Linear Collider Physics Resource Book Snowmass 2001

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronan

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 decademore » 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 built in a few years, it would make sense to wait for the results of each accelerator before planning the next one. Thus, we would wait for the results from the Tevatron before planning the LHC experiments, and wait for the LHC before planning any later stage. In reality accelerators require a long time to construct, and they require such specialized resources and human talent that delay can cripple what would be promising opportunities. In any event, we believe that the case for the linear collider is so compelling and robust that we can justify this facility on the basis of our current knowledge, even before the Tevatron and LHC experiments are done. The physics prospects for the linear collider have been studied intensively for more than a decade, and arguments for the importance of its experimental program have been developed from many different points of view. This book provides an introduction and a guide to this literature. We hope that it will allow physicists new to the consideration of linear collider physics to start from their own personal perspectives and develop their own assessments of the opportunities afforded by a linear collider.« less

Luminosity Limitations of Linear Colliders Based on Plasma Acceleration

DOE PAGES

Lebedev, Valeri; Burov, Alexey; Nagaitsev, Sergei

2016-01-01

Particle acceleration in plasma creates a possibility of exceptionally high accelerating gradients and appears as a very attractive option for future linear electron-positron and/or photon-photon colliders. These high accelerating gradients were already demonstrated in a number of experiments. Furthermore, a linear collider requires exceptionally high beam brightness which still needs to be demonstrated. In this article we discuss major phenomena which limit the beam brightness of accelerated beam and, consequently, the collider luminosity.

Towards TeV-scale electron-positron collisions: the Compact Linear Collider (CLIC)

NASA Astrophysics Data System (ADS)

Doebert, Steffen; Sicking, Eva

2018-02-01

The Compact Linear Collider (CLIC), a future electron-positron collider at the energy frontier, has the potential to change our understanding of the universe. Proposed to follow the Large Hardron Collider (LHC) programme at CERN, it is conceived for precision measurements as well as for searches for new phenomena.

LCFIPlus: A framework for jet analysis in linear collider studies

NASA Astrophysics Data System (ADS)

Suehara, Taikan; Tanabe, Tomohiko

2016-02-01

We report on the progress in flavor identification tools developed for a future e+e- linear collider such as the International Linear Collider (ILC) and Compact Linear Collider (CLIC). Building on the work carried out by the LCFIVertex collaboration, we employ new strategies in vertex finding and jet finding, and introduce new discriminating variables for jet flavor identification. We present the performance of the new algorithms in the conditions simulated using a detector concept designed for the ILC. The algorithms have been successfully used in ILC physics simulation studies, such as those presented in the ILC Technical Design Report.

Beam dynamic simulations of the CLIC crab cavity and implications on the BDS

NASA Astrophysics Data System (ADS)

Shinton, I. R. R.; Burt, G.; Glasman, C. J.; Jones, R. M.; Wolski, A.

2011-11-01

The Compact Linear Collider (CLIC) is a proposed electron positron linear collider design aiming to achieve a centre of mass energy of up to 3 TeV. The main accelerating structures in CLIC operate at an X-band frequency of 11.994 GHz with an accelerating gradient of 100 MV/m. The present design requires the beams to collide at a small crossing angle of 10 mrad per line giving a resultant overall crossing angle of 20 mrad. Transverse deflecting cavities, referred to as "Crab cavities", are installed in the beam delivery system (BDS) of linear collider designs in order to ensure the final luminosity at the interaction point (IP) is comparable to that in a head on collision. We utilise the beam tracking code PLACET combined with the beam-beam code GUINEA-PIG to calculate the resulting luminosity at the IP. We follow a similar tuning procedure to that used for the design of the ILC crab cavities and anitcrab cavities. However an unexpected loss in luminosity of 10% was observed for the 20 mrad design was observed. It was discovered that the action of the crab cavities can affect the geometric aberrations resulting from the sextupoles used to correct chromatic effects in the beam delivery system. This has direct consequences regarding the design of the present CLIC BDS.

Linear Collider Physics Resource Book for Snowmass 2001 - Part 3: Studies of Exotic and Standard Model Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abe, T.; et al.

This Resource Book reviews the physics opportunities of a next-generation e+e- linear collider and discusses options for the experimental program. Part 3 reviews the possible experiments on that can be done at a linear collider on strongly coupled electroweak symmetry breaking, exotic particles, and extra dimensions, and on the top quark, QCD, and two-photon physics. It also discusses the improved precision electroweak measurements that this collider will make available.

Lessons learned from the SLC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phinney, N.

The SLAC Linear Collider (SLC) is the first example of an entirely new type of lepton collider. Many years of effort were required to develop the understanding and techniques needed to approach design luminosity. This paper discusses some of the key issues and problems encountered in producing a working linear collider. These include the polarized source, techniques for emittance preservation, extensive feedback systems, and refinements in beam optimization in the final focus. The SLC experience has been invaluable for testing concepts and developing designs for a future linear collider.

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.

CP-violating top quark couplings at future linear e^+e^- colliders

NASA Astrophysics Data System (ADS)

Bernreuther, W.; Chen, L.; García, I.; Perelló, M.; Poeschl, R.; Richard, F.; Ros, E.; Vos, M.

2018-02-01

We study the potential of future lepton colliders to probe violation of the CP symmetry in the top quark sector. In certain extensions of the Standard Model, such as the two-Higgs-doublet model (2HDM), sizeable anomalous top quark dipole moments can arise, which may be revealed by a precise measurement of top quark pair production. We present results from detailed Monte Carlo studies for the ILC at 500 GeV and CLIC at 380 GeV and use parton-level simulations to explore the potential of high-energy operation. We find that precise measurements in e^+e^- → t\\bar{t} production with subsequent decay to lepton plus jets final states can provide sufficient sensitivity to detect Higgs-boson-induced CP violation in a viable two-Higgs-doublet model. The potential of a linear e^+e^- collider to detect CP-violating electric and weak dipole form factors of the top quark exceeds the prospects of the HL-LHC by over an order of magnitude.

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.

Compendium of Instrumentation Whitepapers on Frontier Physics Needs for Snowmass 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lipton, R.

2013-01-01

Contents of collection of whitepapers include: Operation of Collider Experiments at High Luminosity; Level 1 Track Triggers at HL-LHC; Tracking and Vertex Detectors for a Muon Collider; Triggers for hadron colliders at the energy frontier; ATLAS Upgrade Instrumentation; Instrumentation for the Energy Frontier; Particle Flow Calorimetry for CMS; Noble Liquid Calorimeters; Hadronic dual-readout calorimetry for high energy colliders; Another Detector for the International Linear Collider; e+e- Linear Colliders Detector Requirements and Limitations; Electromagnetic Calorimetry in Project X Experiments The Project X Physics Study; Intensity Frontier Instrumentation; Project X Physics Study Calorimetry Report; Project X Physics Study Tracking Report; The LHCbmore » Upgrade; Neutrino Detectors Working Group Summary; Advanced Water Cherenkov R&D for WATCHMAN; Liquid Argon Time Projection Chamber (LArTPC); Liquid Scintillator Instrumentation for Physics Frontiers; A readout architecture for 100,000 pixel Microwave Kinetic In- ductance Detector array; Instrumentation for New Measurements of the Cosmic Microwave Background polarization; Future Atmospheric and Water Cherenkov ?-ray Detectors; Dark Energy; Can Columnar Recombination Provide Directional Sensitivity in WIMP Search?; Instrumentation Needs for Detection of Ultra-high Energy Neu- trinos; Low Background Materials for Direct Detection of Dark Matter; Physics Motivation for WIMP Dark Matter Directional Detection; Solid Xenon R&D at Fermilab; Ultra High Energy Neutrinos; Instrumentation Frontier: Direct Detection of WIMPs; nEXO detector R&D; Large Arrays of Air Cherenkov Detectors; and Applications of Laser Interferometry in Fundamental Physics Experiments.« less

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.

Finite element analyses of a linear-accelerator electron gun

NASA Astrophysics Data System (ADS)

Iqbal, M.; Wasy, A.; Islam, G. U.; Zhou, Z.

2014-02-01

Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.

Finite element analyses of a linear-accelerator electron gun.

PubMed

Iqbal, M; Wasy, A; Islam, G U; Zhou, Z

2014-02-01

Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.

Charge shielding in the In-situ Storage Image Sensor for a vertex detector at the ILC

NASA Astrophysics Data System (ADS)

Zhang, Z.; Stefanov, K. D.; Bailey, D.; Banda, Y.; Buttar, C.; Cheplakov, A.; Cussans, D.; Damerell, C.; Devetak, E.; Fopma, J.; Foster, B.; Gao, R.; Gillman, A.; Goldstein, J.; Greenshaw, T.; Grimes, M.; Halsall, R.; Harder, K.; Hawes, B.; Hayrapetyan, K.; Heath, H.; Hillert, S.; Jackson, D.; Pinto Jayawardena, T.; Jeffery, B.; John, J.; Johnson, E.; Kundu, N.; Laing, A.; Lastovicka, T.; Lau, W.; Li, Y.; Lintern, A.; Lynch, C.; Mandry, S.; Martin, V.; Murray, P.; Nichols, A.; Nomerotski, A.; Page, R.; Parkes, C.; Perry, C.; O'Shea, V.; Sopczak, A.; Tabassam, H.; Thomas, S.; Tikkanen, T.; Velthuis, J.; Walsh, R.; Woolliscroft, T.; Worm, S.

2009-08-01

The Linear Collider Flavour Identification (LCFI) collaboration has successfully developed the first prototype of a novel particle detector, the In-situ Storage Image Sensor (ISIS). This device ideally suits the challenging requirements for the vertex detector at the future International Linear Collider (ILC), combining the charge storing capabilities of the Charge-Coupled Devices (CCD) with readout commonly used in CMOS imagers. The ISIS avoids the need for high-speed readout and offers low power operation combined with low noise, high immunity to electromagnetic interference and increased radiation hardness compared to typical CCDs. The ISIS is one of the most promising detector technologies for vertexing at the ILC. In this paper we describe the measurements on the charge-shielding properties of the p-well, which is used to protect the storage register from parasitic charge collection and is at the core of device's operation. We show that the p-well can suppress the parasitic charge collection by almost two orders of magnitude, satisfying the requirements for the application.

Linear beam dynamics and ampere class superconducting RF cavities at RHIC

NASA Astrophysics Data System (ADS)

Calaga, Rama R.

The Relativistic Heavy Ion Collider (RHIC) is a hadron collider designed to collide a range of ions from protons to gold. RHIC operations began in 2000 and has successfully completed five physics runs with several species including gold, deuteron, copper, and polarized protons. Linear optics and coupling are fundamental issues affecting the collider performance. Measurement and correction of optics and coupling are important to maximize the luminosity and sustain stable operation. A numerical approach, first developed at SLAC, was implemented to measure linear optics from coherent betatron oscillations generated by ac dipoles and recorded at multiple beam position monitors (BPMs) distributed around the collider. The approach is extended to a fully coupled 2D case and equivalence relationships between Hamiltonian and matrix formalisms are derived. Detailed measurements of the transverse coupling terms are carried out at RHIC and correction strategies are applied to compensate coupling both locally and globally. A statistical approach to determine BPM reliability and performance over the past three runs and future improvements also discussed. Aiming at a ten-fold increase in the average heavy-ion luminosity, electron cooling is the enabling technology for the next luminosity upgrade (RHIC II). Cooling gold ion beams at 100 GeV/nucleon requires an electron beam of approximately 54 MeV and a high average current in the range of 50-200 mA. All existing e-Coolers are based on low energy DC accelerators. The only viable option to generate high current, high energy, low emittance CW electron beam is through a superconducting energy-recovery linac (SC-ERL). In this option, an electron beam from a superconducting injector gun is accelerated using a high gradient (˜ 20 MV/m) superconducting RF (SRF) cavity. The electrons are returned back to the cavity with a 180° phase shift to recover the energy back into the cavity before being dumped. A design and development of a half-cell electron gun and a five-cell SRF linac cavity are presented. Several RF and beam dynamics issues ultimately resulting in an optimum cavity design are discussed in detail.

Physics Goals for the Planned Next Linear Collider Engineering Test Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raubenheimer, Tor O

2001-10-02

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 asmore » of doing experiments to measure beam-induced wakefields in the rf structures and their influence back on the beam.« less

Physics goals for the planned next linear collider engineering test facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Courtlandt L Bohn et al.

2001-06-26

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 asmore » of doing experiments to measure beam-induced wakefields in the rf structures and their influence back on the beam.« less

Physics goals for the planned next linear collider engineering test facility.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bohn, C.; Michelotti, L.; Ostiguy, J.-F.

2001-07-17

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 asmore » of doing experiments to measure beam-induced wakefields in the rf structures and their influence back on the beam.« less

Possible limits of plasma linear colliders

NASA Astrophysics Data System (ADS)

Zimmermann, F.

2017-07-01

Plasma linear colliders have been proposed as next or next-next generation energy-frontier machines for high-energy physics. I investigate possible fundamental limits on energy and luminosity of such type of colliders, considering acceleration, multiple scattering off plasma ions, intrabeam scattering, bremsstrahlung, and betatron radiation. The question of energy efficiency is also addressed.

Finite element analyses of a linear-accelerator electron gun

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iqbal, M., E-mail: muniqbal.chep@pu.edu.pk, E-mail: muniqbal@ihep.ac.cn; Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049; Wasy, A.

Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gunmore » is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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) takesmore » 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 and the fiducials. Beam-based alignment methods ideally only depend upon the BPM resolution and generally provide much better precision. Many of those techniques are described in other contributions to this workshop. In this paper we describe our experiences with a dispersion-free steering algorithm for linacs. This algorithm was first suggested by Raubenheimer and Ruth in 1990 [5]. It h as been studied in simulations for NLC [5], TESLA [6], the S-BAND proposal [7] and CLIC [8]. The dispersion-free steering technique can be applied to the whole linac at once and returns the alignment (or trajectory) that minimizes the dispersive emittance growth of the beam. Thus it allows an extremely fast alignment of the beam-line. As we will show dispersion-free steering is only sensitive to quadrupole misalignments. Wakefield-free steering [3] as mentioned before is a closely related technique that minimizes the emittance growth caused by both dispersion and wakefields. Due to hardware limitations (i.e. insufficient relative range of power supplies) we could not study this method experimentally in the SLC. However, its systematics are very similar to those of dispersion-free steering. The studies of dispersion-free steering which are presented made extensive use of the unique potential of the SLC as the only operating linear collider. We used it to study the performance and problems of advanced beam-based optimization tools in a real beam-line environment and on a large scale. We should mention that the SLC has utilized beam-based alignment for years [9], using the difference of electron and positron trajectories. This method, however, cannot be used in future linear colliders. The goal of our work is to demonstrate the performance of advanced beam-based alignment techniques in linear colliders and to anticipate possible reality-related problems. Those can then be solved in the design state for the next generation of linear colliders.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loew, Greg

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.

Laser-plasma-based linear collider using hollow plasma channels

DOE PAGES

Schroeder, C. B.; Benedetti, C.; Esarey, E.; ...

2016-03-03

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.

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

Reinventing the Accelerator for the High Energy Frontier

ScienceCinema

Rosenzweig, James [UCLA, Los Angeles, California, United States

2017-12-09

The history of discovery in high-energy physics has been intimately connected with progress in methods of accelerating particles for the past 75 years. This remains true today, as the post-LHC era in particle physics will require significant innovation and investment in a superconducting linear collider. The choice of the linear collider as the next-generation discovery machine, and the selection of superconducting technology has rather suddenly thrown promising competing techniques -- such as very large hadron colliders, muon colliders, and high-field, high frequency linear colliders -- into the background. We discuss the state of such conventional options, and the likelihood of their eventual success. We then follow with a much longer view: a survey of a new, burgeoning frontier in high energy accelerators, where intense lasers, charged particle beams, and plasmas are all combined in a cross-disciplinary effort to reinvent the accelerator from its fundamental principles on up.

Alternate approaches to future electron-positron linear colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

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

DOE PAGES

Zha, Hao; Latina, Andrea; Grudiev, Alexej; ...

2016-01-20

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. Furthermore,more » 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).« less

High-yield positron systems for linear colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clendenin, J.E.

1989-04-01

Linear colliders, such as the SLC, are among those accelerators for which a high-yield positron source operating at the repetition rate of the accelerator is desired. The SLC, having electron energies up to 50 GeV, presents the possibility of generating positron bunches with useful charge even exceeding that of the initial electron bunch. The exact positron yield to be obtained depends on the particular capture, transport and damping system employed. Using 31 GeV electrons impinging on a W-type converter phase-space at the target to the acceptance of the capture rf section, the SLC source is capable of producing, for everymore » electron, up to two positrons within the acceptance of the positron damping ring. The design of this source and the performance of the positron system as built are described. Also, future prospects and limitations for high-yield positron systems are discussed. 11 refs., 5 figs., 3 tabs.« less

2009 Linear Collider Workshop of the Americas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seidel, Sally

The 2009 Linear Collider Workshop of the Americas was held on the campus of the University of New Mexico from 29 September to 3 October, 2009. This was a joint meeting of the American Linear Collider Physics Group and the ILC Global Design Effort. Two hundred fifty people attended. The number of scientific contributions was 333. The complete agenda, with links to all of the presentations, is available at physics.unm.edu/LCWA09/. The meeting brought together international experts as well as junior scientists, to discuss the physics potential of the linear collider and advances in detector technology. The validation of detector designsmore » was announced, and the detector design groups planned the next phase of the effort. Detector R&D teams reported on progress on many topics including calorimetry and tracking. Recent accelerator design considerations were discussed in a special session for experimentalists and theorists.« less

Fermilab Today

Science.gov Websites

Fundamental Physics in the Non-Linear Regime 3:30 p.m. Director's Coffee Break - 2nd Flr X-Over 4:00 p.m. All Week archive Fermilab Safety Tip of the Week archive Linear Collider News archive Fermilab Today Committee ECFA Study of Physics and Detectors for a Linear Collider" and GDE member, explained the

Working Group Report: Higgs Boson

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dawson, Sally; Gritsan, Andrei; Logan, Heather

2013-10-30

This report summarizes the work of the Energy Frontier Higgs Boson working group of the 2013 Community Summer Study (Snowmass). We identify the key elements of a precision Higgs physics program and document the physics potential of future experimental facilities as elucidated during the Snowmass study. We study Higgs couplings to gauge boson and fermion pairs, double Higgs production for the Higgs self-coupling, its quantum numbers and $CP$-mixing in Higgs couplings, the Higgs mass and total width, and prospects for direct searches for additional Higgs bosons in extensions of the Standard Model. Our report includes projections of measurement capabilities frommore » detailed studies of the Compact Linear Collider (CLIC), a Gamma-Gamma Collider, the International Linear Collider (ILC), the Large Hadron Collider High-Luminosity Upgrade (HL-LHC), Very Large Hadron Colliders up to 100 TeV (VLHC), a Muon Collider, and a Triple-Large Electron Positron Collider (TLEP).« less

1995 second modulator-klystron workshop: A modulator-klystron workshop for future linear colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-03-01

This second workshop examined the present state of modulator design and attempted an extrapolation for future electron-positron linear colliders. These colliders are currently viewed as multikilometer-long accelerators consisting of a thousand or more RF sources with 500 to 1,000, or more, pulsed power systems. The workshop opened with two introductory talks that presented the current approaches to designing these linear colliders, the anticipated RF sources, and the design constraints for pulse power. The cost of main AC power is a major economic consideration for a future collider, consequently the workshop investigated efficient modulator designs. Techniques that effectively apply the artmore » of power conversion, from the AC mains to the RF output, and specifically, designs that generate output pulses with very fast rise times as compared to the flattop. There were six sessions that involved one or more presentations based on problems specific to the design and production of thousands of modulator-klystron stations, followed by discussion and debate on the material.« less

Performance of a reentrant cavity beam position monitor

NASA Astrophysics Data System (ADS)

Simon, Claire; Luong, Michel; Chel, Stéphane; Napoly, Olivier; Novo, Jorge; Roudier, Dominique; Rouvière, Nelly; Baboi, Nicoleta; Mildner, Nils; Nölle, Dirk

2008-08-01

The beam-based alignment and feedback systems, essential operations for the future colliders, require high resolution beam position monitors (BPMs). In the framework of the European CARE/SRF program, a reentrant cavity BPM with its associated electronics was developed by the CEA/DSM/Irfu in collaboration with DESY. The design, the fabrication, and the beam test of this monitor are detailed within this paper. This BPM is designed to be inserted in a cryomodule, work at cryogenic temperature in a clean environment. It has achieved a resolution better than 10μm and has the possibility to perform bunch to bunch measurements for the x-ray free electron laser (X-FEL) and the International Linear Collider (ILC). Its other features are a small size of the rf cavity, a large aperture (78 mm), and an excellent linearity. A first prototype of a reentrant cavity BPM was installed in the free electron laser in Hamburg (FLASH), at Deutsches Elektronen-Synchrotron (DESY) and demonstrated its operation at cryogenic temperature inside a cryomodule. The second, installed, also, in the FLASH linac to be tested with beam, measured a resolution of approximately 4μm over a dynamic range ±5mm in single bunch.

Higgs, SUSY and the standard model at /γγ colliders

NASA Astrophysics Data System (ADS)

Hagiwara, Kaoru

2001-10-01

In this report, I surveyed physics potential of the γγ option of a linear e +e - collider with the following questions in mind: What new discovery can be expected at a γγ collider in addition to what will be learned at its ' parent' e +e -linear collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e - beams, we find that a γγ collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e -e - system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a γγ collider. CP property of the scalar sector can be explored in detail by making use of linear polarization of the colliding photons, decay angular correlations of final state particles, and the pattern of interference with the Standard Model amplitudes. A few comments are given for SUSY particle studies at a γγ collider, where a pair of charged spinless particles is produced in the s-wave near the threshold. Squark-onium may be discovered. An e ±γ collision mode may measure the Higgs- Z-γ coupling accurately and probe flavor oscillations in the slepton sector. As a general remark, all the Standard Model background simulation tools should be prepared in the helicity amplitude level, so that simulation can be performed for an arbitrary set of Stokes parameters of the incoming photon beams.

A plasma lens for a linear collider final focus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norem, J.; Cline, D.B.; Cole, B.

High density relativistic beams propagating in a plasma are affected by fields induced by plasma motion. We consider the possible use of a plasma cell very close to the interaction point of a linear collider where the self-pinch induced in the relativistic beams can be used to increase the luminosity of colliding beams. We describe the benefits of this self-pinch, as well as some engineering details on the production of the required plasma. 18 refs., 5 figs., 1 tab.

A Multi-TeV Linear Collider Based on CLIC Technology : CLIC Conceptual Design Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aicheler, M; Burrows, P.; Draper, M.

This report describes the accelerator studies for a future multi-TeV e +e - collider based on the Compact Linear Collider (CLIC) technology. The CLIC concept as described in the report is based on high gradient normal-conducting accelerating structures where the RF power for the acceleration of the colliding beams is extracted from a high-current Drive Beam that runs parallel with the main linac. The focus of CLIC R&D over the last years has been on addressing a set of key feasibility issues that are essential for proving the fundamental validity of the CLIC concept. The status of these feasibility studiesmore » are described and summarized. The report also includes a technical description of the accelerator components and R&D to develop the most important parts and methods, as well as a description of the civil engineering and technical services associated with the installation. Several larger system tests have been performed to validate the two-beam scheme, and of particular importance are the results from the CLIC test facility at CERN (CTF3). Both the machine and detector/physics studies for CLIC have primarily focused on the 3 TeV implementation of CLIC as a benchmark for the CLIC feasibility. This report also includes specific studies for an initial 500 GeV machine, and some discussion of possible intermediate energy stages. The performance and operation issues related to operation at reduced energy compared to the nominal, and considerations of a staged construction program are included in the final part of the report. The CLIC accelerator study is organized as an international collaboration with 43 partners in 22 countries. An associated report describes the physics potential and experiments at CLIC and a shorter report in preparation will focus on the CLIC implementation strategy, together with a plan for the CLIC R&D studies 2012–2016. Critical and important implementation issues such as cost, power and schedule will be addressed there.« less

Development of semiconductor tracking: The future linear collider case

NASA Astrophysics Data System (ADS)

Savoy-Navarro, Aurore

2011-04-01

An active R&D on silicon tracking for the linear collider, SiLC, is pursued since several years to develop the new generation of large area silicon trackers for the future linear collider(s). The R&D objectives on new sensors, new front end processing of the signal, and the related mechanical and integration challenges for building such large detectors within the proposed detector concepts are described. Synergies and differences with the LHC construction and upgrades are explained. The differences between the linear collider projects, namely the international linear collider, ILC, and the compact linear collider, CLIC, are discussed as well. Two final objectives are presented for the construction of this important sub-detector for the future linear collider experiments: a relatively short term design based on micro-strips combined or not with a gaseous central tracker and a longer term design based on an all-pixel tracker.The R&D objectives on sensors include single sided micro-strips as baseline for the shorter term with the strips from large wafers (at least 6 in), 200 μm thick, 50 μm pitch and the edgeless and alignment friendly options. This work is conducted by SiLC in collaboration with three technical research centers in Italy, Finland, and Spain and HPK. SiLC is studied as well, using advanced Si sensor technologies for higher granularity trackers especially short strips and pixels all based on 3D technology. New Deep Sub-Micron CMOS mix mode (analog and digital) FE and readout electronics are developed to fully process the detector signals currently adapted to the ILC cycle. It is a high-level processing and a fully programmable ASIC; highly fault tolerant. In its latest version, handling 128 channels will equip these next coming years larger size silicon tracking prototypes at test beams. Connection of the FEE chip on the silicon detector especially in the strip case is a major issue. Very preliminary results with inline pitch adapter based on wiring were just achieved. Bump-bonding or 3D vertical interconnect is the other SiLC R&D objective. The goal is to simplify the overall architecture and decrease the material budget of these devices. Three tracking concepts are briefly discussed, two of which are part of the ILC Letter of Intent of the ILD and SiD detector concepts. These last years, SiLC successfully performed beam tests to experience and test these R&D lines.

Spin formalism and applications to new physics searches

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haber, H.E.

1994-12-01

An introduction to spin techniques in particle physics is given. Among the topics covered are: helicity formalism and its applications to the decay and scattering of spin-1/2 and spin-1 particles, techniques for evaluating helicity amplitudes (including projection operator methods and the spinor helicity method), and density matrix techniques. The utility of polarization and spin correlations for untangling new physics beyond the Standard Model at future colliders such as the LHC and a high energy e{sup +}e{sup {minus}} linear collider is then considered. A number of detailed examples are explored including the search for low-energy supersymmetry, a non-minimal Higgs boson sector,more » and new gauge bosons beyond the W{sup {+-}} and Z.« less

Learning from Higgs physics at future Higgs factories

NASA Astrophysics Data System (ADS)

Gu, Jiayin; Li, Honglei; Liu, Zhen; Su, Shufang; Su, Wei

2017-12-01

Future Higgs factories can reach impressive precision on Higgs property measurements. In this paper, instead of conventional focus of Higgs precision in certain interaction bases, we explore its sensitivity to new physics models at the electron-positron colliders. In particular, we study two categories of new physics models, Standard Model (SM) with a real scalar singlet extension, and Two Higgs Double Model (2HDM) as examples of weakly-interacting models, Minimal Composite Higgs Model (MCHM) and three typical patterns of the more general operator counting for strong interacting models as examples of strong dynamics. We perform a global fit to various Higgs search channels to obtain the 95% C.L. constraints on the model parameter space. In the SM with a singlet extension, we obtain the limits on the singlet-doublet mixing angle sin θ, as well as the more general Wilson coefficients of the induced higher dimensional operators. In the 2HDM, we analyze tree level effects in tan β vs. cos( β - α) plane, as well as the one-loop contributions from the heavy Higgs bosons in the alignment limit to obtain the constraints on heavy Higgs masses for different types of 2HDM. In strong dynamics models, we obtain lower limits on the strong dynamics scale. In addition, once deviations of Higgs couplings are observed, they can be used to distinguish different models. We also compare the sensitivity of various future Higgs factories, namely Circular Electron Positron Collider (CEPC), Future Circular Collider (FCC)-ee and International Linear Collider (ILC).

