Sagan, D.; Smith, J.C.; Tenenbaum, P.; Woodley, M.; Fields, J.; Urban, J.

    2008-11-26

    The goal of this project was to perform simulations of beam transport in linear colliders, with an emphasis on emittance dilution, spin polarization transport, and development and testing of beam based tuning algorithms. Our simulations are based on an existing object-oriented particle-tracking library, Bmad. To facilitate the efficient development of simulations, an accelerator design and analysis program based on Bmad has been developed called Tao (Tool for Accelerator Optics). The three beam-based alignment algorithms, Dispersion Free Steering, Ballistic Alignment (BA), and the Kubo Method have been implemented in Tao. We have studied the effects of magnet misalignments, BPM resolution, beam jitter, stray fields, BPM and steering magnet failure and the effects of various cavity shape wakefields. A parametric study has been conducted in the presence of the above types of errors for all three alignment algorithms. We find that BPM resolution has only modest impact on the effectiveness of beam based alignment. The DFS correction algorithm was found to be very robust in situations where there were BPM and/or steering magnet failures. The wakefields in the main linac are very weak and cause negligible emittance growth. Spin tracking was extended to study all accelerator components between the damping ring and the interaction point, including RF cavities and the helical undulator. We find that there is no significant depolarization in the RTML, main linac or beam delivery system and that the polarization is relatively insensitive to misalignment. We have developed an effective spin rotator. During the final year of the grant we exploited the computing power of our new linux cluster, along with the modeling codes that we had developed, to investigate damping ring physics and design, specifically as it relates to the CESR Test Accelerator project.

  2. Free Electron Laser for Gamma-Gamma Collider at a Low-Energy Option of International Linear Collider

    SciTech Connect

    Saldin, Evgeny; Schneidmiller, Evgeny; Yurkov, Mikhail; Seryi, Andrei; /SLAC

    2009-10-30

    Different scenarios of a start-up with International Linear Collider (ILC) are under discussion at the moment in the framework of the Global Design Effort (GDE). One of them assumes construction of the ILC in stages from some minimum CM energy up to final target of 500 GeV CM energy. Gamma-gamma collider with CM energy of 180GeV is considered as a candidate for the first stage of the facility. In this report we present conceptual design of a free electron laser as a source of primary photons for the first stage of ILC.

  3. Science and Technology of the TESLA Electron-Positron Linear Collider

    NASA Astrophysics Data System (ADS)

    Wagner, Albrecht

    2002-07-01

    Recent analyses of the long term future of particles physics in Asia, Europe, and the U.S.A. have led to the consensus that the next major facility to be built to unravel the secrets of the micro-cosmos is an electron-positron linear collider in the energy range of 500 to 1000 GeV. This collider should be constructed in an as timely fashion as possible to overlap with the Large Hadron Collider, under construction at CERN. Here, the scientific potential and the technological aspects of the TESLA projects, a superconducting collider with an integrated X-ray laser laboratory, are summarised.

  4. New drift chamber for the Mark II detector at the SLAC Linear Collider

    SciTech Connect

    Burchat, P.R.; Hanson, G.G.; Sadrozinski, H.F.W.

    1984-10-01

    The design of the new cylindrical drift chamber for the Mark II detector at the SLAC Linear Collider is described. Prototype tests to determine the working parameters of the chamber and to study possible gas mixtures are discussed.

  5. Final Environmental Assessment for the construction and operation of an office building at the Stanford Linear Accelerator Center. Part 2

    SciTech Connect

    1995-08-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-1107, analyzing the environmental effects relating to the construction and operation of an office building at the Stanford Linear Accelerator Center (SLAC). SLAC is a national facility operated by Stanford University, California, under contract with DOE. The center is dedicated to research in elementary particle physics and in those fields that make use of its synchrotron facilities. The objective for the construction and operation of an office building is to provide adequate office space for existing SLAC Waste Management (WM) personnel, so as to centralize WM personnel and to make WM operations more efficient and effective. Based on the analyses in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required. This report contains the Environmental Assessment, as well as the Finding of No Significant Impact (FONSI).

  6. Millimeter-wave drivers for future linear colliders

    SciTech Connect

    Whittum, D.H.

    1998-04-01

    The challenges for high-gradient mm-wave drive colliders are reviewed. Requirements on power sources are examined, and a particular tube is considered for illustration. Research topics relevant to a compact 1 GeV linac are noted throughout.

  7. Of Linear Colliders, the GDE Workshop at Bangalore, Mughals, Camels, Elephants and Sundials

    SciTech Connect

    Loew, Greg

    2006-04-17

    In this colloquium, the speaker will give a summary of the recent International Linear Collider (ILC) Global Design Effort (GDE) Workshop at Bangalore and how the High Energy Physics community converged to this meeting after many years of electron-positron linear collider design and experimental work. Given that this workshop for the first time took place in India, the speaker will also show a few pictures and talk briefly about what he learned in that fascinating country.

  8. Vibration Stabilization of a Mechanical Model of a X-Band Linear Collider Final Focus Magnet

    SciTech Connect

    Frisch, Josef; Chang, Allison; Decker, Valentin; Doyle, Eric; Eriksson, Leif; Hendrickson, Linda; Himel, Thomas; Markiewicz, Thomas; Partridge, Richard; Seryi, Andrei; /SLAC

    2006-09-28

    The small beam sizes at the interaction point of a X-band linear collider require mechanical stabilization of the final focus magnets at the nanometer level. While passive systems provide adequate performance at many potential sites, active mechanical stabilization is useful if the natural or cultural ground vibration is higher than expected. A mechanical model of a room temperature linear collider final focus magnet has been constructed and actively stabilized with an accelerometer based system.

  9. Quantum suppression of beamstrahlung for future e+e- linear colliders

    SciTech Connect

    Xie, Ming

    1998-05-01

    Beamstrahlung at interaction point may present severe limitations on linear collider performance. The approach to reduce this effect adopted for all current designs at a center-of-mass energy of 0.5 TeV will become more difficult and less effective at higher energy. We discuss the feasibility of an alternative approach, based on an effect known as quantum suppression of beamstrahlung, for future linear colliders at multi-TeV energy.

  10. Transverse wakefield control and feedback in the SLC (SLAC Linear Collider) linear

    SciTech Connect

    Seeman, J.T.; Campisi, I.E.; Herrmannsfeldt, W.; Lee, M.; Petersen, A.; Phinney, N.; Ross, M.; Abrams, G.S.; Adolphsen, C.; Soderstrom, E.

    1987-01-01

    Transverse wakefields in the linac of the SLAC Linear Collider (SLC) have been observed to enlarge the effective emittance of beams which are not properly centered in the accelerating structure. A fast feedback system has been constructed to minimize the enlargement under changing conditions by controlling the beam launching parameters. Theoretical aspects of this transverse feedback system are reviewed as well as the design of the beam sensors, launch controllers, communication equipment and data processing micro-computer. A variety of beam observations have been made. They show that dispersion as well as wakefield effects are important. In the near future the fast transverse feedback system will be beam tested, and algorithms tailored to the noise environment of the SLC will be tried.

  11. Upgrading the Digital Electronics of the PEP-II Bunch Current Monitors at the Stanford Linear Accelerator Center

    SciTech Connect

    Kline, Josh; /SLAC

    2006-08-28

    The testing of the upgrade prototype for the bunch current monitors (BCMs) in the PEP-II storage rings at the Stanford Linear Accelerator Center (SLAC) is the topic of this paper. Bunch current monitors are used to measure the charge in the electron/positron bunches traveling in particle storage rings. The BCMs in the PEP-II storage rings need to be upgraded because components of the current system have failed and are known to be failure prone with age, and several of the integrated chips are no longer produced making repairs difficult if not impossible. The main upgrade is replacing twelve old (1995) field programmable gate arrays (FPGAs) with a single Virtex II FPGA. The prototype was tested using computer synthesis tools, a commercial signal generator, and a fast pulse generator.

  12. To study the emittance dilution in Superconducting Linear Accelerator Design for International Linear Collider (ILC)

    NASA Astrophysics Data System (ADS)

    Ranjan, Kirti; Solyak, Nikolay; Tenenbaum, Peter

    2005-04-01

    Recently the particle physics community has chosen a single technology for the new accelerator, opening the way for the world community to unite and concentrate resources on the design of an International Linear collider (ILC) using superconducting technology. One of the key operational issues in the design of the ILC will be the preservation of the small beam emittances during passage through the main linear accelerator (linac). Sources of emittance dilution include incoherent misalignments of the quadrupole magnets and rf-structure misalignments. In this work, the study of emittance dilution for the 500-GeV center of mass energy main linac of the Superconducting Linear Accelerator design, based on adaptation of the TESLA TDR design is performed using LIAR simulation program. Based on the tolerances of the present design, effect of two important Beam-Based steering algorithms, Flat Steering and Dispersion Free Steering, are compared with respect to the emittance dilution in the main linac. We also investigated the effect of various misalignments on the emittance dilution for these two steering algorithms.

  13. Progress with the JLC/NLC X-Band Linear Collider Design

    NASA Astrophysics Data System (ADS)

    Raubenheimer, T. O.

    An electron/positron linear collider with a center-of-mass energy between 0.5 and 1 TeV would be an important complement to the physics program of the LHC in the next decade. The Next Linear Collider (NLC) is being designed by a US collaboration (FNAL, LBNL, LLNL, and SLAC) which is working closely with the Japanese collaboration that is designing the Japanese Linear Collider (JLC). This paper will discuss the technical difficulties encountered as well as the changes that have been made to the NLC design over the last year. These changes include improvements to the X-band rf system as well as modifications to the beam delivery system. The net effect has been to reduce the length of the collider from about 32 km to 25 km and to reduce the number of klystrons and modulators by a factor of two. Together these lead to significant cost savings.

  14. Detectors for Linear Colliders: Calorimetry at a Future Electron-Positron Collider (3/4)

    ScienceCinema

    None

    2016-07-12

    Calorimetry will play a central role in determining the physics reach at a future e+e- collider. The requirements for calorimetry place the emphasis on achieving an excellent jet energy resolution. The currently favoured option for calorimetry at a future e+e- collider is the concept of high granularity particle flow calorimetry. Here granularity and a high pattern recognition capability is more important than the single particle calorimetric response. In this lecture I will describe the recent progress in understanding the reach of high granularity particle flow calorimetry and the related R&D; efforts which concentrate on test beam demonstrations of the technological options for highly granular calorimeters. I will also discuss alternatives to particle flow, for example the technique of dual readout calorimetry.

  15. Detectors for Linear Colliders: Calorimetry at a Future Electron-Positron Collider (3/4)

    SciTech Connect

    2010-02-17

    Calorimetry will play a central role in determining the physics reach at a future e+e- collider. The requirements for calorimetry place the emphasis on achieving an excellent jet energy resolution. The currently favoured option for calorimetry at a future e+e- collider is the concept of high granularity particle flow calorimetry. Here granularity and a high pattern recognition capability is more important than the single particle calorimetric response. In this lecture I will describe the recent progress in understanding the reach of high granularity particle flow calorimetry and the related R&D; efforts which concentrate on test beam demonstrations of the technological options for highly granular calorimeters. I will also discuss alternatives to particle flow, for example the technique of dual readout calorimetry.

  16. A Laser-Driven Linear Collider: Sample Machine Parameters and Configuration

    SciTech Connect

    Colby, E.R.; England, R.J.; Noble, R.J.; /SLAC

    2011-05-20

    We present a design concept for an e{sup +}e{sup -} linear collider based on laser-driven dielectric accelerator structures, and discuss technical issues that must be addressed to realize such a concept. With a pulse structure that is quasi-CW, dielectric laser accelerators potentially offer reduced beamstrahlung and pair production, reduced event pileup, and much cleaner environment for high energy physics and. For multi-TeV colliders, these advantages become significant.

  17. Production of high intensity electron bunches for the SLAC Linear Collider

    SciTech Connect

    James, M.B.

    1987-08-01

    This thesis describes the design and performance of a high intensity electron injecfor for the SLAC Linear Collider. Motivation for the collider and the specifications for the injector are discussed. An analytic theory of the bunching and capture of electrons by rf fields is discussed in the limit of low space charge and small signal. The design and performance of SLAC's main injector are described to illustrate a successful application of this theory. The bunching and capture of electrons by rf fields are then discussed in the limit of high space charge and large signal, and a description of the design of the collider injector follows. In the limit of high space charge forces and large rf signals, the beam dynamics are considerably more complex and numerical simulations are required to predict particle motion. A computer code which models the longitudinal dynamics of electrons in the presence of space charge and rf fields is described. The results of the simulations, the resulting collider injector design and the various components which make up the collider injector are described. These include the gun, subharmonic bunchers, traveling-wave buncher and velocity-of-light accelerator section. Finally, the performance of the injector is described including the beam intensity, bunch length, transverse emittance and energy spectrum. While the final operating conditions differ somewaht from the design, the performance of the collider injector is in good agreement with the numerical simulations and meets all of the collider specifications. 28 refs.

  18. Application of local area networks to accelerator control systems at the Stanford Linear Accelerator

    SciTech Connect

    Fox, J.D.; Linstadt, E.; Melen, R.

    1983-03-01

    The history and current status of SLAC's SDLC networks for distributed accelerator control systems are discussed. These local area networks have been used for instrumentation and control of the linear accelerator. Network topologies, protocols, physical links, and logical interconnections are discussed for specific applications in distributed data acquisition and control system, computer networks and accelerator operations.

  19. Tests of the FONT3 Linear Collider Intra-Train Beam Feedback System at the ATF

    SciTech Connect

    Burrows, P.N.; Christian, G.; Clarke, C.; Hartin, A.; Dabiri Khah, H.; Molloy, S.; White, G.R.; Frisch, J.C.; Markiewicz, T.W.; McCormick, D.J.; Ross, M.C.; Smith, S.; Smith, T.J.; Kalinin, A.; Perry, C.; /Oxford Instruments

    2006-03-14

    We report preliminary results of beam tests of the FONT3 Linear Collider intra-train position feedback system prototype at the Accelerator Test Facility at KEK. The feedback system incorporates a novel beam position monitor (BPM) processor with a latency below 5 nanoseconds, and a kicker driver amplifier with similar low latency. The 56 nanosecond-long bunchtrain in the ATF extraction line was used to test the prototype BPM processor. The achieved latency will allow a demonstration of intra-train feedback on timescales relevant even for the CLIC Linear Collider design.

  20. Development of a Non-Magnetic Inertial Sensor for Vibration Stabilization in a Linear Collider

    SciTech Connect

    Frisch, Josef; Decker, Valentin; Doyle, Eric; Hendrickson, Linda; Himel, Thomas; Markiewicz, Thomas; Seryi, Andrei; Chang, Allison; Partridge, Richard; /Brown U.

    2006-09-01

    One of the options for controlling vibration of the final focus magnets in a linear collider is to use active feedback based on accelerometers. While commercial geophysics sensors have noise performance that substantially exceeds the requirements for a linear collider, they are physically large, and cannot operate in the strong magnetic field of the detector. Conventional nonmagnetic sensors have excessive noise for this application. We report on the development of a non-magnetic inertial sensor, and on a novel commercial sensor both of which have demonstrated the required noise levels for this application.

  1. Proceedings of the international workshop on next-generation linear colliders

    SciTech Connect

    Riordan, M.

    1988-12-01

    This report contains papers on the next-generation of linear colliders. The particular areas of discussion are: parameters; beam dynamics and wakefields; damping rings and sources; rf power sources; accelerator structures; instrumentation; final focus; and review of beam-beam interaction.

  2. Higgs Coupling Measurements at a 1 TeV Linear Collider

    SciTech Connect

    Barklow, T

    2003-12-18

    Methods for extracting Higgs boson signals at a 1 TeV center-of-mass energy e{sup +}e{sup -} linear collider are described. In addition, estimates are given for the accuracy with which branching fractions can be measured for Higgs boson decays to b{bar b} WW, gg, and {gamma}{gamma}.

  3. Review of studies on conventional linear colliders in the S- and X-Band regime

    SciTech Connect

    Loew, G.A.

    1992-07-01

    This paper gives a status report on the conventional approaches to linear colliders at DESY, KEK, SLAC and INP-Protvino in the S- and X-Band regime. Critical topics are reviewed and a discussion of global issues such as future R D requirements is included.

  4. Review of studies on conventional linear colliders in the S- and X-Band regime

    SciTech Connect

    Loew, G.A.

    1992-07-01

    This paper gives a status report on the conventional approaches to linear colliders at DESY, KEK, SLAC and INP-Protvino in the S- and X-Band regime. Critical topics are reviewed and a discussion of global issues such as future R&D requirements is included.

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

    SciTech Connect

    Moortgat-Pick, G.; Abe, T.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke, J.; 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 U. /Bangalore, Indian Inst. Sci. /Gomel State Tech. U. /SLAC /DESY /Vienna U. /Daresbury /Liverpool U. /Freiburg U. /Vienna, OAW /Wurzburg U. /Fermilab /Uppsala U. /Waseda U., RISE /Warsaw U. /Bonn U. /Aachen, Tech. Hochsch. /Cornell U., Phys. Dept.

    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.

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

    SciTech Connect

    Moortgat-Pick, G.; Abe, T.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke, J.; 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 U. /Bangalore, Indian Inst. Sci. /Gomel State Tech. U. /SLAC /DESY /Vienna U. /Daresbury /Liverpool U. /Freiburg U. /Vienna, OAW /Wurzburg U. /Fermilab /Uppsala U. /Waseda U., RISE /Warsaw U. /Bonn U. /Aachen, Tech. Hochsch. /Cornell U., Phys. Dept.

    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.

  7. A Concept of Plasma Wake Field Acceleration Linear Collider (PWFA-LC)

    SciTech Connect

    Seryi, Andrei; Hogan, Mark; Pei, Shilun; Raubenheimer, Tor; Tenenbaum, Peter; Katsouleas, Tom; Huang, Chengkun; Joshi, Chan; Mori, Warren; Muggli, Patric; /Southern California U.

    2009-10-30

    Plasma Wake-Field Acceleration (PWFA) has demonstrated acceleration gradients above 50 GeV/m. Simulations have shown drive/witness bunch configurations that yield small energy spreads in the accelerated witness bunch and high energy transfer efficiency from the drive bunch to the witness bunch, ranging from 30% for a Gaussian drive bunch to 95% for a shaped longitudinal profile. These results open the opportunity for a linear collider that could be compact, efficient and more cost effective that the present microwave technologies. A concept of a PWFA-based Linear Collider (PWFA-LC) has been developed and is described in this paper. The drive beam generation and distribution, requirements on the plasma cells, and optimization of the interaction region parameters are described in detail. The R&D steps needed for further development of the concept are also outlined.

  8. Alighment and Vibration Issues in TeV Linear Collider Design

    SciTech Connect

    Fischer, G.E.; /SLAC

    2005-08-12

    The next generation of linear colliders will require alignment accuracies and stabilities of component placement at least one, perhaps two, orders of magnitude better than can be achieved by the conventional methods and procedures in practice today. The magnitudes of these component-placement tolerances for current designs of various linear collider subsystems are tabulated. In the micron range, long-term ground motion is sufficiently rapid that on-line reference and mechanical correction systems are called for. Some recent experiences with the upgraded SLAC laser alignment systems and examples of some conceivable solutions for the future are described. The so called ''girder'' problem is discussed in the light of ambient and vibratory disturbances. The importance of the quality of the underlying geology is stressed. The necessity and limitations of particle-beam-derived placement information are mentioned.

  9. Alignment and vibration issues in TeV linear collider design

    SciTech Connect

    Fischer, G.E.

    1989-07-01

    The next generation of linear colliders will require alignment accuracies and stabilities of component placement at least one, perhaps two, orders of magnitude better than can be achieved by the conventional methods and procedures in practice today. The magnitudes of these component-placement tolerances for current designs of various linear collider subsystems are tabulated. In the micron range, long-term ground motion is sufficiently rapid that on-line reference and mechanical correction systems are called for. Some recent experiences with the upgraded SLAC laser alignment systems and examples of some conceivable solutions for the future are described. The so called ''girder'' problem is discussed in the light of ambient and vibratory disturbances. The importance of the quality of the underlying geology is stressed. The necessity and limitations of public-beam-derived placement information are mentioned. 40 refs., 4 figs., 1 tab.

  10. Neutral triple gauge boson production in the large extra dimensions model at linear colliders

    NASA Astrophysics Data System (ADS)

    Hao, Sun; Ya-Jin, Zhou

    2012-10-01

    We consider the neutral triple-gauge boson production process in the context of large extra dimensions (LED) models including the Kaluza-Klein (KK) excited gravitons at future linear colliders, say ILC(CLIC). We consider γγγ, γγZ, γZZ, and ZZZ production processes, and analyze their impacts on both the total cross section and some key distributions. These processes are important for new physics searches at linear colliders. Our results show that KK graviton exchange has the most significant effect on e-e+→γZZ among the four processes with relatively small MS, while it has the largest effect on e-e+→γγγ with larger MS. By using the neutral triple-gauge boson production we could set the discovery limit on the fundamental Plank scale MS up to around 6-9 TeV for δ=4 at the 3 TeV CLIC.

  11. Design of the beam delivery system for the international linear collider.

    SciTech Connect

    Seryi, A.; Amann, J.; Arnold, R.; Asiri, F.; Bane, K.; Carwardine, J.; Saunders, C.; Accelerator Systems Division; SLAC; FNAL

    2008-01-01

    The beam delivery system for the linear collider focuses beams to nanometer sizes at its interaction point, collimates the beam halo to provide acceptable background in the detector and has a provision for state-of-the art beam instrumentation in order to reach the ILCs physics goals. This paper describes the design details and status of the baseline configuration considered for the reference design and also lists alternatives.

  12. A modified post damping ring bunch compressor beamline for the TESLA linear collider

    SciTech Connect

    Philippe R.-G. Piot; Winfried Decking

    2004-03-23

    We propose a modified bunch compressor beamline, downstream of the damping ring, for the TESLA linear collider. This modified beamline uses a third harmonic radio-frequency section based on the 3.9 GHz superconducting cavity under development at Fermilab. In our design the beam deceleration is about {approx}50 MeV instead of {approx}450 MeV in the original design proposed.

  13. Electroweak corrections to W+W-Z and ZZZ production at the linear collider

    NASA Astrophysics Data System (ADS)

    Boudjema, F.; Le, D. N.; Sun, H.; Weber, M. M.

    2010-07-01

    We calculate the electroweak corrections to the production of WWZ and ZZZ at the linear collider in the Standard Model. These processes are important for the extraction of the quartic couplings of the massive gauge bosons which can be a window on the mechanism of spontaneous symmetry breaking. We find that the weak corrections to some kinematic distributions show new features and hence cannot be explained by an overall scale factor.

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

    SciTech Connect

    Brau, James E

    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.

  15. Emittance Preservation in the International Linear Collider Ring to Main Linac Transfer Line

    SciTech Connect

    Tenenbaum, P.; Latina, A.; Smith, J.C.; Kubo, K.; /KEK, Tsukuba

    2007-06-27

    The very small vertical beam emittance in the International Linear Collider (ILC) can be degraded by dispersion, xy coupling, transverse wakefields, and time-varying transverse fields introduced by elements with misalignments, strength errors, xy rotation errors, or yz rotation errors in the Ring to Main Linac (RTML) transfer line. We present a plan for emittance preservation in this beamline which uses local, quasi-local, and global correction schemes. Results of simulations of the emittance preservation algorithm are also presented and discussed.

  16. Simulator For The Linear Collider (SLIC): A Tool For ILC Detector Simulations

    NASA Astrophysics Data System (ADS)

    Graf, Norman; McCormick, Jeremy

    2006-10-01

    The Simulator for the Linear Collider (SLIC) is a detector simulation program based on the GEANT4 toolkit. It is intended to enable end users to easily model detector concepts by providing the ability to fully describe detectors using plain text files read in by a common executable at runtime. The detector geometry, typically the most complex part of a detector simulation, is described at runtime using the Linear Collider Detector Description (LCDD). This system allows end users to create complex detector geometries in a standard XML format rather than procedural code such as C++. The LCDD system is based on the Geometry Description Markup Language (GDML) from the LHC Applications Group (LCG). The geometry system facilitates the study of different full detector design and their variations. SLIC uses the StdHep format to read input created by event generators and outputs events in the Linear Collider IO (LCIO) format. The SLIC package provides a binding to GEANT4 and many additional commands and features for the end user.

  17. Simulator for the Linear Collider (SLIC): a Tool for ILC Detector Simulations

    SciTech Connect

    Graf, N.; McCormick, J.; /SLAC

    2007-02-13

    The Simulator for the Linear Collider (SLIC) is a detector simulation program based on the GEANT4 toolkit. It is intended to enable end users to easily model detector concepts by providing the ability to fully describe detectors using plain text files read in by a common executable at runtime. The detector geometry, typically the most complex part of a detector simulation, is described at runtime using the Linear Collider Detector Description (LCDD). This system allows end users to create complex detector geometries in a standard XML format rather than procedural code such as C++. The LCDD system is based on the Geometry Description Markup Language (GDML) from the LHC Applications Group (LCG). The geometry system facilitates the study of different full detector design and their variations. SLIC uses the StdHep format to read input created by event generators and outputs events in the Linear Collider IO (LCIO) format. The SLIC package provides a binding to GEANT4 and many additional commands and features for the end user.

  18. Proceedings of the workshop on new kinds of positron sources for linear colliders

    SciTech Connect

    Clendenin, J.; Nixon, R.

    1997-06-01

    It has been very clear from the beginning of studies for future linear colliders that the conventional positron source approach, as exemplified by the SLC source, is pushing uncomfortably close to the material limits of the conversion target. Nonetheless, since this type of positron source is better understood and relatively inexpensive to build, it has been incorporated into the initial design studies for the JLC/NLC. New ideas for positron sources for linear colliders have been regularly reported in the literature and at accelerator conferences for at least a decade, and indeed the recirculation scheme associated with the VLEPP design is nearly two decades old. Nearly all the new types of positron sources discussed in this workshop come under the heading of crystals (or channeling), undulators, and Compton. Storage ring and nuclear reactor sources were not discussed. The positron source designs that were discussed have varying degrees of maturity, but except for the case of crystal sources, where proof of principle experiments have been undertaken, experimental results are missing. It is hoped that these presentations, and especially the recommendations of the working groups, will prove useful to the various linear collider groups in deciding if and when new experimental programs for positron sources should be undertaken.

  19. International X-Band Linear Collider Accelerator Structure R&D

    SciTech Connect

    Wang, J.W.; /SLAC

    2009-03-04

    For more than fifteen years before the International Technology Recommendation Panel (ITRP) decision in August, 2004, there were intensive R&D activities and broad international collaboration among the groups at SLAC, KEK, FNAL, LLNL and other labs for the room temperature X-Band accelerator structures. The goal was to provide an optimized design of the main linac structure for the NLC (Next Linear Collider) or GLC (Global Linear Collider). There have been two major challenges in developing X-band accelerator structures for the linear colliders. The first is to demonstrate stable, long-term operation at the high gradient (65 MV/m) that is required to optimize the machine cost. The second is to strongly suppress the beam induced long-range wakefields, which is required to achieve high luminosity. More than thirty X-band accelerator structures with various RF parameters, cavity shapes and coupler types have been fabricated and tested since 1989. A summary of the main achievements and experiences are presented in this talk including the structure design, manufacturing techniques, high power performance, and other structure related issues. Also, the new progress in collaborating with the CLIC, high gradient structures and X-Band structure applications for RF deflectors and others are briefly introduced.

  20. Zeroth-order design report for the next linear collider. Volume 2

    SciTech Connect

    Raubenheimer, T.O.

    1996-05-01

    This Zeroth-Order Design Report (ZDR) for the Next Linear Collider (NLC) has been completed as a feasibility study for a TeV-scale linear collider that incorporates a room-temperature accelerator powered by rf microwaves at 11.424 GHz--similar to that presently used in the SLC, but at four times the rf frequency. The purpose of this study is to examine the complete systems of such a collider, to understand how the parts fit together, and to make certain that every required piece has been included. The ``design`` presented here is not fully engineered in any sense, but to be assured that the NLC can be built, attention has been given to a number of critical components and issues that present special challenges. More engineering and development of a number of mechanical and electrical systems remain to be done, but the conclusion of this study is that indeed the NLC is technically feasible and can be expected to reach the performance levels required to perform research at the TeV energy scale. Volume II covers the following: collimation systems; IP switch and big bend; final focus; the interaction region; multiple bunch issues; control systems; instrumentation; machine protection systems; NLC reliability considerations; NLC conventional facilities. Also included are four appendices on the following topics: An RF power source upgrade to the NLC; a second interaction region for gamma-gamma, gamma-electron; ground motion: theory and measurement; and beam-based feedback: theory and implementation.

  1. Expanded studies of linear collider final focus systems at the Final Focus Test Beam

    SciTech Connect

    Tenenbaum, P.G.

    1995-12-01

    In order to meet their luminosity goals, linear colliders operating in the center-of-mass energy range from 3,50 to 1,500 GeV will need to deliver beams which are as small as a few Manometers tall, with x:y aspect ratios as large as 100. The Final Focus Test Beam (FFTB) is a prototype for the final focus demanded by these colliders: its purpose is to provide demagnification equivalent to those in the future linear collider, which corresponds to a focused spot size in the FFTB of 1.7 microns (horizontal) by 60 manometers (vertical). In order to achieve the desired spot sizes, the FFTB beam optics must be tuned to eliminate aberrations and other errors, and to ensure that the optics conform to the desired final conditions and the measured initial conditions of the beam. Using a combination of incoming-beam diagnostics. beam-based local diagnostics, and global tuning algorithms, the FFTB beam size has been reduced to a stable final size of 1.7 microns by 70 manometers. In addition, the chromatic properties of the FFTB have been studied using two techniques and found to be acceptable. Descriptions of the hardware and techniques used in these studies are presented, along with results and suggestions for future research.

  2. Relativistic-Klystron two-beam accelerator as a power source for future linear colliders

    SciTech Connect

    Lidia, S. M.; Anderson, D. E.; Eylon, S.; Henestroza, E.; Vanecek, D. L.; Yu, S. S.; Houck, T. L.; Westenskow, G. A.

    1999-05-07

    The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2-kA, 1-MeV, induction gun for a prototype relativistic klystron two-beam accelerator (RK-TBA). The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150-ns flat top (1% energy variation), and a normalized edge emittance of less than 300 pi-mm-mr. The prototype accelerator will be used to study, physics, engineering, and costing issues involved in the application of the RK-TBA concept to linear colliders. We have also been studying optimization parameters, such as frequency, for the application of the RK-TBA concept to multi-TeV linear colliders. As an rf power source the RK-TBA scales favorably up to frequencies around 35 GHz. An overview of this work with details of the design and performance of the prototype injector, beam line, and diagnostics will be presented.

  3. Relativistic-Klystron two-beam accelerator as a power source for future linear colliders

    SciTech Connect

    Lidia, S.M.; Anderson, D.E.; Eylon, S.; Henestroza, E.; Vanecek, D.L.; Yu, S.S.; Westenskow, G.A.

    1999-05-01

    The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2-kA, 1-MeV, induction gun for a prototype relativistic klystron two-beam accelerator (RK-TBA). The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150-ns flat top (1{percent} energy variation), and a normalized edge emittance of less than 300 pi-mm-mr. The prototype accelerator will be used to study, physics, engineering, and costing issues involved in the application of the RK-TBA concept to linear colliders. We have also been studying optimization parameters, such as frequency, for the application of the RK-TBA concept to multi-TeV linear colliders. As an rf power source the RK-TBA scales favorably up to frequencies around 35 GHz. An overview of this work with details of the design and performance of the prototype injector, beam line, and diagnostics will be presented. {copyright} {ital 1999 American Institute of Physics.}

  4. Relativistic-klystron two-beam accelerator as a power source for future linear colliders

    SciTech Connect

    Anderson, D E; Eylon, S; Henestroza, E; Houck, T L; Lidia, M; Vanecek, D L; Westenskow, G A; Yu, S S

    1998-10-05

    The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2&A, l-MeV, induction gun for a prototype relativistic klystron two-beam accelerator (RK-TBA). The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150-ns flat top (1% energy variation), and a normalized edge emittance of less than 300 pi-mm-n-n. The prototype accelerator will be used to study physics, engineering, and costing issues involved in the application of the RK-TBA concept to linear colliders. We have also been studying optimization parameters, such as frequency, for the application of the RK-TBA concept to multi-TeV linear colliders. As an rf power source the RK-TBA scales favorably up to frequencies around 35 GHz. An overview of this work with details of the design and performance of the prototype injector, beam line, and diagnostics will be presented.

  5. Zeroth-order design report for the next linear collider. Volume 1

    SciTech Connect

    Raubenheimer, T.O.

    1996-05-01

    This Zeroth Order Design Report (ZDR) for the Next Linear Collider (NLC) has been completed as a feasibility study for a TeV-scale linear collider that incorporates a room-temperature accelerator powered by rf microwaves at 11.424 GHz--similar to that presently used in the SLC, but at four times the rf frequency. The purpose of this study is to examine the complete systems of such a collider, to understand how the parts fit together, and to make certain that every required piece has been included. The design presented here is not fully engineered in any sense, but to be assured that the NLC can be built, attention has been given to a number of critical components and issues that present special challenges. More engineering and development of a number of mechanical and electrical systems remain to be done, but the conclusion of this study is that indeed the NLC is technically feasible and can be expected to reach the performance levels required to perform research at the TeV energy scale. Volume one covers the following: the introduction; electron source; positron source; NLC damping rings; bunch compressors and prelinac; low-frequency linacs and compressors; main linacs; design and dynamics; and RF systems for main linacs.

  6. Cultural resource survey report for construction of office building, driveway, and parking lot at the Stanford Linear Accelerator Center. Part 1

    SciTech Connect

    Perry, M.E.