Magnet reliability in the Fermilab Main Injector and implications for the ILC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tartaglia, M.A.; Blowers, J.; Capista, D.

2007-08-01

The International Linear Collider reference design requires over 13000 magnets, of approximately 135 styles, which must operate with very high reliability. The Fermilab Main Injector represents a modern machine with many conventional magnet styles, each of significant quantity, that has now accumulated many hundreds of magnet-years of operation. We review here the performance of the magnets built for this machine, assess their reliability and categorize the failure modes, and discuss implications for reliability of similar magnet styles expected to be used at the ILC.

Polarized γ source based on Compton backscattering in a laser cavity

NASA Astrophysics Data System (ADS)

Yakimenko, V.; Pogorelsky, I. V.

2006-09-01

We propose a novel gamma source suitable for generating a polarized positron beam for the next generation of electron-positron colliders, such as the International Linear Collider (ILC), and the Compact Linear Collider (CLIC). This 30-MeV polarized gamma source is based on Compton scattering inside a picosecond CO2 laser cavity generated from electron bunches produced by a 4-GeV linac. We identified and experimentally verified the optimum conditions for obtaining at least one gamma photon per electron. After multiplication at several consecutive interaction points, the circularly polarized gamma rays are stopped on a target, thereby creating copious numbers of polarized positrons. We address the practicality of having an intracavity Compton-polarized positron source as the injector for these new colliders.

Double elementary Goldstone Higgs boson production in future linear colliders

NASA Astrophysics Data System (ADS)

Guo, Yu-Chen; Yue, Chong-Xing; Liu, Zhi-Cheng

2018-03-01

The Elementary Goldstone Higgs (EGH) model is a perturbative extension of the Standard Model (SM), which identifies the EGH boson as the observed Higgs boson. In this paper, we study pair production of the EGH boson in future linear electron positron colliders. The cross-sections in the TeV region can be changed to about ‑27%, 163% and ‑34% for the e+e‑→ Zhh, e+e‑→ νν¯hh and e+e‑→ tt¯hh processes with respect to the SM predictions, respectively. According to the expected measurement precisions, such correction effects might be observed in future linear colliders. In addition, we compare the cross-sections of double SM-like Higgs boson production with the predictions in other new physics models.

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.

Kitty for the kitty

NASA Astrophysics Data System (ADS)

2016-11-01

Officials at the International Linear Collider (ILC) - a proposed successor to the Large Hadron Collider at CERN - have turned to Hello Kitty to help promote the project, which is set to be built in Japan.

Learning from Higgs physics at future Higgs factories

DOE PAGES

Gu, Jiayin; Li, Honglei; Liu, Zhen; ...

2017-12-29

Future Higgs factories can reach impressive precision on Higgs property measurements. In this paper, instead of conventional focus of Higgs precision in certain interaction bases, we explored its sensitivity to new physics models at the electron-positron colliders. In particular, we studied two categories of new physics models, Standard Model (SM) with a real scalar singlet extension, and Two Higgs Double Model (2HDM) as examples of weakly-interacting models, Minimal Composite Higgs Model (MCHM) and three typical patterns of the more general operator counting for strong interacting models as examples of strong dynamics. We performed a global fit to various Higgs searchmore » channels to obtain the 95% C.L. constraints on the model parameter space. In the SM with a singlet extension, we obtained the limits on the singlet-doublet mixing angle sin(theta), as well as the more general Wilson coefficients of the induced higher dimensional operators. In the 2HDM, we analyzed tree level effects in tan(beta) vs. cos(beta-alpha) plane, as well as the one-loop contributions from the heavy Higgs bosons in the alignment limit to obtain the constraints on heavy Higgs masses for different types of 2HDM. In strong dynamics models, we obtained lower limits on the strong dynamics scale. In addition, once deviations of Higgs couplings are observed, they can be used to distinguish different models. Here, we also compared the sensitivity of various future Higgs factories, namely Circular Electron Positron Collider (CEPC), Future Circular Collider (FCC)-ee and International Linear Collider (ILC).« less

Learning from Higgs physics at future Higgs factories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, Jiayin; Li, Honglei; Liu, Zhen

Future Higgs factories can reach impressive precision on Higgs property measurements. In this paper, instead of conventional focus of Higgs precision in certain interaction bases, we explored its sensitivity to new physics models at the electron-positron colliders. In particular, we studied two categories of new physics models, Standard Model (SM) with a real scalar singlet extension, and Two Higgs Double Model (2HDM) as examples of weakly-interacting models, Minimal Composite Higgs Model (MCHM) and three typical patterns of the more general operator counting for strong interacting models as examples of strong dynamics. We performed a global fit to various Higgs searchmore » channels to obtain the 95% C.L. constraints on the model parameter space. In the SM with a singlet extension, we obtained the limits on the singlet-doublet mixing angle sin(theta), as well as the more general Wilson coefficients of the induced higher dimensional operators. In the 2HDM, we analyzed tree level effects in tan(beta) vs. cos(beta-alpha) plane, as well as the one-loop contributions from the heavy Higgs bosons in the alignment limit to obtain the constraints on heavy Higgs masses for different types of 2HDM. In strong dynamics models, we obtained lower limits on the strong dynamics scale. In addition, once deviations of Higgs couplings are observed, they can be used to distinguish different models. Here, we also compared the sensitivity of various future Higgs factories, namely Circular Electron Positron Collider (CEPC), Future Circular Collider (FCC)-ee and International Linear Collider (ILC).« less

SLC: The End Game

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raimondi, Pantaleo

The design of the Stanford Linear Collider (SLC) called for a beam intensity far beyond what was practically achievable. This was due to intrinsic limitations in many subsystems and to a lack of understanding of the new physics of linear colliders. Real progress in improving the SLC performance came from precision, non-invasive diagnostics to measure and monitor the beams and from new techniques to control the emittance dilution and optimize the beams. A major contribution to the success of the last 1997-98 SLC run came from several innovative ideas for improving the performance of the Final Focus (FF). This papermore » describes some of the problems encountered and techniques used to overcome them. Building on the SLC experience, we will also present a new approach to the FF design for future high energy linear colliders.« less

DEPFET pixel detector for future e-e+ experiments

NASA Astrophysics Data System (ADS)

Boronat, M.; DEPFET Collaboration

2016-04-01

The DEPFET Collaboration develops highly granular, ultra-thin pixel detectors for outstanding vertex reconstruction at future e+e- collider experiments. A DEPFET sensor provides, simultaneously, position sensitive detector capabilities and in-pixel amplification by the integration of a field effect transistor on a fully depleted silicon bulk. The characterization of the latest DEPFET prototypes has proven that a comfortable signal to noise ratio and excellent single point resolution can be achieved for a sensor thickness of 50 μm. A complete detector concept is being developed for the Belle II experiment at the new Japanese super flavor factory. The close to Belle related final auxiliary ASICs have been produced and found to operate a DEPFET pixel detector of the latest generation with the Belle II required read-out speed. DEPFET is not only the technology of choice for the Belle II vertex detector, but also a solid candidate for the International Linear Collider (ILC). Therefore, in this paper, the status of DEPFET R&D project is reviewed in the light of the requirements of the vertex detector at a future e+e- collider.

The NLC technical program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burke, D.L.

1998-07-01

There are important goals in particle physics to be addressed by a TeV-scale electron-positron linear collider. Recent developments in accelerator physics and technologies aimed for the realization of such a collider are discussed in this paper.

Survey of beam instrumentation used in SLC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ecklund, S.D.

A survey of beam instruments used at SLAC in the SLC machine is presented. The basic utility and operation of each device is briefly described. The various beam instruments used at the Stanford Linear Collider (SLC), can be classified by the function they perform. Beam intensity, position and size are typical of the parameters of beam which are measured. Each type of parameter is important for adjusting or tuning the machine in order to achieve optimum performance. 39 refs.

Statistics of vacuum breakdown in the high-gradient and low-rate regime

NASA Astrophysics Data System (ADS)

Wuensch, Walter; Degiovanni, Alberto; Calatroni, Sergio; Korsbäck, Anders; Djurabekova, Flyura; Rajamäki, Robin; Giner-Navarro, Jorge

2017-01-01

In an increasing number of high-gradient linear accelerator applications, accelerating structures must operate with both high surface electric fields and low breakdown rates. Understanding the statistical properties of breakdown occurrence in such a regime is of practical importance for optimizing accelerator conditioning and operation algorithms, as well as of interest for efforts to understand the physical processes which underlie the breakdown phenomenon. Experimental data of breakdown has been collected in two distinct high-gradient experimental set-ups: A prototype linear accelerating structure operated in the Compact Linear Collider Xbox 12 GHz test stands, and a parallel plate electrode system operated with pulsed DC in the kV range. Collected data is presented, analyzed and compared. The two systems show similar, distinctive, two-part distributions of number of pulses between breakdowns, with each part corresponding to a specific, constant event rate. The correlation between distance and number of pulses between breakdown indicates that the two parts of the distribution, and their corresponding event rates, represent independent primary and induced follow-up breakdowns. The similarity of results from pulsed DC to 12 GHz rf indicates a similar vacuum arc triggering mechanism over the range of conditions covered by the experiments.

Development of a thermionic magnicon amplifier at 11.4 GHz. Final report for period May 16, 1995 - May 15, 2001

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gold, Steven H.; Fliflet, Arne W.

2001-08-25

This is the final report on the research program ''Development of a Thermionic Magnicon Amplifier at 11.4 GHz,'' which was carried out by the Plasma Physics Division of the Naval Research Laboratory. Its goal was to develop a high-power, frequency-doubling X-band magnicon amplifier, an advanced scanning-beam amplifier, for use in future linear colliders. The final design parameters were 61 MW at 11.424 GHz, 59 dB gain, 59% efficiency, 1 microsecond pulselength and 10 Hz repetition rate. At the conclusion of this program, the magnicon was undergoing high-power conditioning, having already demonstrated high-power operation, phase stability, a linear drive curve, amore » small operational frequency bandwidth and a spectrally pure, single-mode output.« less

High-gradient, pulsed operation of superconducting niobium cavities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campisi, I.E.; Farkas, Z.D.

1984-02-01

Tests performed on several Niobium TM/sub 010/ cavities at frequencies of about 2856 MHz using a high-power, pulsed method indicate that, at the end of the charging pulse, peak surface magnetic fields of up to approx. 1300 Oe, corresponding to a peak surface electric field of approx. 68 MV/m, can be reached at 4.2/sup 0/K without appreciable average losses. Further studies of the properties of superconductors under pulsed operation might shed light on fundamental properties of rf superconductivity, as well as lead to the possibility of applying the pulse method to the operation of high-gradient linear colliders. 7 references, 30more » figures, 2 tables.« less

Terahertz-driven linear electron acceleration

PubMed Central

Nanni, Emilio A.; Huang, Wenqian R.; Hong, Kyung-Han; Ravi, Koustuban; Fallahi, Arya; Moriena, Gustavo; Dwayne Miller, R. J.; Kärtner, Franz X.

2015-01-01

The cost, size and availability of electron accelerators are dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency accelerating structures operate with 30–50 MeV m−1 gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional radio-frequency structures. However, laser-driven wakefield accelerators require intense femtosecond sources and direct laser-driven accelerators suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here we demonstrate linear acceleration of electrons with keV energy gain using optically generated terahertz pulses. Terahertz-driven accelerating structures enable high-gradient electron/proton accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. These ultra-compact terahertz accelerators with extremely short electron bunches hold great potential to have a transformative impact for free electron lasers, linear colliders, ultrafast electron diffraction, X-ray science and medical therapy with X-rays and electron beams. PMID:26439410

Terahertz-driven linear electron acceleration

DOE PAGES

Nanni, Emilio A.; Huang, Wenqian R.; Hong, Kyung-Han; ...

2015-10-06

The cost, size and availability of electron accelerators are dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency accelerating structures operate with 30–50 MeVm -1 gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional radio-frequency structures. However, laser-driven wakefield accelerators require intense femtosecond sources and direct laser-driven accelerators suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here we demonstrate linear acceleration of electrons with keV energy gain using optically generated terahertz pulses. Terahertz-driven accelerating structures enable high-gradient electron/protonmore » accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. As a result, these ultra-compact terahertz accelerators with extremely short electron bunches hold great potential to have a transformative impact for free electron lasers, linear colliders, ultrafast electron diffraction, X-ray science and medical therapy with X-rays and electron beams.« less

R&D status of linear collider technology at KEK

NASA Astrophysics Data System (ADS)

Urakawa, Junji

1992-02-01

This paper gives an outline of the Japan Linear Collider (JLC) project, especially JLC-I. The status of the various R&D works is particularly presented for the following topics: (1) electron and positron sources, (2) S-band injector linacs, (3) damping rings, (4) high power klystrons and accelerating structures, (5) the final focus system. Finally, the status of the construction and design studies for the Accelerator Test Facility (ATF) is summarized.

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

ScienceCinema

Battaglia, Marco

2018-01-12

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.

Decoupling correction system in RHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trbojevic, D.; Tepikian, S.; Peggs, S.

A global linear decoupling in the Relativistic Heavy Ion Collider (RHIC) is going to be performed with the three families of skew quadrupoles. The operating horizontal and vertical betatron tunes in the RHIC will be separated by one unit [nu][sub x]=28.19 and [nu][sub y]=29.18. The linear coupling is corrected by minimizing the tune splitting [Delta][nu]-the off diagonal matrix [bold m] (defined by Edwards and Teng). The skew quadrupole correction system is located close to each of the six interaction regions. A detail study of the system is presented by the use of the TEAPOT accelerator physics code. [copyright] 1994 Americanmore » Institute of Physics« less

Some Alignment Considerations for the Next Linear Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruland, R

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.

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.

Performance Analysis of the Ironless Inductive Position Sensor in the Large Hadron Collider Collimators Environment

PubMed Central

Danisi, Alessandro; Masi, Alessandro; Losito, Roberto

2015-01-01

The Ironless Inductive Position Sensor (I2PS) has been introduced as a valid alternative to Linear Variable Differential Transformers (LVDTs) when external magnetic fields are present. Potential applications of this linear position sensor can be found in critical systems such as nuclear plants, tokamaks, satellites and particle accelerators. This paper analyzes the performance of the I2PS in the harsh environment of the collimators of the Large Hadron Collider (LHC), where position uncertainties of less than 20 µm are demanded in the presence of nuclear radiation and external magnetic fields. The I2PS has been targeted for installation for LHC Run 2, in order to solve the magnetic interference problem which standard LVDTs are experiencing. The paper describes in detail the chain of systems which belong to the new I2PS measurement task, their impact on the sensor performance and their possible further optimization. The I2PS performance is analyzed evaluating the position uncertainty (on 30 s), the magnetic immunity and the long-term stability (on 7 days). These three indicators are assessed from data acquired during the LHC operation in 2015 and compared with those of LVDTs. PMID:26569259

Design, Project Execution, and Commissioning of the 1.8 K Superfluid Helium Refrigeration System for SRF Cryomodule Testing

DOE PAGES

Treite, P.; Nuesslein, U.; Jia, Yi; ...

2015-07-15

The Fermilab Cryomodule Test Facility (CMTF) provides a test bed to measure the performance of superconducting radiofrequency (SRF) cryomodules (CM). These SRF components form the basic building blocks of future high intensity accelerators such as the International Linear Collider (ILC) and a Muon Collider. Linde Kryotechnik AG and Linde Cryogenics have designed, constructed and commissioned the superfluid helium refrigerator needed to support SRF component testing at the CMTF Facility. The hybrid refrigerator is designed to operate in a variety of modes and under a wide range of boundary conditions down to 1.8 Kelvin set by CM design. Special features ofmore » the refrigerator include the use of warm and cold compression and high efficiency turbo expanders.This paper gives an overview on the wide range of the challenging cooling requirements, the design, fabrication and the commissioning of the installed cryogenic system.« less

Physics at the e⁺e⁻ linear collider

DOE PAGES

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.

Improved formalism for precision Higgs coupling fits

NASA Astrophysics Data System (ADS)

Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon; Karl, Robert; List, Jenny; Ogawa, Tomohisa; Peskin, Michael E.; Tian, Junping

2018-03-01

Future e+e- colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e+e- data, based on the effective field theory description of corrections to the Standard Model. We apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e+e- colliders.

Design of a 6 TeV muon collider

DOE PAGES

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

2016-09-09

Here, a preliminary 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 themore » $$\\beta$$ functions at collision point are 1 cm in each plane. The ring linear optics, the non-linear chromaticity compensation in the Interaction Region (IR), and the additional non-linear orthogonal correcting knobs are described. Magnet specifications are based on the maximum pole-tip field of 20T in dipoles and 15T in quadrupoles. Careful compensation of the non-linear chromatic and amplitude dependent effects provide a sufficiently large dynamic aperture for the momentum range of up to $$\\pm$$0.5% without considering magnet errors.« less

Nuclotron-Based Ion Collider Facility (nica)

NASA Astrophysics Data System (ADS)

Meshkov, I.; Sissakian, A.; Sorin, A.

2008-09-01

The project of an ion collider accelerator complex NICA that is under development at JINR is presented. The article is based on the Conceptual Design Report (CDR)1 of the NICA project delivered in January 2008. The article contains NICA facility scheme, the facility operation scenario, its elements parameters, the proposed methods of intense ion beam acceleration and achievement of the required luminosity of the collider. The symmetric mode of the collider operation is considered here and most attention is concentrated on the luminosity provision in collisions of uranium ions (nuclei).

SuperB Progress Report for Accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biagini, M.E.; Boni, R.; Boscolo, M.

2012-02-14

This report details the progress made in by the SuperB Project in the area of the Collider since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008. With this document we propose a new electron positron colliding beam accelerator to be built in Italy to study flavor physics in the B-meson system at an energy of 10 GeV in the center-of-mass. This facility is called a high luminosity B-factory with a project name 'SuperB'. This project builds on a long history of successful e+e- colliders built around themore » world, as illustrated in Figure 1.1. The key advances in the design of this accelerator come from recent successes at the DAFNE collider at INFN in Frascati, Italy, at PEP-II at SLAC in California, USA, and at KEKB at KEK in Tsukuba Japan, and from new concepts in beam manipulation at the interaction region (IP) called 'crab waist'. This new collider comprises of two colliding beam rings, one at 4.2 GeV and one at 6.7 GeV, a common interaction region, a new injection system at full beam energies, and one of the two beams longitudinally polarized at the IP. Most of the new accelerator techniques needed for this collider have been achieved at other recently completed accelerators including the new PETRA-3 light source at DESY in Hamburg (Germany) and the upgraded DAFNE collider at the INFN laboratory at Frascati (Italy), or during design studies of CLIC or the International Linear Collider (ILC). The project is to be designed and constructed by a worldwide collaboration of accelerator and engineering staff along with ties to industry. To save significant construction costs, many components from the PEP-II collider at SLAC will be recycled and used in this new accelerator. The interaction region will be designed in collaboration with the particle physics detector to guarantee successful mutual use. The accelerator collaboration will consist of several groups at present universities and national laboratories. In Italy these may include INFN Frascati and the University of Pisa, in the United States SLAC, LBNL, BNL and several universities, in France IN2P3, LAPP, and Grenoble, in Russia BINP, in Poland Krakow University, and in the UK the Cockcroft Institute. The construction time for this collider is a total of about four years. The new tunnel can be bored in about a year. The new accelerator components can be built and installed in about 4 years. The shipping of components from PEP-II at SLAC to Italy will take about a year. A new linac and damping ring complex for the injector for the rings can be built in about three years. The commissioning of this new accelerator will take about a year including the new electron and positron sources, new linac, new damping ring, new beam transport lines, two new collider rings and the Interaction Region. The new particle physics detector can be commissioned simultaneously with the accelerator. Once beam collisions start for particle physics, the luminosity will increase with time, likely reaching full design specifications after about two to three years of operation. After construction, the operation of the collider will be the responsibility of the Italian INFN governmental agency. The intent is to run this accelerator about ten months each year with about one month for accelerator turn-on and nine months for colliding beams. The collider will need to operate for about 10 years to provide the required 50 ab{sup -1} requested by the detector collaboration. Both beams as anticipated in this collider will have properties that are excellent for use as sources for synchrotron radiation (SR). The expected photon properties are comparable to those of PETRA-3 or NSLS-II. The beam lines and user facilities needed to carry out this SR program are being investigated.« less

Linear polarization of gluons and photons in unpolarized collider experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pisano, Cristian; Boer, Daniël; Brodsky, Stanley 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 pairmore » 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.« less

Testing the scalar sector of the twin Higgs model at colliders

NASA Astrophysics Data System (ADS)

Chacko, Zackaria; Kilic, Can; Najjari, Saereh; Verhaaren, Christopher B.

2018-03-01

We consider mirror twin Higgs models in which the breaking of the global symmetry is realized linearly. In this scenario, the radial mode in the Higgs potential is present in the spectrum and constitutes a second portal between the twin and SM sectors. We show that a study of the properties of this particle at colliders, when combined with precision measurements of the light Higgs, can be used to overdetermine the form of the scalar potential, thereby confirming that it possesses an enhanced global symmetry as dictated by the twin Higgs mechanism. We find that, although the reach of the LHC for this state is limited, future linear colliders will be able to explore a significant part of the preferred parameter space, allowing the possibility of directly testing the twin Higgs framework.

Design study of an optical cavity for a future photon collider at ILC

NASA Astrophysics Data System (ADS)

Klemz, G.; Mönig, K.; Will, I.

2006-08-01

Hard photons well above 100 GeV have to be generated in a future photon collider which essentially will be based on the infrastructure of the planned International Linear Collider (ILC). The energy of near-infrared laser photons will be boosted by Compton backscattering against a high-energy relativistic electron beam. For high effectiveness, a very powerful laser system is required that exceeds today's state-of-the-art capabilities. In this paper a design of an auxiliary passive cavity is discussed that resonantly enhances the peak-power of the laser. The properties and prospects of such a cavity are addressed on the basis of the specifications for the European TeV Energy Superconducting Linear Accelerator (TESLA) proposal. Those of the ILC are expected to be similar.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 themore » 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.« less

Improved formalism for precision Higgs coupling fits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon

Future e +e – colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e +e – data, based on the effective field theory description of corrections to the Standard Model. Lastly, we apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e +e – colliders.

Improved formalism for precision Higgs coupling fits

DOE PAGES

Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon; ...

2018-03-20

Future e +e – colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e +e – data, based on the effective field theory description of corrections to the Standard Model. Lastly, we apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e +e – colliders.

1985 Particle Accelerator Conference: Accelerator Engineering and Technology, 11th, Vancouver, Canada, May 13-16, 1985, Proceedings

NASA Astrophysics Data System (ADS)

Strathdee, A.

1985-10-01

The topics discussed are related to high-energy accelerators and colliders, particle sources and electrostatic accelerators, controls, instrumentation and feedback, beam dynamics, low- and intermediate-energy circular accelerators and rings, RF and other acceleration systems, beam injection, extraction and transport, operations and safety, linear accelerators, applications of accelerators, radiation sources, superconducting supercolliders, new acceleration techniques, superconducting components, cryogenics, and vacuum. Accelerator and storage ring control systems are considered along with linear and nonlinear orbit theory, transverse and longitudinal instabilities and cures, beam cooling, injection and extraction orbit theory, high current dynamics, general beam dynamics, and medical and radioisotope applications. Attention is given to superconducting RF structures, magnet technology, superconducting magnets, and physics opportunities with relativistic heavy ion accelerators.

Characteristic W-ino signals in a linear collider from anomaly mediated supersymmetry breaking

NASA Astrophysics Data System (ADS)

Ghosh, Dilip Kumar; Kundu, Anirban; Roy, Probir; Roy, Sourov

2001-12-01

Though the minimal model of anomaly-mediated supersymmetry breaking has been significantly constrained by recent experimental and theoretical work, there are still allowed regions of the parameter space for moderate to large values of tan β. We show that these regions will be comprehensively probed in a s=1 TeV e+e- linear collider. Diagnostic signals to this end are studied by zeroing in on a unique and distinct feature of a large class of models in this genre: a neutral W-ino-like lightest supersymmetric particle closely degenerate in mass with a W-ino-like chargino. The pair production processes e+e--->e+/-Le-/+L, e+/-Re-/+R, e+/-Le-/+R, ν~νbar, χ~01χ~02, χ~02χ~02 are all considered at s=1 TeV corresponding to the proposed DESY TEV Energy Superconducting Linear Accelerator linear collider in two natural categories of mass ordering in the sparticle spectra. The signals analyzed comprise multiple combinations of fast charged leptons (any of which can act as the trigger) plus displaced vertices XD (any of which can be identified by a heavy ionizing track terminating in the detector) and/or associated soft pions with characteristic momentum distributions.

Characteristics of W-26% Re Target Material(LCC-0103)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sunwoo, A.

2003-10-07

The W-26 wt-% Re alloy was selected as a Stanford Linear Collider (SLC) target material for its exceptional physics properties and for the high strength and good ductility at the anticipated target operating temperatures, above the DBTT. After several years of operation, the target failed catastrophically. A detailed microstructural and mechanical characterization of the non-irradiated disk indicates that the material has been PM processed, nonuniformly mechanically worked and stress relieved. As a result, the ductility of the material varies through the thickness of the disk, making it difficult to determine the DBTT. The results of tensile and fatigue properties aremore » reported with the corresponding fractography of the fracture surfaces.« less

OVERMODED HIGH-POWER RF MAGNETIC SWITCHES AND CIRCULATORS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tantawi, Sami

2002-08-20

We present design methodology for active rf magnetic components which are suitable for pulse compression systems of future X-band linear colliders. These components comprise an array of active elements arranged together so that the total electromagnetic field is reduced and the power handling capabilities are increased. The active element of choice is a magnetic material (garnet), which can be switched by changing a biasing magnetic field. A novel design allows these components to operate in the low loss circular waveguide mode TE{sub 01}. We describe the design methodology, the switching elements and circuits.

New central drift chamber for the MARK II at SLC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bartelt, J.E.

A new central drift chamber has been constructed for the Mark II detector for use at the new SLAC Linear Collider (SLC). The design of the chamber is based on a multi-sense-wire cell of the jet chamber type. In addition to drift-time measurements, pulse-height measurements from the sense wires provide electron-hadron separation by dE/dx. The chamber has been tested in operation at PEP before its move to the SLC. The design and construction are described, and measurements from the new chamber are presented.

Proton-Proton and Proton-Antiproton Colliders

NASA Astrophysics Data System (ADS)

Scandale, Walter

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

Proton-Proton and Proton-Antiproton Colliders

NASA Astrophysics Data System (ADS)

Scandale, Walter

2014-04-01

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

Proton-Proton and Proton-Antiproton Colliders

NASA Astrophysics Data System (ADS)

Scandale, Walter

2015-02-01

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

Optimization of detectors for the ILC

NASA Astrophysics Data System (ADS)

Suehara, Taikan; ILD Group; SID Group

2016-04-01

International Linear Collider (ILC) is a next-generation e+e- linear collider to explore Higgs, Beyond-Standard-Models, top and electroweak particles with great precision. We are optimizing our two detectors, International Large Detector (ILD) and Silicon Detector (SiD) to maximize the physics reach expected in ILC with reasonable detector cost and good reliability. The optimization study on vertex detectors, main trackers and calorimeters is underway. We aim to conclude the optimization to establish final designs in a few years, to finish detector TDR and proposal in reply to expected ;green sign; of the ILC project.

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.

Physics at the [Formula: see text] linear collider.