    1995-01-01

    An Environmental Assessment and associated documentation is reported for the construction of an office building and parking lot in support of environmental management personnel activities. As part of the documentation process, the DOE determined that the proposed project constituted an undertaking as defined in Section 106 of the National Historic Preservation Act. In accordance with the regulations implementing Section 106 of the National Historic Preservation Act, a records and literature search and historic resource identification effort were carried out on behalf of the Stanford Linear Accelerator Center (SLAC). This report summarizes cultural resource literature and record searches and a historic resource identification effort.

  7. Experimental validation of a novel compact focusing scheme for future energy-frontier linear lepton colliders.

    PubMed

    White, G R; Ainsworth, R; Akagi, T; Alabau-Gonzalvo, J; Angal-Kalinin, D; Araki, S; Aryshev, A; Bai, S; Bambade, P; Bett, D R; Blair, G; Blanch, C; Blanco, O; Blaskovic-Kraljevic, N; Bolzon, B; Boogert, S; Burrows, P N; Christian, G; Corner, L; Davis, M R; Faus-Golfe, A; Fukuda, M; Gao, J; García-Morales, H; Geffroy, N; Hayano, H; Heo, A Y; Hildreth, M; Honda, Y; Huang, J Y; Hwang, W H; Iwashita, Y; Jang, S; Jeremie, A; Kamiya, Y; Karataev, P; Kim, E S; Kim, H S; Kim, S H; Kim, Y I; Komamiya, S; Kubo, K; Kume, T; Kuroda, S; Lam, B; Lekomtsev, K; Liu, S; Lyapin, A; Marin, E; Masuzawa, M; McCormick, D; Naito, T; Nelson, J; Nevay, L J; Okugi, T; Omori, T; Oroku, M; Park, H; Park, Y J; Perry, C; Pfingstner, J; Phinney, N; Rawankar, A; Renier, Y; Resta-López, J; Ross, M; Sanuki, T; Schulte, D; Seryi, A; Shevelev, M; Shimizu, H; Snuverink, J; Spencer, C; Suehara, T; Sugahara, R; Takahashi, T; Tanaka, R; Tauchi, T; Terunuma, N; Tomás, R; Urakawa, J; Wang, D; Warden, M; Wendt, M; Wolski, A; Woodley, M; Yamaguchi, Y; Yamanaka, T; Yan, J; Yokoya, K; Zimmermann, F

    2014-01-24

    A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed in 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This scheme has many advantageous properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energy-scaled version of the compact focusing optics designed for the ILC collider.

  8. RF power sources for 5--15 TeV linear colliders

    SciTech Connect

    Wilson, P.B.

    1996-09-01

    After outlining the design of the NLC rf system at 1 TeV, the possibility of a leap in linear collider energy into the 5--15 TeV energy range is considered. To keep the active accelerator length and ac wall-plug power within reasonable bounds, higher accelerating gradients at higher rf frequencies will be necessary. Scaling relations are developed for basic rf system parameters as a function of frequency, and some specific parameter examples are given for colliders at 34 Ghz and 91 Ghz. Concepts for rf pulse compression system design and for high power microwave sources at 34 Ghz (for example sheet-beam and multiple-beam klystrons) are briefly discussed.

  9. Double Higgs production in the Two Higgs Doublet Model at the linear collider

    SciTech Connect

    Arhrib, Abdesslam; Benbrik, Rachid; Chiang, C.-W.

    2008-04-21

    We study double Higgs-strahlung production at the future Linear Collider in the framework of the Two Higgs Doublet Models through the following channels: e{sup +}e{sup -}{yields}{phi}{sub i}{phi}{sub j}Z, {phi}{sub i} = h deg., H deg., A deg. All these processes are sensitive to triple Higgs couplings. Hence observations of them provide information on the triple Higgs couplings that help reconstructing the scalar potential. We discuss also the double Higgs-strahlung e{sup +}e{sup -}{yields}h deg. h deg. Z in the decoupling limit where h deg. mimics the SM Higgs boson.

  10. Online beam energy measurement of Beijing electron positron collider II linear accelerator.

    PubMed

    Wang, S; Iqbal, M; Liu, R; Chi, Y

    2016-02-01

    This paper describes online beam energy measurement of Beijing Electron Positron Collider upgraded version II linear accelerator (linac) adequately. It presents the calculation formula, gives the error analysis in detail, discusses the realization in practice, and makes some verification. The method mentioned here measures the beam energy by acquiring the horizontal beam position with three beam position monitors (BPMs), which eliminates the effect of orbit fluctuation, and is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in this paper.

  11. Proposal of the Next Incarnation of Accelerator Test Facility at KEK for the International Linear Collider

    SciTech Connect

    Araki, S.; Hayano, H.; Higashi, Y.; Honda, Y.; Kanazawa, K.; Kubo, K.; Kume, T.; Kuriki, M.; Kuroda, S.; Masuzawa, M.; Naito, T.; Okugi, T.; Sugahara, R.; Takahashi, T.; Tauchi, T.; Terunuma, N.; Toge, N.; Urakawa, J.; Vogel, V.; Yamaoka, H.; Yokoya, K.; /KEK, Tsukuba /Beijing, Inst. High Energy Phys. /Novosibirsk, IYF /Daresbury /CERN /Hiroshima U. /Orsay, LAL /LLNL, Livermore /North Carolina A-T State U. /Oxford U. /Pohang Accelerator Lab. /Queen Mary, U. of London /Royal Holloway, U. of London /DESY /SLAC /University Coll. London /Oregon U. /Tokyo U.

    2005-05-27

    To reach design luminosity, the International Linear Collider (ILC) must be able to create and reliably maintain nanometer size beams. The ATF damping ring is the unique facility where ILC emittances are possible. In this paper we present and evaluate the proposal to create a final focus facility at the ATF which, using compact final focus optics and an ILC-like bunch train, would be capable of achieving 37 nm beam size. Such a facility would enable the development of beam diagnostics and tuning methods, as well as the training of young accelerator physicists.

  12. Online beam energy measurement of Beijing electron positron collider II linear accelerator

    NASA Astrophysics Data System (ADS)

    Wang, S.; Iqbal, M.; Liu, R.; Chi, Y.

    2016-02-01

    This paper describes online beam energy measurement of Beijing Electron Positron Collider upgraded version II linear accelerator (linac) adequately. It presents the calculation formula, gives the error analysis in detail, discusses the realization in practice, and makes some verification. The method mentioned here measures the beam energy by acquiring the horizontal beam position with three beam position monitors (BPMs), which eliminates the effect of orbit fluctuation, and is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in this paper.

  13. An FEL power source for a TeV linear collider

    SciTech Connect

    Hopkins, D.B.; Hoyer, E.H.; Halbach, K.; Sessler, A.M.; Barletta, W.A.; Jong, R.A.; Reginato, L.L.; Yu, S.S.; Bayless, J.R.; Palmer, R.B.

    1988-10-01

    In this paper we consider the design of a power source of a linear collider. We take a conservative approach and hence extrapolate as little as possible from present experience. Thus we establish a ''straw man''; i.e., a design which serves as an ''existence proof'' of a power source for a TeV collider. We take as the parameters to which the power source is designed those presented earlier by R. Palmer; namely: f = 17 GHz, W = 634 MW/m, L = 1.44m, W/sub T/ = 3.87 TW, R = 180 Hz, L/sub c/ = 7.41 km, T/sub p/ = 50 ns, where the quantity f is the desired frequency, W is the power needed per meter (for a gradient of 186 MeV/m), L is the length between feeds, W/sub T/ is the total power required, R is the rep-rate, L/sub c/ is the total length of the collider, and T/sub p/ is the rf pulse width. With no emittance dilution, this collider would produce a luminosity of 7.7 /times/ 10/sup 32/ cm/sup /minus/2/ sec/sup /minus/1/ for single bunch operation or 1.6 /times/ 10/sup 34/ cm/sup /minus/2/ sec/sup /minus/1/ for multi-bunch operating (i.e., 21 bunches). With realistic dilution and R = 386 Hz these luminosity values would be 5.0 /times/ 10/sup 32/ and 1.0 /times/ 10/sup 34/ cm/sup /minus/2/ sec/sup /minus/1/, respectively. 5 refs., 14 figs., 4 tabs.

  14. Photon Collider Physics with Real Photon Beams

    SciTech Connect

    Gronberg, J; Asztalos, S

    2005-11-03

    Photon-photon interactions have been an important probe into fundamental particle physics. Until recently, the only way to produce photon-photon collisions was parasitically in the collision of charged particles. Recent advances in short-pulse laser technology have made it possible to consider producing high intensity, tightly focused beams of real photons through Compton scattering. A linear e{sup +}e{sup -} collider could thus be transformed into a photon-photon collider with the addition of high power lasers. In this paper they show that it is possible to make a competitive photon-photon collider experiment using the currently mothballed Stanford Linear Collider. This would produce photon-photon collisions in the GeV energy range which would allow the discovery and study of exotic heavy mesons with spin states of zero and two.

  15. DCal: A custom integrated circuit for calorimetry at the International Linear Collider

    SciTech Connect

    Hoff, James R.; Mekkaoui, Abderrazek; Yarema, Ray; Drake, Gary; Repond, Jose; /Argonne

    2005-10-01

    A research and development collaboration has been started with the goal of producing a prototype hadron calorimeter section for the purpose of proving the Particle Flow Algorithm concept for the International Linear Collider. Given the unique requirements of a Particle Flow Algorithm calorimeter, custom readout electronics must be developed to service these detectors. This paper introduces the DCal or Digital Calorimetry Chip, a custom integrated circuit developed in a 0.25um CMOS process specifically for this International Linear Collider project. The DCal is capable of handling 64 channels, producing a 1-bit Digital-to-Analog conversion of the input (i.e. hit/no hit). It maintains a 24-bit timestamp and is capable of operating either in an externally triggered mode or in a self-triggered mode. Moreover, it is capable of operating either with or without a pipeline delay. Finally, in order to permit the testing of different calorimeter technologies, its analog front end is capable of servicing Particle Flow Algorithm calorimeters made from either Resistive Plate Chambers or Gaseous Electron Multipliers.

  16. High-Power Multimode X-Band RF Pulse Compression System for Future Linear Colliders

    SciTech Connect

    Tantawi, S.G.; Nantista, C.D.; Dolgashev, V.A.; Pearson, C.; Nelson, J.; Jobe, K.; Chan, J.; Fant, K.; Frisch, J.; Atkinson, D.; /LLNL, Livermore

    2005-08-10

    We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC). The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II) pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  17. High-power multimode X-band rf pulse compression system for future linear colliders

    NASA Astrophysics Data System (ADS)

    Tantawi, Sami G.; Nantista, Christopher D.; Dolgashev, Valery A.; Pearson, Chris; Nelson, Janice; Jobe, Keith; Chan, Jose; Fant, Karen; Frisch, Josef; Atkinson, Dennis

    2005-04-01

    We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC). The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II) pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  18. A prototype RF power source system for the X-band linear collider

    SciTech Connect

    Mizuno, H.

    1995-07-05

    Since 1988, R&D of the X-band klystron in KEK has been carried out, and in this R&D program the two types of the X-band klystrons has been designed and tested (REF-1,2,3). The first one is the 30MW class klystron named XB-50k. This rather moderate peak power klystron was designed as the first step to the 100MW class klystron, and in 1992, could achieve 26MW peak power successfully. This XB-50k{number_sign}1a had supplied the RF power to the first X-band accelerating structure high power test in autumn of 1992. The second klystron named XB-72k in this R&D program, was designed as the first 100MW class klystron which could fulfill the minimum power requirement for the RF power source of the X-band linac in the next generation of several hundreds GeV electron positron linear colliders. The first XB-72k{number_sign}1 was tested in 1992 and 1993, and successfully achieved the peak spring and also achieved 95MW. In order to verify the technological feasibility of the conventional klystron power system as the possible candidate of the future X-band linear collider, the prototype RF power system including the RF pulse compression scheme and the modulator is discussed. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  19. A prototype RF power source system for the X-band linear collider

    NASA Astrophysics Data System (ADS)

    Mizuno, H.

    1995-07-01

    Since 1988, R&D of the X-band klystron in KEK has been carried out, and in this R&D program the two types of the X-band klystrons has been designed and tested (REF-1,2,3). The first one is the 30MW class klystron named XB-50k. This rather moderate peak power klystron was designed as the first step to the 100MW class klystron, and in 1992, could achieve 26MW peak power successfully. This XB-50k♯1a had supplied the RF power to the first X-band accelerating structure high power test in autumn of 1992. The second klystron named XB-72k in this R&D program, was designed as the first 100MW class klystron which could fulfill the minimum power requirement for the RF power source of the X-band linac in the next generation of several hundreds GeV electron positron linear colliders. The first XB-72k♯1 was tested in 1992 and 1993, and successfully achieved the peak spring and also achieved 95MW. In order to verify the technological feasibility of the conventional klystron power system as the possible candidate of the future X-band linear collider, the prototype RF power system including the RF pulse compression scheme and the modulator is discussed.

  20. State of the art in electromagnetic modeling for the Compact Linear Collider

    SciTech Connect

    Candel, Arno; Kabel, Andreas; Lee, Lie-Quan; Li, Zenghai; Ng, Cho; Schussman, Greg; Ko, Kwok; /SLAC

    2009-07-10

    SLAC's Advanced Computations Department (ACD) has developed the parallel 3D electromagnetic time-domain code T3P for simulations of wakefields and transients in complex accelerator structures. T3P is based on state-of-the-art Finite Element methods on unstructured grids and features unconditional stability, quadratic surface approximation and up to 6th-order vector basis functions for unprecedented simulation accuracy. Optimized for large-scale parallel processing on leadership supercomputing facilities, T3P allows simulations of realistic 3D structures with fast turn-around times, aiding the design of the next generation of accelerator facilities. Applications include simulations of the proposed two-beam accelerator structures for the Compact Linear Collider (CLIC) - wakefield damping in the Power Extraction and Transfer Structure (PETS) and power transfer to the main beam accelerating structures are investigated.

  1. Adjustable Permanent Quadrupoles Using Rotating Magnet Material Rods for the Next Linear Collider

    SciTech Connect

    James T Volk et al.

    2001-09-24

    The proposed Next Linear Collider (NLC) will require over 1400 adjustable quadrupoles between the main linacs' accelerator structures. These 12.7 mm bore quadrupoles will have a range of integrated strength from 0.6 to 132 Tesla, with a maximum gradient of 135 Tesla per meter, an adjustment range of +0-20% and effective lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micrometer during the 20% adjustment. In an effort to reduce estimated costs and increase reliability, several designs using hybrid permanent magnets have been developed. All magnets have iron poles and use either Samarium Cobalt or Neodymium Iron to provide the magnetic fields. Two prototypes use rotating rods containing permanent magnetic material to vary the gradient. Gradient changes of 20% and center shifts of less than 20 microns have been measured. These data are compared to an equivalent electromagnet prototype.

  2. 50-MW X-band klystron sources for the next generation of linear colliders

    SciTech Connect

    Caryotakis, G.; Eppley, K.; Fant, K.; Fowkes, R.; Phillips, R.; Tantawi, S.; Vlieks, A.; Wright, E.

    1994-06-01

    The first in a new series of high-power pulsed klystrons has been tested with the following results: Frequency = 11.4 GHz, beam voltage = 415 kV, power output = 51 MW, pulse length = 1.5 {mu}s, and efficiency = 37%. Several tubes of this type will be used in the Next Linear Collider Test Accelerator (NLCTA) at SLAC. The rf performance of the klystron, which employs a standing-wave extended-interaction output circuit, is closely approximated by simulations performed with the SLAC CONDOR code. The same code predicts considerably higher efficiency, using a traveling-wave output circuit. A klystron with such a circuit will be constructed in the future. Another klystron is also planned in which beam confinement is accomplished by a periodic permanent magnet (PPM) stack, for which simulations also predict good performance.

  3. Experimental gyroklystron research at the University of Maryland for application to TeV linear colliders

    SciTech Connect

    Lawson, W.; Granatstein, V.L.; Hogan, B.; Koc, U.V.; Latham, P.E.; Main, W.; Matthews, H.W.; Nusinovich, G.S.; Reiser, M.; Striffler, C.D.; Tantawi, S.

    1992-12-31

    X-Band and K-Band gyroklystrons are being evaluated for possible application to future linear colliders. So far we have examined the different two- and three-cavity configurations. We have achieved a maximum peak power of 27 MW in {approximately}1 {mu}s pulses at a gain of 36 dB and an efficiency exceeding 32%. The nominal parameters include a 430 kV. 150--200 A beam with an average perpendicular to parallel velocity ratio near one. In this paper, we detail our progress to date and describe our plans for future experiments that should culminate in amplifier outputs in excess of 100 MW in 1 {mu}s pulses.

  4. Experimental gyroklystron research at the University of Maryland for application to TeV linear colliders

    SciTech Connect

    Lawson, W.; Granatstein, V.L.; Hogan, B.; Koc, U.V.; Latham, P.E.; Main, W.; Matthews, H.W.; Nusinovich, G.S.; Reiser, M.; Striffler, C.D.; Tantawi, S.

    1992-01-01

    X-Band and K-Band gyroklystrons are being evaluated for possible application to future linear colliders. So far we have examined the different two- and three-cavity configurations. We have achieved a maximum peak power of 27 MW in [approximately]1 [mu]s pulses at a gain of 36 dB and an efficiency exceeding 32%. The nominal parameters include a 430 kV. 150--200 A beam with an average perpendicular to parallel velocity ratio near one. In this paper, we detail our progress to date and describe our plans for future experiments that should culminate in amplifier outputs in excess of 100 MW in 1 [mu]s pulses.

  5. Radiation calculations and shielding considerations for the design of the Next Linear Collider

    SciTech Connect

    Nelson, W.R.; Rokni, S.H.; Vylet, V.

    1996-11-01

    The authors describe some of the work that they have done as a contribution to the Next Linear Collider (NLC) Zeroth-Order Design Report (ZDR), with specific emphasis placed on radiation-protection issues. However, because of the very nature of this machine--namely, extremely-small beam spots of high intensity--a new approach in accelerator radiation-protection philosophy appears to be warranted. Accordingly, the presentation will first take a look at recent design studies directed at protecting the machine itself, since this has resulted in a much better understanding of the very short exposure times involved whenever beam is lost and radiation sources are created. At the end of the paper, the authors suggest a Beam Containment System (BCS) that would provide an independent, redundant guarantee that exposure times are, indeed, kept very short. This, in turn, has guided them in the determination of the transverse shield thickness for the machine.

  6. Analysis and Control of Wakefields in X-Band Crab Cavities for Compact Linear Collider

    SciTech Connect

    Ambattu, P.K.; Burt, G.; Khan, V.F.; Jones, R.M.; Dexter, A.; Dolgashev, V.; /SLAC

    2012-04-25

    The Compact Linear Collider requires a crab cavity on each beamline prior to the interaction point to rotate the bunches before collision. The cavities are X-band travelling wave type and are located close to the final doublet of the beam delivery system. This makes the beam very sensitive to transverse momentum imparted by wakefields; hence the wakefields must be tightly controlled. Of special concerns are the orthogonal polarization of the operating mode and the fundamental monopole mode of the crab cavity. The former mode is at the same frequency as the operating mode of a cylindrically symmetric cavity and the latter one is at a lower frequency and hence is difficult to damp using a single means. In this paper major problematic modes of the crab cavity are investigated and damping requirements for them are calculated. Possibility of meeting the required wakefield control using waveguide damping and choke damping is thoroughly investigated. As a comparison, damped-detuning is also investigated.

  7. Results from a Prototype Chicane-Based Energy Spectrometer for a Linear Collider

    SciTech Connect

    Lyapin, A.; Schreiber, H.J.; Viti, M.; Adolphsen, C.; Arnold, R.; Boogert, S.; Boorman, G.; Chistiakova, M.V.; Gournaris, F.; Duginov, V.; Hast, C.; Hildreth, M.; Hlaing, C.; Jackson, F.; Khainovsky, O.; Kolomensky, Yu.G.; Kostromin, S.; Kumar, K.; Maiheu, B.; McCormick, D.; Miller, D.J.; /University Coll. London /Dubna, JINR /UC, Berkeley /LBL, Berkeley /Caltech /UC, Berkeley /LBL, Berkeley /Cambridge U. /SLAC /Cambridge U. /Fermilab /University Coll. London /SLAC

    2011-02-28

    The International Linear Collider (ILC) and other proposed high energy e{sup +}e{sup -} machines aim to measure with unprecedented precision Standard Model quantities and new, not yet discovered phenomena. One of the main requirements for achieving this goal is a measurement of the incident beam energy with an uncertainty close to 10{sup -4}. This article presents the analysis of data from a prototype energy spectrometer commissioned in 2006-2007 in SLAC's End Station A beamline. The prototype was a 4-magnet chicane equipped with beam position monitors measuring small changes of the beam orbit through the chicane at different beam energies. A single bunch energy resolution close to 5 {center_dot} 10{sup -4} was measured, which is satisfactory for most scenarios. We also report on the operational experience with the chicane-based spectrometer and suggest ways of improving its performance.

  8. Anomalous WWγ couplings with beam polarization at the Compact Linear Collider

    NASA Astrophysics Data System (ADS)

    Arı, V.; Billur, A. A.; İnan, S. C.; Köksal, M.

    2016-05-01

    We study the anomalous WWγ couplings at the Compact Linear Collider through the processes e+e- →W+W-, e-e+ →e-γ*e+ →e+νeW- and e-e+ →e-γ*γ*e+ →e-W+W-e+ (γ* is the Weizsacker-Williams photon). We give the 95% confidence level limits for unpolarized and polarized electron (positron) beam on the anomalous couplings for various values of the integrated luminosities and center-of-mass energies. We show that the obtained limits on the anomalous couplings through these processes can highly improve the current experimental limits. In addition, our limits with beam polarization are approximately two times better than the unpolarized case.

  9. Neutral Higgs boson pair production at the linear collider in the noncommutative standard model

    SciTech Connect

    Das, Prasanta Kumar; Prakash, Abhishodh; Mitra, Anupam

    2011-03-01

    We study the Higgs boson pair production at the linear collider in the noncommutative extension of the standard model using the Seiberg-Witten map of this to the first order of the noncommutative parameter {Theta}{sub {mu}{nu}}. Unlike the standard model (where the process is forbidden) here the Higgs boson pair directly interacts with the photon. We find that the pair production cross section can be quite significant for the noncommutative scale {Lambda} lying in the range 0.5 TeV to 1.0 TeV. Using the experimental (LEP 2, Tevatron, and global electroweak fit) bound on the Higgs mass, we obtain 626 GeV{<=}{Lambda}{<=}974 GeV.

  10. 600 kV modulator design for the SLAC Next Linear Collider Test Accelerator

    SciTech Connect

    Harris, K.; de Lamare, J.; Nesterov, V.; Cassel, R.

    1992-07-01

    Preliminary design for the SLAC Next Linear Collider Test Accelerator (NLCTA) requires a pulse power source to produce a 600 kV, 600 A, 1.4 {mu}s, 0.1% flat top pulse with rise and fall times of approximately 100 ns to power an X-Band klystron with a microperveance of 1.25 at {approx} 100 MW peak RF power. The design goals for the modulator, including those previously listed, are peak modulator pulse power of 340 MW operating at 120 Hz. A three-stage darlington pulse-forming network, which produces a >100 kV, 1.4 {mu}s pulse, is coupled to the klystron load through a 6:1 pulse transformer. Careful consideration of the transformer leakage inductance, klystron capacitance, system layout, and component choice is necessary to produce the very fast rise and fall times at 600 kV operating continuously at 120 Hz.

  11. Fine Grained Silicon-Tungsten Calorimetry for a Linear Collider Detector

    SciTech Connect

    Strom, D.; Frey, R.; Breidenbach, M.; Freytag, D.; Graf, N.; Haller, G.; Milgrome, O.; Radeka, V.; /Brookhaven

    2006-02-08

    A fine grained silicon-tungsten calorimeter is ideal for use as the electromagnetic calorimeter in a linear collider detector optimized for particle-flow reconstruction. We are designing a calorimeter that is based on readout chips which are bump bonded to the silicon wafers that serve as the active medium in the calorimeter. By using integrated electronics we plan to demonstrate that fine granularity can be achieved at a reasonable price. Our design minimizes the gap between tungsten layers leading to a small Moliere radius, an important figure of merit for particle-flow detectors. Tests of the silicon detectors to be used in a test beam prototype as well as timing measurements based on similar silicon detectors are discussed.

  12. Full quantum treatment of spin-dependent beam-beam processes at linear colliders

    NASA Astrophysics Data System (ADS)

    Hartin, Anthony

    2011-05-01

    Depolarisation processes at future linear colliders need to be understood as precisely as possible. To that end a theoretical consideration of the spin flip process and its radiative corrections is presented here. The spin flip process contains a divergence and it is useful to repeat the calculation of its transition rate using a coordinate system which makes the physical nature of the divergence apparent. It is argued that the radiative corrections to the spin flip process should be considered within the Furry Picture. The Electron Self Energy in the external field is being explicitly re-examined in order to establish the presence of UV divergences and the procedure required to remove them. A calculation of the Vertex Correction in an external field is being performed and results obtained so far for special kinematics are consistent with known results.

  13. Design of 140 MW X-band Relativistic Klystron for Linear Collider

    NASA Astrophysics Data System (ADS)

    Dolbilov, G. V.; Azorsky, N. I.; Shvetsov, V. S.; Balakin, V. E.; Avrakhov, P. V.; Kazakov, S. Yu.; Teryaev, V. E.; Vogel, V. F.

    1997-05-01

    It has been reported at EPAC-96 on successful experimental results on achievement of 100 MW output rf power in a wide aperture (15 mm), high gain (80 dB) 14 GHz VLEPP klystron with distributed suppression of parasitic oscillations (G.V. Dolbilov et al., Proc. EPAC-96, Sitges (Barselona), 10-14 June, 1996, Vol. 3, p. 2143). This report presents design of an electrodynamic structure of the X-band klystron for linear collider with a higher efficiency up to 56 % which will be achieved at the same parameters of the electron beam (U = 1 MeV, I = 250 A, emittance 0.05 π cm\\cdotrad). Design rf output power of the klystron is 140 MW. Experimental investigations of electrodynamic structure of the klystron are planned to perform using the driving beam of the JINR LIA-3000 induction accelerator (E = 1 MeV, I = 250 A, τ = 250 ns).

  14. Physics Goals for the Planned Next Linear Collider Engineering Test Facility

    NASA Astrophysics Data System (ADS)

    Raubenheimer, T. O.

    2001-10-01

    The Next Linear Collider (NLC) Collaboration is planning to construct an Engineering Test Facility (ETF) at Fermilab. As presently envisioned, the ETF would comprise a fundamental unit of the NLC main linac to include X-band klystrons and modulators, a delay-line power-distribution system (DLDS), and NLC accelerating structures that serve as loads. The principal purpose of the ETF is to validate stable operation of the power-distribution system, first without beam, then with a beam having the NLC pulse structure. This paper concerns the possibility of configuring and using the ETF to accelerate beam with an NLC pulse structure, as well as of doing experiments to measure beam-induced wakefields in the rf structures and their influence back on the beam.

  15. Bunch Compressor Beamlines for the Tesla and S Band Linear Colliders

    SciTech Connect

    Emma, Paul J

    2003-06-20

    A detailed design for a single stage beam bunch length compressor for both the TESLA and the S-Band Linear Collider (SBLC) is presented. Compression is achieved by introducing an energy-position correlation along the bunch with an rf section at zero-crossing phase followed by a short bending section with energy dependent path length (momentum compaction). The motivation for a wiggler design is presented and many of the critical single bunch tolerances are evaluated. A solenoid based spin rotator is included in the design and transverse emittance tuning elements, diagnostics and tuning methods are described. Bunch length limitations due to second order momentum compaction and sinusoidal rf shape are discussed with options for compensation. Finally, the disadvantages of bunch compression using a 180{sup o} arc are discussed.

  16. Investigation into electron cloud effects in the International Linear Collider positron damping ring

    SciTech Connect

    Crittenden, J.A.; Conway, J.; Dugan, G.F.; Palmer, M.A.; Rubin, D.L.; Shanks, J.; Sonnad, K.G.; Boon, L.; Harkay, K.; Ishibashi, T.; Furman, M.A.; Guiducci, S.; Pivi, M.T.F.; Wang, L.; Crittenden, J.A.; Conway, J.; Dugan, G.F.; Palmer, M.A.; Rubin, D.L.; Shanks, J.; Sonnad, K.G.; Boon, L.; Harkay, K.; Ishibashi, T.; Furman, M.A.; Guiducci, S.; Pivi, M.T.F.; Wang, L.

    2014-02-28

    We report modeling results for electron cloud buildup and instability in the International Linear Collider positron damping ring. Updated optics, wiggler magnets, and vacuum chamber designs have recently been developed for the 5 GeV, 3.2-km racetrack layout. An analysis of the synchrotron radiation profile around the ring has been performed, including the effects of diffuse and specular photon scattering on the interior surfaces of the vacuum chamber. The results provide input to the cloud buildup simulations for the various magnetic field regions of the ring. The modeled cloud densities thus obtained are used in the instability threshold calculations. We conclude that the mitigation techniques employed in this model will suffice to allow operation of the damping ring at the design operational specifications

  17. Degradation of multibunch luminosity in a linear collider due to cumulative beam breakup

    SciTech Connect

    Courtlandt L. Bohn; Michael J. Syphers; Daniel Schulte

    2001-06-26

    Beam-excited transverse wakes in accelerating radiofrequency structures will influence the transverse offsets of each bunch in a multibunch train, causing the projected emittance of the bunch train to grow. An analytic theory of this phenomenon that includes the mitigating influence of a correlated energy spread across the bunch train was recently devised and applied to electron-positron linear colliders. We use the results of this theory to estimate analytically the associated degradation of multibunch luminosity in terms of top-level parameters for the two beams, the two accelerators, and the final-focus system. Then we compare the estimates with results from GUINEA-PIG, a code that includes the detailed physics of beam-beam interactions.

  18. Ground motion optimized orbit feedback design for the future linear collider

    NASA Astrophysics Data System (ADS)

    Pfingstner, J.; Snuverink, J.; Schulte, D.

    2013-03-01

    The future linear collider has strong stability requirements on the position of the beam along the accelerator and at the interaction point (IP). The beam position will be sensitive to dynamic imperfections in particular ground motion. A number of mitigation techniques have been proposed to be deployed in parallel: active and passive quadrupole stabilization and positioning as well as orbit and IP feedback. This paper presents a novel design of the orbit controller in the main linac and beam delivery system. One global feedback controller is proposed based on an SVD-controller (Singular Value Decomposition) that decouples the large multi-input multi-output system into many independent single-input single-output systems. A semi-automatic procedure is proposed for the controller design of the independent systems by exploiting numerical models of ground motion and measurement noise to minimize a target parameter, e.g. luminosity loss. The novel design for the orbit controller is studied for the case of the Compact Linear Collider (CLIC) in integrated simulations, which include all proposed mitigation methods. The impact of the ground motion on the luminosity performance is examined in detail. It is shown that with the proposed orbit controller the tight luminosity budget for ground motion effects is fulfilled and accordingly, an essential feasibility issue of CLIC has been addressed. The orbit controller design is robust and allows for a relaxed BPM resolution, while still maintaining a strong ground motion suppression performance compared to traditional methods. We believe that the described method could easily be applied to other accelerators and light sources.

  19. A note on the relationship between the emittance, the beta function and the energy in a linear collider

    SciTech Connect

    Rees, J.

    1986-11-01

    Scaling laws for linear colliders are considered for the case of laterally round Gaussian beams and for the case that mutual pinching of the beams can be ignored. Based on these assumptions, the relationship is found between the interaction area, beta function, beam emittance, and energy for a linear collider in order to show the need for substantial improvements in the feasible values of accelerator parameters to reach a center of mass energy of 0.7 TeV. Pinch is then taken into account. (LEW)

  20. Linear beam-beam tune shift calculations for the Tevatron Collider

    SciTech Connect

    Johnson, D.

    1989-01-12

    A realistic estimate of the linear beam-beam tune shift is necessary for the selection of an optimum working point in the tune diagram. Estimates of the beam-beam tune shift using the ''Round Beam Approximation'' (RBA) have over estimated the tune shift for the Tevatron. For a hadron machine with unequal lattice functions and beam sizes, an explicit calculation using the beam size at the crossings is required. Calculations for various Tevatron lattices used in Collider operation are presented. Comparisons between the RBA and the explicit calculation, for elliptical beams, are presented. This paper discusses the calculation of the linear tune shift using the program SYNCH. Selection of a working point is discussed. The magnitude of the tune shift is influenced by the choice of crossing points in the lattice as determined by the pbar ''cogging effects''. Also discussed is current cogging procedures and presents results of calculations for tune shifts at various crossing points in the lattice. Finally, a comparison of early pbar tune measurements with the present linear tune shift calculations is presented. 17 refs., 13 figs., 3 tabs.

  1. Interim report on the Global Design Effort Global International Linear Collider (ILC) R&D

    SciTech Connect

    Harrison, M.

    2011-04-30

    The International Linear Collider: A Technical Progress Report marks the halfway point towards the Global Design Effort fulfilling its mandate to follow up the ILC Reference Design Report with a more optimised Technical Design Report (TDR) by the end of 2012. The TDR will be based on much of the work reported here and will contain all the elements needed to propose the ILC to collaborating governments, including a technical design and implementation plan that are realistic and have been better optimised for performance, cost and risk. We are on track to develop detailed plans for the ILC, such that once results from the Large Hadron Collider (LHC) at CERN establish the main science goals and parameters of the next machine, we will be in good position to make a strong proposal for this new major global project in particle physics. The two overriding issues for the ILC R&D programme are to demonstrate that the technical requirements for the accelerator are achievable with practical technologies, and that the ambitious physics goals can be addressed by realistic ILC detectors. This GDE interim report documents the impressive progress on the accelerator technologies that can make the ILC a reality. It highlights results of the technological demonstrations that are giving the community increased confidence that we will be ready to proceed with an ILC project following the TDR. The companion detector and physics report document likewise demonstrates how detector designs can meet the ambitious and detailed physics goals set out by the ILC Steering Committee. LHC results will likely affect the requirements for the machine design and the detectors, and we are monitoring that very closely, intending to adapt our design as those results become available.