PubMed

Moortgat-Pick, G; Baer, H; Battaglia, M; Belanger, G; Fujii, K; Kalinowski, J; Heinemeyer, S; Kiyo, Y; Olive, K; Simon, F; Uwer, P; Wackeroth, D; Zerwas, P M; Arbey, A; Asano, M; Bagger, J; Bechtle, P; Bharucha, A; Brau, J; Brümmer, F; Choi, S Y; Denner, A; Desch, K; Dittmaier, S; Ellwanger, U; Englert, C; Freitas, A; Ginzburg, I; Godfrey, S; Greiner, N; Grojean, C; Grünewald, M; Heisig, J; Höcker, A; Kanemura, S; Kawagoe, K; Kogler, R; Krawczyk, M; Kronfeld, A S; Kroseberg, J; Liebler, S; List, J; Mahmoudi, F; Mambrini, Y; Matsumoto, S; Mnich, J; Mönig, K; Mühlleitner, M M; Pöschl, R; Porod, W; Porto, S; Rolbiecki, K; Schmitt, M; Serpico, P; Stanitzki, M; Stål, O; Stefaniak, T; Stöckinger, D; Weiglein, G; Wilson, G W; Zeune, L; Moortgat, F; Xella, S; Bagger, J; Brau, J; Ellis, J; Kawagoe, K; Komamiya, S; Kronfeld, A S; Mnich, J; Peskin, M; Schlatter, D; Wagner, A; Yamamoto, H

A comprehensive review of physics at an [Formula: see text] linear collider in the energy range of [Formula: see text] GeV-3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focusses 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.

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.

Static beam-based alignment for the Ring-To-Main-Linac of the Compact Linear Collider

NASA Astrophysics Data System (ADS)

Han, Y.; Latina, A.; Ma, L.; Schulte, D.

2017-06-01

The Compact Linear Collider (CLIC) is a future multi-TeV collider for the post-Large Hadron Collider era. It features high-gradient acceleration and ultra-low emittance to achieve its ambitious goals of high collision energy and peak luminosity. Beam-based alignment (BBA) techniques are mandatory for CLIC to preserve the ultra-low emittances from the damping rings to the interaction point. In this paper, a detailed study of BBA techniques has been carried out for the entire 27 km long ``Ring-To-Main-Linac'' (RTML) section of the CLIC, to correct realistic static errors such as element position offsets, angle, magnetic strength and dynamic magnetic centre shifts. The correction strategy is proved to be very effective and leads to a relaxation of the pre-alignment tolerances for the component installation in the tunnel. This is the first time such a large scale and complex lattice has been corrected to match the design budgets. The techniques proposed could be applied to similarly sized facilities, such as the International Linear Collider, where a similar RTML section is used, or free-electron lasers, which, being equipped with linacs and bunch compressors, present challenges similar to those of the CLIC RTML. Moreover, a new technique is investigated for the emittance tuning procedure: the direct measurement of the interactions between the beams and a set of a few consecutive laser wires. The speed of this technique can be faster comparing to the traditional techniques based on emittance reconstructed from beam size measurements at several positions.

Testing the scalar sector of the twin Higgs model at colliders

DOE PAGES

Chacko, Zackaria; Kilic, Can; Najjari, Saereh; ...

2018-03-22

We consider Mirror Twin Higgs models in which the breaking of the global symmetry is realized linearly. In this scenario, the radial mode in the Higgs potential is present in the spectrum, and constitutes a second portal between the twin and SM sectors. We show that a study of the properties of this particle at colliders, when combined with precision measurements of the light Higgs, can be used to overdetermine the form of the scalar potential, thereby confirming that it possesses an enhanced global symmetry as dictated by the Twin Higgs mechanism. We find that, although the reach of themore » LHC for this state is limited, future linear colliders will be able to explore a significant part of the preferred parameter space, allowing the possibility of directly testing the Twin Higgs framework.« less

Testing the scalar sector of the twin Higgs model at colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chacko, Zackaria; Kilic, Can; Najjari, Saereh

We consider Mirror Twin Higgs models in which the breaking of the global symmetry is realized linearly. In this scenario, the radial mode in the Higgs potential is present in the spectrum, and constitutes a second portal between the twin and SM sectors. We show that a study of the properties of this particle at colliders, when combined with precision measurements of the light Higgs, can be used to overdetermine the form of the scalar potential, thereby confirming that it possesses an enhanced global symmetry as dictated by the Twin Higgs mechanism. We find that, although the reach of themore » LHC for this state is limited, future linear colliders will be able to explore a significant part of the preferred parameter space, allowing the possibility of directly testing the Twin Higgs framework.« less

CCD developments for particle colliders

NASA Astrophysics Data System (ADS)

Stefanov, Konstantin D.

2006-09-01

Charge Coupled Devices (CCDs) have been successfully used in several high-energy physics experiments over the last 20 years. Their small pixel size and excellent precision provide superb tool for studying of short-lived particles and understanding the nature at fundamental level. Over the last years the Linear Collider Flavour Identification (LCFI) collaboration has developed Column-Parallel CCDs (CPCCD) and CMOS readout chips to be used for the vertex detector at the International Linear Collider (ILC). The CPCCDs are very fast devices capable of satisfying the challenging requirements imposed by the beam structure of the superconducting accelerator. First set of prototype devices have been designed, manufactured and successfully tested, with second-generation chips on the way. Another idea for CCD-based device, the In-situ Storage Image Sensor (ISIS) is also under development and the first prototype is in production.

Singlet-catalyzed electroweak phase transitions and precision Higgs boson studies

NASA Astrophysics Data System (ADS)

Profumo, Stefano; Ramsey-Musolf, Michael J.; Wainwright, Carroll L.; Winslow, Peter

2015-02-01

We update the phenomenology of gauge-singlet extensions of the Standard Model scalar sector and their implications for the electroweak phase transition. Considering the introduction of one real scalar singlet to the scalar potential, we analyze present constraints on the potential parameters from Higgs coupling measurements at the Large Hadron Collider (LHC) and electroweak precision observables for the kinematic regime in which no new scalar decay modes arise. We then show how future precision measurements of Higgs boson signal strengths and the Higgs self-coupling could probe the scalar potential parameter space associated with a strong first-order electroweak phase transition. We illustrate using benchmark precision for several future collider options, including the high-luminosity LHC, the International Linear Collider, Triple-Large Electron-Positron collider, the China Electron-Positron Collider, and a 100 TeV proton-proton collider, such as the Very High Energy LHC or the Super Proton-Proton Collider. For the regions of parameter space leading to a strong first-order electroweak phase transition, we find that there exists considerable potential for observable deviations from purely Standard Model Higgs properties at these prospective future colliders.

CLIC CDR - physics and detectors: CLIC conceptual design report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berger, E.; Demarteau, M.; Repond, J.

This report forms part of the Conceptual Design Report (CDR) of the Compact LInear Collider (CLIC). The CLIC accelerator complex is described in a separate CDR volume. A third document, to appear later, will assess strategic scenarios for building and operating CLIC in successive center-of-mass energy stages. It is anticipated that CLIC will commence with operation at a few hundred GeV, giving access to precision standard-model physics like Higgs and top-quark physics. Then, depending on the physics landscape, CLIC operation would be staged in a few steps ultimately reaching the maximum 3 TeV center-of-mass energy. Such a scenario would maximizemore » the physics potential of CLIC providing new physics discovery potential over a wide range of energies and the ability to make precision measurements of possible new states previously discovered at the Large Hadron Collider (LHC). The main purpose of this document is to address the physics potential of a future multi-TeV e{sup +}e{sup -} collider based on CLIC technology and to describe the essential features of a detector that are required to deliver the full physics potential of this machine. The experimental conditions at CLIC are significantly more challenging than those at previous electron-positron colliders due to the much higher levels of beam-induced backgrounds and the 0.5 ns bunch-spacing. Consequently, a large part of this report is devoted to understanding the impact of the machine environment on the detector with the aim of demonstrating, with the example of realistic detector concepts, that high precision physics measurements can be made at CLIC. Since the impact of background increases with energy, this document concentrates on the detector requirements and physics measurements at the highest CLIC center-of-mass energy of 3 TeV. One essential output of this report is the clear demonstration that a wide range of high precision physics measurements can be made at CLIC with detectors which are challenging, but considered feasible following a realistic future R&D program.« less

Diagnostics of the Fermilab Tevatron using an AC dipole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyamoto, Ryoichi

2008-08-01

The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for the Tevatron, a fast-oscillating (f ~ 20 kHz) dipole magnet which can be adiabatically turned on and off to establish sustained coherent oscillations of themore » beam particles without affecting the transverse emittance. By utilizing an existing magnet and a higher power audio amplifier, the cost of the Tevatron AC dipole system became relatively inexpensive. We discuss corrections which must be applied to the driven oscillation measurements to obtain the proper interpretation of beam optical parameters from AC dipole studies. After successful operations of the Tevatron AC dipole system, AC dipole systems, similar to that in the Tevatron, will be build for the CERN LHC. We present several measurements of linear optical parameters (beta function and phase advance) for the Tevatron, as well as studies of non-linear perturbations from sextupole and octupole elements.« less

The International Linear Collider Technical Design Report - Volume 2: Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baer, Howard; Barklow, Tim; Fujii, Keisuke

2013-06-26

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

The International Linear Collider Technical Design Report - Volume 4: Detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behnke, Ties

2013-06-26

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

USLCSG Task Force

Science.gov Websites

Unites States Linear Collider Steering Group dot dot dot dot What's New! June 2003 Meeting Welcome to the USLCSG Task Force at the Stanford Linear Accelerator Center [Enter] dot dot SLAC Page Owners

Probing 6D operators at future e - e + colliders

NASA Astrophysics Data System (ADS)

Chiu, Wen Han; Leung, Sze Ching; Liu, Tao; Lyu, Kun-Feng; Wang, Lian-Tao

2018-05-01

We explore the sensitivities at future e - e + colliders to probe a set of six-dimensional operators which can modify the SM predictions on Higgs physics and electroweak precision measurements. We consider the case in which the operators are turned on simultaneously. Such an analysis yields a "conservative" interpretation on the collider sensitivities, complementary to the "optimistic" scenario where the operators are individually probed. After a detail analysis at CEPC in both "conservative" and "optimistic" scenarios, we also considered the sensitivities for FCC-ee and ILC. As an illustration of the potential of constraining new physics models, we applied sensitivity analysis to two benchmarks: holographic composite Higgs model and littlest Higgs model.

Potential and challenges of the physics measurements with very forward detectors at linear colliders

NASA Astrophysics Data System (ADS)

Božović Jelisavčić, Ivanka; Kačarević, G.; Lukić, S.; Poss, S.; Sailer, A.; Smiljanić, I.; FCAL Collaboration

2016-04-01

The instrumentation of the very forward region of a detector at a future linear collider (ILC, CLIC) is briefly reviewed. The status of the FCAL R&D activity is given with emphasis on physics and technological challenges. The current status of studies on absolute luminosity measurement, luminosity spectrum reconstruction and high-energy electron identification with the forward calorimeters is given. The impact of FCAL measurements on physics studies is illustrated with an example of the σHWW ṡBR (H →μ+μ-) measurement at 1.4 TeV CLIC.

Calorimetry at the International Linear Collider

NASA Astrophysics Data System (ADS)

Repond, José

2007-03-01

The physics potential of the International Linear Collider depends critically on the jet energy resolution of its detector. Detector concepts are being developed which optimize the jet energy resolution, with the aim of achieving σjet=30%/√{Ejet}. Under the assumption that Particle Flow Algorithms (PFAs), which combine tracking and calorimeter information to reconstruct the energy of hadronic jets, can provide this unprecedented jet energy resolution, calorimeters with very fine granularity are being developed. After a brief introduction outlining the principles of PFAs, the current status of various calorimeter prototype construction projects and their plans for the next few years will be reviewed.

Infrared weak corrections to strongly interacting gauge boson scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ciafaloni, Paolo; Urbano, Alfredo

2010-04-15

We evaluate the impact of electroweak corrections of infrared origin on strongly interacting longitudinal gauge boson scattering, calculating all-order resummed expressions at the double log level. As a working example, we consider the standard model with a heavy Higgs. At energies typical of forthcoming experiments (LHC, International Linear Collider, Compact Linear Collider), the corrections are in the 10%-40% range, with the relative sign depending on the initial state considered and on whether or not additional gauge boson emission is included. We conclude that the effect of radiative electroweak corrections should be included in the analysis of longitudinal gauge boson scattering.

Accelerators for America's Future

NASA Astrophysics Data System (ADS)

Bai, Mei

2016-03-01

Particle accelerator, a powerful tool to energize beams of charged particles to a desired speed and energy, has been the working horse for investigating the fundamental structure of matter and fundermental laws of nature. Most known examples are the 2-mile long Stanford Linear Accelerator at SLAC, the high energy proton and anti-proton collider Tevatron at FermiLab, and Large Hadron Collider that is currently under operation at CERN. During the less than a century development of accelerator science and technology that led to a dazzling list of discoveries, particle accelerators have also found various applications beyond particle and nuclear physics research, and become an indispensible part of the economy. Today, one can find a particle accelerator at almost every corner of our lives, ranging from the x-ray machine at the airport security to radiation diagnostic and therapy in hospitals. This presentation will give a brief introduction of the applications of this powerful tool in fundermental research as well as in industry. Challenges in accelerator science and technology will also be briefly presented

The BABAR detector: Upgrades, operation and performance

NASA Astrophysics Data System (ADS)

Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; del Amo Sanchez, P.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prudent, X.; Robbe, P.; Tisserand, V.; Zghiche, A.; Grauges, E.; Garra Tico, J.; Lopez, L.; Martinelli, M.; Palano, A.; Pappagallo, M.; Pompili, A.; Chen, G. P.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Stugu, B.; Sun, L.; Abrams, G. S.; Battaglia, M.; Borgland, A. W.; Breon, A. B.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Charles, E.; Clark, A. R.; Day, C. T.; Furman, M.; Gill, M. S.; Groysman, Y.; Jacobsen, R. G.; Kadel, R. W.; Kadyk, J. A.; Kerth, L. T.; Kolomensky, Yu. G.; Kral, J. F.; Kukartsev, G.; LeClerc, C.; Levi, M. E.; Lynch, G.; Merchant, A. M.; Mir, L. M.; Oddone, P. J.; Orimoto, T. J.; Osipenkov, I. L.; Pripstein, M.; Roe, N. A.; Romosan, A.; Ronan, M. T.; Shelkov, V. G.; Suzuki, A.; Tackmann, K.; Tanabe, T.; Wenzel, W. A.; Zisman, M.; Barrett, M.; Bright-Thomas, P. G.; Ford, K. E.; Harrison, T. J.; Hart, A. J.; Hawkes, C. M.; Knowles, D. J.; Morgan, S. E.; O'Neale, S. W.; Penny, R. C.; Smith, D.; Soni, N.; Watson, A. T.; Watson, N. K.; Goetzen, K.; Held, T.; Koch, H.; Kunze, M.; Lewandowski, B.; Pelizaeus, M.; Peters, K.; Schmuecker, H.; Schroeder, T.; Steinke, M.; Fella, A.; Antonioli, E.; Boyd, J. T.; Chevalier, N.; Cottingham, W. N.; Foster, B.; Mackay, C.; Walker, D.; Abe, K.; Asgeirsson, D. J.; Cuhadar-Donszelmann, T.; Fulsom, B. G.; Hearty, C.; Knecht, N. S.; Mattison, T. S.; McKenna, J. A.; Thiessen, D.; Khan, A.; Kyberd, P.; McKemey, A. K.; Randle-Conde, A.; Saleem, M.; Sherwood, D. J.; Teodorescu, L.; Blinov, V. E.; Bukin, A. D.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Korol, A. A.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Telnov, V. I.; Todyshev, K. Yu.; Yushkov, A. N.; Best, D. S.; Bondioli, M.; Bruinsma, M.; Chao, M.; Curry, S.; Eschrich, I.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Martin, E. C.; McMahon, S.; Mommsen, R. K.; Stoker, D. P.; Abachi, S.; Buchanan, C.; Hartfiel, B. L.; Weinstein, A. J. R.; Atmacan, H.; Foulkes, S. D.; Gary, J. W.; Layter, J.; Liu, F.; Long, O.; Shen, B. C.; Vitug, G. M.; Wang, K.; Yasin, Z.; Zhang, L.; Hadavand, H. K.; Hill, E. J.; Paar, H. P.; Rahatlou, S.; Schwanke, U.; Sharma, V.; Berryhill, J. W.; Campagnari, C.; Cunha, A.; Dahmes, B.; Hong, T. M.; Kovalskyi, D.; Kuznetsova, N.; Levy, S. L.; Lu, A.; Mazur, M. A.; Richman, J. D.; Verkerke, W.; Beck, T. W.; Beringer, J.; Eisner, A. M.; Flacco, C. J.; Grillo, A. A.; Grothe, M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Nesom, G.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Spencer, E.; Spradlin, P.; Turri, M.; Walkowiak, W.; Wang, L.; Wilder, M.; Williams, D. C.; Wilson, M. G.; Winstrom, L. O.; Chen, E.; Cheng, C. H.; Doll, D. A.; Dorsten, M. P.; Dvoretskii, A.; Echenard, B.; Erwin, R. J.; Fang, F.; Flood, K.; Hitlin, D. G.; Metzler, S.; Narsky, I.; Oyang, J.; Piatenko, T.; Porter, F. C.; Ryd, A.; Samuel, A.; Yang, S.; Zhu, R. Y.; Andreassen, R.; Devmal, S.; Geld, T. L.; Jayatilleke, S.; Mancinelli, G.; Meadows, B. T.; Mishra, K.; Sokoloff, M. D.; Abe, T.; Antillon, E. A.; Barillari, T.; Becker, J.; Blanc, F.; Bloom, P. C.; Chen, S.; Clifton, Z. C.; Derrington, I. M.; Destree, J.; Dima, M. O.; Ford, W. T.; Gaz, A.; Gilman, J. D.; Hachtel, J.; Hirschauer, J. F.; Johnson, D. R.; Kreisel, A.; Nagel, M.; Nauenberg, U.; Olivas, A.; Rankin, P.; Roy, J.; Ruddick, W. O.; Smith, J. G.; Ulmer, K. A.; van Hoek, W. C.; Wagner, S. R.; West, C. G.; Zhang, J.; Ayad, R.; Blouw, J.; Chen, A.; Eckhart, E. A.; Harton, J. L.; Hu, T.; Toki, W. H.; Wilson, R. J.; Winklmeier, F.; Zeng, Q. L.; Altenburg, D.; Feltresi, E.; Hauke, A.; Jasper, H.; Karbach, M.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Brandt, T.; Brose, J.; Colberg, T.; Dahlinger, G.; Dickopp, M.; Eckstein, P.; Futterschneider, H.; Kaiser, S.; Kobel, M. J.; Krause, R.; Müller-Pfefferkorn, R.; Mader, W. F.; Maly, E.; Nogowski, R.; Otto, S.; Schubert, J.; Schubert, K. R.; Schwierz, R.; Sundermann, J. E.; Volk, A.; Wilden, L.; Bernard, D.; Brochard, F.; Cohen-Tanugi, J.; Dohou, F.; Ferrag, S.; Latour, E.; Mathieu, A.; Renard, C.; Schrenk, S.; T'Jampens, S.; Thiebaux, Ch.; Vasileiadis, G.; Verderi, M.; Anjomshoaa, A.; Bernet, R.; Clark, P. J.; Lavin, D. R.; Muheim, F.; Playfer, S.; Robertson, A. I.; Swain, J. E.; Watson, J. E.; Xie, Y.; Andreotti, D.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Carassiti, V.; Cecchi, A.; Cibinetto, G.; Cotta Ramusino, A.; Evangelisti, F.; Fioravanti, E.; Franchini, P.; Garzia, I.; Landi, L.; Luppi, E.; Malaguti, R.; Negrini, M.; Padoan, C.; Petrella, A.; Piemontese, L.; Santoro, V.; Sarti, A.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; Finocchiaro, G.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; de Sangro, R.; Santoni, M.; Zallo, A.; Bagnasco, S.; Buzzo, A.; Capra, R.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M. M.; Minutoli, S.; Monge, M. R.; Musico, P.; Passaggio, S.; Pastore, F. C.; Patrignani, C.; Pia, M. G.; Robutti, E.; Santroni, A.; Tosi, S.; Bhuyan, B.; Prasad, V.; Bailey, S.; Brandenburg, G.; Chaisanguanthum, K. S.; Lee, C. L.; Morii, M.; Won, E.; Wu, J.; Adametz, A.; Dubitzky, R. S.; Marks, J.; Schenk, S.; Uwer, U.; Klose, V.; Lacker, H. M.; Aspinwall, M. L.; Bhimji, W.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Flack, R. L.; Gaillard, J. R.; Gunawardane, N. J. W.; Morton, G. W.; Nash, J. A.; Nikolich, M. B.; Panduro Vazquez, W.; Sanders, P.; Smith, D.; Taylor, G. P.; Tibbetts, M.; Behera, P. K.; Chai, X.; Charles, M. J.; Grenier, G. J.; Hamilton, R.; Lee, S.-J.; Mallik, U.; Meyer, N. T.; Chen, C.; Cochran, J.; Crawley, H. B.; Dong, L.; Eyges, V.; Fischer, P.-A.; Lamsa, J.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gao, Y. Y.; Gritsan, A. V.; Guo, Z. J.; Lae, C. K.; Schott, G.; Albert, J. N.; Arnaud, N.; Beigbeder, C.; Breton, D.; Davier, M.; Derkach, D.; Dû, S.; Firmino da Costa, J.; Grosdidier, G.; Höcker, A.; Laplace, S.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Malaescu, B.; Nief, J. Y.; Petersen, T. C.; Plaszczynski, S.; Pruvot, S.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Tocut, V.; Trincaz-Duvoid, S.; Wang, L. L.; Wormser, G.; Bionta, R. M.; Brigljević, V.; Lange, D. J.; Simani, M. C.; Wright, D. M.; Bingham, I.; Burke, J. P.; Chavez, C. A.; Coleman, J. P.; Forster, I. J.; Fry, J. R.; Gabathuler, E.; Gamet, R.; George, M.; Hutchcroft, D. E.; Kay, M.; Parry, R. J.; Payne, D. J.; Schofield, K. C.; Sloane, R. J.; Touramanis, C.; Azzopardi, D. E.; Bellodi, G.; Bevan, A. J.; Clarke, C. K.; Cormack, C. M.; Di Lodovico, F.; Dixon, P.; George, K. A.; Menges, W.; Potter, R. J. L.; Sacco, R.; Shorthouse, H. W.; Sigamani, M.; Strother, P.; Vidal, P. B.; Brown, C. L.; Cowan, G.; Flaecher, H. U.; George, S.; Green, M. G.; Hopkins, D. A.; Jackson, P. S.; Kurup, A.; Marker, C. E.; McGrath, P.; McMahon, T. R.; Paramesvaran, S.; Salvatore, F.; Vaitsas, G.; Winter, M. A.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Prencipe, E.; Allison, J.; Alwyn, K. E.; Bailey, D. S.; Barlow, N. R.; Barlow, R. J.; Chia, Y. M.; Edgar, C. L.; Forti, A. C.; Fullwood, J.; Hart, P. A.; Hodgkinson, M. C.; Jackson, F.; Jackson, G.; Kelly, M. P.; Kolya, S. D.; Lafferty, G. D.; Lyon, A. J.; Naisbit, M. T.; Savvas, N.; Weatherall, J. H.; West, T. J.; Williams, J. C.; Yi, J. I.; Anderson, J.; Farbin, A.; Hulsbergen, W. D.; Jawahery, A.; Lillard, V.; Roberts, D. A.; Schieck, J. R.; Simi, G.; Tuggle, J. M.; Blaylock, G.; Dallapiccola, C.; Hertzbach, S. S.; Kofler, R.; Koptchev, V. B.; Li, X.; Moore, T. B.; Salvati, E.; Saremi, S.; Staengle, H.; Willocq, S. Y.; Cowan, R.; Dujmic, D.; Fisher, P. H.; Henderson, S. W.; Koeneke, K.; Lang, M. I.; Sciolla, G.; Spitznagel, M.; Taylor, F.; Yamamoto, R. K.; Yi, M.; Zhao, M.; Zheng, Y.; Klemetti, M.; Lindemann, D.; Mangeol, D. J. J.; Mclachlin, S. E.; Milek, M.; Patel, P. M.; Robertson, S. H.; Biassoni, P.; Cerizza, G.; Lazzaro, A.; Lombardo, V.; Neri, N.; Palombo, F.; Pellegrini, R.; Stracka, S.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Kroeger, R.; Reidy, J.; Sanders, D. A.; Summers, D. J.; Zhao, H. W.; Godang, R.; Brunet, S.; Cote, D.; Nguyen, X.; Simard, M.; Taras, P.; Viaud, B.; Nicholson, H.; Cavallo, N.; De Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Monorchio, D.; Onorato, G.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Baak, M. A.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Allmendinger, T.; Benelli, G.; Brau, B.; Corwin, L. A.; Gan, K. K.; Honscheid, K.; Hufnagel, D.; Kagan, H.; Kass, R.; Morris, J. P.; Rahimi, A. M.; Regensburger, J. J.; Smith, D. S.; Ter-Antonyan, R.; Wong, Q. K.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Iwasaki, M.; Kolb, J. A.; Lu, M.; Potter, C. T.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Borsato, E.; Castelli, G.; Colecchia, F.; Crescente, A.; Dal Corso, F.; Dorigo, A.; Fanin, C.; Furano, F.; Gagliardi, N.; Galeazzi, F.; Margoni, M.; Marzolla, M.; Michelon, G.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Solagna, P.; Stevanato, E.; Stroili, R.; Tiozzo, G.; Voci, C.; Akar, S.; Bailly, P.; Ben-Haim, E.; Bonneaud, G.; Briand, H.; Chauveau, J.; Hamon, O.; John, M. J. J.; Lebbolo, H.; Leruste, Ph.; Malclès, J.; Marchiori, G.; Martin, L.; Ocariz, J.; Perez, A.; Pivk, M.; Prendki, J.; Roos, L.; Sitt, S.; Stark, J.; Thérin, G.; Vallereau, A.; Biasini, M.; Covarelli, R.; Manoni, E.; Pennazzi, S.; Pioppi, M.; Angelini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Bucci, F.; Calderini, G.; Carpinelli, M.; Cenci, R.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Morganti, M.; Morsani, F.; Paoloni, E.; Raffaelli, F.; Rizzo, G.; Sandrelli, F.; Triggiani, G.; Walsh, J. J.; Haire, M.; Judd, D.; Biesiada, J.; Danielson, N.; Elmer, P.; Fernholz, R. E.; Lau, Y. P.; Lu, C.; Miftakov, V.; Olsen, J.; Lopes Pegna, D.; Sands, W. R.; Smith, A. J. S.; Telnov, A. V.; Tumanov, A.; Varnes, E. W.; Baracchini, E.; Bellini, F.; Bulfon, C.; Buccheri, E.; Cavoto, G.; D'Orazio, A.; Di Marco, E.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Jackson, P. D.; Lamanna, E.; Leonardi, E.; Li Gioi, L.; Lunadei, R.; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Polci, F.; del Re, D.; Renga, F.; Safai Tehrani, F.; Serra, M.; Voena, C.; Bünger, C.; Christ, S.; Hartmann, T.; Leddig, T.; Schröder, H.; Wagner, G.; Waldi, R.; Adye, T.; Bly, M.; Brew, C.; Condurache, C.; De Groot, N.; Franek, B.; Geddes, N. I.; Gopal, G. P.; Olaiya, E. O.; Ricciardi, S.; Roethel, W.; Wilson, F. F.; Xella, S. M.; Aleksan, R.; Bourgeois, P.; Emery, S.; Escalier, M.; Esteve, L.; Gaidot, A.; Ganzhur, S. F.; Giraud, P.-F.; Georgette, Z.; Graziani, G.; Hamel de Monchenault, G.; Kozanecki, W.; Langer, M.; Legendre, M.; London, G. W.; Mayer, B.; Micout, P.; Serfass, B.; Vasseur, G.; Yèche, Ch.; Zito, M.; Allen, M. T.; Akre, R.; Aston, D.; Azemoon, T.; Bard, D. J.; Bartelt, J.; Bartoldus, R.; Bechtle, P.; Becla, J.; Benitez, J. F.; Berger, N.; Bertsche, K.; Boeheim, C. T.; Bouldin, K.; Boyarski, A. M.; Boyce, R. F.; Browne, M.; Buchmueller, O. L.; Burgess, W.; Cai, Y.; Cartaro, C.; Ceseracciu, A.; Claus, R.; Convery, M. R.; Coupal, D. P.; Craddock, W. W.; Crane, G.; Cristinziani, M.; DeBarger, S.; Decker, F. J.; Dingfelder, J. C.; Donald, M.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Ecklund, S.; Erickson, R.; Fan, S.; Field, R. C.; Fisher, A.; Fox, J.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Gaponenko, I.; Glanzman, T.; Gowdy, S. J.; Graham, M. T.; Grenier, P.; Hadig, T.; Halyo, V.; Haller, G.; Hamilton, J.; Hanushevsky, A.; Hasan, A.; Hast, C.; Hee, C.; Himel, T.; Hryn'ova, T.; Huffer, M. E.; Hung, T.; Innes, W. R.; Iverson, R.; Kaminski, J.; Kelsey, M. H.; Kim, H.; Kim, P.; Kharakh, D.; Kocian, M. L.; Krasnykh, A.; Krebs, J.; Kroeger, W.; Kulikov, A.; Kurita, N.; Langenegger, U.; Leith, D. W. G. S.; Lewis, P.; Li, S.; Libby, J.; Lindquist, B.; Luitz, S.; Lüth, V.; Lynch, H. L.; MacFarlane, D. B.; Marsiske, H.; McCulloch, M.; McDonald, J.; Melen, R.; Menke, S.; Metcalfe, S.; Messner, R.; Moss, L. J.; Mount, R.; Muller, D. R.; Neal, H.; Nelson, D.; Nelson, S.; Nordby, M.; Nosochkov, Y.; Novokhatski, A.; O'Grady, C. P.; O'Neill, F. G.; Ofte, I.; Ozcan, V. E.; Perazzo, A.; Perl, M.; Petrak, S.; Piemontese, M.; Pierson, S.; Pulliam, T.; Ratcliff, B. N.; Ratkovsky, S.; Reif, R.; Rivetta, C.; Rodriguez, R.; Roodman, A.; Salnikov, A. A.; Schietinger, T.; Schindler, R. H.; Schwarz, H.; Schwiening, J.; Seeman, J.; Smith, D.; Snyder, A.; Soha, A.; Stanek, M.; Stelzer, J.; Su, D.; Sullivan, M. K.; Suzuki, K.; Swain, S. K.; Tanaka, H. A.; Teytelman, D.; Thompson, J. M.; Tinslay, J. S.; Trunov, A.; Turner, J.; van Bakel, N.; van Winkle, D.; Va'vra, J.; Wagner, A. P.; Weaver, M.; Weinstein, A. J. R.; Weber, T.; West, C. A.; Wienands, U.; Wisniewski, W. J.; Wittgen, M.; Wittmer, W.; Wright, D. H.; Wulsin, H. W.; Yan, Y.; Yarritu, A. K.; Yi, K.; Yocky, G.; Young, C. C.; Ziegler, V.; Chen, X. R.; Liu, H.; Park, W.; Purohit, M. V.; Singh, H.; Weidemann, A. W.; White, R. M.; Wilson, J. R.; Yumiceva, F. X.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Edwards, A. J.; Majewski, S. A.; Meyer, T. I.; Miyashita, T. S.; Petersen, B. A.; Roat, C.; Ahmed, M.; Ahmed, S.; Alam, M. S.; Bula, R.; Ernst, J. A.; Jain, V.; Liu, J.; Pan, B.; Saeed, M. A.; Wappler, F. R.; Zain, S. B.; Gorodeisky, R.; Guttman, N.; Peimer, D.; Soffer, A.; De Silva, A.; Lund, P.; Krishnamurthy, M.; Ragghianti, G.; Spanier, S. M.; Wogsland, B. J.; Eckmann, R.; Ritchie, J. L.; Ruland, A. M.; Satpathy, A.; Schilling, C. J.; Schwitters, R. F.; Wray, B. C.; Drummond, B. W.; Izen, J. M.; Kitayama, I.; Lou, X. C.; Ye, S.; Bianchi, F.; Bona, M.; Gallo, F.; Gamba, D.; Pelliccioni, M.; Bomben, M.; Borean, C.; Bosisio, L.; Cossutti, F.; Della Ricca, G.; Dittongo, S.; Grancagnolo, S.; Lanceri, L.; Poropat, P.; Rashevskaya, I.; Vitale, L.; Vuagnin, G.; Manfredi, P. F.; Re, V.; Speziali, V.; Frank, E. D.; Gladney, L.; Guo, Q. H.; Panetta, J.; Azzolini, V.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D. A.; Oyanguren, A.; Agarwal, A.; Albert, J.; Banerjee, Sw.; Bernlochner, F. U.; Brown, C. M.; Choi, H. H. F.; Fortin, D.; Fransham, K. B.; Hamano, K.; Kowalewski, R.; Lewczuk, M. J.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Back, J. J.; Gershon, T. J.; Harrison, P. F.; Ilic, J.; Latham, T. E.; Mohanty, G. B.; Puccio, E.; Band, H. R.; Chen, X.; Cheng, B.; Dasu, S.; Datta, M.; Eichenbaum, A. M.; Hollar, J. J.; Hu, H.; Johnson, J. R.; Kutter, P. E.; Li, H.; Liu, R.; Mellado, B.; Mihalyi, A.; Mohapatra, A. K.; Pan, Y.; Pierini, M.; Prepost, R.; Scott, I. J.; Tan, P.; Vuosalo, C. O.; von Wimmersperg-Toeller, J. H.; Wu, S. L.; Yu, Z.; Greene, M. G.; Kordich, T. M. B.