  2. Application of quasi-optical approach to construct RF power supply for TeV linear colliders

    NASA Astrophysics Data System (ADS)

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

    1995-02-01

    An idea to use a quasi-optical approach for constructing an RF power supply for TeV linear e +e - colliders is developed. The RF source of the proposed scheme is composed of a large number of low-power RF amplifiers commutated by quasi-optical elements. The RF power of this source is transmitted to the accelerating structure of the collider by means of quasi-optical waveguides and mirrors. Such an approach enables one not only to decrease the required peak RF power by several orders of magnitude with respect to the traditional approach based on standard klystron technique, but also to achieve the required level of reliability, as it is based on well-developed technology of serial microwave devices. To illustrate the proposed scheme, a conceptual project of 2 × 500 GeV X-band collider is considered. Accelerating structure of the collider is of the standard travelling wave type and the RF source is assumed to be composed of 0.7 MW klystrons. All equipment of such a collider is placed in a tunnel of 12 × 6 m 2 cross section. It is shown that such a collider may be constructed at the present level of accelerator technique.

  3. Modification and Measurement of the Adjustable Permanent Magnet Quadrupole for the Final Focus in a Linear Collider

    SciTech Connect

    Kuroda, S.; Okugi, T.; Tauchi, T.; Fujisawa, H.; Ichikawa, M.; Iwashita, Y.; Tajima, Y.; Kumada, M.; Spencer, Cherrill M.; /SLAC

    2008-01-18

    An adjustable permanent magnet quadrupole has been developed for the final focus (FF) in a linear collider. Recent activities include a newly fabricated inner ring to demonstrate the strongest field gradient at a smaller bore diameter of 15mm and a magnetic field measurement system with a new rotating coil. The prospects of the R&D will be discussed.

  4. Damage test for International Linear Collider positron generation target at KEKB

    NASA Astrophysics Data System (ADS)

    Kuriki, M.; Mimashi, T.; Saito, K.; Kikuchi, M.; Kamitani, T.

    2006-07-01

    ILC (International Linear Collider) is aiming to conduct electron-positron collisions at 1 TeV center-of-mass energy. One bunch train will contain up to 2800 3.2 nC bunches with a 308 ns bunch spacing or 5600 1.6 nC bunches with a 154 ns spacing. The bunch-train length will be 0.9 ms. Because of this extremely large amount of beam in a train, serious damage to a positron production target driven by 6 GeV incident electron beam is of concern. As the ILC positron source, several different methods have been proposed. The target hardness is a key point concerning the selection. In this article, we report on a test experiment to examine the target hardness by using a stored electron beam in KEKB HER (High Energy Ring). The project name is IPPAK (ILC Positron Project At KEKB). By manipulating the abort kicker, a condition similar to that of the ILC positron production target can be reproduced. The experiment was carried out on June 29 and 30, 2005. The target was seriously damaged under the heaviest condition (KEKB mode), but the damage was less and nothing for those of the ILC mode. Possible impacts to the ILC positron production scheme are also discussed.

  5. Probing triple Higgs couplings of the two Higgs doublet model at a linear collider

    SciTech Connect

    Arhrib, Abdesslam; Benbrik, Rachid; Chiang, C.-W.

    2008-06-01

    We study double Higgs production at the future linear collider in the framework of the two Higgs doublet models through the following channels: e{sup +}e{sup -}{yields}{phi}{sub i}{phi}{sub j}Z, {phi}{sub i}=h{sup 0}, H{sup 0}, A{sup 0}, H{sup {+-}}. All these processes are sensitive to triple Higgs couplings. Hence observations of them provide information on the triple Higgs couplings that help reconstructing the scalar potential. We also discuss the double Higgs-Strahlung e{sup +}e{sup -}{yields}h{sup 0}h{sup 0}Z in the decoupling limit where h{sup 0} mimics the standard model Higgs boson. The processes e{sup +}e{sup -}{yields}h{sup 0}h{sup 0}Z and e{sup +}e{sup -}{yields}h{sup 0}H{sup 0}Z are also discussed in the fermiophobic limit where distinctive signatures such as 4{gamma}+X, 2{gamma}+X, and 6{gamma}+X are expected in the Type-I two Higgs doublet model.

  6. Beam dynamics design of the Compact Linear Collider Drive Beam injector

    NASA Astrophysics Data System (ADS)

    Hajari, Sh. Sanaye; Shaker, H.; Doebert, S.

    2015-11-01

    In the Compact Linear Collider (CLIC) the RF power for the acceleration of the Main Beam is extracted from a high-current Drive Beam that runs parallel to the main linac. The longitudinal and transverse beam dynamics of the Drive Beam injector has been studied in detail and optimized. The injector consists of a thermionic gun followed by a bunching system, some accelerating structures, and a magnetic chicane. The bunching system contains three sub-harmonic bunchers, a prebuncher, and a traveling wave buncher all embedded in a solenoidal magnetic field. The main characteristic of the Drive Beam injector is the phase coding process done by the sub-harmonic bunching system operating at half the acceleration frequency. This process is essential for the frequency multiplication of the Drive Beam. During the phase coding process the unwanted satellite bunches are produced that adversely affects the machine power efficiency. The main challenge is to reduce the population of particles in the satellite bunches in the presence of strong space-charge forces due to the high beam current. The simulation of the beam dynamics has been carried out with PARMELA with the goal of optimizing the injector performance compared to the existing model studied for the Conceptual Design Report (CDR). The emphasis of the optimization was on decreasing the satellite population, the beam loss in the magnetic chicane and limiting the beam emittance growth in transverse plane.

  7. Experimental program to build a multimegawatt lasertron for super linear colliders

    SciTech Connect

    Garwin, E.L.; Herrmannsfeldt, W.B.; Sinclair, C.; Weaver, J.N.; Welch, J.J.; Wilson, P.B.

    1985-04-01

    A lasertron (a microwave ''triode'' with an RF output cavity and an RF modulated laser to illuminate a photocathode) is a possible high power RF amplifier for TeV linear colliders. As the first step toward building a 35 MW, S-band lasertron for a proof of principle demonstration, a 400 kV dc diode is being designed with a GaAs photocathode, a drift-tube and a collector. After some cathode life tests are made in the diode, an RF output cavity will replace the drift tube and a mode-locked, frequency-doubled, Nd:YAG laser, modulated to produce a 1 us-long comb of 60 ps pulses at a 2856 MHz rate, will be used to illuminate the photocathode to make an RF power source out of the device. This paper discusses the plans for the project and includes some results of numerical simulation studies of the lasertron as well as some of the ultra-high vacuum and mechanical design requirements for incorporating a photocathode.

  8. A CMOS pixel sensor prototype for the outer layers of linear collider vertex detector

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Morel, F.; Hu-Guo, C.; Himmi, A.; Dorokhov, A.; Hu, Y.

    2015-01-01

    The International Linear Collider (ILC) expresses a stringent requirement for high precision vertex detectors (VXD). CMOS pixel sensors (CPS) have been considered as an option for the VXD of the International Large Detector (ILD), one of the detector concepts proposed for the ILC. MIMOSA-31 developed at IPHC-Strasbourg is the first CPS integrated with 4-bit column-level ADC for the outer layers of the VXD, adapted to an original concept minimizing the power consumption. It is composed of a matrix of 64 rows and 48 columns. The pixel concept combines in-pixel amplification with a correlated double sampling (CDS) operation in order to reduce the temporal noise and fixed pattern noise (FPN). At the bottom of the pixel array, each column is terminated with a self-triggered analog-to-digital converter (ADC). The ADC design was optimized for power saving at a sampling frequency of 6.25 MS/s. The prototype chip is fabricated in a 0.35 μm CMOS technology. This paper presents the details of the prototype chip and its test results.

  9. Attaining high luminosity in linear e sup + e sup minus colliders

    SciTech Connect

    Palmer, R.B.

    1990-11-01

    The attainment of high luminosity in linear colliders is a complex problem because of the interdependence of the critical parameters. For instance, changing the number of particles per bunch affects the damping ring design and thus the emittance; it affects the wakefields in the linac and thus the momentum spread; the momentum spread affects the final focus design and thus the final {beta}*; but the emittance change also affects the final focus design; and all these come together to determine the luminosity, disruption and beamstrahlung at the intersection. Changing the bunch length, or almost any other parameter, has a similar chain reaction. Dealing with this problem by simple scaling laws is very difficult because one does not know which parameter is going to be critical, and thus which should be held constant. One can only maximize the luminosity by a process of search and iteration. The process can be facilitated with the aid of a computer program. Examples can then be optimized for maximum luminosity, and compared to the optimized solutions with different approaches. This paper discusses these approaches.

  10. The two-loop soft function for heavy quark pair production at future linear colliders

    NASA Astrophysics Data System (ADS)

    von Manteuffel, Andreas; Schabinger, Robert M.; Zhu, Hua Xing

    2015-08-01

    We report on the calculation of the threshold soft function for heavy quark pair production in e+e- annihilation at two-loop order. Our main result is a generalization of the familiar Drell-Yan threshold soft function to the case of nonzero primary quark mass. We set up a framework based on the method of differential equations which allows for the straightforward calculation of the bare soft function to arbitrarily high orders in the dimensional regularization parameter. Remarkably, we find that we can obtain the bare two-loop Drell-Yan soft function from the heavy quark soft function to the order in epsilon required for a two-loop calculation by making simple replacements. We expect that our results will be of use, both as an important input for precision physics calculations at linear colliders and, more formally, as a first step toward a better understanding of the connection between vacuum matrix elements of massive soft Wilson lines and vacuum matrix elements of massless soft Wilson lines.

  11. Proposing a Laser Based Beam Size Monitor for the Future Linear Collider

    SciTech Connect

    Ross, Marc C

    2001-12-10

    Compton scattering techniques for the measurement of the transverse beam size of particle beams at future linear colliders (FLC) are proposed. At several locations of the beam delivery system (BDS) of the FLC, beam spot sizes ranging from several hundreds to a few micrometers have to be measured. This is necessary to verify beam optics, to obtain the transverse beam emittance, and to achieve the highest possible luminosity. The large demagnification of the beam in the BDS and the high beam power puts extreme conditions on any measuring device. With conventional techniques at their operational limit in FLC scenarios, new methods for the detection of the transverse beam size have to be developed. For this laser based techniques are proposed capable of measuring high power beams with sizes in the micrometer range. In this paper general aspects and critical issues of a generic device are outlined and specific solutions proposed. Plans to install a laser wire experiment at an accelerator test facility are presented.

  12. An Automated Magnet Positioning System For Use in the Next Linear Collider

    SciTech Connect

    Viola, Robert J

    2006-02-21

    The Next Linear Collider (NLC) is conceived as the world's most powerful electron-positron particle accelerator. Throughout the NLC, the beam itself will be used to measure errors in the positions of the lattice elements. This beam-based alignment strategy is an essential element of the NLC's design and precision adjustment systems have been identified as a critical enabling technology. Square One proposes a new type of precision manipulator that could be adapted for applications throughout the accelerator. As envisioned, this Tri-Sphere Adjustment System will possess up to six, non-redundant degrees of freedom, be capable of sub-micron resolutions and have ultimate load capacities in excess of 10,000 kg. The system will accommodate thermal expansions and contractions of the objects being supported and can be either motorized or manually actuated. Phase I development tasks will include detailed manipulator design, solution of the associated kinematic equations of motion and evaluation of actuators, gear reducers and transmission systems. The Phase I effort will culminate in the fabrication and full evaluation of a system prototype. A successfully developed Tri-Sphere manipulator could also be used to actively position critical fusion optics, adjust communication dishes or perform parts handling tasks in harsh manufacturing environments.

  13. A vertically integrated pixel readout device for the Vertex Detector at the International Linear Collider

    SciTech Connect

    Deptuch, Grzegorz; Christian, David; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

    2008-12-01

    3D-Integrated Circuit technology enables higher densities of electronic circuitry per unit area without the use of nanoscale processes. It is advantageous for mixed mode design with precise analog circuitry because processes with conservative feature sizes typically present lower process dispersions and tolerate higher power supply voltages, resulting in larger separation of a signal from the noise floor. Heterogeneous wafers (different foundries or different process families) may be combined with some 3D integration methods, leading to the optimization of each tier in the 3D stack. Tracking and vertexing in future High-Energy Physics (HEP) experiments involves construction of detectors composed of up to a few billions of channels. Readout electronics must record the position and time of each measurement with the highest achievable precision. This paper reviews a prototype of the first 3D readout chip for HEP, designed for a vertex detector at the International Linear Collider. The prototype features 20 x 20 {micro}m{sup 2} pixels, laid out in an array of 64 x 64 elements and was fabricated in a 3-tier 0.18 {micro}m Fully Depleted SOI CMOS process at MIT-Lincoln Laboratory. The tests showed correct functional operation of the structure. The chip performs a zero-suppressed readout. Successive submissions are planned in a commercial 3D bulk 0.13 {micro}m CMOS process to overcome some of the disadvantages of an FDSOI process.

  14. IMPROVEMENTS IN EMITTANCE WAKE FIELD OPTIMIZATION FOR THE SLAC LINEAR COLLIDER

    SciTech Connect

    Decker, Franz-Josef

    2003-05-01

    The transverse emittances in the SLAC Linear Collider can be severely diluted by collective wakefield effects and dispersion. For the 1997/98 SLC/SLD run important changes were implemented in the way the emittance is optimized. Early in the linac, where the energy spread is large due to BNS damping, the emittance growth is dominated by dispersion. In this regime emittance tuning bumps may introduce additional wakefield tails and their use is now avoided. At the end of the linac the energy spread is minimal and the emittance measurement is most sensitive to wakefield emittance dilution. In previous years, the emittances were tuned on wire scanners located near but not at the end of the linac (after about 90% of its length). Simulations show that emittance growth of up to 100% can occur in the remaining 10%. In this run wire scanners at the entrance of the Final Focus, the last place where the emittances can be measured, were used for the optimization. Screens at the end of the linac allow additional real time monitoring of the beam sizes. We show that the different tuning strategy provided significantly improved emittances at the interaction point of the SLC.

  15. Current Status of the Next Linear Collider X-Band Klystron Development Program

    SciTech Connect

    Caryotakis, G.; Haase, A.A.; Jongewaard, E.N.; Pearson, C.; Sprehn, D.W.; /SLAC

    2005-05-09

    Klystrons capable of driving accelerator sections in the Next Linear Collider (NLC) have been developed at SLAC during the last decade. In addition to fourteen 50 MW solenoid-focused devices and a 50 MW Periodic Permanent Magnet focused (PPM) klystron, a 500 kV 75 MW PPM klystron was tested in 1999 to 80 MW with 3 {micro}s pulses, but very low duty. Subsequent 75 MW prototypes aimed for low-cost manufacture by employing reusable focusing structures external to the vacuum, similar to a solenoid electromagnet. During the PPM klystron development, several partners (CPI, EEV and Toshiba) have participated by constructing partial or complete PPM klystrons. After early failures during testing of the first two devices, SLAC has recently tested this design (XP3-3) to the full NLC specifications of 75 MW, 1.6 {micro}s pulse length, and 120 Hz. This 14.4 kW average power operation came with an efficiency of 50%. The XP3-3 average and peak output power, together with the focusing method, arguably makes it the most advanced high power klystron ever built anywhere in the world. Design considerations and test results for these latest prototypes will be presented.

  16. A Multi-moded Delay Line RF Distribution System for the Next = Linear Collider

    NASA Astrophysics Data System (ADS)

    Tantawi, Sami

    1998-04-01

    The Delay Line Distribution System (DLDS) (H. Mizuno, Y. Otake, "A New Rf Power Distribution System For X Band Linac Equivalent To An Rf Pulse Compression Scheme Of Factor 2**N," 17th International Linac Conference (LINAC94), Tsukuba, Japan, Aug 21 - 26, 1994) is an alternative to conventional pulse compression which enhances the peak power of an rf source while matching the long pulse of that source to the shorter filling time of the accelerator structure. We present a variation on that scheme that combines the parallel delay lines of the system into one single line. The power of several sources is combined into a single waveguide delay line using a multi-mode launcher. The output mode of the launcher is determined by the phase coding of the input signals. The combined power is extracted using several mode extractors each extracts only one single mode. Hence, the phase coding of the sources controls the output port of the combined power. The power is, then, fed to the local accelerator structures. We present a detailed design of such a system, including several implementation methods for the launchers, extractors, and ancillary high power rf components. The system is designed so that it can handle the 600 MW peak power required for the high-gradient linacs of the Next Linear Collider, while maintaining high efficiency.

  17. Multimoded rf delay line distribution system for the Next Linear Collider

    NASA Astrophysics Data System (ADS)

    Tantawi, S. G.; Nantista, C.; Kroll, N.; Li, Z.; Miller, R.; Ruth, R.; Wilson, P.; Neilson, J.

    2002-03-01

    The delay line distribution system is an alternative to conventional pulse compression, which enhances the peak power of rf sources while matching the long pulse of those sources to the shorter filling time of accelerator structures. We present an implementation of this scheme that combines pairs of parallel delay lines of the system into single lines. The power of several sources is combined into a single waveguide delay line using a multimode launcher. The output mode of the launcher is determined by the phase coding of the input signals. The combined power is extracted from the delay line using mode-selective extractors, each of which extracts a single mode. Hence, the phase coding of the sources controls the output port of the combined power. The power is then fed to the local accelerator structures. We present a detailed design of such a system, including several implementation methods for the launchers, extractors, and ancillary high power rf components. The system is designed so that it can handle the 600 MW peak power required by the Next Linear Collider design while maintaining high efficiency.

  18. Radiation and Thermal Analysis of Superconducting Quadrupoles in the Interaction Region of Linear Collider

    SciTech Connect

    Drozhdin, A.I.; Kashikhin, V.V.; Kashikhin, V.S.; Lopes, M.L.; Mokhov, N.V.; Zlobin, A.V.; Seryi, Andrei; /SLAC

    2011-10-14

    Radiation heat deposition in the superconducting magnets of the Interaction Region (IR) of a linear collider can be a serious issue that limits the magnet operating margins and shortens the material lifetime. Radiation and thermal analyses of the IR quadrupoles in the incoming and extraction beam lines of the ILC are performed in order to determine the magnet limits. This paper presents an analysis of the radial, azimuthal and longitudinal distributions of heat deposition in the incoming and disrupted beam doublets. Operation margins of the magnets based on NbTi superconductor are calculated and compared. The radiation and thermal analysis of the ILC IR quadrupoles based on Rutherford type cables was performed. It was found that the peak radiation heat deposition takes place in the second extraction quadrupole QFEX2. The maximum power density in the coil is {approx}17mW/g. This is rather high, comparing to the proton machines (LHC). However, the fast radial decay of the heat deposition together with the high thermal conductivity of the Rutherford type cable limits the coil temperatures to a moderate level. It was determined that both 2-layer and 4-layer QFEX2 magnet designs have thermal margins of a factor of {approx}4 at the nominal gradient of 31.3 T/m. Because of the large margins, these magnets can easily accommodate possible changes in the IR optics and heat deposition levels.

  19. A concept of a wide aperture klystron with RF absorbing drift tubes for a linear collider

    NASA Astrophysics Data System (ADS)

    Dolbilov, G. V.; Azorsky, N. I.; Fateev, A. A.; Lebedev, N. I.; Petrov, V. A.; Shvetsov, V. S.; Yurkov, M. V.; Balakin, V. E.; Avrakhov, P. V.; Kazakov, S. Yu.; Solyak, N. A.; Teryaev, V. E.; Vogel, V. F.

    1996-02-01

    This paper is devoted to a problem of the optimal design of the electrodynamic structure of the X-band klystron for a linear collider. It is shown that the optimal design should provide a large aperture and a high power gain, about 80 dB. The most severe problem arising here is that of parasitic self-excitation of the klystron, which becomes more complicated at increasing aperture and power gain. Our investigations have shown that traditional methods for suppressing the self-excitation become ineffective at the desired technical parameters of the klystron. In this paper we present a novel concept of a wide aperture klystron with distributed suppression of parasitic oscillations. Results of an experimental study of the wide-aperture relativistic klystron for VLEPP are presented. Investigations have been performed using the driving beam of the JINR LIA-3000 induction accelerator ( E = 1 MeV, I = 250 A, τ = 250 ns). To suppress self-excitation parasitic modes we have used the technique of RF absorbing drift tubes. As a result, we have obtained design output parameters of the klystron and achieved a level of 100 MW output power.

  20. Impact of detector solenoid on the Compact Linear Collider luminosity performance

    NASA Astrophysics Data System (ADS)

    Inntjore Levinsen, Y.; Dalena, B.; Tomás, R.; Schulte, D.

    2014-05-01

    In order to obtain the necessary luminosity with a reasonable amount of beam power, the Compact LInear Collider (CLIC) design includes an unprecedented collision beam size of σy=1 nm vertically and σx=45 nm horizontally. With exceptionally small and flat beams, the luminosity can be significantly degraded due to the combination of the experimental solenoid field and a large crossing angle. The two main effects reducing the luminosity are y-x'-coupling and an increase of vertical dispersion. Additionally, incoherent synchrotron radiation (ISR) from the orbit deflection created by the solenoid field increases the beam emittance and results in unrecoverable luminosity degradation. A novel approach to evaluate the ISR effect from a realistic solenoid field without knowledge of the full compensation of the geometric aberrations is presented. This approach is confirmed by a detailed study of the correction techniques to compensate the beam optics distortions. The unrecoverable luminosity loss due to ISR for CLIC at 3 TeV has been evaluated, and found to be around 4% to 5% for the solenoid design under study.

  1. Long bunch trains measured using a prototype cavity beam position monitor for the Compact Linear Collider

    NASA Astrophysics Data System (ADS)

    Cullinan, F. J.; Boogert, S. T.; Farabolini, W.; Lefevre, T.; Lunin, A.; Lyapin, A.; Søby, L.; Towler, J.; Wendt, M.

    2015-11-01

    The Compact Linear Collider (CLIC) requires beam position monitors (BPMs) with 50 nm spatial resolution for alignment of the beam line elements in the main linac and beam delivery system. Furthermore, the BPMs must be able to make multiple independent measurements within a single 156 ns long bunch train. A prototype cavity BPM for CLIC has been manufactured and tested on the probe beam line at the 3rd CLIC Test Facility (CTF3) at CERN. The transverse beam position is determined from the electromagnetic resonant modes excited by the beam in the two cavities of the pickup, the position cavity and the reference cavity. The mode that is measured in each cavity resonates at 15 GHz and has a loaded quality factor that is below 200. Analytical expressions for the amplitude, phase and total energy of signals from long trains of bunches have been derived and the main conclusions are discussed. The results of the beam tests are presented. The variable gain of the receiver electronics has been characterized using beam excited signals and the form of the signals for different beam pulse lengths with the 2 /3 ns bunch spacing has been observed. The sensitivity of the reference cavity signal to charge and the horizontal position signal to beam offset have been measured and are compared with theoretical predictions based on laboratory measurements of the BPM pickup and the form of the resonant cavity modes as determined by numerical simulation. Finally, the BPM was calibrated so that the beam position jitter at the BPM location could be measured. It is expected that the beam jitter scales linearly with the beam size and so the results are compared to predicted values for the latter.

  2. Measurement of the B meson decaying to psi meson-S meson-neutral kaon branching fraction on BaBar at the Stanford Linear Accelerator Center

    NASA Astrophysics Data System (ADS)

    Olivas, Alexander Raymond, Jr.

    The decays of B0 mesons to hadronic final states remains a rich area of physics on BaBar. Not only do the cc¯ -K final states (e.g. B0 → psi(2 S)K0) allow for the measurement of CP Violation, but the branching fractions provide a sensitive test of the theoretical methods used to account for low energy non-perturbative QCD effects. We present the measurement of the branching fraction for the decay B0 → psi(2S)K s. The data set consists of 88.8 +/- 1.0 x 10 6 BB¯ pairs collected on the e +e- → Upsilon(4 S) resonance on BaBar/PEP-II at the Stanford Linear Accelerator Center (SLAC). This analysis features a modification of present cuts, with respect to those published so far on BaBar, on the Ks → pi +pi- and psi(2S) → J/psipi+pi- which aim at reducing the background while keeping the signal intact. Various data selection criteria are studied for the lepton modes (e+ e- and mu+mu- ) of the J/psi and psi(2S) to improve signal purity as well as study the stability of the resultant branching fractions.

  3. Measurement of the B0 ---> Psi (2S) Lambda0 Branching Fraction on BaBar at the Stanford Linear Accelerator Center (Abstract Only)

    SciTech Connect

    Olivas, Alexander Raymond, Jr.; /Colorado U.

    2005-11-16

    The decays of B{sup 0} mesons to hadronic final states remains a rich area of physics on BaBar. Not only do the c{bar c}-K final states (e.g. B{sup 0} {yields} {psi}(2S)K{sup 0}) allow for the measurement of CP Violation, but the branching fractions provide a sensitive test of the theoretical methods used to account for low energy non-perturbative QCD effects. They present the measurement of the branching fraction for the decay B{sup 0} {yields} {psi}(2S)K{sub s}. The data set consists of 88.8 {+-} 1.0 x 10{sup 6} B{bar b} pairs collected on the e{sup +}e{sup -} {yields} {Upsilon}(4S) resonance on BaBar/PEP-II at the Stanford Linear Accelerator Center (SLAC). This analysis features a modification of present cuts, with respect to those published so far on BaBar, on the K{sub S} {yields} {pi}{sup +}{pi}{sup -} and {psi}(2S) {yields} J/{psi}{pi}{sup +}{pi}{sup -} which aim at reducing the background while keeping the signal intact. Various data selection criteria are studied for the lepton modes (e{sup +}e{sup -} and {mu}{sup +}{mu}{sup -}) of the J/{psi} and {psi}(2S) to improve signal purity as well as study the stability of the resultant branching fractions.

  4. SiD Linear Collider Detector R&D, DOE Final Report

    SciTech Connect

    Brau, James E.; Demarteau, Marcel

    2015-05-15

    The Department of Energy’s Office of High Energy Physics supported the SiD university detector R&D projects in FY10, FY11, and FY12 with no-cost extensions through February, 2015. The R&D projects were designed to advance the SiD capabilities to address the fundamental questions of particle physics at the International Linear Collider (ILC): • What is the mechanism responsible for electroweak symmetry breaking and the generation of mass? • How do the forces unify? • Does the structure of space-time at small distances show evidence for extra dimensions? • What are the connections between the fundamental particles and forces and cosmology? Silicon detectors are used extensively in SiD and are well-matched to the challenges presented by ILC physics and the ILC machine environment. They are fast, robust against machine-induced background, and capable of very fine segmentation. SiD is based on silicon tracking and silicon-tungsten sampling calorimetry, complemented by powerful pixel vertex detection, and outer hadronic calorimetry and muon detection. Radiation hard forward detectors which can be read out pulse by pulse are required. Advanced calorimetry based on a particle flow algorithm (PFA) provides excellent jet energy resolution. The 5 Tesla solenoid is outside the calorimeter to improve energy resolution. PFA calorimetry requires fine granularity for both electromagnetic and hadronic calorimeters, leading naturally to finely segmented silicon-tungsten electromagnetic calorimetry. Since silicon-tungsten calorimetry is expensive, the detector architecture is compact. Precise tracking is achieved with the large magnetic field and high precision silicon microstrips. An ancillary benefit of the large magnetic field is better control of the e⁺e⁻ pair backgrounds, permitting a smaller radius beampipe and improved impact parameter resolution. Finally, SiD is designed with a cost constraint in mind. Significant advances and new capabilities have been made and

  5. Nanosecond-Timescale Intra-Bunch-Train Feedback for the Linear Collider: Results of the FONT2 Run

    SciTech Connect

    Barlow, R.; Dufau, M.; Kalinin, A.; Myatt, G.; Perry, C.; Burrows, P.N.; Hartin, T.; Hussain, S.M.; Molloy, S.; White, G.R.; Adolphsen, C.; Frisch, J.C.; Hendrickson, L.; Jobe, R.K.; Markiewicz, T.; McCormick, D.J.; Nelson, J.; Ross, M.C.; Smith, S.; Smith, T.J.; /SLAC

    2005-05-11

    We report on experimental results from the December 2003/January 2004 data run of the Feedback On Nanosecond Timescales (FONT) experiment at the Next Linear Collider Test Accelerator at SLAC. We built a second-generation prototype intra-train beam-based feedback system incorporating beam position monitors, fast analogue signal processors, a feedback circuit, fast-risetime amplifiers and stripline kickers. We applied a novel real-time charge-normalization scheme to account for beam current variations along the train. We used the system to correct the position of the 170-nanosecond-long bunchtrain at NLCTA. We achieved a latency of 53 nanoseconds, representing a significant improvement on FONT1 (2002), and providing a demonstration of intra-train feedback for the Linear Collider.

  6. Detectors for Linear Colliders: Physics Requirements and Experimental Conditions (1/4)

    ScienceCinema

    None

    2016-07-12

    How is the anticipated physics program of a future e+e- collider shaping the R&D; for new detectors in collider particle physics ? This presentation will review the main physics requirements and experimental conditions comparing to LHC and LEP. In particular, I shall discuss how e+e- experimentation is expected to change moving from LEP-2 up to multi-TeV energies.

  7. Detectors for Linear Colliders: Physics Requirements and Experimental Conditions (1/4)

    SciTech Connect

    2010-02-15

    How is the anticipated physics program of a future e+e- collider shaping the R&D; for new detectors in collider particle physics ? This presentation will review the main physics requirements and experimental conditions comparing to LHC and LEP. In particular, I shall discuss how e+e- experimentation is expected to change moving from LEP-2 up to multi-TeV energies.

  8. The Silicon Detector (SiD) And Linear Collider Detector R&D in Asia And North America

    SciTech Connect

    Brau, J.E.; Breidenbach, M.; Fujii, Y.; /KEK, Tsukuba

    2005-08-11

    In Asia and North America research and development on a linear collider detector has followed complementary paths to that in Europe. Among the developments in the US has been the conception of a detector built around silicon tracking, which relies heavily on a pixel (CCD) vertex detector, and employs a silicon tungsten calorimeter. Since this detector is quite different from the TESLA detector, we describe it here, along with some of the sub-system specific R&D in these regions.

  9. Future e/sup +/e/sup -/ linear colliders and beam-beam effects

    SciTech Connect

    Wilson, P.B.

    1986-05-01

    Numerous concepts, ranging from conventional to highly exotic, hae been proposed for the acceleration of electrons and positrons to very high energies. For any such concept to be viable, it must be possible to produce from it a set of consistent parameters for one of these ''benchmark'' machines. Attention is directed to the choice of parameters for a collider in the 300 GeV energy range, operating at a gradient on the order of 200 MV/m, using X-band power sources to drive a conventional disk-loaded accelerating structure. These rf power sources, while not completely conventional represent a reasonable extrapolation from present technology. The choice of linac parameters is strongly coupled to various beam-beam effects which take place when the electron and positron bunches collide. We summarize these beam-beam effects, and then return to the rf design of a 650 GeV center-of-mass collider. 14 refs.

  10. The Next Linear Collider Test Accelerator's RF Pulse Compression And Transmission

    SciTech Connect

    Tantawi, S.G.; Adelphson, C.; Holmes, S.; Lavine, Theodore L.; Loewen, R.J.; Nantista, C.; Pearson, C.; Pope, R.; Rifkin, J.; Ruth, R.D.; Vlieks, A.E.; /SLAC

    2011-09-14

    The overmoded rf transmission and pulsed power compression system for SLAC's Next Linear Collider (NLC) program requires a high degree of transmission efficiency and mode purity to be economically feasible. To this end, a number of new, high power components and systems have been developed at X-band, which transmit rf power in the low loss, circular TE01 mode with negligible mode conversion. In addition, a highly efficient SLED-II* pulse compressor has been developed and successfully tested at high power. The system produced a 200 MW, 250 ns wide pulse with a near-perfect flat-top. In this paper we describe the design and test results of the high power pulse compression system using SLED-II. The NLC rf systems use low loss highly over-moded circular waveguides operating in the TE01 mode. The efficiency of the systems is sensitive to the mode purity of the mode excited inside these guides. We used the so called flower petal mode transducer [2] to excite the TE01 mode. This type of mode transducer is efficient, compact and capable of handling high levels of power. To make more efficient systems, we modified this device by adding several mode selective chokes to act as mode purifiers. To manipulate the rf signals we used these modified mode converters to convert back and forth between over-moded circular waveguides and single-moded WR90 rectangular waveguides. Then, we used the relatively simple rectangular waveguide components to do the actual manipulation of rf signals. For example, two mode transducers and a mitered rectangular waveguide bend comprise a 90 degree bend. Also, a magic tee and four mode transducers would comprise a four-port-hybrid, etc. We will discuss the efficiency of an rf transport system based on the above methodology. We also used this methodology in building the SLEDII pulse compression system. At SLAC we built 4 of these pulse systems. In this paper we describe the SLEDII system and compare the performance of these 4 systems at SLAC. We

  11. Depolarization in the SLC Collider Arcs

    SciTech Connect

    Emma, P.; Limberg, T.; Rossmanith, R.

    1994-06-01

    In the 1993 running cycle of the Stanford Linear Collider, electron spin polarization measurements with a Moller polarimeter at the end of the linac and a Compton polarimeter near the interaction point (IP) indicated a relative polarization loss of up to 20% across the arc. The authors present calculations of the depolarizing effects where variations in energy, energy spread and transverse emittance as well as changes in orbit and initial spin orientation are taken into account. They compare their results with measurements and conclude that, in standard operating conditions, the relative polarization loss is only 3{+-}2%.

  12. Higgs sectors in which the only light higgs boson is CP-odd and linear collider strategies for its discovery

    SciTech Connect

    Tom Farris, John F. Gunion and Heather E. Logan

    2002-02-18

    We survey techniques for finding a CP-odd Higgs boson, A{sup 0}, at the Linear Collider that do not depend upon the presence of other light Higgs bosons. The potential reach in [m{sub A{sup 0}}, tan {beta}] parameter space for various production/discovery modes is evaluated and regions where discovery might not be possible at a given {radical}s are delineated. We give, for the first time, results for e{sup +}e{sup -} {yields} {nu}{bar {nu}} A{sup 0} one-loop W boson fusion production.

  13. Status of the Zee-Babu model for neutrino mass and possible tests at a like-sign linear collider

    NASA Astrophysics Data System (ADS)

    Schmidt, Daniel; Schwetz, Thomas; Zhang, He

    2014-08-01

    We provide an updated scan of the allowed parameter space of the two-loop Zee-Babu model for neutrino mass. Taking into account most recent experimental data on μ→eγ as well as the mixing angle θ13 we obtain lower bounds on the masses of the singly and doubly charged scalars of between 1 and 2 TeV, with some dependence on perturbativity and fine-tuning requirements. This makes the scalars difficult to observe at LHC with 14 TeV even with optimistic assumptions on the luminosity, and would require a multi-TeV linear collider to see the scalar resonances. We point out, however, that a sub-TeV linear collider in the like-sign mode may be able to observe lepton flavor violating processes such as e-e-→μ-μ- due to contact interactions induced by the doubly charged scalar with masses up to around 10 TeV. We investigate the possibility to distinguish the Zee-Babu model from the Higgs triplet model using such processes.

  14. Quadrupole Alignment and Trajectory Correction for Future Linear Colliders: SLC Tests of a Dispersion-Free Steering Algorithm

    SciTech Connect

    Assmann, R

    2004-06-08

    The feasibility of future linear colliders depends on achieving very tight alignment and steering tolerances. All proposals (NLC, JLC, CLIC, TESLA and S-BAND) currently require a total emittance growth in the main linac of less than 30-100% [1]. This should be compared with a 100% emittance growth in the much smaller SLC linac [2]. Major advances in alignment and beam steering techniques beyond those used in the SLC are necessary for the next generation of linear colliders. In this paper, we present an experimental study of quadrupole alignment with a dispersion-free steering algorithm. A closely related method (wakefield-free steering) takes into account wakefield effects [3]. However, this method can not be studied at the SLC. The requirements for future linear colliders lead to new and unconventional ideas about alignment and beam steering. For example, no dipole correctors are foreseen for the standard trajectory correction in the NLC [4]; beam steering will be done by moving the quadrupole positions with magnet movers. This illustrates the close symbiosis between alignment, beam steering and beam dynamics that will emerge. It is no longer possible to consider the accelerator alignment as static with only a few surveys and realignments per year. The alignment in future linear colliders will be a dynamic process in which the whole linac, with thousands of beam-line elements, is aligned in a few hours or minutes, while the required accuracy of about 5 pm for the NLC quadrupole alignment [4] is a factor of 20 higher than in existing accelerators. The major task in alignment and steering is the accurate determination of the optimum beam-line position. Ideally one would like all elements to be aligned along a straight line. However, this is not practical. Instead a ''smooth curve'' is acceptable as long as its wavelength is much longer than the betatron wavelength of the accelerated beam. Conventional alignment methods are limited in accuracy by errors in the survey

  15. Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector

    NASA Astrophysics Data System (ADS)

    Abramowicz, H.; Abusleme, A.; Afanaciev, K.; Aguilar, J.; Alvarez, E.; Avila, D.; Benhammou, Y.; Bortko, L.; Borysov, O.; Bergholz, M.; Bozovic-Jelisavcic, I.; Castro, E.; Chelkov, G.; Coca, C.; Daniluk, W.; Dumitru, L.; Elsener, K.; Fadeyev, V.; Firlej, M.; Firu, E.; Fiutowski, T.; Ghenescu, V.; Gostkin, M.; Henschel, H.; Idzik, M.; Ishikawa, A.; Kananov, S.; Kollowa, S.; Kotov, S.; Kotula, J.; Kozhevnikov, D.; Kruchonok, V.; Krupa, B.; Kulis, Sz.; Lange, W.; Lesiak, T.; Levy, A.; Levy, I.; Lohmann, W.; Lukic, S.; Milke, C.; Moron, J.; Moszczynski, A.; Neagu, A. T.; Novgorodova, O.; Oliwa, K.; Orlandea, M.; Pandurovic, M.; Pawlik, B.; Preda, T.; Przyborowski, D.; Rosenblat, O.; Sailer, A.; Sato, Y.; Schumm, B.; Schuwalow, S.; Smiljanic, I.; Smolyanskiy, P.; Swientek, K.; Teodorescu, E.; Terlecki, P.; Wierba, W.; Wojton, T.; Yamaguchi, S.; Yamamoto, H.; Zawiejski, L.; Zgura, I. S.; Zhemchugov, A.

    2015-05-01

    Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e- collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.

  16. International Linear Collider Reference Design Report Volume 2: Physics at the ILC

    SciTech Connect

    Aarons, Gerald; Abe, Toshinori; Abernathy, Jason; Ablikim, Medina; Abramowicz, Halina; Adey, David; Adloff, Catherine; Adolphsen, Chris; Afanaciev, Konstantin; Agapov, Ilya; Ahn, Jung-Keun; Aihara, Hiroaki; Akemoto, Mitsuo; del Carmen Alabau, Maria; Albert, Justin; Albrecht, Hartwig; Albrecht, Michael; Alesini, David; Alexander, Gideon; Alexander, Jim; Allison, Wade; /SLAC /Tokyo U. /Victoria U. /Beijing, Inst. High Energy Phys. /Tel Aviv U. /Birmingham U. /Annecy, LAPP /Minsk, High Energy Phys. Ctr. /DESY /Royal Holloway, U. of London /CERN /Pusan Natl. U. /KEK, Tsukuba /Orsay, LAL /Notre Dame U. /Frascati /Cornell U., Phys. Dept. /Oxford U. /Hefei, CUST /Bangalore, Indian Inst. Sci. /Fermilab

    2011-11-14

    The triumph of 20th century particle physics was the development of the Standard Model and the confirmation of many of its aspects. Experiments determined the particle constituents of ordinary matter, and identified four forces that hold matter together and transform it from one form to another. Particle interactions were found to obey precise laws of relativity and quantum theory. Remarkable features of quantum physics were observed, including the real effects of 'virtual' particles on the visible world. Building on this success, particle physicists are now able to address questions that are even more fundamental, and explore some of the deepest mysteries in science. The scope of these questions is illustrated by this summary from the report Quantum Universe: (1) Are there undiscovered principles of nature; (2) How can we solve the mystery of dark energy; (3) Are there extra dimensions of space; (4) Do all the forces become one; (5) Why are there so many particles; (6) What is dark matter? How can we make it in the laboratory; (7) What are neutrinos telling us; (8) How did the universe begin; and (9) What happened to the antimatter? A worldwide program of particle physics investigations, using multiple approaches, is already underway to explore this compelling scientific landscape. As emphasized in many scientific studies, the International Linear Collider is expected to play a central role in what is likely to be an era of revolutionary advances. Discoveries from the ILC could have breakthrough impact on many of these fundamental questions. Many of the scientific opportunities for the ILC involve the Higgs particle and related new phenomena at Terascale energies. The Standard Model boldly hypothesizes a new form of Terascale energy, called the Higgs field, that permeates the entire universe. Elementary particles acquire mass by interacting with this field. The Higgs field also breaks a fundamental electroweak force into two forces, the electromagnetic and weak

  17. Beam collimation and machine detector interface at the International Linear Collider

    SciTech Connect

    Mokhov, N.V.; Drozhdin, A.I.; Kostin, M.A.; /Fermilab

    2005-05-01

    Synchrotron radiation, beam-gas scattering and beam halo interactions with collimators and other components in the ILC beam delivery system (BDS) would create fluxes of muons and other secondaries which could exceed the tolerable levels at a detector by a few orders of magnitude. It is shown that with a multi-stage collimation system, magnetized iron spoilers which fill the tunnel and a set of masks in the detector, one can hopefully meet the design goals. Results of modeling with the STRUCT and MARS15 codes of beam loss and energy deposition effects are presented in this paper. We focus on the collimation system and mask performance optimization, short- and long-term survivability of the critical components (spoilers, absorbers and magnets), dynamic heat loads and radiation levels in magnets and other components, and machine-related backgrounds in collider detectors.

  18. A method for the precision mass measurement of the stop quark at the international linear collider.

    SciTech Connect

    Freitas, A.; Milstene, C.; Schmitt, M.; Sopczak, A.; High Energy Physics; Univ. of Chicago; Univ. Aurich; FNAL; Northwestern Univ.; Lancaster Univ.

    2008-09-16

    Many supersymmetric models predict new particles within the reach of the next generation of colliders. For an understanding of the model structure and the mechanism(s) of symmetry breaking, it is important to know the masses of the new particles precisely. In this article the measurement of the mass of the scalar partner of the top quark (stop) at an e{sup +}e{sup -} collider is studied. A relatively light stop is motivated by attempts to explain electroweak baryogenesis and can play an important role in dark matter relic density. A method is presented which makes use of cross-section measurements near the pair-production threshold as well as at higher center-of-mass energies. It is shown that this method not only increases the statistical precision, but also greatly reduces the systematic uncertainties, which can be important. Numerical results are presented, based on a realistic event simulation, for two signal selection strategies: using conventional selection cuts, and using an Iterative Discriminant Analysis (IDA). Our studies indicate that a precision of {Delta}m{tilde t}{sub 1} = 0.42 GeV can be achieved, representing a major improvement over previous studies. While the analysis of stops is particularly challenging due to the possibility of stop hadronization, the general procedure could be applied to the mass measurement of other particles as well. We also comment on the potential of the IDA to discover a stop quark in this scenario, and we revisit the accuracy of the theoretical predictions for the neutralino relic density.

  19. A Method for the Precision Mass Measurement of the Stop Quark at the International Linear Collider

    SciTech Connect

    Freitas, Ayres; Milstene, Caroline; Schmitt, Michael; Sopczak, Andre; /Lancaster U.

    2007-12-01

    Many supersymmetric models predict new particles within the reach of the next generation of colliders. For an understanding of the model structure and the mechanism(s) of symmetry breaking, it is important to know the masses of the new particles precisely. In this article the measurement of the mass of the scalar partner of the top quark (stop) at an e{sup +}e{sup -} collider is studied. A relatively light stop is motivated by attempts to explain electroweak baryogenesis and can play an important role in dark matter relic density. A method is presented which makes use of cross-section measurements near the pair-production threshold as well as at higher center-of-mass energies. It is shown that this method not only increases the statistical precision, but also greatly reduces the systematic uncertainties, which can be important. numerical results are presented, based on a realistic event simulation, for two signal selection strategies: using conventional selection cuts, and using an Iterative Discriminant Analysis (IDA). The studies indicate that a precision of {Delta}m{sub {bar t}{sub 1}} = 0.42 GeV can be achieved, representing a major improvement over previous studies. While the analysis of stops is particularly challenging due to the possibility of stop hadronization, the general procedure could be applied to the mass measurement of other particles as well. They also comment on the potential of the IDA to discover a stop quark in this scenario, and they revisit the accuracy of the theoretical predictions for the neutralino relic density.

  20. High Energy Colliders

    NASA Astrophysics Data System (ADS)

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

    INTRODUCTION PHYSICS CONSIDERATIONS GENERAL REQUIRED LUMINOSITY FOR LEPTON COLLIDERS THE EFFECTIVE PHYSICS ENERGIES OF HADRON COLLIDERS HADRON-HADRON MACHINES LUMINOSITY SIZE AND COST CIRCULAR e^{+}e^- MACHINES LUMINOSITY SIZE AND COST e^{+}e^- LINEAR COLLIDERS LUMINOSITY CONVENTIONAL RF SUPERCONDUCTING RF AT HIGHER ENERGIES γ - γ COLLIDERS μ ^{+} μ^- COLLIDERS ADVANTAGES AND DISADVANTAGES DESIGN STUDIES STATUS AND REQUIRED R AND D COMPARISION OF MACHINES CONCLUSIONS DISCUSSION

  1. Higgs bosons production and decay at future e + e - linear colliders as a probe of the B-L model

    NASA Astrophysics Data System (ADS)

    Ramírez-Sánchez, F.; Gutiérrez-Rodríguez, A.; Hernández-Ruíz, M. A.

    2016-09-01

    We study the phenomenology of the light and heavy Higgs boson production and decay in the context of a U{(1)}{{B}-{{L}}} extension of the standard model with an additional Z\\prime boson at future {e}+{e}- linear colliders with center-of-mass energies of \\sqrt{s}=500\\unicode{8211}3000\\text{ GeV} and integrated luminosities of { L }=500-2000{{fb}}-1. The study includes the processes {e}+{e}-\\to (Z,Z\\prime )\\to {Zh} and {e}+{e}-\\to (Z,Z\\prime )\\to {ZH}, considering both the resonant and non-resonant effects. We find that the total number of expected Zh and ZH events can reach 909, 124 and 97, 487, respectively, which is a very optimistic scenario and thus it would be possible to perform precision measurements for both Higgs bosons h and H, as well as for the Z\\prime boson in future high-energy and high-luminosity {e}+{e}- colliders experiments. Our study complements other studies on the B-L model and on the Higgs-strahlung processes {e}+{e}-\\to (Z,Z\\prime )\\to {Zh} and {e}+{e}-\\to (Z,Z\\prime )\\to {ZH}.

  2. Effects of quadrupole fringe fields in final focus systems for linear colliders

    NASA Astrophysics Data System (ADS)

    Patecki, Marcin; Tomás, Rogelio

    2014-10-01

    Quadrupole fringe fields in the final focus system can be a source of aberrations in the interaction point transverse beam sizes. This paper investigates the fringe field impact on the transverse beam size in the ATF2, ILC, and CLIC lattices in the linear and non-linear regimes. The linear effects are studied by replacing the hard-edge quadrupolar field by the more realistic gradient fall-off. To address the nonlinear effects, the fringe fields are represented as high order kicks added to both sides of the hard-edge magnets. It will be shown that the linear fringe fields effects can be easily cured by tuning the quadrupole strengths. On the other hand, mitigation of the nonlinear fringe fields effects is more difficult and requires use of octupole magnets or, alternatively, increasing the value of interaction point horizontal beta function βx*.

  3. Recent electron-cloud simulation results for the main damping rings of the NLC and TESLA linear colliders

    SciTech Connect

    Pivi, M.; Raubenheimer, T.O.; Furman, M.A.

    2003-05-01

    In the beam pipe of the Main Damping Ring (MDR) of the Next Linear Collider (NLC), ionization of residual gases and secondary emission give rise to an electron-cloud which stabilizes to equilibrium after few bunch trains. In this paper, we present recent computer simulation results for the main features of the electron cloud at the NLC and preliminary simulation results for the TESLA main damping rings, obtained with the code POSINST that has been developed at LBNL, and lately in collaboration with SLAC, over the past 7 years. Possible remedies to mitigate the effect are also discussed. We have recently included the possibility to simulate different magnetic field configurations in our code including solenoid, quadrupole, sextupole and wiggler.

  4. Quartic gauge boson couplings at linear colliders. Interplay of WWZ/ZZZ production and WW-fusion

    NASA Astrophysics Data System (ADS)

    Han, Tao; He, Hong-Jian; Yuan, C.-P.

    1998-03-01

    We study new physics effects to the quartic gauge boson couplings formulated by the electroweak chiral Lagrangian. Five next-to-leading order operators characterize the anomalous quartic gauge interactions which involve pure Goldstone boson dynamics for the electroweak symmetry breaking. We estimate the typical size of these couplings in different strongly-interacting models and examine the sensitivity to directly probing them via the WWZ/ZZZ triple gauge boson production at the high energy linear colliders. The important roles of polarized e- and e+ beams are stressed. We then compare the results with those from the W-pair production of the WW-fusion processes, and analyze the interplay of these two production mechanisms for an improved probe of the quartic gauge boson interactions.

  5. Beam-based measurements of long-range transverse wakefields in the Compact Linear Collider main-linac accelerating structure

    NASA Astrophysics Data System (ADS)

    Zha, Hao; Latina, Andrea; Grudiev, Alexej; De Michele, Giovanni; Solodko, Anastasiya; Wuensch, Walter; Schulte, Daniel; Adli, Erik; Lipkowitz, Nate; Yocky, Gerald S.

    2016-01-01

    The baseline design of CLIC (Compact Linear Collider) uses X-band accelerating structures for its main linacs. In order to maintain beam stability in multibunch operation, long-range transverse wakefields must be suppressed by 2 orders of magnitude between successive bunches, which are separated in time by 0.5 ns. Such strong wakefield suppression is achieved by equipping every accelerating structure cell with four damping waveguides terminated with individual rf loads. A beam-based experiment to directly measure the effectiveness of this long-range transverse wakefield and benchmark simulations was made in the FACET test facility at SLAC using a prototype CLIC accelerating structure. The experiment showed good agreement with the simulations and a strong suppression of the wakefields with an unprecedented minimum resolution of 0.1 V /(pC mm m ) .

  6. Stanford Geothermal Program

    SciTech Connect

    R. Horn

    1999-06-30

    Reliable measurement of steam-water relative permeability functions is of great importance for geothermal reservoir performance simulation. Despite their importance, these functions are poorly known due to the lack of fundamental understanding of steam-water flows, and the difficulty of making direct measurements. The Stanford Geothermal Program has used an X-ray CT (Computer Tomography) scanner to obtain accurate saturation profiles by direct measurement. During the last five years, the authors have carried out experiments with nitrogen-water flow and with steam-water flow, and examined the effects of heat transfer and phase change by comparing these sets of results. In porous rocks, it was found that the steam-water relative permeabilities follow Corey type relationships similar to those in nitrogen-water flow, but that the irreducible gas phase saturation is smaller for steam than for nitrogen. The irreducible saturations represent substantial fractions of the recoverable energy in place yet are hard to determine in the field. Understanding the typical magnitude of irreducible saturations will lead to a much clearer forecast of geothermal field performance. In fracture flow, indirect measurements suggested that the relative permeabilities follow a linear (or ''X-curve'') behavior - but there is still considerable uncertainty in the knowledge of this behavior.

  7. Design, Simulation and Testing of a Precision Alignment Frame for the Next Linear Collider

    SciTech Connect

    Fitsos, P

    2004-06-18

    An alignment frame is developed to support 3 Beam Position Monitors (BPM's) for detecting and ultimately aligning the electron beam from a linear accelerator. This report discusses the design details, preliminary modal analysis of the alignment frame as well as the addition of a metrology frame in the final phase of development.

  8. Report of Snowmass 2001 working group E2: Electron - positron colliders from the phi to the Z

    SciTech Connect

    Zhen-guo Zhao et al.

    2002-12-23

    We report on the status and plans of experiments now running or proposed for electron-positron colliders at energies between the {phi} and the Z. The e{sup +}e{sup -}B and charm factories we considered were PEP-II/BABAR, KEKB/Belle, superKEK, SuperBABAR, and CESR-c/CLEO-c. We reviewed the programs at the {phi} factory at Frascati and the proposed PEP-N facility at Stanford Linear Accelerator Center. We studied the prospects for B physics with a dedicated linear collider Z factory, associated with the TESLA high energy linear collider. In all cases, we compared the physics reach of these facilities with that of alternative experiments at hadron colliders or fixed target facilities.

  9. The E166 experiment: Development of an Undulator-Based Polarized Positron Source for the International Linear Collider

    SciTech Connect

    Kovermann, J.; Stahl, A.; Mikhailichenko, A.A.; Scott, D.; Moortgat-Pick, G.A.; Gharibyan, V.; Pahl, P.; Poschl, R.; Schuler, K.P.; Laihem, K.; Riemann, S.; Schalicke, A.; Dollan, R.; Kolanoski, H.; Lohse, T.; Schweizer, T.; McDonald, K.T.; Batygin, Y.; Bharadwaj, V.; Bower, G.; Decker, F.J.; /SLAC /Tel Aviv U. /Tennessee U.

    2011-11-14

    A longitudinal polarized positron beam is foreseen for the international linear collider (ILC). A proof-of-principle experiment has been performed in the final focus test beam at SLAC to demonstrate the production of polarized positrons for implementation at the ILC. The E166 experiment uses a 1 m long helical undulator in a 46.6 GeV electron beam to produce a few MeV photons with a high degree of circular polarization. These photons are then converted in a thin target to generate longitudinally polarized e{sup +} and e{sup -}. The positron polarization is measured using a Compton transmission polarimeter. The data analysis has shown asymmetries in the expected vicinity of 3.4% and {approx}1% for photons and positrons respectively and the expected positron longitudinal polarization is covering a range from 50% to 90%. The full exploitation of the physics potential of an international linear collider (ILC) will require the development of polarized positron beams. Having both e{sup +} and e{sup -} beams polarized will provide new insight into structures of couplings and thus give access to physics beyond the standard model [1]. The concept for a polarized positron source is based on circularly polarized photon sources. These photons are then converted to longitudinally polarized e{sup +} and e{sup -} pairs. While in an experiment at KEK [1a], Compton backscattering is used [2], the E166 experiment uses a helical undulator to produce polarized photons. An undulator-based positron source for the ILC has been proposed in [3,4]. The proposed scheme for an ILC positron source is illustrated in figure 1. In this scheme, a 150 GeV electron beam passes through a 120 m long helical undulator to produce an intense photon beam with a high degree of circular polarization. These photons are converted in a thin target to e{sup +} e{sup -} pairs. The polarized positrons are then collected, pre-accelerated to the damping ring and injected to the main linac. The E166 experiment is

  10. Demonstration of a high-field short-period superconducting helical undulator suitable for future TeV-scale linear collider positron sources.

    PubMed

    Scott, D J; Clarke, J A; Baynham, D E; Bayliss, V; Bradshaw, T; Burton, G; Brummitt, A; Carr, S; Lintern, A; Rochford, J; Taylor, O; Ivanyushenkov, Y

    2011-10-21

    The first demonstration of a full-scale working undulator module suitable for future TeV-scale positron-electron linear collider positron sources is presented. Generating sufficient positrons is an important challenge for these colliders, and using polarized e(+) would enhance the machine's capabilities. In an undulator-based source polarized positrons are generated in a metallic target via pair production initiated by circularly polarized photons produced in a helical undulator. We show how the undulator design is developed by considering impedance effects on the electron beam, modeling and constructing short prototypes before the successful fabrication, and testing of a final module.

  11. Photon collider Higgs factories

    NASA Astrophysics Data System (ADS)

    Telnov, V. I.

    2014-09-01

    The discovery of the Higgs boson (and still nothing else) have triggered appearance of many proposals of Higgs factories for precision measurement of the Higgs properties. Among them there are several projects of photon colliders (PC) without e+e- in addition to PLC based on e+e- linear colliders ILC and CLIC. In this paper, following a brief discussion of Higgs factories physics program I give an overview of photon colliders based on linear colliders ILC and CLIC, and of the recently proposed photon-collider Higgs factories with no e+e- collision option based on recirculation linacs in ring tunnels.

  12. Gamma-gamma colliders

    SciTech Connect

    Kim, K.J.; Sessler, A.

    1996-06-01

    Gamma-gamma colliders make intense beams of gamma rays and have them collide so as to make elementary particles. The authors show, in this article, that constructing a gamma-gamma collider as an add-on to an electron-positron linear collider is possible with present technology and that it does not require much additional cost. Furthermore, they show that the resulting capability is very interesting from a particle physics point of view. An overview of a linear collider, with a second interaction region devoted to {gamma}{gamma} collisions is shown.

  13. A precise measurement of the left-right asymmetry of Z Boson production at the SLAC linear collider

    SciTech Connect

    1994-09-01

    We present a precise measurement of the left-right cross section asymmetry of Z boson production (A{sub LR}) observed in 1993 data at the SLAC linear collider. The A{sub LR} experiment provides a direct measure of the effective weak mixing angle through the initial state couplings of the electron to the Z. During the 1993 run of the SLC, the SLD detector recorded 49,392 Z events produced by the collision of longitudinally polarized electrons on unpolarized positrons at a center-of-mass energy of 91.26 GeV. A Compton polarimeter measured the luminosity-weighted electron polarization to be (63.4{+-}1.3)%. ALR was measured to be 0.1617{+-}0.0071(stat.){+-}0.0033(syst.), which determines the effective weak mixing angle to be sin {sup 2}{theta}{sub W}{sup eff} = 0.2292{+-}0.0009(stat.){+-}0.0004(syst.). This measurement of A{sub LR} is incompatible at the level of two standard deviations with the value predicted by a fit of several other electroweak measurements to the Standard Model.

  14. Mending the Stanford Campus.

    ERIC Educational Resources Information Center

    Lockwood, Charles

    1998-01-01

    Describes efforts to reclaim the historical campus plan for Stanford University (California), including preserving views; restoring open space; realigning streets and pedestrian paths; consolidating parking; connecting paths; adding a new shuttle bus, bike lanes, and bike parking; and correcting the haphazard development of athletic and recreation…

  15. Stanford's Online Strategy

    ERIC Educational Resources Information Center

    Waters, John K.

    2013-01-01

    Stanford University (CA) is MOOC Central. While the school may not have launched the first massive open online course (MOOC), its efforts have propelled the concept to the forefront of higher education in a matter of months. Starting with Sebastian Thrun's Introduction to Artificial Intelligence course, which enrolled 160,000 students, Stanford…

  16. Faculty Handbook, Stanford University.

    ERIC Educational Resources Information Center

    Stanford Univ., CA.

    University policies, regulations, and procedures that apply to faculty members directly or indirectly, as well as the university's organization and governance, are described in the 1975 handbook. A brief history of Stanford's academic development and a bibliography to other information sources related to academic affairs are also provided.…

  17. The Stanford Flood.

    ERIC Educational Resources Information Center

    Leighton, Philip D.

    1979-01-01

    Describes, from the flood to the start of freeze-drying operations, the preservation efforts of Stanford University regarding books damaged by water in the Green Library in November 1978. Planning, action, and mopping-up activities are chronicled, and 20 suggestions are offered as guidance in future similar situations. (JD)

  18. Design study of beam dynamics issues for 1 TeV next linear collider based upon the relativistic-klystron two-beam accelerator

    SciTech Connect

    Li, H.; Goffeney, N.; Henestroza, E.; Sessler, A.; Yu, S.; Houck, T.; Westenskow, G.

    1994-11-01

    A design study has recently been conducted for exploring the feasibility of a relativistic-klystron two-beam accelerator (RK-TBA) system as a rf power source for a 1 TeV linear collider. The author present, in this paper, the beam dynamics part of this study. They have achieved in their design study acceptable transverse and longitudinal beam stability properties for the resulting high efficiency and low cost RK-TBA.

  19. Design study of beam dynamics issues for a one TeV next linear collider based upon the relativistic klystron two-beam accelerator

    SciTech Connect

    Li, H.; Houck, T.; Goffeney, N.; Henestroza, E.; Sessler, A.; Westenskow, G.; Yu, S.

    1995-06-01

    A design study has recently been conducted for exploring the feasibility of a relativistic-klystron two-beam accelerator (RK-TBA) system as a rf power source for a 1 TeV linear collider. We present, in this paper, the beam dynamics part of this study. We have achieved in our design study acceptable transverse and longitudinal beam stability properties for the resulting high efficiency and low cost RK-TBA. {copyright} 1995 {ital American Institute of Physics}.

  20. Presentations from the 3rd Workshop On Super Flavor Factory Based On Linear Collider Technology (Super B III) ,14-16 Jun 2006, Menlo Park, California

    SciTech Connect

    MacFarlane, D.

    2006-11-10

    This workshop was aimed at continuing discussions of the design for a very high luminosity e{sup +}e{sup -} collider using many of the same technical approaches as for the International Linear Collider. On this basis, the previous two meetings at Frascati have explored several new and promising ideas for reaching luminosities as high as 10{sup 36} cm{sup -2} s{sup -1} or more. We expect to continue the development of a coherent concept for the machine at the June meeting, ultimately aiming at a full written description of the concept by the end of 2006. The workshop also studied the capability of SuperB for a full range of flavor physics, and the corresponding requirements and demands on the associated detector.

  1. 77 FR 59661 - Notice of Inventory Completion: Stanford University Archaeology Center, Stanford, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-28

    ... National Park Service Notice of Inventory Completion: Stanford University Archaeology Center, Stanford, CA AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: The Stanford University Archaeology... to be culturally affiliated with the human remains may contact the Stanford University...

  2. Hosing Instability of the Drive Electron Beam in the E157 Plasma-Wakefield Acceleration Experiment at the Stanford Linear Accelerator

    SciTech Connect

    Blue, Brent Edward; /SLAC /UCLA

    2005-10-10

    In the plasma-wakefield experiment at SLAC, known as E157, an ultra-relativistic electron beam is used to both excite and witness a plasma wave for advanced accelerator applications. If the beam is tilted, then it will undergo transverse oscillations inside of the plasma. These oscillations can grow exponentially via an instability know as the electron hose instability. The linear theory of electron-hose instability in a uniform ion column predicts that for the parameters of the E157 experiment (beam charge, bunch length, and plasma density) a growth of the centroid offset should occur. Analysis of the E157 data has provided four critical results. The first was that the incoming beam did have a tilt. The tilt was much smaller than the radius and was measured to be 5.3 {micro}m/{delta}{sub z} at the entrance of the plasma (IP1.) The second was the beam centroid oscillates in the ion channel at half the frequency of the beam radius (betatron beam oscillations), and these oscillations can be predicted by the envelope equation. Third, up to the maximum operating plasma density of E157 ({approx}2 x 10{sup 14} cm{sup -3}), no growth of the centroid offset was measured. Finally, time-resolved data of the beam shows that up to this density, no significant growth of the tail of the beam (up to 8ps from the centroid) occurred even though the beam had an initial tilt.

  3. Preliminary design report of a relativistic-Klystron two-beam-accelerator based power source for a 1 TeV center-of-mass next linear collider

    SciTech Connect

    Yu, S.; Goffeney, N.; Henestroza, E.

    1995-02-22

    A preliminary point design for an 11.4 GHz power source for a 1 TeV center-of-mass Next Linear Collider (NLC) based on the Relativistic-Klystron Two-Beam-Accelerator (RK-TBA) concept is presented. The present report is the result of a joint LBL-LLNL systems study. consisting of three major thrust areas: physics, engineering, and costing. The new RK-TBA point design, together with our findings in each of these areas, are reported.

  4. Rational Budgeting? The Stanford Case.

    ERIC Educational Resources Information Center

    Chaffee, Ellen Earle

    The budget decision making process at Stanford University, California, from 1970 through 1979 was evaluated in relation to the allocation of general funds to 38 academic departments. Using Simon's theory of bounded rationality and an organizational level of analysis, the Stanford decision process was tested for its rationality through…

  5. Environmental assessment for the proposed B-Factory (Asymmetric Electron Positron Collider)

    SciTech Connect

    Not Available

    1993-11-01

    This document presents the potential environmental consequences associated with the construction and operation of an Asymmetric Electron Positron Collider, also known as a B-Factory. DOE proposes to modify either the existing Positron-Electron Project at the Stanford Linear Accelerator Center (SLAC) or the Cornell Electron Storage Ring (CESR) at Cornell University. PEP and CESR provide the most technically promising and practical options for a B-Factory. A B-Factory can be constructed by modifying the existing facilities and with minor or no conventional construction. Details involved with the upgrade along with two alternatives to the proposed action are described.

  6. A New Chicane Experiment in PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders

    SciTech Connect

    Pivi, M. T.; Pivi, M.T.F.; Ng, J.S.T.; Arnett, D.; Cooper, F.; Kharakh, D.; King, F.K.; Kirby, R.E.; Kuekan, B.; Lipari, J.J.; Munro, M.; Olszewski, J.; Raubenheimer, T.O.; Seeman, J.; Spencer, C.M.; Wang, L.; Wittmer, W.; Celata, C.M.; Furman, M.A.; Smith, B.

    2008-06-11

    Beam instability caused by the electron cloud has been observed in positron and proton storage rings, and it is expected to be a limiting factor in the performance of future colliders [1-3]. The effect is expected to be particularly severe in magnetic field regions. To test possible mitigation methods in magnetic fields, we have installed a new 4-dipole chicane experiment in the PEP-II Low Energy Ring (LER) at SLAC with both bare and TiN-coated aluminum chambers. In particular, we have observed a large variation of the electron flux at the chamber wall as a function of the chicane dipole field. We infer this is a new high order resonance effect where the energy gained by the electrons in the positron beam depends on the phase of the electron cyclotron motion with respect to the bunch crossing, leading to a modulation of the secondary electron production. Presumably the cloud density is modulated as well and this resonance effect could be used to reduce its magnitude in future colliders. We present the experimental results obtained during January 2008 until the April final shut-down of the PEP-II machine.

  7. A New Chicane Experiment In PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders

    SciTech Connect

    Pivi, M.T.F.; Ng, J.S.T.; Arnett, D.; Cooper, F.; Kharakh, D.; King, F.K.; Kirby, R.E.; Kuekan, B.; Lipari, J.J.; Munro, M.; Olszewski, J.; Raubenheimer, T.O.; Seeman, J.; Smith, B.; Spencer, C.M.; Wang, L.; Wittmer, W.; Celata, C.M.; Furman, M.A.; /SLAC /LBL, Berkeley

    2008-07-03

    Beam instability caused by the electron cloud has been observed in positron and proton storage rings, and it is expected to be a limiting factor in the performance of future colliders [1-3]. The effect is expected to be particularly severe in magnetic field regions. To test possible mitigation methods in magnetic fields, we have installed a new 4-dipole chicane experiment in the PEP-II Low Energy Ring (LER) at SLAC with both bare and TiN-coated aluminum chambers. In particular, we have observed a large variation of the electron flux at the chamber wall as a function of the chicane dipole field. We infer this is a new high order resonance effect where the energy gained by the electrons in the positron beam depends on the phase of the electron cyclotron motion with respect to the bunch crossing, leading to a modulation of the secondary electron production. Presumably the cloud density is modulated as well and this resonance effect could be used to reduce its magnitude in future colliders. We present the experimental results obtained during January 2008 until the April final shut-down of the PEP-II machine.