2013-11-01

The BABAR detector operated successfully at the PEP-II asymmetric e+e- collider at the SLAC National Accelerator Laboratory from 1999 to 2008. This report covers upgrades, operation, and performance of the collider and the detector systems, as well as the trigger, online and offline computing, and aspects of event reconstruction since the beginning of data taking.

The BaBar detector: Upgrades, operation and performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, B.; Barate, R.; Boutigny, D.

2013-11-01

The BaBar detector operated successfully at the PEP-II asymmetric e+e- collider at the SLAC National Accelerator Laboratory from 1999 to 2008. This report covers upgrades, operation, and performance of the collider and the detector systems, as well as the trigger, online and offline computing, and aspects of event reconstruction since the beginning of data taking.

Frequency and temperature dependence of electrical breakdown at 21, 30, and 39 GHz.

PubMed

Braun, H H; Döbert, S; Wilson, I; Wuensch, W

2003-06-06

A TeV-range e(+)e(-) linear collider has emerged as one of the most promising candidates to extend the high energy frontier of experimental elementary particle physics. A high accelerating gradient for such a collider is desirable to limit its overall length. Accelerating gradient is mainly limited by electrical breakdown, and it has been generally assumed that this limit increases with increasing frequency for normal-conducting accelerating structures. Since the choice of frequency has a profound influence on the design of a linear collider, the frequency dependence of breakdown has been measured using six exactly scaled single-cell cavities at 21, 30, and 39 GHz. The influence of temperature on breakdown behavior was also investigated. The maximum obtainable surface fields were found to be in the range of 300 to 400 MV/m for copper, with no significant dependence on either frequency or temperature.

Frequency and Temperature Dependence of Electrical Breakdown at 21, 30, and 39GHz

NASA Astrophysics Data System (ADS)

Braun, H. H.; Döbert, S.; Wilson, I.; Wuensch, W.

2003-06-01

A TeV-range e+e- linear collider has emerged as one of the most promising candidates to extend the high energy frontier of experimental elementary particle physics. A high accelerating gradient for such a collider is desirable to limit its overall length. Accelerating gradient is mainly limited by electrical breakdown, and it has been generally assumed that this limit increases with increasing frequency for normal-conducting accelerating structures. Since the choice of frequency has a profound influence on the design of a linear collider, the frequency dependence of breakdown has been measured using six exactly scaled single-cell cavities at 21, 30, and 39GHz. The influence of temperature on breakdown behavior was also investigated. The maximum obtainable surface fields were found to be in the range of 300 to 400 MV/m for copper, with no significant dependence on either frequency or temperature.

Commissioning of the Electron-Positron Collider VEPP-2000 after the Upgrade

NASA Astrophysics Data System (ADS)

Shatunov, Yu.; Belikov, O.; Berkaev, D.; Gorchakov, K.; Zharinov, Yu.; Zemlyanskii, I.; Kasaev, A.; Kirpotin, A.; Koop, I.; Lysenko, A.; Motygin, S.; Perevedentsev, E.; Prosvetov, V.; Rabusov, D.; Rogovskii, Yu.; Senchenko, A.; Timoshenko, M.; Shatilov, D.; Shatunov, P.; Shvarts, D.

2018-05-01

The VEPP-2000 electron-positron collider has been operating at BINP since 2010. Applying the concept of round colliding beams allows us to reach the record value of the beam-beam parameter, ξ 0.12. The VEPP-2000 upgrade, including the connection to the new BINP Injection Complex, the improvement of the BEP booster, and the BEP-VEPP-2000 transfer channels for operation at 1 GeV, substantially increases the installation luminosity. Data collection is in progress.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Juwen; /SLAC; Lewandowski, James

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

Femto-second synchronisation with a waveguide interferometer

NASA Astrophysics Data System (ADS)

Dexter, A. C.; Smith, S. J.; Woolley, B. J.; Grudiev, A.

2018-03-01

CERN's compact linear collider CLIC requires crab cavities on opposing linacs to rotate bunches of particles into alignment at the interaction point (IP). These cavities are located approximately 25 metres either side of the IP. The luminosity target requires synchronisation of their RF phases to better than 5 fs r.m.s. This is to be achieved by powering both cavities from one high power RF source, splitting the power and delivering it along two waveguide paths that are controlled to be identical in length to within a micrometre. The waveguide will be operated as an interferometer. A high power phase shifter for adjusting path lengths has been successfully developed and operated in an interferometer. The synchronisation target has been achieved in a low power prototype system.

Radiative return capabilities of a high-energy, high-luminosity e + e - collider

DOE PAGES

Karliner, Marek; Low, Matthew; Rosner, Jonathan L.; ...

2015-08-14

An electron-positron collider operating at a center-of-mass energy E CM can collect events at all lower energies through initial-state radiation (ISR or radiative return). We explore the capabilities for radiative return studies by a proposed high-luminosity collider at E CM = 250 or 90 GeV, to fill in gaps left by lower-energy colliders such as PEP, PETRA, TRISTAN, and LEP. These capabilities are compared with those of the lower-energy e +e - colliders as well as hadron colliders such as the Tevatron and the CERN Large Hadron Collider (LHC). Some examples of accessible questions in dark photon searches and heavymore » flavor spectroscopy are given.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubo, Kiyoshi

2003-07-07

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

Space-charge limitations in a collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fedotov, A.; Heimerle, M.

Design of several projects which envision hadron colliders operating at low energies such as NICA at JINR [1] and Electron-Nucleon Collider at FAIR [2] is under way. In Brookhaven National Laboratory (BNL), a new physics program requires operation of Relativistic Heavy Ion Collider (RHIC) with heavy ions at low energies at g=2.7-10 [3]. In a collider, maximum achievable luminosity is typically limited by beam-beam effects. For heavy ions significant luminosity degradation, driving bunch length and transverse emittance growth, comes from Intrabeam Scattering (IBS). At these low energies, IBS growth can be effectively counteracted, for example, with cooling techniques. If IBSmore » were the only limitation, one could achieve small hadron beam emittance and bunch length with the help of cooling, resulting in a dramatic luminosity increase. However, as a result of low energies, direct space-charge force from the beam itself is expected to become the dominant limitation. Also, the interplay of both beambeam and space-charge effects may impose an additional limitation on achievable maximum luminosity. Thus, understanding at what values of space-charge tune shift one can operate in the presence of beam-beam effects in a collider is of great interest for all of the above projects. Operation of RHIC for Low-Energy physics program started in 2010 which allowed us to have a look at combined impact of beam-beam and space-charge effects on beam lifetime experimentally. Here we briefly discuss expected limitation due to these effects with reference to recent RHIC experience.« less

Fourth standard model family neutrino at future linear colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.more » 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.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raubenheimer, T.O.

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 NLCmore » 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.« less

Large Hadron Collider commissioning and first operation.

PubMed

Myers, S

2012-02-28

A history of the commissioning and the very successful early operation of the Large Hadron Collider (LHC) is described. The accident that interrupted the first commissioning, its repair and the enhanced protection system put in place are fully described. The LHC beam commissioning and operational performance are reviewed for the period from 2010 to mid-2011. Preliminary plans for operation and future upgrades for the LHC are given for the short and medium term.

Considerations on Energy Frontier Colliders after LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiltsev, Vladimir

2016-11-15

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

Superstrong Adjustable Permanent Magnet for a Linear Collider Final Focus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mihara, T.

A superstrong permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens for the linear collider because of its compactness and low power consumption. The first fabricated prototype of our PMQ achieved a 300T/m superstrong field gradient with a 100mm overall magnet radius and a 7mm bore radius, but a drawback is its fixed strength. Therefore, a second prototype of PMQ, whose strength is adjustable, was fabricated. Its strength adjustability is based on the ''double ring structure'', rotating subdivided magnet slices separately. This second prototype is being tested. Some of the early results are presented.

Heavy neutrino mixing and single production at linear collider

NASA Astrophysics Data System (ADS)

Gluza, J.; Maalampi, J.; Raidal, M.; Zrałek, M.