  8. Discriminating between Z Prime -boson effects and effects of anomalous gauge couplings in the double production of W{sup {+-}} bosons at a linear collider

    SciTech Connect

    Andreev, Vasili V.; Pankov, A. A.

    2013-06-15

    The potential of the International Linear electron-positron Collider (ILC) for seeking, in the annihilation production of W{sup {+-}}-boson pairs, signals induced by new neutral gauge bosons predicted by models belonging to various classes and featuring an extended gauge sector is studied. Limits that will be obtained at ILC for the parameters and masses of Z Prime bosons are compared with present-day and future data from the Large Hadron Collider (LHC). The possibility of discriminating between the effects of Z-Z Prime mixing and signals induced by anomalous gauge couplings (AGC) is demonstrated within theoretically motivated trilinear gauge models involving several free anomalous parameters. It is found that the sensitivity of ILC to the effects of Z-Z Prime mixing in the process e{sup +}e{sup -} {yields} W{sup +}W{sup -} and its ability to discriminate between these two new-physics scenarios, Z Prime and AGC, become substantially higher upon employing polarized initial (e{sup +}e{sup -}) and final (W{sup {+-}}) states.

  9. Searches for new neutral gauge Z' bosons at the e{sup +}e{sup -} International Linear Collider and their identification

    SciTech Connect

    Babich, A. A. Pankov, A. A. Tsytrinov, A. V. Karpenko, N. V.

    2010-05-15

    The potential of the electron-positron International Linear Collider for searches for and the separation of signals induced by new neutral gauge bosons predicted by various classes of models featuring an extended gauge sector is investigated. The analysis presented in this article was performed for processes of annihilation fermion-pair production and was based on the use of differential polarization observables, which ensure a higher sensitivity (in relation to integrated observables) of the processes being considered to Z'-boson parameters. Thresholds for discovering and identifying new neutral gauge bosons associated with models belonging to the E{sub 6} and LR, as well as the ALR and SSM, classes are determined. In particular, it is shown that polarization experiments at a 0.5-TeV electron-positron collider of integrated luminosity 100 fb{sup -1} would make it possible to identify unambiguously the entire set of Z'-boson models (Z'{sub SSM}, Z'{sub {phi}}, Z'{sub {eta}}, Z'{sub {chi}}, Z'{sub LRS}, and Z'{sub ALR}) for M{sub Z'} < 6{radical}s and to improve considerably the respective estimates expected from experiments with unpolarized particles.

  10. Higgs bosons production and decay at future e + e ‑ linear colliders as a probe of the B–L model

    NASA Astrophysics Data System (ADS)

    Ramírez-Sánchez, F.; Gutiérrez-Rodríguez, A.; Hernández-Ruíz, M. A.

    2016-09-01

    We study the phenomenology of the light and heavy Higgs boson production and decay in the context of a U{(1)}{{B}-{{L}}} extension of the standard model with an additional Z\\prime boson at future {e}+{e}- linear colliders with center-of-mass energies of \\sqrt{s}=500\\unicode{8211}3000\\text{ GeV} and integrated luminosities of { L }=500-2000{{fb}}-1. The study includes the processes {e}+{e}-\\to (Z,Z\\prime )\\to {Zh} and {e}+{e}-\\to (Z,Z\\prime )\\to {ZH}, considering both the resonant and non-resonant effects. We find that the total number of expected Zh and ZH events can reach 909, 124 and 97, 487, respectively, which is a very optimistic scenario and thus it would be possible to perform precision measurements for both Higgs bosons h and H, as well as for the Z\\prime boson in future high-energy and high-luminosity {e}+{e}- colliders experiments. Our study complements other studies on the B–L model and on the Higgs-strahlung processes {e}+{e}-\\to (Z,Z\\prime )\\to {Zh} and {e}+{e}-\\to (Z,Z\\prime )\\to {ZH}.

  11. 14. Photocopy of 1872 photograph by Eadweard Muybridge in Stanford ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Photocopy of 1872 photograph by Eadweard Muybridge in Stanford University Archives, PC 6. SEWING ROOM ('BIRD ROOM').LEFT TO RIGHT, ANNA MARIA LATHROP (MRS. STANFORD'S SISTER), MRS. JANE ANN (DYER) LATHROP (MRS. STANFORD'S MOTHER), ELIZABETH PHILLIPS (MRS. JOSIAH) STANFORD (GOV. STANFORD'S MOTHER), JANE LATHROP (MRS. LELAND) STANFORD AND HER SON, LELAND, JR. - Leland Stanford House, 800 N Street, Sacramento, Sacramento County, CA

  12. A systems study of an RF power source for a 1 TeV next linear collider based upon the relativistic-klystron two-beam accelerator

    SciTech Connect

    Yu, S.; Goffeney, N.; Deadrick, F.

    1994-11-01

    A systems study, including physics, engineering and costing, has been conducted to assess the feasibility of a relativistic-klystron two-beam-accelerator (RK-TBA) system as a RF power source candidate for a 1 TeV linear collider. Several key issues associated with a realizable RK-TBA system have been addressed, and corresponding schemes have been developed and examined quantitatively. A point design example has been constructed to present a concrete conceptual design which has acceptable transverse and longitudinal beam stability properties. The overall efficiency of RF production for such a power source is estimated to be 36%, and the cost of the full system is estimated to be less than 1 billion dollars.

  13. A systems study of an RF power source for a 1 TeV next linear collider based upon the relativistic-klystron two-beam accelerator

    SciTech Connect

    Yu, S.; Deadrick, F.; Goffeney, N.; Henestroza, E.; Houck, T.; Li, H.; Peters, C.; Reginato, L.; Sessler, A.; Vanecek, D.; Westenskow, G.

    1995-07-05

    A systems study, including physics, engineering, and costing, has been conducted to assess the feasibility of a relativistic-klystron two-beam-accelerator (RK-TBA) system as a RF power source candidate for a 1 TeV linear collider. Several key issues associated with a realizable RK-TBA system have been addressed, and corresponding schemes have been developed and examined quantitatively. A point design example has been constructed to present a concrete conceptual design which has acceptable transverse and longitudinal beam stability properties. The overall efficiency of RF production for such a power source is estimated to be 36%, and the cost of the full system is estimated to be less than 1 billion dollars. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  14. Exotic colliders

    SciTech Connect

    Chattopadhyay, S.

    1994-11-01

    The motivation, feasibility and potential for two unconventional collider concepts - the Gamma-Gamma Collider and the Muon Collider - are described. The importance of the development of associated technologies such as high average power, high repetition rate lasers and ultrafast phase-space techniques are outlined.

  15. Temporal characterization of the Stanford Mid-IR FEL by frequency-resolved optical gating

    SciTech Connect

    Richman, B.A.; DeLong, K.W.; Trebino, R.

    1995-02-01

    We measure the time-dependent intensity and phase of laser pulses from the Stanford Mid-IR FEL. We present the first measurements of near-transform-limited, linearly chirped, and sideband modulated FEL pulses.

  16. Photon collider at TESLA

    NASA Astrophysics Data System (ADS)

    Telnov, Valery

    2001-10-01

    High energy photon colliders ( γγ, γe) based on backward Compton scattering of laser light is a very natural addition to e +e - linear colliders. In this report, we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case, the γγ luminosity in the high energy part of spectrum can reach about (1/3) Le +e -. Typical cross-sections of interesting processes in γγ collisions are higher than those in e +e - collisions by about one order of magnitude, so the number of events in γγ collisions will be more than that in e +e - collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is "an optical storage ring (optical trap)" with a diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based on the linear collider TESLA, its possible parameters and existing problems.

  17. Muon colliders

    SciTech Connect

    Palmer, R.B. |; Sessler, A.; Skrinsky, A.

    1996-01-01

    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 {micro}{sup +}{micro}{sup {minus}}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.

  18. Linear Collider Test Facility: Twiss Parameter Analysis at the IP/Post-IP Location of the ATF2 Beam Line

    SciTech Connect

    Bolzon, Benoit; Jeremie, Andrea; Bai, Sha; Bambade, Philip; White, Glen; /SLAC

    2012-07-02

    At the first stage of the ATF2 beam tuning, vertical beam size is usually bigger than 3 {micro}m at the IP. Beam waist measurements using wire scanners and a laser wire are usually performed to check the initial matching of the beam through to the IP. These measurements are described in this paper for the optics currently used ({beta}{sub x} = 4cm and {beta}{sub y} = 1mm). Software implemented in the control room to automate these measurements with integrated analysis is also described. Measurements showed that {beta} functions and emittances were within errors of measurements when no rematching and coupling corrections were done. However, it was observed that the waist in the horizontal (X) and vertical (Y) plane was abnormally shifted and simulations were performed to try to understand these shifts. They also showed that multiknobs are needed in the current optics to correct simultaneously {alpha}{sub x}, {alpha}{sub y} and the horizontal dispersion (D{sub x}). Such multiknobs were found and their linearity and orthogonality were successfully checked using MAD optics code. The software for these multiknobs was implemented in the control room and waist scan measurements using the {alpha}{sub y} knob were successfully performed.

  19. Functional Requirements on the Design of the Detectors and the Interaction Region of an e e- Linear Collider with a Push-Pull Arrangement of Detectors

    SciTech Connect

    Parker, B.; Mikhailichenko, A.; Buesser, K.; Hauptman, J.; Tauchi, T.; Burrows, P.; Markiewicz, T.; Oriunno, M.; Seryi, A.; Markiewicz, T.; /SLAC

    2009-06-02

    The Interaction Region of the International Linear Collider is based on two experimental detectors working in a push-pull mode. A time efficient implementation of this model sets specific requirements and challenges for many detector and machine systems, in particular the IR magnets, the cryogenics and the alignment system, the beamline shielding, the detector design and the overall integration. This paper attempts to separate the functional requirements of a push pull interaction region and machine detector interface from any particular conceptual or technical solution that might have been proposed to date by either the ILC Beam Delivery Group or any of the three detector concepts. As such, we hope that it provides a set of ground rules for interpreting and evaluating the MDI parts of the proposed detector concept's Letters of Intent, due March 2009. The authors of the present paper are the leaders of the IR Integration Working Group within Global Design Effort Beam Delivery System and the representatives from each detector concept submitting the Letters Of Intent.

  20. Prompt J /ψ production in association with a c c ¯ pair within the framework of nonrelativistic QCD via photon-photon collisions at the International Linear Collider

    NASA Astrophysics Data System (ADS)

    Sun, Zhan; Wu, Xing-Gang; Zhang, Hong-Fei

    2015-10-01

    We present a systematical study on the prompt J /ψ production in association with a c c ¯ pair via the process, γ γ →H (c c ¯)+c +c ¯, within the framework of nonrelativistic QCD at the future high-energy e+e- collider—International Linear Collider (ILC), including both direct and feed-down contributions. For direct J /ψ production, the states with color-octet channels, especially the P3 J[8] and S1 0[8] ones, provide a dominant contribution to the production cross section, which are about 52 times over that of the color-singlet one. This is clearly shown by the transverse momentum (pt) and rapidity distributions. The feed-down contribution from ψ' and χc J (J =0 , 1, 2) is sizable, which is about 20% to the total prompt cross section. Besides the yields, we also calculate the J /ψ polarization parameter λ . In the small pt region, the polarization of the prompt J /ψ is longitudinal due to large contributions through the P3 J[8] channel, and becomes transverse in the high pt region due to the S3 1[8] channel. Thus the J /ψ production via photon-photon collisions at the ILC shall provide a useful platform for testing the color-octet mechanism.

  1. Hypersonic research at Stanford University

    NASA Technical Reports Server (NTRS)

    Candler, Graham; Maccormack, Robert

    1988-01-01

    The status of the hypersonic research program at Stanford University is discussed and recent results are highlighted. The main areas of interest in the program are the numerical simulation of radiating, reacting and thermally excited flows, the investigation and numerical solution of hypersonic shock wave physics, the extension of the continuum fluid dynamic equations to the transition regime between continuum and free-molecule flow, and the development of novel numerical algorithms for efficient particulate simulations of flowfields.

  2. Beam Rounders for Circular Colliders

    SciTech Connect

    A. Burov; S. Nagaitsev; Ya. Derbenev

    2001-07-01

    By means of linear optics, an arbitrary uncoupled beam can be locally transformed into a round (rotation-invariant) state and then back. This provides an efficient way to round beams in the interaction region of circular colliders.

  3. Beam rounders for circular colliders

    SciTech Connect

    A. Burov and S. Nagaitsev

    2002-12-10

    By means of linear optics, an arbitrary uncoupled beam can be locally transformed into a round (rotation-invariant) state and then back. This provides an efficient way to round beams in the interaction region of circular colliders.

  4. SLAC Linear Collider waveguide valve

    SciTech Connect

    Dean, N.R.; Fowkes, W.R.; Hoyt, M.W.; Schwarz, H.D.; Tillmann, E.F.

    1987-03-01

    A waveguide valve with a peak rf power handling capability of 70 MW and a reliable vacuum seal was needed for changing the new SLC klystrons. The original SLAC indium seal valve experienced rf breakdown above 35 MW and did not make a reliable vacuum seal. A new design was developed which incorporates the old valve housing but employs a new concept. The indium-knife edge seal has been replaced by an O-ring seal mechanism, which is transported to an rf-free environment during high power operation. The O-ring ''garage door'' seal rf currents are reduced to a manageable level through the use of an rf choke plunger which has a rejection capability in excess of 20 dB. The isolation between the high power rf and the O-ring chamber exceeds 100 dB.

  5. Ion colliders

    SciTech Connect

    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

  6. The Stanford Picosecond FEL Center

    SciTech Connect

    Schwettman, H.A.; Smith, T.I.; Swent, R.L.

    1995-12-31

    In the past two years, FELs have decisively passed the threshold of scientific productivity. There are now six FEL facilities in the United States and Europe, each delivering more than 2000 hours of FEL beam time per year. at the present time approximately 100 papers are published each in referred journals describing optics experiments performed with FELs. Despite the recent success there are important challenges the FEL facilities must address. At Stanford these challenges include: (1) Providing sufficient experimental time at reasonable cost: At Stanford we provide 2000 hours of experimental time per year at a cost of approximately $500 per hour: We are now studying options for markedly increasing experimental time and decreasing cost per hour. (2) Competing effectively with conventional lasers in the mid-IR: Despite the NRC report we do not intend to concede the mid-IR to conventional lasers. FELs are capable of providing optical beams of exceptional quality and stability, and they can also be remarkable flexible devices. Improvements in our superconducting linac driver and our optical beam conditioning systems will dramatically enhance our FEL experimental capabilities. (3) making the transition from first generation to second generation experiments: Important pump-probe and photon echo experiments have been performed at Stanford and others are feasible using present capabilities. None-the-less we are now investing substantial experimental time to improving signal-to-noise and developing other optical cababilities. (4) Extending operation to the far-infrared where the FEL is unique inits capabilities: {open_quotes}FIREFLY{close_quotes} will extend our FEL capabilities to 100 microns. We are now seeking funds for optical instrumentation. (5) Creating and maintaining a good environment for graduate students.

  7. Photon-photon colliders

    SciTech Connect

    Sessler, Andrew M.

    1996-01-01

    Since the seminal work by Ginsburg, et al., the subject of giving the Next Linear Collider photon-photon capability, as well as electron-positron capability, has drawn much attention [1]. A 1990 article by V.I. Telnov describes the situation at that time [2]. In March 1994, the first workshop on this subject was held [3]. 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.

  8. Photon-photon colliders

    SciTech Connect

    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. Muon Collider

    SciTech Connect

    Palmer, R.

    2009-10-19

    Parameters are given of muon colliders with center of mass energies of 1.5 and 3 TeV. Pion production is from protons on a mercury target. Capture, decay, and phase rotation yields bunch trains of both muon signs. Six dimensional cooling reduces the emittances until the trains are merged into single bunches, one of each sign. Further cooling in 6 dimensions is then applied, followed by final transverse cooling in 50 T solenoids. After acceleration the muons enter the collider ring. Ongoing R&D is discussed.

  10. Achievement Components of Stanford-Binet Performance.

    ERIC Educational Resources Information Center

    Washington, Ernest D.; And Others

    A curriculum was devised by working backward from Stanford-Binet items to specification of a universe of content for which the Stanford-Binet could serve as a content-valid achievement test. It was reasoned that this curriculum should home. This curriculum was tested on 20 4-year-old disadvantaged children in Champaign-Urbana, Illinois. The…

  11. An Afterburner at the ILC: The Collider Viewpoint

    SciTech Connect

    Raubenheimer, Tor O.

    2004-12-07

    The concept of a high-gradient plasma wakefield accelerator is considered as an upgrade path for the International Linear Collider, a future linear collider. Basic parameters are presented based on those developed for the SLC 'Afterburner'. Basic layout considerations are described and the primary concerns related to the collider operation are discussed.

  12. An Afterburner at the ILC: The Collider Viewpoint

    SciTech Connect

    Raubenheimer, T

    2004-09-01

    The concept of a high-gradient plasma wakefield accelerator is considered as an upgrade path for the International Linear Collider, a future linear collider. Basic parameters are presented based on those developed for the SLC ''Afterburner.'' Basic layout considerations are described and the primary concerns related to the collider operation are discussed.

  13. The Stanford Synchrotron Radiation Laboratory, 20 years of synchrotron light

    SciTech Connect

    Cantwell, K.

    1993-08-01

    The Stanford Synchrotron Radiation Laboratory (SSRL) is now operating as a fully dedicated light source with low emittance electron optics, delivering high brightness photon beams to 25 experimental stations six to seven months per year. On October 1, 1993 SSRL became a Division of the Stanford Linear Accelerator Center, rather than an Independent Laboratory of Stanford University, so that high energy physics and synchrotron radiation now function under a single DOE contract. The SSRL division of SLAC has responsibility for operating, maintaining and improving the SPEAR accelerator complex, which includes the storage ring and a 3 GeV injector. SSRL has thirteen x-ray stations and twelve VUV/Soft x-ray stations serving its 600 users. Recently opened to users is a new spherical grating monochromator (SGM) and a multiundulator beam line. Circularly polarized capabilities are being exploited on a second SGM line. New YB{sub 66} crystals installed in a vacuum double-crystal monochromator line have sparked new interest for Al and Mg edge studies. One of the most heavily subscribed stations is the rotation camera, which has been recently enhanced with a MAR imaging plate detector system for protein crystallography on a multipole wiggler. Under construction is a new wiggler-based structural molecular biology beam line with experimental stations for crystallography, small angle scattering and x-ray absorption spectroscopy. Plans for new developments include wiggler beam lines and associated facilities specialized for environmental research and materials processing.

  14. SLAC-Linac-Collider (SLC) Project

    SciTech Connect

    Wiedemann, H.

    1981-02-01

    The proposed SLAC Linear Collider Project (SLC) and its features are described in this paper. In times of ever increasing costs for energy the electron storage ring principle is about to reach its practical limit. A new class of colliding beam beam facilities, the Linear Colliders, are getting more and more attractive and affordable at very high center-of-mass energies. The SLC is designed to be a poineer of this new class of colliding beam facilities and at the same time will serve as a valuable tool to explore the high energy physics at the level of 100 GeV in the center-of-mass system.

  15. Status and future directions for advanced accelerator research - conventional and non-conventional collider concepts

    SciTech Connect

    Siemann, R.H.

    1997-01-01

    The relationship between advanced accelerator research and future directions for particle physics is discussed. Comments are made about accelerator research trends in hadron colliders, muon colliders, and e{sup +}3{sup {minus}} linear colliders.

  16. Quantum-beamsstrahlung laser collider

    SciTech Connect

    Tajima, T.; Chattopadyay, S.; Xie, M.

    1997-11-01

    An e{sup +}e{sup {minus}} linear collider at energies beyond a TeV runs into a problem of severe beamsstrahlung, characterized by {Upsilon} on the order of unity (and beyond). In the regime of extremely high {Upsilon} the beamsstrahlung may be largely suppressed due to the quantum effect. In the design of an e{sup +}e{sup {minus}} collider there are two ways to satisfy the collider physics constraints. One is to decrease the number of particles per bunch (and thus to increase the repetition rate) and the other is to decrease the longitudinal bunch length. The former approach can limit {Upsilon}, while the latter boosts it. (It may be useful to reevaluate the future collider parameters in view of this.) The laser wakefield driver for a collider in comparison with the microwave driver naturally offers a very short bunch length, which is appropriate for the latter collider option. The authors show that this choice of collider design with a short bunch length and high {Upsilon} has advantages and provide sample design parameters at 5 TeV. Such sample design parameters challenge them in a number of fronts, such as the preservation of high quality bunches, efficient high repetition rate lasers, etc. The collision point physics simulated by the CAIN code shows a surprisingly well preserved luminosity spectrum.

  17. The Stanford equivalence principle program

    NASA Technical Reports Server (NTRS)

    Worden, Paul W., Jr.; Everitt, C. W. Francis; Bye, M.

    1989-01-01

    The Stanford Equivalence Principle Program (Worden, Jr. 1983) is intended to test the uniqueness of free fall to the ultimate possible accuracy. The program is being conducted in two phases: first, a ground-based version of the experiment, which should have a sensitivity to differences in rate of fall of one part in 10(exp 12); followed by an orbital experiment with a sensitivity of one part in 10(exp 17) or better. The ground-based experiment, although a sensitive equivalence principle test in its own right, is being used for technology development for the orbital experiment. A secondary goal of the experiment is a search for exotic forces. The instrument is very well suited for this search, which would be conducted mostly with the ground-based apparatus. The short range predicted for these forces means that forces originating in the Earth would not be detectable in orbit. But detection of Yukawa-type exotic forces from a nearby large satellite (such as Space Station) is feasible, and gives a very sensitive and controllable test for little more effort than the orbiting equivalence principle test itself.

  18. Collider physics

    SciTech Connect

    Not Available

    1991-01-01

    This past year our group participated in both the D0 experiment at Fermilab and the SDC experiment at the SSC. Most of our effort was concentrated on the D0 project, where we contributed as much manpower as possible to the commissioning of the detector in preparation for the coming collider run. Our SDC work consisted of the investigation of one of the candidate technologies for the forward calorimeter. On the D0 experiment, our primary responsibilities have been in the areas of electronics commissioning and in the establishment of triggers for the coming collider run. We have also actively participated in the physics studies and have contributed to the upgrade effort as much as time has permitted. Our group has also participated in the cosmic ray run and in the D0 test beam. In view of our contributions, James White was selected as a member of the D0 Trigger board, and Jay Wightman is being trained as one of the global experts'' who are responsible for keeping the detector operational during the run. In addition, Amber Boehnlein has played a major role in the Level-2 trigger commissioning. A more detailed description of these activities is given in this paper.

  19. 77 FR 59968 - Notice of Intent To Repatriate Cultural Items: Stanford University Archaeology Center, Stanford, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... National Park Service Notice of Intent To Repatriate Cultural Items: Stanford University Archaeology Center... Archaeology Center, in consultation with the appropriate Indian tribes, has determined that the cultural items... affiliated with the cultural items may contact the Stanford University Archaeology Center....

  20. The super collider revisited

    SciTech Connect

    Hussein, M.S.; Pato, M.P. )

    1992-05-20

    In this paper, the authors suggest a revised version of the Superconducting Super Collider (SSC) that employs the planned SSC first stage machine as an injector of 0.5 TeV protons into a power laser accelerator. The recently developed Non-linear Amplification of Inverse Bremsstrahlung Acceleration (NAIBA) concept dictates the scenario of the next stage of acceleration. Post Star Wars lasers, available at several laboratories, can be used for the purpose. The 40 TeV CM energy, a target of the SSC, can be obtained with a new machine which can be 20 times smaller than the planned SSC.

  1. The Polarized Electron Source for the International Collider (ILC) Project

    SciTech Connect

    Brachmann, A.; Clendenin, J. E.; Garwin, E. L.; Ioakeimidi, K.; Kirby, R. E.; Maruyama, T.; Prescott, C. Y.; Sheppard, J.; Turner, J.; Zhou, F.

    2007-06-13

    The ILC project will be the next large high energy physics tool that will use polarized electrons (and positrons). For this machine spin physics will play an important role. The polarized electron source design is based on electron injectors built for the Stanford Linear Collider (polarized) and Tesla Test Facility (un-polarized). The ILC polarized electron source will provide a 5GeV spin polarized electron beam for injection into the ILC damping ring. Although most ILC machine parameters have been achieved by the SLC or TTF source, features of both must be integrated into one design. The bunch train structure presents unique challenges to the source laser drive system. A suitable laser system has not yet been demonstrated and is part of the ongoing R and D program for ILC at SLAC. Furthermore, ILC injector R and D incorporates photocathode development, increasing available polarization, and improving operational properties in gun vacuum systems. Another important area of research and development is advancing the design of DC and RF electron gun technology for polarized sources. This presentation presents the current status of the design and outlines aspects of the relevant R and D program carried out within the ILC community.

  2. The Polarized Electron Source for the International Collider (ILC) Project

    SciTech Connect

    Brachmann, A.; Clendenin, J.E.; Garwin, E.L.; Ioakeimidi, K.; Kirby, R.e.; Maruyama, T.; Prescott, C.Y.; Sheppard, J.; Turner, J.; Zhou, F.; /SLAC

    2006-12-01

    ILC project will be the next large high energy physics tool that will use polarized electrons (and positrons). For this machine spin physics will play an important role. The polarized electron source design is based on electron injectors built for the Stanford Linear Collider (polarized) and Tesla Test Facility (un-polarized). The ILC polarized electron source will provide a 5GeV spin polarized electron beam for injection into the ILC damping ring. Although most ILC machine parameters have been achieved by the SLC or TTF source, features of both must be integrated into one design. The bunch train structure presents unique challenges to the source laser drive system. A suitable laser system has not yet been demonstrated and is part of the ongoing R&D program for ILC at SLAC. Furthermore, ILC injector R&D incorporates photocathode development, increasing available polarization, and improving operational properties in gun vacuum systems. Another important area of research and development is advancing the design of DC and RF electron gun technology for polarized sources. This presentation presents the current status of the design and outlines aspects of the relevant R&D program carried out within the ILC community.

  3. The Stanford how things work project

    NASA Technical Reports Server (NTRS)

    Fikes, Richard; Gruber, Tom; Iwasaki, Yumi

    1994-01-01

    We provide an overview of the Stanford How Things Work (HTW) project, an ongoing integrated collection of research activities in the Knowledge Systems Laboratory at Stanford University. The project is developing technology for representing knowledge about engineered devices in a form that enables the knowledge to be used in multiple systems for multiple reasoning tasks and reasoning methods that enable the represented knowledge to be effectively applied to the performance of the core engineering task of simulating and analyzing device behavior. The central new capabilities currently being developed in the project are automated assistance with model formulation and with verification that a design for an electro-mechanical device satisfies its functional specification.

  4. 75 FR 18482 - Stanford University Habitat Conservation Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-12

    ... 0648-XV36 Stanford University Habitat Conservation Plan AGENCIES: National Marine Fisheries Service... habitat conservation plan, and receipt of application; notice of public meeting. SUMMARY: This notice... Incidental Take and Implementation of Stanford University ] Habitat Conservation Plan (Plan), and...

  5. The Stanford Library Flood Restoration Project.

    ERIC Educational Resources Information Center

    Buchanan, Sally

    1979-01-01

    Describes the restoration project for approximately 50,000 volumes damaged in a flood at the Stanford University Libraries: the freezing and vacuum drying of damaged books, their subsequent repair by a special project staff, and various tests conducted in the vacuum chamber on how best to dry the books. (Author)

  6. A Close Look at Stanford v. Kentucky.

    ERIC Educational Resources Information Center

    Update on Law-Related Education, 2000

    2000-01-01

    Discusses whether the imposition of capital punishment on an individual for a crime committed as a juvenile constitutes cruel and unusual punishment under the Eighth Amendment of the U.S. Constitution. Explores the crimes of Kevin Stanford and David Allen who were 16 and 17 respectively when they each committed murder. (CMK)

  7. Computer-Assisted Instruction at Stanford.

    ERIC Educational Resources Information Center

    Suppes, Patrick

    Programs for computer-assisted instruction (CAI) which were developed at Stanford University from 1963-70 are described, and prospects for CAI in the 1970's are considered briefly. The programs include ones in arithmetic, logic, and reading for elementary grades and in basic Russian and remedial algebra for college students. Of these, the logic…

  8. Phase and amplitude control system for Stanford Linear Accelerator

    SciTech Connect

    Yoo, S.J.

    1983-09-26

    The computer controlled phase and amplitude detection system measures the instantaneous phase and amplitude of a 1 micro-second 2856 MHz rf pulse at a 180 Hz rate. This will be used for phase feedback control, and also for phase and amplitude jitter measurement. The program, which was originally written by John Fox and Keith Jobe, has been modified to improve the function of the system. The software algorithms used in the measurement are described, as is the performance of the prototype phase and amplitude detector system.

  9. Collider Signal I :. Resonance

    NASA Astrophysics Data System (ADS)

    Tait, Tim M. P.

    2010-08-01

    These TASI lectures were part of the summer school in 2008 and cover the collider signal associated with resonances in models of physics beyond the Standard Model. I begin with a review of the Z boson, one of the best-studied resonances in particle physics, and review how the Breit-Wigner form of the propagator emerges in perturbation theory and discuss the narrow width approximation. I review how the LEP and SLAC experiments could use the kinematics of Z events to learn about fermion couplings to the Z. I then make a brief survey of models of physics beyond the Standard Model which predict resonances, and discuss some of the LHC observables which we can use to discover and identify the nature of the BSM physics. I finish up with a discussion of the linear moose that one can use for an effective theory description of a massive color octet vector particle.

  10. Stanford Geothermal Program, reservoir and injection technology

    SciTech Connect

    Horne, R.; Ramey, H.J. Jr.; Miller, F.G.; Brigham, W.E.; Kruger, P.

    1988-12-01

    This annual report of the Stanford Geothermal Program presents major projects in reservoir and injection technology. The four include: (1) an application of the boundary element method to front tracking and pressure transient testing; (2) determination of fracture aperture, a multi-tracer approach; (3) an analysis of tracer and thermal transients during reinjection; and, (4) pressure transient modeling of a non-uniformly fractured reservoir. (BN)

  11. Who Sank The Khaki Submarine At Stanford? A Study of Decision-Making At Stanford University.

    ERIC Educational Resources Information Center

    Kemerer, Frank R.; And Others

    From the late 1960s to the spring of 1970 there was an acceleration of anti-war protest and political movements. At Stanford University this period was characterized by controversy, deep divisions within the university community, disruption of classes, student strikes, and the presence of uniformed police on campus. In this environment of…

  12. The International Linear Collider Progress Report 2015

    SciTech Connect

    Yamamoto, Akira

    2015-07-15

    The ILC technical design is now being adapted to the preferred candidate site. Changes in layout are being managed by a rigorous change-control procedure. Series production of cavities for the European XFEL has shown that cavities can be mass-produced in industry with a performance well above XFEL requirements and close to that needed for the ILC. A number of technical developments are under way with a view to further reducing the ILC cost. This work must continue through the preparatory stage for ILC construction once resources become available. A summary of the design updates and of the further preparatory work needed is summarized in tabular form in the Appendix.

  13. The Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Myers, Stephen

    The Large Hadron Collider (LHC) was first suggested (in a documented way) in 1983 [1] as a possible future hadron collider to be installed in the 27 km "LEP" tunnel. More than thirty years later the collider has been operated successfully with beam for three years with spectacular performance and has discovered the long-sought-after Higgs boson. The LHC is the world's largest and most energetic particle collider. It took many years to plan and build this large complex machine which promises exciting, new physics results for many years to come...

  14. The development of colliders

    SciTech Connect

    Sessler, A.M.

    1997-03-01

    During the period of the 50`s and the 60`s colliders were developed. Prior to that time there were no colliders, and by 1965 a number of small devices had worked, good understanding had been achieved, and one could speculate, as Gersh Budker did, that in a few years 20% of high energy physics would come from colliders. His estimate was an under-estimate, for now essentially all of high energy physics comes from colliders. The author presents a brief review of that history: sketching the development of the concepts, the experiments, and the technological advances which made it all possible.

  15. Information Retrieval (SPIRES) and Library Automation (BALLOTS) at Stanford University.

    ERIC Educational Resources Information Center

    Ferguson, Douglas, Ed.

    At Stanford University, two major projects have been involved jointly in library automation and information retrieval since 1968: BALLOTS (Bibliographic Automation of Large Library Operations) and SPIRES (Stanford Physics Information Retrieval System). In early 1969, two prototype applications were activated using the jointly developed systems…

  16. 75 FR 27708 - Stanford University Habitat Conservation Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    ... INFORMATION: Need for Correction In the Federal Register of April 12, 2010, in FR Doc. 2010-8300, on page... 0648-XV36 Stanford University Habitat Conservation Plan AGENCIES: National Marine Fisheries Service... Register on April 12, 2010, announcing the availability of the Stanford University Habitat...

  17. The Predictive Validity of the Stanford Early School Achievement Test

    ERIC Educational Resources Information Center

    Ames, Steven G.; And Others

    1977-01-01

    A sample of first grade children were pretested with the Stanford Early School Achievement Test and posttested with the Stanford Achievement Test. Results demonstrated moderate validity of theformer for predicting first grade achievement. Prediction was better in verbal achievement than in mathematics achievement. (Author/JKS)

  18. The future of the Large Hadron Collider and CERN.

    PubMed

    Heuer, Rolf-Dieter

    2012-02-28

    This paper presents the Large Hadron Collider (LHC) and its current scientific programme and outlines options for high-energy colliders at the energy frontier for the years to come. The immediate plans include the exploitation of the LHC at its design luminosity and energy, as well as upgrades to the LHC and its injectors. This may be followed by a linear electron-positron collider, based on the technology being developed by the Compact Linear Collider and the International Linear Collider collaborations, or by a high-energy electron-proton machine. This contribution describes the past, present and future directions, all of which have a unique value to add to experimental particle physics, and concludes by outlining key messages for the way forward.

  19. Colliders and brane vector phenomenology

    SciTech Connect

    Clark, T. E.; Love, S. T.; Xiong, C.; Nitta, Muneto; Veldhuis, T. ter

    2008-12-01

    Brane world oscillations manifest themselves as massive vector gauge fields. Their coupling to the standard model is deduced using the method of nonlinear realizations of the spontaneously broken higher dimensional space-time symmetries. Brane vectors are stable and weakly interacting and therefore escape particle detectors unnoticed. LEP and Tevatron data on the production of a single photon in conjunction with missing energy are used to delineate experimentally excluded regions of brane vector parameter space. The additional region of parameter space accessible to the LHC as well as a future lepton linear collider is also determined by means of this process.

  20. Towards future circular colliders

    NASA Astrophysics Data System (ADS)

    Benedikt, Michael; Zimmermann, Frank

    2016-09-01

    The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) presently provides proton-proton collisions at a center-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics program 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 (FCCee) 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 Nb3 S n superconductor, for the FCC-hh hadron collider, and a highly-efficient superconducting radiofrequency system for the FCC-ee lepton collider. Following the FCC concept, the Institute of High Energy Physics (IHEP) in Beijing has initiated a parallel design study for an e + e - Higgs factory in China (CEPC), which is to be succeeded by a high-energy hadron collider (SPPC). At present a tunnel circumference of 54 km and a hadron collider c.m. energy of about 70 TeV are being considered. After a brief look at the LHC, this article reports the motivation and the present status of the FCC study, some of the primary design challenges and R&D subjects, as well as the emerging global collaboration.

  1. Accelerator R&D toward Muon Collider and Neutrino Factory

    NASA Astrophysics Data System (ADS)

    Shiltsev, V.

    2010-12-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture, accelerate and collide high intensity beams of muons. At present, a high-luminosity multi-TeV muon collider presents a viable option for the next generation lepton-lepton collider, which is believed to be needed to fully explore high energy physics in the era following LHC discoveries. Such a collider can offer superb energy resolution, smaller size, and potentially cost and power consumption compared to multi-TeV e + e - linear colliders. This article briefly reviews the motivation, design and status of accelerator R&D for Muon Collider and Neutrino Factory.

  2. Accelerator R&D toward Muon Collider and Neutrino Factory

    SciTech Connect

    Shiltsev, Vladimir; /Fermilab

    2009-10-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture, accelerate and collide high intensity beams of muons. At present, a high-luminosity multi-TeV muon collider presents a viable option for the next generation lepton-lepton collider, which is believed to be needed to fully explore high energy physics in the era following LHC discoveries. Such a collider can offer superb energy resolution, smaller size, and potentially cost and power consumption compared to multi-TeV e{sup +}e{sup -} linear colliders. This article briefly reviews the motivation, design and status of accelerator R&D for Muon Collider and Neutrino Factory.

  3. Environmental radiation effects from muon and tau colliders and their impact on facility licensing.

    PubMed

    Bevelacqua, J J

    2012-11-01

    Although contemporary accelerators only affect their local radiation environment, muon and tau colliders produce radiation profiles that extend far beyond their site boundaries. These radiation profiles affect the licensing and siting of these planned accelerators. The analysis presented herein suggests that a linear collider concept with the lepton beams collided in air offers a means to limit the environmental radiation effects from these accelerators.

  4. Hadron hadron collider group

    SciTech Connect

    Palmer, R.; Peoples, J.; Ankenbrandt, C.

    1982-01-01

    The objective of this group was to make a rough assessment of the characteristics of a hadron-hadron collider which could make it possible to study the 1 TeV mass scale. Since there is very little theoretical guidance for the type of experimental measurements which could illuminate this mass scale, we chose to extend the types of experiments which have been done at the ISR, and which are in progress at the SPS collider to these higher energies.

  5. FFAG Designs for Muon Collider Acceleration

    SciTech Connect

    Berg, J. Scott

    2014-01-13

    I estimate FFAG parameters for a muon collider with a 70mm longitudinal emittance. I do not discuss the lower emittance beam for a Higgs factory. I produce some example designs, giving only parameters relevant to estimating cost and performance. The designs would not track well, but the parameters of a good design will be close to those described. I compare these cost estimates to those for a fast-ramping synchrotron and a recirculating linear accelerator. I conclude that FFAGs do not appear to be cost-effective for the large longitudinal emittance in a high-energy muon collider.

  6. The Stanford Preschool Internal-External Scale: Extension to Kindergarteners

    ERIC Educational Resources Information Center

    Chartier, George M.; And Others

    1976-01-01

    The Stanford Preschool Internal-External Scale (SPIES) was administered to middle class kindergarten children to investigate whether the characteristics of the test would remain stable as it did for the normative sample. (Author/DEP)

  7. On the use of iterative techniques for feedforward control of transverse angle and position jitter in linear particle beam accelerators

    SciTech Connect

    Barr, D.S.

    1994-11-01

    It is possible to use feedforward predictive control for transverse position and trajectory-angle jitter correction. The control procedure is straightforward, but creation of the predictive filter is not as obvious. The two processes tested were the least mean squares (LMS) and Kalman inter methods. The controller parameters calculated offline are downloaded to a real-time analog correction system between macropulses. These techniques worked well for both interpulse (pulse-to-pulse) correction and intrapulse (within a pulse) correction with the Kalman filter method being the clear winner. A simulation based on interpulse data taken at the Stanford Linear Collider showed an improvement factor of almost three in the average rms jitter over standard feedback techniques for the Kalman filter. An improvement factor of over three was found for the Kalman filter on intrapulse data taken at the Los Alamos Meson Physics Facility. The feedforward systems also improved the correction bandwidth.

  8. The Large Hadron Collider.

    PubMed

    Evans, Lyndon

    2012-02-28

    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.

  9. The Muon Collider

    SciTech Connect

    Zisman, Michael S

    2010-05-17

    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&D program. After describing the ingredients of the facility, the ongoing R&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.

  10. The Muon Collider

    SciTech Connect

    Zisman, Michael S.

    2011-01-05

    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&D program. After describing the ingredients of the facility, the ongoing R&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.

  11. The large hadron collider

    NASA Astrophysics Data System (ADS)

    Brüning, O.; Burkhardt, H.; Myers, S.

    2012-07-01

    The Large Hadron Collider (LHC) is the world’s largest and most energetic particle collider. It took many years to plan and build this large complex machine which promises exciting, new physics results for many years to come. We describe and review the machine design and parameters, with emphasis on subjects like luminosity and beam conditions which are relevant for the large community of physicists involved in the experiments at the LHC. First collisions in the LHC were achieved at the end of 2009 and followed by a period of a rapid performance increase. We discuss what has been learned so far and what can be expected for the future.

  12. Muon collider design

    SciTech Connect

    Palmer, R. |; Sessler, A.; Skrinsky, A.

    1996-03-01

    The possibility of muon colliders was introduced by Skrinsky et al., Neuffer, and others. More recently, several workshops and collaboration meetings have greatly increased the level of discussion. In this paper we present scenarios for 4 TeV and 0.5 TeV colliders based on an optimally designed proton source, and for a lower luminosity 0.5 TeV demonstration based on an upgraded version of the AGS. It is assumed that a demonstration version based on upgrades of the FERMILAB machines would also be possible. 53 refs., 25 figs., 8 tabs.

  13. High energy colliders

    SciTech Connect

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

    1997-02-01

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

  14. History of narcolepsy at Stanford University.

    PubMed

    Mignot, Emmanuel J M

    2014-05-01

    Although narcolepsy was first described in the late nineteenth century in Germany and France, much of the research on this disorder has been conducted at Stanford University, starting with Drs. William C. Dement and Christian Guilleminault in the 1970s. The prevalence of narcolepsy was established, and a canine model discovered. Following the finding in Japan that almost all patients with narcolepsy carry a specific HLA subtype, HLA-DR2, Hugh Mac Devitt, F. Carl Grumet, and Larry Steinman initiated immunological studies, but results were generally negative. Using the narcoleptic canines, Dr. Nishino and I established that stimulants increased wakefulness by stimulating dopaminergic transmission while antidepressants suppress cataplexy via adrenergic reuptake inhibition. A linkage study was initiated with Dr. Grumet in 1988, and after 10 years of work, the canine narcolepsy gene was cloned by in 1999 and identified as the hypocretin (orexin) receptor 2. In 1992, studying African Americans, we also found that DQ0602 rather than DR2 was a better marker for narcolepsy across all ethnic groups. In 2000, Dr. Nishino and I, in collaboration with Dr. Lammers in the Netherlands, found that hypocretin 1 levels in the cerebrospinal fluid (CSF) were undetectable in most cases, establishing hypocretin deficiency as the cause of narcolepsy. Pursuing this research, our and Dr. Siegel's group, examining postmortem brains, found that the decreased CSF hypocretin 1 was secondary to the loss the 70,000 neurons producing hypocretin in the hypothalamus. This finding revived the autoimmune hypothesis but attempts at demonstrating immune targeting of hypocretin cells failed until 2013. At this date, Dr. Elisabeth Mellins and I discovered that narcolepsy is characterized by the presence of autoreactive CD4(+) T cells to hypocretin fragments when presented by DQ0602. Following reports that narcolepsy cases were triggered by vaccinations and infections against influenza A 2009 pH1N1, a new

  15. High luminosity muon collider design

    SciTech Connect

    Palmer, R.; Gallardo, J.

    1996-10-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should be regarded as complementary. Parameters are given of 4 TeV high luminosity {mu}{sup +}{mu}{sup {minus}} collider, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders.

  16. Heavy Meson Production at a Low-Energy Photon Collider

    SciTech Connect

    Asztalos, S

    2004-04-15

    A low-energy {gamma}{gamma} collider has been discussed in the context of a testbed for a {gamma}{gamma} interaction region at the Next Linear Collider(NLC). We consider the production of heavy mesons at such a testbed using Compton-backscattered photons and demonstrate that their production rivals or exceeds those by BELLE, BABAR or LEP where they are produced indirectly via virtual {gamma}{gamma} luminosities.

  17. Future Accelerators, Muon Colliders, and Neutrino Factories

    SciTech Connect

    Richard A Carrigan, Jr.

    2001-12-19

    Particle physics is driven by five great topics. Neutrino oscillations and masses are now at the fore. The standard model with extensions to supersymmetry and a Higgs to generate mass explains much of the field. The origins of CP violation are not understood. The possibility of extra dimensions has raised tantalizing new questions. A fifth topic lurking in the background is the possibility of something totally different. Many of the questions raised by these topics require powerful new accelerators. It is not an overstatement to say that for some of the issues, the accelerator is almost the experiment. Indeed some of the questions require machines beyond our present capability. As this volume attests, there are parts of the particle physics program that have been significantly advanced without the use of accelerators such as the subject of neutrino oscillations and many aspects of the particle-cosmology interface. At this stage in the development of physics, both approaches are needed and important. This chapter first reviews the status of the great accelerator facilities now in operation or coming on within the decade. Next, midrange possibilities are discussed including linear colliders with the adjunct possibility of gamma-gamma colliders, muon colliders, with precursor neutrino factories, and very large hadron colliders. Finally visionary possibilities are considered including plasma and laser accelerators.

  18. Bouncing and Colliding Branes

    SciTech Connect

    Lehners, Jean-Luc

    2007-11-20

    In a braneworld description of our universe, we must allow for the possibility of having dynamical branes around the time of the big bang. Some properties of such domain walls in motion are discussed here, for example the ability of negative-tension domain walls to bounce off spacetime singularities and the consequences for cosmological perturbations. In this context, we will also review a colliding branes solution of heterotic M-theory that has been proposed as a model for early universe cosmology.

  19. Muon Collider Progress: Accelerators

    SciTech Connect

    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.

  20. SPIRES (Stanford Public Information Retrieval System) 1970-71 Annual Report.

    ERIC Educational Resources Information Center

    Parker, Edwin B.

    SPIRES (Stanford Public Information REtrieval System) is a computer information storage and retrieval system being developed at Stanford University with funding from the National Science Foundation. SPIRES has two major goals: to provide a user-oriented, interactive, on-line retrieval system for a variety of researchers at Stanford; and to support…

  1. SPIRES (STANFORD PHYSICS INFORMATION RETRIEVAL SYSTEM). ANNUAL REPORT.

    ERIC Educational Resources Information Center

    PARKER, EDWIN B.

    SPIRES WAS PLANNED AS A FIVE-YEAR EFFORT TO DEVELOP AND STUDY AN EXPERIMENTAL SYSTEM FOR PROVIDING FOR THE SCIENTIFIC INFORMATION NEEDS OF PHYSICISTS AT STANFORD. THERE ARE TWO COMPONENTS TO THE SPIRES PROJECT. ONE IS TO STUDY THE INFORMATION NEEDS AND INFORMATION-SEEKING BEHAVIOR OF A USER POPULATION OF ABOUT 100 HIGH- ENERGY PHYSICISTS. DETAILS…

  2. Information Systems to Support a Decision Process at Stanford.

    ERIC Educational Resources Information Center

    Chaffee, Ellen Earle

    1982-01-01

    When a rational decision process is desired, information specialists can contribute information and also contribute to the process in which that information is used, thereby promoting rational decision-making. The contribution of Stanford's information specialists to rational decision-making is described. (MLW)

  3. The Stanford University Medical Center and the Federal Government.

    ERIC Educational Resources Information Center

    Rosenzweig, Robert M.; And Others

    The Stanford University Medical Center consists of three main units: a medical school, a set of outpatient clinics, and a hospital. Financing of the center's functions cannot be carried out without federal support, and a network of relationships with government agencies has emerged. The impact of these relationships was discussed with key…

  4. Coverage of the Stanford Prison Experiment in Introductory Psychology Textbooks

    ERIC Educational Resources Information Center

    Griggs, Richard A.

    2014-01-01

    Zimbardo's 1971 Stanford Prison Experiment (SPE), one of the most famous studies in psychology, is discussed in most introductory textbooks. The present study is concerned with the nature of this coverage, given that there have been myriad criticisms, especially recently, of the SPE. These criticisms concern both Zimbardo's situationist…

  5. Coverage of the Stanford Prison Experiment in Introductory Psychology Courses

    ERIC Educational Resources Information Center

    Bartels, Jared M.; Milovich, Marilyn M.; Moussier, Sabrina

    2016-01-01

    The present study examined the coverage of Stanford prison experiment (SPE), including criticisms of the study, in introductory psychology courses through an online survey of introductory psychology instructors (N = 117). Results largely paralleled those of the recently published textbook analyses with ethical issues garnering the most coverage,…

  6. Stanford and Berlin: The Spheres of Politics and Intellect

    ERIC Educational Resources Information Center

    Shils, Edward

    1972-01-01

    Comparison of the cases of H. Bruce Franklin, a professor relieved of his duties at Stanford University because of his political actions, and Ernest Mandell, a professor at the Free University of Berlin who was denied appointment on the grounds of his political activities. (HS)

  7. Research Training in Medical Informatics: The Stanford Experience.

    ERIC Educational Resources Information Center

    Shortliffe, Edward H.; Fagan, Lawrence M.

    1989-01-01

    Stanford University created an interdisciplinary program to train researchers and academic leaders in the field of medical information sciences. The program is described, identifying experiences of interest to people developing such a program. The program's background and history, students, curriculum and philosophy, and lessons learned are…

  8. Computer-Assisted Instruction: Stanford's 1965-66 Arithmetic Program.

    ERIC Educational Resources Information Center

    Suppes, Patrick; And Others

    A review of the possibilities and challenges of computer-assisted instruction (CAI), and a brief history of CAI projects at Stanford serve to give the reader the context of the particular program described and analyzed in this book. The 1965-66 arithmetic drill-and-practice program is described, summarizing the curriculum and project operation. An…

  9. Hadron-hadron colliders

    SciTech Connect

    Month, M.; Weng, W.T.

    1983-06-21

    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.

  10. Muon Colliders and Neutrino Factories *

    NASA Astrophysics Data System (ADS)

    Geer, Steve

    2009-11-01

    Over the past decade, there has been significant progress in developing the concepts and technologies needed to produce, capture, and accelerate O(1021) muons per year. These developments have paved the way for a new type of neutrino source (neutrino factory) and a new type of very high energy lepton-antilepton collider (muon collider). This article reviews the motivation, design, and research and development for future neutrino factories and muon colliders.

  11. Muon Colliders and Neutrino Factories

    SciTech Connect

    Geer, Steve; /Fermilab

    2009-11-01

    Over the past decade, there has been significant progress in developing the concepts and technologies needed to produce, capture, and accelerate {Omicron}(10{sup 21}) muons per year. These developments have paved the way for a new type of neutrino source (neutrino factory) and a new type of very high energy lepton-antilepton collider (muon collider). This article reviews the motivation, design, and research and development for future neutrino factories and muon colliders.

  12. Muon colliders and neutrino factories

    SciTech Connect

    Geer, S.; /Fermilab

    2010-09-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate {Omicron}(10{sup 21}) muons/year. This development prepares the way for a new type of neutrino source (Neutrino Factory) and a new type of very high energy lepton-antilepton collider (Muon Collider). This article reviews the motivation, design and R&D for Neutrino Factories and Muon Colliders.

  13. 1998 NASA-ASEE-Stanford Summer Faculty Fellowship Program

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This report presents the essential features and highlights of the 1998 Summer Faculty Fellowship Program at Ames Research Center and Dryden Flight Research Center in a comprehensive and concise form. Summary reports describing the fellows' technical accomplishments are enclosed in the attached technical report. The proposal for the 1999 NASA-ASEE-Stanford Summer Faculty Fellowship Program is being submitted under separate cover. Of the 31 participating fellows, 27 were at Ames and 4 were at Dryden. The Program's central feature is the active participation by each fellow in one of the key technical activities currently under way at either the NASA Ames Research Center or the NASA Dryden Flight Research Center. The research topic is carefully chosen in advance to satisfy the criteria of: (1) importance to NASA, (2) high technical level, and (3) a good match to the interests, ability, and experience of the fellow, with the implied possibility of NASA-supported follow-on work at the fellow's home institution. Other features of the Summer Faculty Fellowship Program include participation by the fellows in workshops and seminars at Stanford, the Ames Research Center, and other off-site locations. These enrichment programs take place either directly or remotely, via the Stanford Center for Professional Development, and also involve specific interactions between fellows and Stanford faculty on technical and other academic subjects. A few, brief remarks are in order to summarize the fellows' opinions of the summer program. It is noteworthy that 90% of the fellows gave the NASA-Ames/Dryden- Stanford program an "excellent" rating and the remaining 10%, "good." Also, 100% would recommend the program to their colleagues as an effective means of furthering their professional development as teachers and researchers. Last, but not least, 87% of the fellows stated that a continuing research relationship with their NASA colleagues' organization probably would be maintained. Therefore

  14. Results from hadron colliders

    SciTech Connect

    Pondrom, L.G. )

    1990-12-14

    The present status of hadron collider physics is reviewed. The total cross section for {bar p} + p has been measured at 1.8 TeV: {sigma}{sub tot} = 72.1 {plus minus} 3.3 mb. New data confirm the UA2 observation of W/Z {yields} {bar q}q. Precision measurements of M{sub W} by UA2 and CDF give an average value M{sub W} = 80.13 {plus minus} 0.30 GeV/c{sup 2}. When combined with measurements of M{sub Z} from LEP and SLC this number gives sin{sup 2}{theta}{sub W} = 0.227 {plus minus} 0.006, or m{sub top} = 130{sub {minus}60}{sup +40} GeV/c{sup 2} from the EWK radiative correction term {Delta}r. Evidence for hadron colliders as practical sources of b quarks has been strengthened, while searches for t quarks have pushed the mass above M{sub W}: m{sub top} > 89 GeV/c{sup 2} 95% cl (CDF Preliminary). Searches beyond the standard model based on the missing E{sub T} signature have not yet produced any positive results. Future prospects for the discovery of the top quark in the range m{sub top} < 200 GeV/c{sup 2} look promising. 80 refs., 35 figs., 7 tabs.

  15. Stanford Synchrotron Radiation Laboratory 1991 activity report. Facility developments January 1991--March 1992

    SciTech Connect

    Cantwell, K.; St. Pierre, M.

    1992-12-31

    SSRL is a national facility supported primarily by the Department of Energy for the utilization of synchrotron radiation for basic and applied research in the natural sciences and engineering. It is a user-oriented facility which welcomes proposals for experiments from all researchers. The synchrotron radiation is produced by the 3.5 GeV storage ring, SPEAR, located at the Stanford Linear Accelerator Center (SLAC). SPEAR is a fully dedicated synchrotron radiation facility which operates for user experiments 7 to 9 months per year. SSRL currently has 24 experimental stations on the SPEAR storage ring. There are 145 active proposals for experimental work from 81 institutions involving approximately 500 scientists. There is normally no charge for use of beam time by experimenters. This report summarizes the activity at SSRL for the period January 1, 1991 to December 31, 1991 for research. Facility development through March 1992 is included.

  16. [Stanford type a acute aortic dissection with pectus excavatum].

    PubMed

    Kuwata, Toshiyuki; Fukuda, Hirotsugu; Yoshitatsu, Masao; Yamada, Yasuyuki; Shibasaki, Ikuko; Inoue, Yuho; Hori, Takayuki; Ogawa, Hironaga; Tsuchiya, Go; Shimizu, Riha; Takei, Yusuke

    2012-11-01

    Pectus excavatum is generally an isolated abnormality of the chest wall. However, some patients have a concomitant pectus deformity and cardiac & aortic disease. Decisions must be made regarding the operative approach and whether the pectus excavatum should be corrected during the same session. We report 2 patients with acute Stanford type A aortic dissection and pectus excavatum who underwent emergency operation. In case 1, median sternotomy is an unsuitable approach for open heart surgery, since the heart and great vessels are displace into the left hemithorax. But combined sternotomy and left anterior thoracotomy provided excellent surgical exposure. In case 2, we proceeded with a leftsided costotomy of four ribs and place a normal chest retractor providing as excellent exposure as combined sternotomy and left anterior thoracotomy. A left-sided costotomy of four ribs can be performed safely, eliminating the risks of median sternotomy in acute stanford type A aortic dissection with pectus excavatum.

  17. Stanford Geothermal Program, reservoir and injection technology. Fourth annual report

    SciTech Connect

    Horne, R.; Ramey, H.J. Jr.; Miller, F.G.; Brigham, W.E.; Kruger, P.

    1988-12-01

    This annual report of the Stanford Geothermal Program presents major projects in reservoir and injection technology. The four include: (1) an application of the boundary element method to front tracking and pressure transient testing; (2) determination of fracture aperture, a multi-tracer approach; (3) an analysis of tracer and thermal transients during reinjection; and, (4) pressure transient modeling of a non-uniformly fractured reservoir. (BN)

  18. ALPs at colliders

    NASA Astrophysics Data System (ADS)

    Mimasu, Ken; Sanz, Verónica

    2015-06-01

    New pseudo-scalars, often called axion-like particles (ALPs), abound in model-building and are often associated with the breaking of a new symmetry. Traditional searches and indirect bounds are limited to light axions, typically in or below the KeV range for ALPs coupled to photons. We present collider bounds on ALPs from mono-γ, tri-γ and mono-jet searches in a model independent fashion, as well as the prospects for the LHC and future machines. We find that they are complementary to existing searches, as they are sensitive to heavier ALPs and have the capability to cover an otherwise inaccessible region of parameter space. We also show that, assuming certain model dependent correlations between the ALP coupling to photons and gluons as well as considering the validity of the effective description of ALP interactions, mono-jet searches are in fact more suitable and effective in indirectly constraining ALP scenarios.

  19. Muon Collider design status

    SciTech Connect

    Alexahin, Y.; /Fermilab

    2010-09-01

    Muon Collider (MC) - proposed by G.I. Budker and A.N. Skrinsky a few decades ago - is now considered as the most exciting option for the energy frontier machine in the post-LHC era. A national Muon Accelerator Program (MAP) is being formed in the USA with the ultimate goal of building a MC at the Fermilab site with c.o.m. energy in the range 1.5-3 TeV and luminosity of {approx} 1.5 {center_dot} 10{sup 34} cm{sup -2} s{sup -1}. As the first step on the way to MC it envisages construction of a Neutrino Factory (NF) for high-precision neutrino experiments. The baseline scheme of the NF-MC complex is presented and possible options for its main components are discussed.

  20. Crystal Ball: On the Future High Energy Colliders

    SciTech Connect

    Shiltsev, Vladimir

    2015-09-20

    High energy particle colliders have been in the forefront of particle physics for more than three decades. 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). A number of next generation collider facilities have been proposed and are currently under consideration for the medium- and far-future of the accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance reach and cost range. We briefly review such post-LHC options as linear e+e- colliders in Japan (ILC) or at CERN (CLIC), muon collider, and circular lepton or hadron colliders in China (CepC/SppC) and Europe (FCC). We conclude with a look into ultimate energy reach accelerators based on plasmas and crystals, and some perspectives for the far future of accelerator-based particle physics.

  1. The chromatic correction in RHIC (Relativistic Heavy Ion Collider)

    SciTech Connect

    Lee, S.Y.; Dell, G.F.; Hahn, H.; Parzen, G.

    1987-01-01

    The scheme for the correction of chromatic effects in the Relativistic Heavy Ion Collider at BNL is discussed. This scheme uses six families of sextupoles excited by four independent power supplies, and provides adequate control of linear and quadratic terms in the tune vs momentum dependence and reduces the variation of the betatron amplitude, vs momentum.

  2. Alternative positron-target design for electron-positron colliders

    SciTech Connect

    Donahue, R.J. ); Nelson, W.R. )

    1991-04-01

    Current electron-positron linear colliders are limited in luminosity by the number of positrons which can be generated from targets presently used. This paper examines the possibility of using an alternate wire-target geometry for the production of positrons via an electron-induced electromagnetic cascade shower. 39 refs., 38 figs., 5 tabs.

  3. Hadron collider physics at UCR

    SciTech Connect

    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.

  4. One Hundred Years of History at Stanford University: Thoracic and Cardiovascular Surgery.

    PubMed

    Woo, Y Joseph; Reitz, Bruce A

    2015-01-01

    The history of thoracic and cardiovascular surgery at Stanford spans a century long period, beginning not long after the founding of Stanford University. Pioneering Stanford surgeons have made landmark discoveries and innovations in pulmonary, transplantation, thoracic aortic, mechanical circulatory support, minimally invasive, valvular, and congenital heart surgery. Fundamental research formed the foundation underlying these and many other advances. Educating and training the subsequent leaders of cardiothoracic surgery has throughout this century-long history constituted a mission of the highest merit.

  5. When Black Holes Collide

    NASA Technical Reports Server (NTRS)

    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.

  6. Collider Physics an Experimental Introduction

    NASA Astrophysics Data System (ADS)

    Elvezio Pagliarone, Carmine

    2011-04-01

    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 Michoacán, 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.

  7. Beam collimation at hadron colliders

    SciTech Connect

    Nikolai V. Mokhov

    2003-08-12

    Operational and accidental beam losses in hadron colliders can have a serious impact on machine and detector performance, resulting in effects ranging from minor to catastrophic. Principles and realization are described for a reliable beam collimation system required to sustain favorable background conditions in the collider detectors, provide quench stability of superconducting magnets, minimize irradiation of accelerator equipment, maintain operational reliability over the life of the machine, and reduce the impact of radiation on personnel and the environment. Based on detailed Monte-Carlo simulations, such a system has been designed and incorporated in the Tevatron collider. Its performance, comparison to measurements and possible ways to further improve the collimation efficiency are described in detail. Specifics of the collimation systems designed for the SSC, LHC, VLHC, and HERA colliders are discussed.

  8. Physicists dream of supersized collider

    NASA Astrophysics Data System (ADS)

    Hao, Cindy

    2015-12-01

    Particle physicists in China are hopeful that the Chinese government will allocate 1 billion yuan (about £104m) to design what would be the world's largest particle accelerator - the Circular Electron Positron Collider (CEPC).

  9. The prototype design of the Stanford Relativity Gyro Experiment

    NASA Technical Reports Server (NTRS)

    Parkinson, Bradford W.; Everitt, C. W. Francis; Turneaure, John P.; Parmley, Richard T.

    1987-01-01

    The Stanford Relativity Gyroscope Experiment constitutes a fundamental test of Einstein's General Theory of Relativity, probing such heretofore untested aspects of the theory as those that relate to spin by means of drag-free satellite-borne gyroscopes. General Relativity's prediction of two orthogonal precessions (motional and geodetic) for a perfect Newtonian gyroscope in polar orbit has not yet been experimentally assessed, and will mark a significant advancement in experimental gravitation. The technology employed in the experiment has been under development for 25 years at NASA's Marshall Space Flight Center. Four fused quartz gyroscopes will be used.

  10. Precise attitude control of the Stanford relativity satellite.

    NASA Technical Reports Server (NTRS)

    Bull, J. S.; Debra, D. B.

    1973-01-01

    A satellite being designed by the Stanford University to measure (with extremely high precision) the effect of General Relativity is described. Specifically, the satellite will measure two relativistic precessions predicted by the theory: the geodetic effect (6.9 arcsec/yr), due solely to motion about the earth, and the motional effect (0.05 arcsec/yr), due to rotation of the earth. The gyro design requirements, including the requirement for precise attitude control and a dynamic model for attitude control synthesis, are discussed. Closed loop simulation of the satellite's natural dynamics on an analog computer is described.

  11. Location and direction dependent effects in collider physics from noncommutativity

    SciTech Connect

    Haghighat, Mansour; Okada, Nobuchika; Stern, Allen

    2010-07-01

    We examine the leading order noncommutative corrections to the differential and total cross sections for e{sup +}e{sup -{yields}}qq. After averaging over the Earth's rotation, the results depend on the latitude for the collider, as well as the direction of the incoming beam. They also depend on the scale and direction of the noncommutativity. Using data from LEP, we exclude regions in the parameter space spanned by the noncommutative scale and angle relative to the Earth's axis. We also investigate possible implications for phenomenology at the future International Linear Collider.

  12. High Energy Colliders as Tools to Understand the Early Universe

    SciTech Connect

    Tait, Tim

    2008-08-16

    Cosmological observations have reached a new era of precision, and reveal many interesting and puzzling features of the Universe. I will briefly review two of the most exciting mysteries: the nature of the dark components of the Universe, and the origin of the asymmetry between matter and anti-matter. I will argue that our best hope of unraveling these questions will need to combine information from the heavens with measurements in the lab at high energy particle accelerators. The end of run II of the Tevatron, the up-coming Large Hadron Collider and proposed International Linear Collider all have great potential to help us answer these questions in the near future.

  13. Physics at Future Circular Colliders

    NASA Astrophysics Data System (ADS)

    Kotwal, Ashutosh

    2016-03-01

    The Large Hadron Collider has been a grand success with the discovery of the Higgs boson, with bright prospects for additional discoveries since the recent increase in collider energy and the anticipated large datasets. Big open questions such as the nature of dark matter, the origin of the matter-antimatter asymmetry in the Universe, and the theoretical puzzle of the finely-tuned parameters in the Higgs sector, demand new physics principles that extend the established Standard Model paradigm. Future circular colliders in a substantially larger tunnel can house both a high luminosity electron-positron collider for precision measurements of Higgs and electroweak parameters, as well as a very high energy proton-proton collider which can directly manifest particles associated with these new physics principles. We discuss the physics goals of these future circular colliders, and the prospects for elucidating fundamental new laws of nature that will significantly extend our understanding of the Universe. Detailed studies of the discovery potential in specific benchmark models will be presented, with implications for detector design.

  14. Muon muon collider: Feasibility study

    SciTech Connect

    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.

  15. Redefining Scientist-Educator Partnerships: Science in Service at Stanford

    NASA Astrophysics Data System (ADS)

    Beck, K.

    2005-05-01

    The Stanford Solar Observatories Group and Haas Center for Public Service have created an innovative model for scientist-educator partnerships in which science students are trained and mentored by public service education professionals to create outreach events for local communities. The program, Science in Service, is part of the EPO plan for the Solar Group's participation in NASA's Solar Dynamics Observatory mission. Based on the principles of service learning, the Science in Service Program mentors college science students in best practices for communicating science and engages these students in public service projects that center on teaching solar science. The program goals are to - Enhance and expand the learning experiences that pre-college students, from underserved and underrepresented groups in particular, have in science and technology. - Promote leadership in community service in the area of science and engineering among the next generation of scientists and engineers, today's undergraduate students. - Encourage science and engineering faculty to think creatively about their outreach requirements and to create a community of faculty committed to quality outreach programs. This talk will describe the unique advantages and challenges of a research-public service partnership, explain the structure of Stanford's Science in Service Program, and present the experiences of the undergraduates and the outreach communities that have been involved in the program.

  16. Design, development and evaluation of Stanford/Ames EVA prehensors

    NASA Technical Reports Server (NTRS)

    Leifer, Larry J.; Aldrich, J.; Leblanc, M.; Sabelman, E.; Schwandt, D.

    1988-01-01

    Space Station operations and maintenance are expected to make unprecedented demands on astronaut EVA. With Space Station expected to operate with an 8 to 10 psi atmosphere (4 psi for Shuttle operations), the effectivness of pressurized gloves is called into doubt at the same time that EVA activity levels are to be increased. To address the need for more frequent and complex EVA missions and also to extend the dexterity, duration, and safety of EVA astronauts, NASA Ames and Stanford University have an ongoing cooperative agreement to explore and compare alternatives. This is the final Stanford/Ames report on manually powered Prehensors, each of which consists of a shroud forming a pressure enclosure around the astronaut's hand, and a linkage system to transfer the motions and forces of the hand to mechanical digits attached to the shroud. All prehensors are intended for attachment to a standard wrist coupling, as found on the AX-5 hard suit prototype, so that realistic tests can be performed under normal and reduced gravity as simulated by water flotation.

  17. Follow the Money: Engineering at Stanford and UC Berkeley during the Rise of Silicon Valley

    ERIC Educational Resources Information Center

    Adams, Stephen B.

    2009-01-01

    A comparison of the engineering schools at UC Berkeley and Stanford during the 1940s and 1950s shows that having an excellent academic program is necessary but not sufficient to make a university entrepreneurial (an engine of economic development). Key factors that made Stanford more entrepreneurial than Cal during this period were superior…

  18. Stanford's 1990 Graduates Didn't Wait Long To Give Back in a Big Way.

    ERIC Educational Resources Information Center

    Carr, Sarah

    2000-01-01

    Reports that the class of 1990 of Stanford University (California) has pledged a record total for a class 10 years out of college. Suggests that Stanford's close relationship to Silicon Valley is responsible but that the volatility of the stock market illustrates the risks involved in fund raising from young Internet entrepreneurs. The $7.5…

  19. Stanford University: The Building Energy Retrofit Programs. Green Revolving Funds in Action: Case Study Series

    ERIC Educational Resources Information Center

    Flynn, Emily

    2011-01-01

    Stanford University's Energy Retrofit Program was created in 1993 to target resource reduction and conservation focused projects on campus. Fahmida Ahmed, Associate Director of the Department of Sustainability and Energy Management, says that Stanford has been investing in sustainability and energy-efficiency since the late 1970s, longer than many…

  20. Promoting the "Public Welfare" in Wartime: Stanford University during World War II

    ERIC Educational Resources Information Center

    Dorn, Charles

    2005-01-01

    As with many U.S. colleges and universities during World War II, Stanford University responded to the demands of mobilization by increasing its commitment to technical training and adopting a defense research agenda. In a striking departure from this national trend, however, Stanford also established its School of Humanities in 1942. By examining…

  1. Corrected Mental Age Scores for the Stanford-Binet Intelligence Scale

    ERIC Educational Resources Information Center

    Shorr, David N.; And Others

    1977-01-01

    Discrepancies between the mental age (MA) scores and the mean performance of chronological age (CA) groups in the latest revision of the Stanford-Binet Intelligence Scale are noted. A table is presented for converting published Stanford-Binet MA scores into MA scores that are congruent with the above definition. (Author)

  2. The Case for the Stanford-Binet L-M as a Supplemental Test.

    ERIC Educational Resources Information Center

    Silverman, Linda Kreger; Kearney, Katheryn

    1992-01-01

    The Stanford-Binet IV is compared to the original version and criticized for having less power to measure the high end of intelligence and for having norms that discriminate against gifted students. Strengths of the Stanford-Binet L-M are pointed out, and use of both scales for different purposes is recommended. (JDD)

  3. A Survey of Perceptions by School Psychologists of the Stanford-Binet IV.

    ERIC Educational Resources Information Center

    Obringer, S. John

    1988-01-01

    A survey of 97 school psychologists found that the majority felt they needed additional training in administering, scoring, and interpreting the fourth edition of the Stanford-Binet Intelligence Scale. Thirty-four percent were using the fourth edition. Rank ordering of instruments of choice was: Wechsler scales, Kaufman Scale, old Stanford-Binet,…

  4. Relation Between ITPA Average Deviation and Stanford-Binet Intelligence Scores

    ERIC Educational Resources Information Center

    Burns, Edward

    1976-01-01

    The relation between average deviation, as determined using the Illinois Test of Psycholinguistic Abilities, and Stanford-Binet intelligence scores was examined using a preschool sample. Results revealed a curvilinear relation between total average deviation and Stanford-Binet intelligence scores. Use of average deviation as an index of "learning…

  5. Use of the Stanford Binet Fourth Edition in Identifying Young Gifted Children.

    ERIC Educational Resources Information Center

    Kitano, Margie K.; DeLeon, Josie

    1988-01-01

    The impact of the Stanford Binet Fourth Edition was compared with the Stanford Binet L-M on the identification of gifted children for a university affiliated preschool. The fourth edition test composite identified fewer preschool age children as gifted when the criterion was set at 1.5 standard deviations above the mean. (Author/JDD)

  6. Relationships Between the 1960 Stanford-Binet Scale and Group Measures of Intelligence and Achievement

    ERIC Educational Resources Information Center

    Churchill, William D.; Smith, Stuart E.

    1974-01-01

    This study is concerned with the determination of relationships between the 1960 Revised Stanford-Binet Intelligence Scale, the Lorge-Thorndike Intelligence Test, and the Iowa Tests of Basic Skills. The primary objective of the investigation was to determine the predictive validity of the 1960 Stanford-Binet over a period of eight years. (Author)

  7. The Stanford-Binet: An Evaluation of the Technical Data Available Since the 1972 Restandardization.

    ERIC Educational Resources Information Center

    Waddell, Deborah D.

    1980-01-01

    A review of the technical data available on the 1972 norms edition of the Stanford-Binet demonstrates how inadequate these data are. The Stanford-Binet should not continue to be used in important decision making processes unless this weakness is corrected. (Author)

  8. Ratio Developmental Quotients from the Bayley Are Comparable to Later IQs from the Stanford-Binet.

    ERIC Educational Resources Information Center

    Goldstein, Donald J.; Sheaffer, Christopher I.

    1988-01-01

    Ratio developmental quotients from Bayley Scales administered after age 30 months were compared to Stanford Binet IQs secured later for 42 mentally retarded children. Means were almost identical suggesting use of Bayley ratio quotients with children too old for the Bayley norms and too retarded for the Stanford Binet. (Author/DB)

  9. Introduction to the Structure and Application of the Stanford-Binet Intelligence Scale-Fourth Edition.

    ERIC Educational Resources Information Center

    Glutting, Joseph J.

    1989-01-01

    Introduces Stanford-Binet Intelligence Scale-Fourth Edition (SB4) as an attempt to revitalize Stanford-Binet by maintaining links with previous editions while simultaneously incorporating more recent developments found in other popular tests of intelligence. Discusses the SB4's theoretical foundation, materials and administration, scaling,…

  10. NEUTRINO RADIATION CHALLENGES AND PROPOSED SOLUTIONS FOR MANY-TEV MUON COLLIDERS

    SciTech Connect

    KING,B.J.

    2000-05-05

    Neutrino radiation is expected to impose major design and siting constraints on many-TeV muon colliders. Previous predictions for radiation doses at TeV energy scales are briefly reviewed and then modified for extension to the many-TeV energy regime. The energy-cubed dependence of lower energy colliders is found to soften to an increase of slightly less than quadratic when averaged over the plane of the collider ring and slightly less than linear for the radiation hot spots downstream from straight sections in the collider ring. Despite this, the numerical values are judged to be sufficiently high that any many-TeV muon colliders will likely be constructed on large isolated sites specifically chosen to minimize or eliminate human exposure to the neutrino radiation. It is pointed out that such sites would be of an appropriate size scale to also house future proton-proton and electron-positron colliders at the high energy frontier, which naturally leads to conjecture on the possibilities for a new world laboratory for high energy physics. Radiation dose predictions are also presented for the speculative possibility of linear muon colliders. These have greatly reduced radiation constraints relative to circular muon colliders because radiation is only emitted in two pencil beams directed along the axes of the opposing linacs.

  11. Design of a 6 TeV Muon Collider

    SciTech Connect

    Wang, M-H.; Nosochkov, Y.; Cai, Y.; Palmer, M.

    2015-06-01

    A design of a muon collider ring with the center of mass energy of 6 TeV is presented. The ring circumference is about 6.3 km, and the $\\beta$ functions at collision point are 1 cm in both planes. The ring linear optics, the non-linear chromaticity correction scheme in the Interaction Region (IR), and the additional non-linear field orthogonal knobs are described. The IR magnet specifications are based on the maximum pole tip field of 20 T in dipoles and 15 T in quadrupoles. The results of the beam dynamics optimization for maximum dynamic aperture are presented.

  12. Muon Collider Task Force Report

    SciTech Connect

    Ankenbrandt, C.; Alexahin, Y.; Balbekov, V.; Barzi, E.; Bhat, C.; Broemmelsiek, D.; Bross, A.; Burov, A.; Drozhdin, A.; Finley, D.; Geer, S.; /Fermilab /Argonne /Brookhaven /Jefferson Lab /LBL, Berkeley /MUONS Inc., Batavia /UCLA /UC, Riverside /Mississippi U.

    2007-12-01

    Muon Colliders offer a possible long term path to lepton-lepton collisions at center-of-mass energies {radical}s {ge} 1 TeV. In October 2006 the Muon Collider Task Force (MCTF) proposed a program of advanced accelerator R&D aimed at developing the Muon Collider concept. The proposed R&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&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&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.

  13. Recent results from hadron colliders

    SciTech Connect

    Frisch, H.J. )

    1990-12-10

    This is a summary of some of the many recent results from the CERN and Fermilab colliders, presented for an audience of nuclear, medium-energy, and elementary particle physicists. The topics are jets and QCD at very high energies, precision measurements of electroweak parameters, the remarkably heavy top quark, and new results on the detection of the large flux of B mesons produced at these machines. A summary and some comments on the bright prospects for the future of hadron colliders conclude the talk. 39 refs., 44 figs., 3 tabs.

  14. Introduction to high-energy physics and the Stanford Linear Accelerator Center (SLAC)

    SciTech Connect

    Clearwater, S.

    1983-03-01

    The type of research done at SLAC is called High Energy Physics, or Particle Physics. This is basic research in the study of fundamental particles and their interactions. Basic research is research for the sake of learning something. Any practical application cannot be predicted, the understanding is the end in itself. Interactions are how particles behave toward one another, for example some particles attract one another while others repel and still others ignore each other. Interactions of elementary particles are studied to reveal the underlying structure of the universe.

  15. Radiation Safety System for Stanford Synchrotron Radiation Laboratory

    SciTech Connect

    Liu, J

    2004-03-12

    Radiation Safety System (RSS) at the Stanford Synchrotron Radiation Laboratory is summarized and reviewed. The RSS, which is designed to protect people from prompt radiation hazards from accelerator operation, consists of the Access Control System (ACS) and the Beam Containment System (BCS). The ACS prevents people from being exposed to the lethal radiation level inside the shielding housing (called a PPS area at SLAC). The ACS for a PPS area consists of the shielding housing, beam inhibiting devices, and a standard entry module at each entrance. The BCS protects people from the prompt radiation hazards outside a PPS area under both normal and abnormal beam loss situations. The BCS consists of the active power (current/energy) limiting devices, beam stoppers, shielding, and an active radiation monitor system. The policies and practices in setting up the RSS at SLAC are illustrated.

  16. Engineering aspects of the Stanford relativity gyro experiment

    NASA Technical Reports Server (NTRS)

    Everitt, C. W. F.; Debra, D. B.

    1981-01-01

    According to certain theoretical predictions, the Newtonian laws of motion must be corrected for the effect of a gravitational field. Schiff (1960) proposed an experiment which would demonstrate the effect predicted by Einstein's Theory of General Relativity on a gyroscope. The experiment has been under development at Stanford University since 1961. The requirements involved make it necessary that the test be performed in a satellite to take advantage of weightlessness in space. In a discussion of engineering developments related to the experiment, attention is given to the development of proportional helium thrusters, the simulation of the attitude control system, aspects of inner loop control, the mechanization of the two-loop attitude control system, the effects of helium slosh on spacecraft pointing, and the data instrumentation system.

  17. STANSORT - Stanford Remote Sensing Laboratory pattern recognition and classification system

    NASA Technical Reports Server (NTRS)

    Honey, F. R.; Prelat, A.; Lyon, R. J. P.

    1974-01-01

    The principal barrier to routine use of the ERTS multispectral scanner computer compatible tapes, rather than photointerpretation examination of the images, has been the high computing costs involved due to the large quantity of information (4 Mbytes) contained in a scene. STANSORT, the interactive program package developed at Stanford Remote Sensing Laboratories alleviates this problem, providing an extremely rapid, flexible and low cost tool for data reduction, scene classification, species searches and edge detection. The primary classification procedure, utilizing a search with variable gate widths, for similarities in the normalized, digitized spectra is described along with associated procedures for data refinement and extraction of information. The more rigorous statistical classification procedures are also explained.

  18. SUPRI (Stanford University Petroleum Research Institute) heavy oil research program

    SciTech Connect

    Brigham, W.E.; Ramey, H.J. Jr.; Aziz, K.; Castanier, L.

    1990-01-01

    This report is a summary of the work performed under Department of Energy contract FG19-87BC14126 during the period February 22, 1987 to February 21, 1990. During that period the Stanford University Petroleum Research Institute has published twenty-two technical reports and professional papers. This report presents in general terms the scope of work of SUPRI which is divided in five main projects: reservoir properties, in-situ combustion, improvement of steam injection by additives, well-to-well formation evaluation, and field support services. The results obtained during the period of performance of the contract are then presented in the form of abstracts from the technical reports and papers written during the period of performance.

  19. Muon Muon Collider: Feasibility Study

    SciTech Connect

    Gallardo, J.C.; Palmer, R.B.; Tollestrup, A.V.; Sessler, A.M.; Skrinsky, A.N.; 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

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup -2}s{sup -1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice - we believe - to allow us 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 wich 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. Muons because of their large mass compared to an electron, do not produce significant synchrotron radiation. As a result there is negligible beamstrahlung and high energy collisions are not limited by this phenomena. In addition, muons can be accelerated in circular devices which will be considerably smaller than two full-energy linacs as required in an e{sup +} - e{sup -} collider. A hadron collider would require a CM energy 5 to 10 times higher than 4 TeV to have an equivalent energy reach. Since the accelerator size is limited by the strength of bending magnets, the hadron collider for the same physics reach would have to be much larger than the muon collider. In addition, muon collisions should be cleaner than hadron collisions. There are many detailed particle

  20. Ground motion data for International Collider models

    SciTech Connect

    Volk, J.T.; LeBrun, P.; Shiltsev, V.; Singatulin, S.; /Fermilab

    2007-11-01

    The proposed location for the International Linear Collider (ILC) in the Americas region is Fermilab in Batavia Illinois. If built at this location the tunnels would be located in the Galena Platteville shale at a depth of 100 or more meters below the surface. Studies using hydro static water levels and seismometers have been conducted in the MINOS hall and the LaFrange Mine in North Aurora Illinois to determine the level of ground motion. Both these locations are in the Galena Platteville shale and indicate the typical ground motion to be expected for the ILC. The data contains both natural and cultural noise. Coefficients for the ALT law are determined. Seismic measurements at the surface and 100 meters below the surface are presented.

  1. Pulse Capacitors for Next Generation Linear Colliders. Final Report

    SciTech Connect

    Hooker, M.W.

    2000-03-03

    During this Phase I SBIR research program, Nanomaterials Research Corporation (NRC) successfully demonstrated high-voltage multilayer capacitors produced from sub-100 nm ceramic powders. The devices produced by NRC exhibited properties that make them particularly useful for pulse power applications. These properties include (1) high capacitance (2) low loss (3) high breakdown voltage (4) high insulation resistance and (5) rapid discharge characteristics. Furthermore, the properties of the nanostructured capacitors were consistently found to exceed those of components that represent the state of the art within the industry. Encouraged by these results, NRC is planning to submit a Phase II proposal with the objective of securing seed capital to continue this development effort.

  2. Review of linear collider beam-beam interaction

    SciTech Connect

    Chen, P.

    1989-01-01

    Three major effects from the interaction of e/sup +/e/sup /minus// beams---disruption, beamstrahlung, and electron-positron pair creation---are reviewed. For the disruption effects we discuss the luminosity enhancement factor, the maximum and rms disruption angles, and the ''kink instability''. All the results are obtained from computer simulations. Scaling laws for the numerical results and theoretical explanations of the computer acquired phenomena are offered wherever possible. For the beamstrahlung effects we concentrate only on the final electron energy spectrum resulting from multiple photon radiation process, and the deflection angle associated with low energy particles. For the effects from electron-positron pair creation, both coherent and incoherent processes of beamstrahlung pair creation are discussed. In addition to the estimation on total number of such pairs, we also look into the energy spectrum and the deflection angle. 17 refs., 23 figs., 1 tab.

  3. Detectors for Linear Colliders: Tracking and Vertexing (2/4)

    SciTech Connect

    2010-02-15

    Efficient and precise determination of the flavour of partons in multi-hadron final states is essential to the anticipated LC physics program. This makes tracking in the vicinity of the interaction region of great importance. Tracking extrapolation and momentum resolution are specified by precise physics requirements. The R&D; towards detectors able to meet these specifications will be discussed, together with some of their application beyond particle physics.

  4. New final focus system for the SLAC linear collider

    SciTech Connect

    Toge, N.; Ash, W.W.; Chao, Y.C.; Erickson, R.; Gray, R.; Mansour, D.; Spencer, C.M.; Ziemann, V. ); Band, H. . Dept. of Physics); Bazarko, A.O. . Dept. of Physics); Hertzbach, S.S.; Kofler, R.R. . Dept. of Physics); Turk, J. (Yale Univ., New

    1991-05-01

    The final focus system of the SLC has been upgraded by replacing the final quadrupole magnets with higher gradient superconducting magnets positioned closer to the interaction point. The parameters of the new system have been chosen to be compatible with the SLD detector with a minimum of changes to other final focus components. Commissioning plans for the new system are also presented. 5 refs., 1 fig.

  5. International Linear Collider Accelerator Physics R&D

    SciTech Connect

    George D. Gollin; Michael Davidsaver; Michael J. Haney; Michael Kasten; Jason Chang; Perry Chodash; Will Dluger; Alex Lang; Yehan Liu

    2008-09-03

    ILC work at Illinois has concentrated primarily on technical issues relating to the design of the accelerator. Because many of the problems to be resolved require a working knowledge of classical mechanics and electrodynamics, most of our research projects lend themselves well to the participation of undergraduate research assistants. The undergraduates in the group are scientists, not technicians, and find solutions to problems that, for example, have stumped PhD-level staff elsewhere. The ILC Reference Design Report calls for 6.7 km circumference damping rings (which prepare the beams for focusing) using “conventional” stripline kickers driven by fast HV pulsers. Our primary goal was to determine the suitability of the 16 MeV electron beam in the AØ region at Fermilab for precision kicker studies.We found that the low beam energy and lack of redundancy in the beam position monitor system complicated the analysis of our data. In spite of these issues we concluded that the precision we could obtain was adequate to measure the performance and stability of a production module of an ILC kicker, namely 0.5%. We concluded that the kicker was stable to an accuracy of ~2.0% and that we could measure this precision to an accuracy of ~0.5%. As a result, a low energy beam like that at AØ could be used as a rapid-turnaround facility for testing ILC production kicker modules. The ILC timing precision for arrival of bunches at the collision point is required to be 0.1 picosecond or better. We studied the bunch-to-bunch timing accuracy of a “phase detector” installed in AØ in order to determine its suitability as an ILC bunch timing device. A phase detector is an RF structure excited by the passage of a bunch. Its signal is fed through a 1240 MHz high-Q resonant circuit and then down-mixed with the AØ 1300 MHz accelerator RF. We used a kind of autocorrelation technique to compare the phase detector signal with a reference signal obtained from the phase detector’s response to an event at the beginning of the run. We determined that the device installed in our beam, which was instrumented with an 8-bit 500 MHz ADC, could measure the beam timing to an accuracy of 0.4 picoseconds. Simulations of the device showed that an increase in ADC clock rate to 2 GHz would improve measurement precision by the required factor of four. As a result, we felt that a device of this sort, assuming matters concerning dynamic range and long-term stability can be addressed successfully, would work at the ILC. Cost effective operation of the ILC will demand highly reliable, fault tolerant and adaptive solutions for both hardware and software. The large numbers of subsystems and large multipliers associated with the modules in those subsystems will cause even a strong level of unit reliability to become an unacceptable level of system availability. An evaluation effort is underway to evaluate standards associated with high availability, and to guide ILC development with standard practices and well-supported commercial solutions. One area of evaluation involves the Advanced Telecom Computing Architecture (ATCA) hardware and software. We worked with an ATCA crate, processor monitors, and a small amount of ATCA circuit boards in order to develop a backplane “spy” board that would let us watch the ATCA backplane communications and pursue development of an inexpensive processor monitor that could be used as a physics-driven component of the crate-level controls system. We made good progress, and felt that we had determined a productive direction to extend this work. We felt that we had learned enough to begin designing a workable processor monitor chip if there were to be sufficient interest in ATCA shown by the ILC community. Fault recognition is a challenging issue in the crafting a high reliability controls system. With tens of thousands of independent processors running hundreds of thousands of critical processes, how can the system identify that a problem has arisen and determine the appropriate steps to take to correct, or compensate, for the failure? One possible solution might come through the use of the OpenClovis supervisory system, which runs on Linux processors and allows a select set of processors to monitor the behavior of individual processes and processors in a large, distributed controls network. We found that OpenClovis exhibited an irritating amount of sensitivity to the exact version of the Linux kernel running on the processors, and that it was poorly equipped to help us sort through problems that arose through conflicts so deep in the operating systems of the processors. But once this issue was addressed, we found that it performed as expected, recognizing crashes and process (and processor) failures.

  6. A 30 MW, 10 GHz gyroklystron with linear collider application

    SciTech Connect

    Lawson, W.; Latham, P.E.; Calame, J.; Skopec, M.; Welsh, D.; Hogan, B.; Naiman, M.; Striffler, C.D.; Reiser, M.; Granatstein, V.L. ); Read, M.E. )

    1989-01-01

    In this paper, the final preparations for bringing the University of Maryland's 10 GHz, 30 MW gyroklystron experiment on-line are discussed. We describe the initial operation of the modulator and the acceptance tests performed on the electron gun. We explain the enhanced circuit modelling and present a two-cavity design which predicts an efficiency of 33% and a gain of 27 dB. The realization of the design is also discussed. In addition, we briefly discuss the output waveguide and the diagnostics for beam and rf characterization. Finally, a four-cavity circuit design is presented with its predicted operating parameters that can achieve the necessary gain and efficiency required for accelerator application. 14 refs., 11 figs., 5 tabs.

  7. Vibration Model Validation for Linear Collider Detector Platforms

    SciTech Connect

    Bertsche, Kirk; Amann, J.W.; Markiewicz, T.W.; Oriunno, M.; Weidemann, A.; White, G.; /SLAC

    2012-05-16

    The ILC and CLIC reference designs incorporate reinforced-concrete platforms underneath the detectors so that the two detectors can each be moved onto and off of the beamline in a Push-Pull configuration. These platforms could potentially amplify ground vibrations, which would reduce luminosity. In this paper we compare vibration models to experimental data on reinforced concrete structures, estimate the impact on luminosity, and summarize implications for the design of a reinforced concrete platform for the ILC or CLIC detectors.

  8. BEAM DELIVERY LAYOUT FOR THE NEXT LINEAR COLLIDER

    SciTech Connect

    Seryi, A

    2004-07-13

    This paper presents the latest design and layout of the NLC Beam Delivery System (BDS) for the first and second interaction region (IR). This includes the beam switchyard, skew correction and emittance diagnostics section, the collimation system integrated with the final focus, the primary and post linac tune-up beam dumps, and the arcs of the second interaction region beamline. The layout and optics are optimized to deliver design luminosity in the entire energy range from 90 GeV to 1.3 TeV CM, with the first IR BDS also having the capability of being extended to multi-TeV.

  9. The MARX Modulator Development Program for the International Linear Collider

    SciTech Connect

    Leyh, G.E.; /SLAC

    2006-06-12

    The ILC Marx Modulator Development Program at SLAC is working towards developing a full-scale ILC Marx ''Reference Design'' modulator prototype, with the goal of significantly reducing the size and cost of the ILC modulator while improving overall modulator efficiency and availability. The ILC Reference Design prototype will provide a proof-of-concept model to industry in advance of Phase II SBIR funding, and also allow operation of the new 10MW L-Band Klystron prototypes immediately upon their arrival at SLAC.

  10. Precision measurement of a particle mass at the linear collider

    SciTech Connect

    Milstene, C.; Freitas, A.; Schmitt, M.; Sopczak, A.; /Lancaster U.

    2007-06-01

    Precision measurement of the stop mass at the ILC is done in a method based on cross-sections measurements at two different center-of-mass energies. This allows to minimize both the statistical and systematic errors. In the framework of the MSSM, a light stop, compatible with electro-weak baryogenesis, is studied in its decay into a charm jet and neutralino, the Lightest Supersymmetric Particle (LSP), as a candidate of dark matter. This takes place for a small stop-neutralino mass difference.

  11. Detectors for Linear Colliders: Tracking and Vertexing (2/4)

    ScienceCinema

    None

    2016-07-12

    Efficient and precise determination of the flavour of partons in multi-hadron final states is essential to the anticipated LC physics program. This makes tracking in the vicinity of the interaction region of great importance. Tracking extrapolation and momentum resolution are specified by precise physics requirements. The R&D; towards detectors able to meet these specifications will be discussed, together with some of their application beyond particle physics.

  12. Development of Polarized Photocathodes for the Linear Collider

    SciTech Connect

    Richard Prepost

    2009-12-22

    In prior years a Wisconsin-SLAC collaboration developed polarized photocathodes which were used for the SLAC SLD and fixed target programs. Currently, the R&D program goal is the development of a polarized electron source (PES) which meets the ILC requirements for polarization, charge, lifetime, and pulse structure. There are two parts to this program. One part is the continued improvement of photocathode structures with higher polarization. The second part is the design and development of the laser system used to drive the photocathode. The long pulse train for the ILC introduces new challenges for the PES. 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 photocathode load-lock system. The collaboration with SLAC is through the Polarized Photocathode Research Collaboration (PPRC). Senior SLAC personnel include T. Maruyama, J. Clendenin, R. Kirby, and A. Brachmann.

  13. International Linear Collider Technical Design Report (Volumes 1 through 4)

    SciTech Connect

    Harrison M.

    2013-03-27

    The design report consists of four volumes: Volume 1, Executive Summary; Volume 2, Physics; Volume 3, Accelerator (Part I, R and D in the Technical Design Phase, and Part II, Baseline Design); and Volume 4, Detectors.

  14. Detectors for Linear Colliders: Detector design for a Future Electron-Positron Collider (4/4)

    ScienceCinema

    None

    2016-07-12

    In this lecture I will discuss the issues related to the overall design and optimization of a detector for ILC and CLIC energies. I will concentrate on the two main detector concepts which are being developed in the context of the ILC. Here there has been much recent progress in developing realistic detector models and in understanding the physics performance of the overall detector concept. In addition, I will discuss the how the differences in the detector requirements for the ILC and CLIC impact the overall detector design.

  15. Tevatron Collider Status and Prospects

    SciTech Connect

    Moore, Ronald S.

    2009-10-01

    The Tevatron proton-antiproton collider at Fermilab continues operation as the world's highest energy particle accelerator by delivering luminosity at a center-of-mass energy of 1.96 TeV. We review recent performance and plans for the remainder of Run 2.

  16. CERN's Large Hadron Collider project

    NASA Astrophysics Data System (ADS)

    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.

  17. B physics at hadron colliders

    SciTech Connect

    Butler, J.N.; /Fermilab

    2005-09-01

    This paper discusses the physics opportunity and challenges for doing high precision B physics experiments at hadron colliders. It describes how these challenges have been addressed by the two currently operating experiments, CDF and D0, and how they are addressed by three experiments, ATLAS, CMS, and LHCb, at the LHC.

  18. Muon Colliders: The Next Frontier

    ScienceCinema

    Tourun, Yagmur [Illinois Institute of Technology, Chicago, Illinois, United States

    2016-07-12

    Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be "at least 20 years away" for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

  19. Muon Colliders: The Next Frontier

    SciTech Connect

    Tourun, Yagmur

    2009-07-29

    Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be 'at least 20 years away' for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

  20. Muon Colliders: The Next Frontier

    SciTech Connect

    Tourun, Yagmur

    2009-07-29

    Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be "at least 20 years away" for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

  1. Physics at hadron colliders: Experimental view

    SciTech Connect

    Siegrist, J.L.

    1987-08-01

    The physics of the hadron-hadron collider experiment is considered from an experimental point of view. The problems encountered in determination of how well the standard model describes collider results are discussed. 53 refs., 58 figs.

  2. P{bar P} collider physics

    SciTech Connect

    Demarteau, M.

    1992-04-01

    A brief introduction to {bar p}p collider physics is given. Selected results from the collider experiments at the CERN S{bar p}pS and the Tevatron collider are described. The emphasis is on experimental aspects of {bar p}p collisions. Minimum bias physics and the production of jets, Intermediate Vector Bosons and heavy flavors is reviewed. The outlook for physics at hadron colliders for the near future is briefly discussed.

  3. From Neutrino Factory to Muon Collider

    SciTech Connect

    Geer, S.; /Fermilab

    2010-01-01

    Both Muon Colliders and Neutrino Factories require a muon source capable of producing and capturing {Omicron}(10{sup 21}) muons/year. This paper reviews the similarities and differences between Neutrino Factory and Muon Collider accelerator complexes, the ongoing R&D needed for a Muon Collider that goes beyond Neutrino Factory R&D, and some thoughts about how a Neutrino Factory on the CERN site might eventually be upgraded to a Muon Collider.

  4. HIGH ENERGY PHYSICS POTENTIAL AT MUON COLLIDERS

    SciTech Connect

    PARSA,Z.

    2000-04-07

    In this paper, high energy physics possibilities and future colliders are discussed. The {mu}{sup +} {mu}{sup {minus}} collider and experiments with high intensity muon beams as the stepping phase towards building Higher Energy Muon Colliders (HEMC) are briefly reviewed and encouraged.

  5. Design of a 6 TeV muon collider

    NASA Astrophysics Data System (ADS)

    Wang, M.-H.; Nosochkov, Y.; Cai, Y.; Palmer, M.

    2016-09-01

    A preliminary lattice design of a muon collider ring with the center-of-mass (CM) energy of 6 TeV is presented. The ring circumference is 6.3 km, and the beta function at collision point is β* = 1 cm in each plane. The ring linear optics, a local non-linear chromaticity compensation in the Interaction Region (IR), additional IR non-linear correction knobs, and the effects of non-linear fringe field are discussed. Magnet specifications are based on the maximum pole-tip field of 20 T in dipoles and 15 T in quadrupoles. Careful compensation of the non-linear chromatic and amplitude dependent effects provides a sufficiently large dynamic aperture for the momentum range of up to ± 0.5% without considering magnet errors.

  6. Future Electron-Hadron Colliders

    SciTech Connect

    Litvinenko, V.

    2010-05-23

    Outstanding research potential of electron-hadron colliders (EHC) was clearly demonstrated by first - and the only - electron-proton collider HERA (DESY, Germany). Physics data from HERA revealed new previously unknown facets of Quantum Chromo-Dynamics (QCD). EHC is an ultimate microscope probing QCD in its natural environment, i.e. inside the hadrons. In contrast with hadrons, electrons are elementary particles with known initial state. Hence, scattering electrons from hadrons provides a clearest pass to their secrets. It turns EHC into an ultimate machine for high precision QCD studies and opens access to rich physics with a great discovery potential: solving proton spin puzzle, observing gluon saturation or physics beyond standard model. Access to this physics requires high-energy high-luminosity EHCs and a wide reach in the center-of-mass (CM) energies. This paper gives a brief overview of four proposed electron-hadron colliders: ENC at GSI (Darmstadt, Germany), ELIC/MEIC at TJNAF (Newport News, VA, USA), eRHIC at BNL (Upton, NY, USA) and LHeC at CERN (Geneva, Switzerland). Future electron-hadron colliders promise to deliver very rich physics not only in the quantity but also in the precision. They are aiming at very high luminosity two-to-four orders of magnitude beyond the luminosity demonstrated by the very successful HERA. While ENC and LHeC are on opposite side of the energy spectrum, eRHIC and ELIC are competing for becoming an electron-ion collider (EIC) in the U.S. Administrations of BNL and Jlab, in concert with US DoE office of Nuclear Physics, work on the strategy for down-selecting between eRHIC and ELIC. The ENC, EIC and LHeC QCD physics programs to a large degree are complimentary to each other and to the LHC physics. In last decade, an Electron Ion Collider (EIC) collaboration held about 25 collaboration meetings to develop physics program for EIC with CM energy {approx}100 GeV. One of these meetings was held at GSI, where ENC topic was in the

  7. Early Geologic Education in California--Berkeley and Stanford Show the Way.

    ERIC Educational Resources Information Center

    Norris, Robert M.

    1981-01-01

    Traces the early history of geological education in California universities, with emphasis upon programs at Berkeley and Stanford. Among the pioneers in the field were Joseph LeConte, Andrew C. Lawson, and John C. Branner. (WB)

  8. Sun-Earth Day WEBCAST - NASA TV; Host Paul Mortfield, Astronomer Stanford Solar Center and visiting

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Sun-Earth Day WEBCAST - NASA TV; Host Paul Mortfield, Astronomer Stanford Solar Center and visiting students from San Francisco Bay Area Schools Documentation Technology Branch Video communications van (code-JIT)

  9. Big Machines and Big Science: 80 Years of Accelerators at Stanford

    SciTech Connect

    Loew, Gregory

    2008-12-16

    Longtime SLAC physicist Greg Loew will present a trip through SLAC's origins, highlighting its scientific achievements, and provide a glimpse of the lab's future in 'Big Machines and Big Science: 80 Years of Accelerators at Stanford.'

  10. COLLIDE: Collisions into Dust Experiment

    NASA Technical Reports Server (NTRS)

    Colwell, Joshua E.

    1999-01-01

    The Collisions Into Dust Experiment (COLLIDE) was completed and flew on STS-90 in April and May of 1998. After the experiment was returned to Earth, the data and experiment were analyzed. Some anomalies occurred during the flight which prevented a complete set of data from being obtained. However, the experiment did meet its criteria for scientific success and returned surprising results on the outcomes of very low energy collisions into powder. The attached publication, "Low Velocity Microgravity Impact Experiments into Simulated Regolith," describes in detail the scientific background, engineering, and scientific results of COLLIDE. Our scientific conclusions, along with a summary of the anomalies which occurred during flight, are contained in that publication. We offer it as our final report on this grant.

  11. Luminosity limitations for Electron-Ion Collider

    SciTech Connect

    Valeri Lebedev

    2000-09-01

    The major limitations on reaching the maximum luminosity for an electron ion collider are discussed in application to the ring-ring and linac-ring colliders. It is shown that with intensive electron cooling the luminosity of 10{sup 33} cm{sup -2} s{sup -1} is feasible for both schemes for the center-of-mass collider energy above approximately 15 GeV. Each scheme has its own pros and cons. The ring-ring collider is better supported by the current accelerator technology while the linac-ring collider suggests unique features for spin manipulations of the electron beam. The article addresses a general approach to a choice of collider scheme and parameters leaving details for other conference publications dedicated to particular aspects of the ring-ring and linac-ring colliders.

  12. Caroline B. Palmer: Pioneer Physician Anesthetist and First Chair of Anesthesia at Stanford.

    PubMed

    Brodsky, Jay B; Saidman, Lawrence J

    2015-12-01

    Caroline B. Palmer was appointed as Chief of Anesthesia at Cooper Medical College (soon renamed as Stanford Medical School) in 1909. For the next 28 years, she was an innovative leader, a clinical researcher, and a strong advocate for recognition of anesthesiology as a medical specialty. To honor her accomplishments, the operating room suite in the new Stanford Hospital will be named after this pioneering woman anesthesiologist.

  13. Kinematic and dynamic analyses of the Stanford/JPL robot hand. [MACSYMA

    SciTech Connect

    Johnson, V.J.; Starr, G.P.

    1987-11-01

    This report develops the kinematic and dynamic equations for one finger of the three-fingered Stanford/JPL robot hand and documents the physical parameters needed to implement the equations. The equations can be used in control schemes for position and force control of the Stanford/JPL robot hand. The output file for the MACSYMA program is given. 4 refs., 6 figs., 1 tab.

  14. Caroline B. Palmer: Pioneer Physician Anesthetist and First Chair of Anesthesia at Stanford.

    PubMed

    Brodsky, Jay B; Saidman, Lawrence J

    2015-12-01

    Caroline B. Palmer was appointed as Chief of Anesthesia at Cooper Medical College (soon renamed as Stanford Medical School) in 1909. For the next 28 years, she was an innovative leader, a clinical researcher, and a strong advocate for recognition of anesthesiology as a medical specialty. To honor her accomplishments, the operating room suite in the new Stanford Hospital will be named after this pioneering woman anesthesiologist. PMID:26579663

  15. State of hadron collider physics

    SciTech Connect

    Grannis, P.D. |

    1993-12-01

    The 9th Topical Workshop on Proton-Antiproton Collider Physics in Tsukuba Japan demonstrated clearly the enormous breadth of physics accessible in hadron cowders. Although no significant chinks were reported in the armor of the Standard Model, new results presented in this meeting have expanded our knowledge of the electroweak and strong interactions and have extended the searches for non-standard phenomena significantly. Much of the new data reported came from the CDF and D0 experiments at the Fermilab cowder. Superb operation of the Tevatron during the 1992-1993 Run and significant advances on the detector fronts -- in particular, the emergence of the new D0 detector as a productive physics instrument in its first outing and the addition of the CDF silicon vertex detector -- enabled much of this advance. It is noteworthy however that physics from the CERN collider experiments UA1 and UA4 continued to make a large impact at this meeting. In addition, very interesting summary talks were given on new results from HERA, cosmic ray experiments, on super-hadron collider physics, and on e{sup +}e{sup {minus}} experiments at LEP and TRISTAN. These summaries are reported in elsewhere in this volume.

  16. Fermilab Collider: Performance and plans

    SciTech Connect

    Finley, D.A.

    1993-12-01

    The Fermilab collider program has completed its first physics run with two major detectors, CDF and DO. Recent performance of the Fermilab accelerator complex during Run Ia is presented, along with plans to improve the luminosity of the collider. The beam-beam tune shift limitations of previous runs have been avoided by the successful implementation of electrostatic separators in the Tevatron. The simultaneous operation of two high luminosity sections is provided by two matched low beta inserts. The Antiproton Source has increased its performance over the previous run as measured by stack size and stacking rate. The Linac will be upgraded from 200 MeV to 400 MeV in order to lessen the space charge tune shift upon injection into the Booster and provide proton beams with increased intensity with the same emittance. Higher luminosity requires more bunches in the Tevatron to again avoid the limitation due to the beam-beam interaction. Until it is replaced with the Main Injector, the Main Ring will remain as the most significant bottleneck on the performance of the collider.

  17. On the use of iterative techniques for feedforward control of transverse angle and position jitter in linear particle beam accelerators

    SciTech Connect

    Barr, D.S.

    1995-05-05

    It is possible to use feedforward predictive control for transverse position and trajectory-angle jitter correction. The control procedure is straightforward, but creation of the predictive filter is not as obvious. The two process tested were the least mean squares (LMS) and Kalman filter methods. The controller parameters calculated offline are downloaded to a real-time analog correction system between macropulses. These techniques worked well for both interpulse (pulse-to-pulse) correction and intrapulse (within a pulse) correction with the Kalman filter method being the clear winner. A simulation based on interpulse data taken at the Stanford Linear Collider showed an improvement factor of almost three in the average rms jitter over standard feedback techniques for the Kalman filter. An improvement factor of over three was found for the Kalman filter on intrapulse data taken at the Los Alamos Meson Physics Facility. The feedforward systems also improved the correction bandwidth. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  18. The Chronobiology of Stanford Type A Aortic Dissections

    PubMed Central

    DeAnda, Abe; Grossi, Eugene A.; Balsam, Leora B.; Moon, Marc R.; Barlow, Clifford W.; Navia, Daniel O.; Ursomanno, Patricia; Ziganshin, Bulat A.; Rabinovich, Annette E.; Elefteriades, John A.; Smith, Julian A.

    2015-01-01

    Background Seasonal variations of Stanford Type A dissections (STADs) have been previously described in the Northern Hemisphere (NH). This study sought to determine if these variation are mirrored in the Southern Hemisphere (SH). Methods Data from patients treated surgically for STADs were retrospectively obtained from existing administrative and clinical databases from NH and SH sites. Data points of interest included age, sex, date of dissection, and 30-day mortality. The dates of dissections (independent of year) were then organized by season. Results A total of 1418 patients were identified (729 NH and 689 SH) with complete data available for 1415; 896 patients were male with a mean age was 61 ± 14 years, and the overall 30-day mortality was 17.3%. Comparison of NH and SH on a month-to-month basis demonstrated a 6-month phase shift and a significant difference by season, with STADs occurring predominantly in the winter and least in the summer. Decomposition of the monthly incidence using Fourier analysis revealed the phase shift of the primary harmonic to be –21.9 and 169.8 degrees (days), respectively, for NH and SH. The resultant 191.7 day difference did not exactly correspond to the anticipated 6-month difference but was compatible with the original hypothesis. Conclusion Chronobiology plays a role in the occurrence of STADs with the highest occurrence in the winter months independent of the hemisphere. Season is not the predominant reason why aortas dissect, but for patients at risk, the increase in systemic vascular resistance during the winter months may account for the seasonal variations seen. PMID:27390746

  19. Indirect probe of electroweak-interacting particles at future lepton colliders

    NASA Astrophysics Data System (ADS)

    Harigaya, Keisuke; Ichikawa, Koji; Kundu, Anirban; Matsumoto, Shigeki; Shirai, Satoshi

    2015-09-01

    Various types of electroweak-interacting particles, which have non-trivial charges under the SU(2) L × U(1) Y gauge symmetry, appear in various extensions of the Standard Model. These particles are good targets of future lepton colliders, such as the International Linear Collider (ILC), the Compact LInear Collider (CLIC) and the Future Circular Collider of electrons and positrons (FCC-ee). An advantage of the experiments is that, even if their beam energies are below the threshold of the production of the new particles, quantum effects of the particles can be detected through high precision measurements. We estimate the capability of future lepton colliders to probe electroweak-interacting particles through the quantum effects, with particular focus on the wino, the Higgsino and the so-called minimal dark matters, and found that a particle whose mass is greater than the beam energy by 100-1000 GeV is detectable by measuring di-fermion production cross sections with O(0.1)% accuracy. In addition, with the use of the same analysis, we also discuss the sensitivity of the future colliders to model independent higher dimensional operators, and found that the cutoff scales corresponding to the operators can be probed up to a few ten TeV.

  20. LHC: The Large Hadron Collider

    SciTech Connect

    Lincoln, Don

    2015-03-04

    The Large Hadron Collider (or LHC) is the world’s most powerful particle accelerator. In 2012, scientists used data taken by it to discover the Higgs boson, before pausing operations for upgrades and improvements. In the spring of 2015, the LHC will return to operations with 163% the energy it had before and with three times as many collisions per second. It’s essentially a new and improved version of itself. In this video, Fermilab’s Dr. Don Lincoln explains both some of the absolutely amazing scientific and engineering properties of this modern scientific wonder.

  1. Colliding-beam-accelerator lattice

    SciTech Connect

    Claus, J.; Cornacchia, M.; Courant, E.D.; Parzen, G.

    1983-01-01

    We describe the lattice of the Colliding Beam Accelerator, a 400 x 400 GeV pp facility proposed for construction at Brookhaven National Laboratory. The structure adopted is very versatile, in part in consequence of its desirable behavior as function of momentum deviation and as function of the betatron tunes. Each of the six insertions can be arranged to meet specific requirements at the crossing points as illustrated by a discussion of the tuneable low-beta insertions. The luminosity in these low-beta insertions (2 x 10/sup 33/ cm/sup -2/ sec/sup -1/) would be an order of magnitude larger than the standard insertions.

  2. Tevatron instrumentation: boosting collider performance

    SciTech Connect

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

    2006-05-01

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

  3. LHC: The Large Hadron Collider

    ScienceCinema

    Lincoln, Don

    2016-07-12

    The Large Hadron Collider (or LHC) is the world’s most powerful particle accelerator. In 2012, scientists used data taken by it to discover the Higgs boson, before pausing operations for upgrades and improvements. In the spring of 2015, the LHC will return to operations with 163% the energy it had before and with three times as many collisions per second. It’s essentially a new and improved version of itself. In this video, Fermilab’s Dr. Don Lincoln explains both some of the absolutely amazing scientific and engineering properties of this modern scientific wonder.

  4. Muon Colliders and Neutrino Factories

    SciTech Connect

    Kaplan, Daniel M.

    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.

  5. Colliding with a crunching bubble

    SciTech Connect

    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.

  6. Tevatron collider operations and plans

    SciTech Connect

    Peter H. Garbincius

    2004-06-17

    Fermilab's Tevatron is a proton-antiproton collider with center of mass energy of 1.96 TeV. The antiprotons are produced by 125 GeV protons from the Main Injector striking a stainless steel target. The 8 GeV antiprotons are collected and cooled in the Debuncher and Accumulator rings of the Antiproton Source and, just recently, in the Recycler ring before acceleration by the Main Injector and the Tevatron. In addition to energy, a vital parameter for generating physics data is the Luminosity delivered to the experiments given by a formula that is listed in detail in the paper.

  7. Estimates of Fermilab Tevatron collider performance

    SciTech Connect

    Dugan, G.

    1991-09-01

    This paper describes a model which has been used to estimate the average luminosity performance of the Tevatron collider. In the model, the average luminosity is related quantitatively to various performance parameters of the Fermilab Tevatron collider complex. The model is useful in allowing estimates to be developed for the improvements in average collider luminosity to be expected from changes in the fundamental performance parameters as a result of upgrades to various parts of the accelerator complex.

  8. Disentangling the unparticles with polarized beams at e{sup +}e{sup -} colliders

    SciTech Connect

    Huitu, Katri; Rai, Santosh Kumar

    2008-02-01

    A recently proposed idea of unparticles arising due to a scale invariant sector in the theory can give rise to effective operators with different Lorentz structures. We show that, by using the different polarization options at the future linear e{sup +}e{sup -} colliders, the nature of these effective operators can be easily understood. The unique feature of a complex phase in the propagator of the unparticle can also be understood distinctively for the different spins by exploiting the initial beam polarizations at the International Linear Collider.

  9. FUTURE LEPTON COLLIDERS AND LASER ACCELERATION

    SciTech Connect

    PARSA,Z.

    2000-05-30

    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.

  10. Accessing the Distribution of Linearly Polarized Gluons in Unpolarized Hadrons

    SciTech Connect

    Boer, Daniel; Brodsky, Stanley J.; Mulders, Piet J.; Pisano, Cristian; /Cagliari U. /INFN, Cagliari

    2011-08-19

    Gluons inside unpolarized hadrons can be linearly polarized provided they have a nonzero transverse momentum. The simplest and theoretically safest way to probe this distribution of linearly polarized gluons is through cos2{phi} asymmetries in heavy quark pair or dijet production in electron-hadron collisions. Future Electron-Ion Collider (EIC) or Large Hadron electron Collider (LHeC) experiments are ideally suited for this purpose. Here we estimate the maximum asymmetries for EIC kinematics.

  11. Hadron colliders (SSC/LHC)

    SciTech Connect

    Chao, A.W.; Palmer, R.B. |; Evans, L.; Gareyte, J.; Siemann, R.H.

    1992-12-31

    The nominal SSC and LHC designs should operate conservatively at luminosities up to 10{sup 33} cm{sup {minus}2} s{sup {minus}1}. This luminosity is dictated by the event rates that can be handled by the detectors. However, this limit is event dependent (e.g. it does not take much of a detector to detect the event pp {yields} elephant; all one needs is extremely high luminosity). As such, it is useful to explore the possibility of going beyond the 10{sup 33} cm{sup {minus}2} s{sup {minus}1} level. Such exploration will also improve the accelerator physics understanding of pp collider designs. If the detector limitations are removed, the first accelerator limits occur when the luminosity is at the level of 10{sup 34} cm{sup {minus}2}s{sup {minus}1}. These accelerator limits will first be reviewed. The authors will then continue on to explore even higher luminosity as the ultimate limit of pp colliders. Accelerator technologies needed to achieve this ultimate luminosity as well as the R and D needed to reach it are discussed.

  12. Very large hadron collider (VLHC)

    SciTech Connect

    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.

  13. RF sources for future colliders

    NASA Astrophysics Data System (ADS)

    Phillips, Robert M.

    1997-02-01

    As we push particle colliders to 1-TeV center-of-mass collision energy and beyond, we require much more from our RF energy sources, both in terms of the RF performance and the number required for a given machine. In order to conserve real estate, the operating frequency of future colliders is apt to be higher than the S-band used for the SLAC SLC. It is this inevitable trend toward higher frequencies which presents the source designer with the greatest challenge. This paper is about that challenge. For reasons which will become clear, as we go to frequencies substantially above X-band, we will require sources other than klystrons, probably of the type referred to as "fast-wave devices," such as FEL or gyro-based amplifiers, or two-beam accelerators. Because these are discussed elsewhere in this conference, I will stick to the klystron as my model in describing the challenges to be overcome, as well as the criteria which must be met by alternative sources for new accelerators.

  14. Computing and data handling requirements for SSC (Superconducting Super Collider) and LHC (Large Hadron Collider) experiments

    SciTech Connect

    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.

  15. Research and Development of Future Muon Collider

    SciTech Connect

    Yonehara, K.; /Fermilab

    2012-05-01

    Muon collider is a considerable candidate of the next generation high-energy lepton collider machine. A novel accelerator technology must be developed to overcome several intrinsic issues of muon acceleration. Recent research and development of critical beam elements for a muon accelerator, especially muon beam phase space ionization cooling channel, are reviewed in this paper.

  16. Search for top quark at Fermilab Collider

    SciTech Connect

    Sliwa, K.; The CDF Collaboration

    1991-10-01

    The status of a search for the top quark with Collider Detector at Fermilab (CDF), based on a data sample recorded during the 1988--1989 run is presented. The plans for the next Fermilab Collider run in 1992--1993 and the prospects of discovering the top quark are discussed. 19 refs., 4 figs., 2 tabs.

  17. Polarization Effects at a Muon Collider

    SciTech Connect

    Parsa, Z.

    1998-11-01

    For Muon Colliders, Polarization will be a useful tool if high polarization is achievable with little luminosity loss. Formulation and effects of beam polarization and luminosity including polarization effects in Higgs resonance studies are discussed for improving precision measurements and Higgs resonance ''discovery'' capability e.g. at the First Muon Collider (FMC).

  18. Bilepton production at hadron colliders

    NASA Astrophysics Data System (ADS)

    Dion, B.; Grégoire, T.; London, D.; Marleau, L.; Nadeau, H.

    1999-04-01

    We examine, as model-independently as possible, the production of bileptons at hadron colliders. When a particular model is necessary or useful, we choose the 3-3-1 model. We consider a variety of processes: qq¯-->Y++Y--, ud¯-->Y++Y-, ūd-->Y+Y--, qq¯-->Y++e-e-, qq¯-->φ++φ--, ud¯-->φ++φ-, and ūd-->φ+φ--, where Y and φ are vector and scalar bileptons, respectively. Given the present low-energy constraints, we find that, at the Fermilab Tevatron, vector bileptons are unobservable, while light scalar bileptons (Mφ<~300 GeV) are just barely observable. At the CERN LHC, the reach is extended considerably: vector bileptons of mass MY<~1 TeV are observable, as are scalar bileptons of mass Mφ<~850 GeV.

  19. Disformal dark energy at colliders

    NASA Astrophysics Data System (ADS)

    Brax, Philippe; Burrage, Clare; Englert, Christoph

    2015-08-01

    Disformally coupled, light scalar fields arise in many of the theories of dark energy and modified gravity that attempt to explain the accelerated expansion of the Universe. They have proved difficult to constrain with precision tests of gravity because they do not give rise to fifth forces around static nonrelativistic sources. However, because the scalar field couples derivatively to standard model matter, measurements at high-energy particle colliders offer an effective way to constrain and potentially detect a disformally coupled scalar field. Here we derive new constraints on the strength of the disformal coupling from LHC run 1 data and provide a forecast for the improvement of these constraints from run 2. We additionally comment on the running of disformal and standard model couplings in this scenario under the renormalization group flow.

  20. XXth Hadron Collider Physics Symposium

    NASA Astrophysics Data System (ADS)

    In 2009, the Hadron Collider Physics Symposium took place in Evian (France), on the shore of the Geneva Lake, from 16-20 November. It was jointly organised by CERN and the French HEP community (CNRS-IN2P3 and CEA-IRFU). This year's symposium come at an important time for both the Tevatron and LHC communities. It stimulated the completion of analyses for a significant Tevatron data sample, and it allowed an in-depth review of the readiness of the LHC and its detectors just before first collisions. The programme includes sessions on top-quark and electro-weak physics, QCD, B physics, new phenomena, electro-weak symmetry breaking, heavy ions, and the status and commissioning of the LHC machine and its experiments. Conference website : http://hcp2009.in2p3.fr/

  1. Collider searches for extra dimensions

    SciTech Connect

    Landsberg, Greg; /Brown U.

    2004-12-01

    Searches for extra spatial dimensions remain among the most popular new directions in our quest for physics beyond the Standard Model. High-energy collider experiments of the current decade should be able to find an ultimate answer to the question of their existence in a variety of models. Until the start of the LHC in a few years, the Tevatron will remain the key player in this quest. In this paper, we review the most recent results from the Tevatron on searches for large, TeV{sup -1}-size, and Randall-Sundrum extra spatial dimensions, which have reached a new level of sensitivity and currently probe the parameter space beyond the existing constraints. While no evidence for the existence of extra dimensions has been found so far, an exciting discovery might be just steps away.

  2. Collider Detector at Fermilab (CDF)

    SciTech Connect

    Jensen, H.B.

    1985-10-01

    A description of the Collider Detector at Fermilab (CDF) is given. It is a calorimetric detector, which covers almost the complete solid angle around the interaction region with segmented calorimeter ''towers''. A 1.5 Tesla superconducting solenoid, 3m in diameter and 5m long, provides a uniform magnetic field in the central region for magnetic analysis of charged particles. The magnetic field volume is filled with a large cylindrical drift chamber and a set of Time Projection Chambers. Muon detection is accomplished with drift chambers outside the calorimeters in the central region and with large magnetized steel toroids and associated drift chambers in the forward-backward regions. The electronics has a large dynamic range to allow measurement of both high energy clusters and small energy depositions made by penetrating muons. Interesting events are identified by a trigger system which, together with the rest of the data acquisition system, is FASTBUS based.

  3. Mutual colliding impact fast ignition

    SciTech Connect

    Winterberg, Friedwardt

    2014-09-15

    It is proposed to apply the well established colliding beam technology of high energy physics to the fast hot spot ignition of a highly compressed DT (deuterium-tritium) target igniting a larger D (deuterium) burn, by accelerating a small amount of solid deuterium, and likewise a small amount of tritium, making a head-on collision in the center of the target, projecting them through conical ducts situated at the opposite side of the target and converging in its center. In their head-on collision, the relative collision velocity is 5/3 times larger compared to the collision velocity of a stationary target. The two pieces have for this reason to be accelerated to a smaller velocity than would otherwise be needed to reach upon impact the same temperature. Since the velocity distribution of the two head-on colliding projectiles is with its two velocity peaks non-Maxwellian, the maximum cross section velocity product turns out to be substantially larger than the maximum if averaged over a Maxwellian. The D and T projectiles would have to be accelerated with two sabots driven by powerful particle or laser beams, permitting a rather large acceleration length. With the substantially larger cross section-velocity product by virtue of the non-Maxwellian velocity distribution, a further advantage is that the head-on collision produces a large magnetic field by the thermomagnetic Nernst effect, enhancing propagating burn. With this concept, the ignition of the neutron-less hydrogen-boron (HB{sup 11}) reaction might even be possible in a heterogeneous assembly of the hydrogen and the boron to reduce the bremsstrahlung-losses, resembling the heterogeneous assembly in a graphite-natural uranium reactor, there to reduce the neutron losses.

  4. The Stanford Automated Mounter: Pushing the limits of sample exchange at the SSRL macromolecular crystallography beamlines

    DOE PAGESBeta

    Russi, Silvia; Song, Jinhu; McPhillips, Scott E.; Cohen, Aina E.

    2016-02-24

    The Stanford Automated Mounter System, a system for mounting and dismounting cryo-cooled crystals, has been upgraded to increase the throughput of samples on the macromolecular crystallography beamlines at the Stanford Synchrotron Radiation Lightsource. This upgrade speeds up robot maneuvers, reduces the heating/drying cycles, pre-fetches samples and adds an air-knife to remove frost from the gripper arms. As a result, sample pin exchange during automated crystal quality screening now takes about 25 s, five times faster than before this upgrade.

  5. An investigation of ground-based observations of solar oscillations at Stanford

    NASA Technical Reports Server (NTRS)

    Henning, Harald M. J.

    1987-01-01

    Data obtained in the last 8 years of solar differential Doppler observations at Stanford were considered. The four best time series of data were examined in detail. The sources of error in the data were investigated and removed where possible. In particular, the contribution resulting from transparency variations in the sky was examined. Detection method applicable to data with low signal to noise ratio and low filling factor were developed and utilized for the investigation of global solar modes of oscillations in the data. The frequencies of p-modes were measured and identified. The presence of g-modes were also determined in the Stanford data.

  6. The Stanford Automated Mounter: pushing the limits of sample exchange at the SSRL macromolecular crystallography beamlines

    PubMed Central

    Russi, Silvia; Song, Jinhu; McPhillips, Scott E.; Cohen, Aina E.

    2016-01-01

    The Stanford Automated Mounter System, a system for mounting and dismounting cryo-cooled crystals, has been upgraded to increase the throughput of samples on the macromolecular crystallography beamlines at the Stanford Synchrotron Radiation Lightsource. This upgrade speeds up robot maneuvers, reduces the heating/drying cycles, pre-fetches samples and adds an air-knife to remove frost from the gripper arms. Sample pin exchange during automated crystal quality screening now takes about 25 s, five times faster than before this upgrade. PMID:27047309

  7. Future proton and electron colliders: Dreams for the 1990's

    SciTech Connect

    Richter, B.

    1988-10-01

    In this paper I have reviewed the possibilities for new colliders that might be available in the 1990's. One or more new proton should be available in the late-90s based on plans of Europe, the US and the USSR. The two very high energy machines, LHC and SSC, are quite expensive, and their construction will be more decided by the politicians' view on the availability of resources than by the physicists' view of the need for new machines. Certainly something will be built, but the question is when. New electron colliders beyond LEP II could be available in the late 1990's as well. Most of the people who have looked at this problem believe that at a minimum three years of RandD are required before a proposal can be made, two years will be required to convince the authorities to go ahead, and five years will be required to build such a machine. Thus the earliest time a new electron collider at high energy could be available is around 1988. A strong international RandD program will be required to meet that schedule. In the field of B factories, PSI's proposal is the first serious step beyond the capabilities of CESR. There are other promising techniques but these need more RandD. The least RandD would be required for the asymmetric storage ring systems, while the most would be required for high luminosity linear colliders. For the next decade, high energy physics will be doing its work at the high energy frontier with Tevatron I and II, UNK, SLC, LEP I and II, and HERA. The opportunities for science presented by experiments at these facilities are very great, and it is to be hoped that the pressure for funding to construct the next generation facilities will not badly affect the operating budgets of the ones we now have or which will soon be turning on. 9 refs., 12 figs., 6 tabs.

  8. STANFORD PROGRAM IN COMPUTER-ASSISTED INSTRUCTION, PROGRESS REPORT 7, FOR THE PERIOD APRIL 1, 1967 TO JUNE 30, 1967.

    ERIC Educational Resources Information Center

    ATKINSON, RICHARD C.; SUPPES, PATRICK

    THIS REPORT DESCRIBES THE PROJECTS IN COMPUTER-ASSISTED INSTRUCTION CONDUCTED AT THE STANFORD LABORATORY FOR COMPUTER-ASSISTED LEARNING AND TEACHING AND AT THE STANFORD-BRENTWOOD COMPUTER-ASSISTED INSTRUCTION (CAI) LABORATORY. THE MAJOR ACTIVITIES, WHICH ARE REPORTED FOR THE PERIOD FROM APRIL 1 TO JUNE 30, 1967, ARE (1) READING AND MATHEMATICS AT…

  9. STANFORD PROGRAM IN COMPUTER-ASSISTED INSTRUCTION, PROGRESS REPORT 6, FOR THE PERIOD JANUARY 1, 1967 TO MARCH 31, 1967.

    ERIC Educational Resources Information Center

    ATKINSON, RICHARD C.; SUPPES, PATRICK

    THIS REPORT DESCRIBES THE PROJECTS IN COMPUTER-ASSISTED INSTRUCTION CONDUCTED AT THE STANFORD LABORATORY FOR COMPUTER-ASSISTED LEARNING AND TEACHING AND AT THE STANFORD-BRENTWOOD COMPUTER-ASSISTED INSTRUCTION (CAI) LABORATORY. THE MAJOR ACTIVITIES, WHICH ARE REPORTED FOR THE PERIOD FROM JANUARY 1 THROUGH MARCH 31, 1967, ARE RELATED TO (1) READING…

  10. Stanford-Binet and WAIS IQ Differences and Their Implications for Adults with Intellectual Disability (aka Mental Retardation)

    ERIC Educational Resources Information Center

    Silverman, Wayne; Miezejeski, Charles; Ryan, Robert; Zigman, Warren; Krinsky-McHale, Sharon; Urv, Tiina

    2010-01-01

    Stanford-Binet and Wechsler Adult Intelligence Scale (WAIS) IQs were compared for a group of 74 adults with intellectual disability (ID). In every case, WAIS Full Scale IQ was higher than the Stanford-Binet Composite IQ, with a mean difference of 16.7 points. These differences did not appear to be due to the lower minimum possible score for the…

  11. Degrees Granted and Course Enrollments by Field of Study. Second in a Series about the Stanford Curriculum Study.

    ERIC Educational Resources Information Center

    Boli, John; And Others

    As part of the Stanford Curriculum Study, information is provided on the university's approach to monitoring undergraduate education through research into student academic records. Trends in bachelor's degrees granted in the various departments from 1960-1961 to 1981-1982 at Stanford are charted and compared to national trends. Course enrollments…

  12. Brief Report: Data on the Stanford-Binet Intelligence Scales (5th Ed.) in Children with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Coolican, Jamesie; Bryson, Susan E.; Zwaigenbaum, Lonnie

    2008-01-01

    The Fifth Edition of the Stanford-Binet Intelligence Scales (SB5; Roid, G. H. (2003). "Stanford Binet intelligence scales" (5th ed.). Itasca, IL: Riverside Publishing) is relatively new, with minimal published research on general populations and none with special populations. The present study provides information on the cognitive profiles of…

  13. Mean-Score Differences between the WISC-R and the Stanford-Binet Intelligence Scale: Fourth Edition.

    ERIC Educational Resources Information Center

    Prewett, Peter N.; Matavich, Mark A.

    1992-01-01

    Evaluation of mean score differences between the Stanford-Binet Intelligence Scale (Fourth Edition) and the Wechsler Intelligence Scale for Children (Revised) (WISC-R) for 126 children with academic difficulties found the Stanford-Binet composite score was significantly higher than the WISC-R score at the lower end of the ability continuum but…

  14. Relationships between Scores of Gifted Children on the Stanford-Binet IV and Woodcock-Johnson Tests of Achievement.

    ERIC Educational Resources Information Center

    Carvajal, Howard; And Others

    1989-01-01

    Forty-five gifted children, ages 11-17, were tested with the Stanford-Binet Intelligence Scale and the Woodcock-Johnson Tests of Achievement. Results indicated 18 of 20 correlations between the area and composite scores were significant. The Stanford-Binet Short-Term Memory standard age score mean was lower than other scores' means. (Author/JDD)

  15. Stanford Synchrotron Radiation Laboratory. Activity report for 1988

    SciTech Connect

    Cantwell, K.

    1996-01-01

    For SSRL operations, 1988 was a year of stark contrasts. The first extended PEP parasitic running since the construction of our two beam lines on that storage ring took place in November and December. Four experiments discussed below, were performed and detailed operational procedures which allowed synchrotron radiation an high energy users to coexist were established. SSRL anticipates that there will be significant amounts of beam time when PEP is run again for high energy physics. On the other hand, activity on SPEAR consisted of brief parasitic running on the VUV lines in December when the ring was operated at 1.85 GeV for colliding beam experiments. There was no dedicated SPEAR running throughout the entire calendar year. This is the first time since dedicated SPEAR operation was initiated in 1980 that there was no such running. The decision was motivated by both cost and performance factors, as discussed in Section 1 of this report. Fortunately, SLAC and SSRL have reached an agreement on SPEAR and PEP dedicated time charges which eliminates the cost volatility which was so important in the cancellation of the June-July dedicated SPEAR run. As discussed in Section 2, the 3 GeV SPEAR injector construction is proceeding on budget and on schedule. The injector will overcome the difficulties associated with the SLC-era constraint of only two injections per day. SSR and SLAC have also embarked on a program to upgrade SPEAR to achieve high reliability and performance. As a consequence, SSRL`s users may anticipate a highly effective SPEAR by 1991, at the latest. At that time, SPEAR is expected to be fully dedicated to synchrotron radiation research and operated by SSRL. Also contained in this report is a discussion of the improvements to SSRL`s experimental facilities and highlights of the experiments of the past year.

  16. Gifted Students' Individual Differences in Distance-Learning Computer-Based Calculus and Linear Algebra.

    ERIC Educational Resources Information Center

    Cope, Eric W.; Suppes, Patrick

    2002-01-01

    Examined student performance in distance computer-based calculus and linear algebra courses offered by Stanford University to pre-college students as part of their Education Program for Gifted youth (EPGY). Puts special emphasis on modeling student performance over time and on capturing long-term trend effects using stochastic and nonlinear…

  17. On the Future High Energy Colliders

    SciTech Connect

    Shiltsev, Vladimir

    2015-09-28

    High energy particle colliders have been in the forefront of particle physics for more than three decades. 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). A number of the next generation collider facilities have been proposed and are currently under consideration for the medium and far-future of accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance potential and cost range.

  18. Compensatable muon collider calorimeter with manageable backgrounds

    DOEpatents

    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.

  19. The Stanford Medical Youth Science Program: Educational and Science-Related Outcomes

    ERIC Educational Resources Information Center

    Crump, Casey; Ned, Judith; Winkleby, Marilyn A.

    2015-01-01

    Biomedical preparatory programs (pipeline programs) have been developed at colleges and universities to better prepare youth for entering science- and health-related careers, but outcomes of such programs have seldom been rigorously evaluated. We conducted a matched cohort study to evaluate the Stanford Medical Youth Science Program's Summer…

  20. What Do Universities Really Owe Industry? The Case of Solid State Electronics at Stanford

    ERIC Educational Resources Information Center

    Lecuyer, Christophe

    2005-01-01

    It is widely argued that, in the United States, the Department of Defense dictated the intellectual contours of academic science and engineering during the Cold War. However, in important ways, American science was also deeply influenced by industry. Between 1955 and 1985, Stanford University embraced three waves of industrial innovation in solid…