1997-02-01

We study the single production of heavy neutrinos via the processes e- e+ -> νN and e- γ -> W- N at future linear colliders. As a base of our considerations we take a wide class of models, both with vanishing and non-vanishing left-handed Majorana neutrino mass matrix mL. We perform a model independent analyses of the existing experimental data and find connections between the characteristic of heavy neutrinos (masses, mixings, CP eigenvalues) and the mL parameters. We show that with the present experimental constraints heavy neutrino masses almost up to the collision energy can be tested in the future experiments.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adolphsen, Chris

2013-06-26

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

The International Linear Collider Technical Design Report - Volume 1: Executive Summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behnke, Ties; Brau, James E.; Foster, Brian

2013-06-26

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adolphsen, Chris

2013-06-26

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

Efficiency Versus Instability in Plasma Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lebedev, Valeri; Burov, Alexey; Nagaitsev, Sergei

2017-01-05

Plasma wake-field acceleration in a strongly nonlinear (a.k.a. the blowout) regime is one of the main candidates for future high-energy colliders. For this case, we derive a universal efficiency-instability relation, between the power efficiency and the key instability parameter of the witness bunch. We also show that in order to stabilize the witness bunch in a regime with high power efficiency, the bunch needs to have high energy spread, which is not presently compatible with collider-quality beam properties. It is unclear how such limitations could be overcome for high-luminosity linear colliders.

Optimal Model-Based Fault Estimation and Correction for Particle Accelerators and Industrial Plants Using Combined Support Vector Machines and First Principles Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sayyar-Rodsari, Bijan; Schweiger, Carl; /SLAC /Pavilion Technologies, Inc., Austin, TX

2010-08-25

Timely estimation of deviations from optimal performance in complex systems and the ability to identify corrective measures in response to the estimated parameter deviations has been the subject of extensive research over the past four decades. The implications in terms of lost revenue from costly industrial processes, operation of large-scale public works projects and the volume of the published literature on this topic clearly indicates the significance of the problem. Applications range from manufacturing industries (integrated circuits, automotive, etc.), to large-scale chemical plants, pharmaceutical production, power distribution grids, and avionics. In this project we investigated a new framework for buildingmore » parsimonious models that are suited for diagnosis and fault estimation of complex technical systems. We used Support Vector Machines (SVMs) to model potentially time-varying parameters of a First-Principles (FP) description of the process. The combined SVM & FP model was built (i.e. model parameters were trained) using constrained optimization techniques. We used the trained models to estimate faults affecting simulated beam lifetime. In the case where a large number of process inputs are required for model-based fault estimation, the proposed framework performs an optimal nonlinear principal component analysis of the large-scale input space, and creates a lower dimension feature space in which fault estimation results can be effectively presented to the operation personnel. To fulfill the main technical objectives of the Phase I research, our Phase I efforts have focused on: (1) SVM Training in a Combined Model Structure - We developed the software for the constrained training of the SVMs in a combined model structure, and successfully modeled the parameters of a first-principles model for beam lifetime with support vectors. (2) Higher-order Fidelity of the Combined Model - We used constrained training to ensure that the output of the SVM (i.e. the parameters of the beam lifetime model) are physically meaningful. (3) Numerical Efficiency of the Training - We investigated the numerical efficiency of the SVM training. More specifically, for the primal formulation of the training, we have developed a problem formulation that avoids the linear increase in the number of the constraints as a function of the number of data points. (4) Flexibility of Software Architecture - The software framework for the training of the support vector machines was designed to enable experimentation with different solvers. We experimented with two commonly used nonlinear solvers for our simulations. The primary application of interest for this project has been the sustained optimal operation of particle accelerators at the Stanford Linear Accelerator Center (SLAC). Particle storage rings are used for a variety of applications ranging from 'colliding beam' systems for high-energy physics research to highly collimated x-ray generators for synchrotron radiation science. Linear accelerators are also used for collider research such as International Linear Collider (ILC), as well as for free electron lasers, such as the Linear Coherent Light Source (LCLS) at SLAC. One common theme in the operation of storage rings and linear accelerators is the need to precisely control the particle beams over long periods of time with minimum beam loss and stable, yet challenging, beam parameters. We strongly believe that beyond applications in particle accelerators, the high fidelity and cost benefits of a combined model-based fault estimation/correction system will attract customers from a wide variety of commercial and scientific industries. Even though the acquisition of Pavilion Technologies, Inc. by Rockwell Automation Inc. in 2007 has altered the small business status of the Pavilion and it no longer qualifies for a Phase II funding, our findings in the course of the Phase I research have convinced us that further research will render a workable model-based fault estimation and correction for particle accelerators and industrial plants feasible.« less

Low Emittance Guns for the ILC Polarized Electron Beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clendenin, J. E.; Brachmann, A.; Ioakeimidi, K.

Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressedmore » by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of {>=}200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while {>=}500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns.« less

Low Emittance Guns for the ILC Polarized Electron Beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clendenin, J.E.; Brachmann, A.; Ioakeimidi, K.

Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressedmore » by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of {ge}200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while {ge}500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns.« less

In vacuum diamond sensor scanner for beam halo measurements in the beam line at the KEK Accelerator Test Facility

NASA Astrophysics Data System (ADS)

Liu, S.; Bogard, F.; Cornebise, P.; Faus-Golfe, A.; Fuster-Martínez, N.; Griesmayer, E.; Guler, H.; Kubytskyi, V.; Sylvia, C.; Tauchi, T.; Terunuma, N.; Bambade, P.

2016-10-01

The investigation of beam halo transverse distributions is important for the understanding of beam losses and the control of backgrounds in Future Linear Colliders (FLC). A novel in vacuum diamond sensor (DSv) scanner with four strips has been designed and developed for the investigation of the beam halo transverse distributions and also for the diagnostics of Compton recoil electrons after the interaction point (IP) of ATF2, a low energy (1.3 GeV) prototype of the final focus system for the ILC and CLIC linear collider projects. Using the DSv, a dynamic range of ∼106 has been successfully demonstrated and confirmed for the first time in simultaneous beam core (∼109 electrons) and beam halo (∼103 electrons) measurements at ATF2. This report presents the characterization, performance studies and tests of diamond sensors using an α source, as well as using the electron beams at PHIL, a low energy < 5 MeV photo-injector at LAL, and at ATF2. First beam halo measurement results using the DSv at ATF2 with different beam intensities and vacuum levels are also presented. Such measurements not only allow one to evaluate the different sources of beam halo generation but also to define the requirements for a suitable collimation system to be installed at ATF2, as well as to optimize its performance during future operation.

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

ScienceCinema

Thomson, Mark

2018-04-16

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.

Stability of soliton families in nonlinear Schrödinger equations with non-parity-time-symmetric complex potentials

NASA Astrophysics Data System (ADS)

Yang, Jianke; Nixon, Sean

2016-11-01

Stability of soliton families in one-dimensional nonlinear Schrödinger equations with non-parity-time (PT)-symmetric complex potentials is investigated numerically. It is shown that these solitons can be linearly stable in a wide range of parameter values both below and above phase transition. In addition, a pseudo-Hamiltonian-Hopf bifurcation is revealed, where pairs of purely-imaginary eigenvalues in the linear-stability spectra of solitons collide and bifurcate off the imaginary axis, creating oscillatory instability, which resembles Hamiltonian-Hopf bifurcations of solitons in Hamiltonian systems even though the present system is dissipative and non-Hamiltonian. The most important numerical finding is that, eigenvalues of linear-stability operators of these solitons appear in quartets (λ , - λ ,λ* , -λ*), similar to conservative systems and PT-symmetric systems. This quartet eigenvalue symmetry is very surprising for non- PT-symmetric systems, and it has far-reaching consequences on the stability behaviors of solitons.

Minimal supersymmetric B - L extension of the standard model, heavy H and light h Higgs boson production and decay at future e + e - linear colliders

NASA Astrophysics Data System (ADS)

Ramírez-Sánchez, F.; Gutierrez-Rodríguez, A.; Hernández-Ruiz, M. A.

2017-10-01

We study the phenomenology of the light h and heavy H Higgs boson production and decay in the context of a U(1) B - L extension of the standard model with an additional Z´ boson at future e + e - linear colliders with center-of-mass energies of √𝑠 = 500 - 3000 GeV and integrated luminosities of L = 500 - 2000 fb-1. The study includes the processes e + e - → (Z, Z´) → Zh and e + e - → (Z, Z´) → ZH, considering both the resonant and non-resonant effects. We find that the total number of expected Zh and ZH events can reach 106 and 105, respectively, which is a very optimistic scenario allowing us to perform precision measurements for both Higgs bosons h and H, as well as for the Z‧ boson in future high-energy and high-luminosity e + e - colliders.

Top-up injection schemes for future circular lepton collider

NASA Astrophysics Data System (ADS)

Aiba, M.; Goddard, B.; Oide, K.; Papaphilippou, Y.; Saá Hernández, Á.; Shwartz, D.; White, S.; Zimmermann, F.

2018-02-01

Top-up injection is an essential ingredient for the future circular lepton collider (FCC-ee) to maximize the integrated luminosity and it determines the design performance. In ttbar operation mode, with a beam energy of 175 GeV, the design lifetime of ∼1 h is the shortest of the four anticipated operational modes, and the beam lifetime may be even shorter in actual operation. A highly robust top-up injection scheme is consequently imperative. Various top-up methods are investigated and a number of suitable schemes are considered in developing alternative designs for the injection straight section of the collider ring. For the first time, we consider multipole-kicker off-energy injection, for minimizing detector background in top-up operation, and the use of a thin wire septum in a lepton storage ring, for maximizing the luminosity.

Pair Production of the Doubly Charged Leptons Associated with a Gauge Boson γ or Z in e+e- and γγ Collisions at Future Linear Colliders

NASA Astrophysics Data System (ADS)

Zeng, Qing-Guo; Ji, Li; Yang, Shuo

2015-03-01

In this paper, we investigate the production of a pair of doubly charged leptons associated with a gauge boson V(γ or Z) at future linear colliders via e+e- and γγ collisions. The numerical results show that the possible signals of the doubly charged leptons may be detected via the processes e+e- → VX++X-- and γγ → VX++X-- at future ILC or CLIC experiments. Supported in part by the National Natural Science Foundation of China under Grants Nos. 11275088, 11205023, 11375248 and the Program for Liaoning Excellent Talents in University under Grant No. LJQ2014135

Mechanism of vacuum breakdown in radio-frequency accelerating structures

NASA Astrophysics Data System (ADS)

Barengolts, S. A.; Mesyats, V. G.; Oreshkin, V. I.; Oreshkin, E. V.; Khishchenko, K. V.; Uimanov, I. V.; Tsventoukh, M. M.

2018-06-01

It has been investigated whether explosive electron emission may be the initiating mechanism of vacuum breakdown in the accelerating structures of TeV linear electron-positron colliders (Compact Linear Collider). The physical processes involved in a dc vacuum breakdown have been considered, and the relationship between the voltage applied to the diode and the time delay to breakdown has been found. Based on the results obtained, the development of a vacuum breakdown in an rf electric field has been analyzed and the main parameters responsible for the initiation of explosive electron emission have been estimated. The formation of craters on the cathode surface during explosive electron emission has been numerically simulated, and the simulation results are discussed.

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.

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.

Low emittance electron storage rings

NASA Astrophysics Data System (ADS)

Levichev, E. B.

2018-01-01

Low-emittance electron (positron) beams are essential for synchrotron light sources, linear collider damping rings, and circular Crab Waist colliders. In this review, the principles and methods of emittance minimization are discussed, prospects for developing relativistic electron storage rings with small beam phase volume are assessed, and problems related to emittance minimization are examined together with their possible solutions. The special features and engineering implementation aspects of various facilities are briefly reviewed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bane, K.L.F.; Adolphsen, C.; Li, Z.

In a future linear collider, such as the International Linear Collider (ILC), trains of high current, low emittance bunches will be accelerated in a linac before colliding at the interaction point. Asymmetries in the accelerating cavities of the linac will generate fields that will kick the beam transversely and degrade the beam emittance and thus the collider performance. In the main linac of the ILC, which is filled with TESLA-type superconducting cavities, it is the fundamental (FM) and higher mode (HM) couplers that are asymmetric and thus the source of such kicks. The kicks are of two types: one, duemore » to (the asymmetry in) the fundamental RF fields and the other, due to transverse wakefields that are generated by the beam even when it is on axis. In this report we calculate the strength of these kicks and estimate their effect on the ILC beam. The TESLA cavity comprises nine cells, one HM coupler in the upstream end, and one (identical, though rotated) HM coupler and one FM coupler in the downstream end (for their shapes and location see Figs. 1, 2) [1]. The cavity is 1.1 m long, the iris radius 35 mm, and the coupler beam pipe radius 39 mm. Note that the couplers reach closer to the axis than the irises, down to a distance of 30 mm.« less

Left-handed and right-handed U(1) gauge symmetry

NASA Astrophysics Data System (ADS)

Nomura, Takaaki; Okada, Hiroshi

2018-01-01

We propose a model with the left-handed and right-handed continuous Abelian gauge symmetry; U(1) L × U(1) R . Then three right-handed neutrinos are naturally required to achieve U(1) R anomaly cancellations, while several mirror fermions are also needed to do U(1) L anomaly cancellations. Then we formulate the model, and discuss its testability of the new gauge interactions at collider physics such as the large hadron collider (LHC) and the international linear collider (ILC). In particular, we can investigate chiral structure of the interactions by the analysis of forward-backward asymmetry based on polarized beam at the ILC.

High-power klystrons

NASA Astrophysics Data System (ADS)

Siambis, John G.; True, Richard B.; Symons, R. S.

1994-05-01

Novel emerging applications in advanced linear collider accelerators, ionospheric and atmospheric sensing and modification and a wide spectrum of industrial processing applications, have resulted in microwave tube requirements that call for further development of high power klystrons in the range from S-band to X-band. In the present paper we review recent progress in high power klystron development and discuss some of the issues and scaling laws for successful design. We also discuss recent progress in electron guns with potential grading electrodes for high voltage with short and long pulse operation via computer simulations obtained from the code DEMEOS, as well as preliminary experimental results. We present designs for high power beam collectors.

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 a reproducible way.

Accelerator Science: Circular vs. Linear

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lincoln, Don

Particle accelerator are scientific instruments that allow scientists to collide particles together at incredible energies to study the secrets of the universe. However, there are many manners in which particle accelerators can be constructed. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of circular and linear accelerators.

Observations of beam losses due to bound-free pair production in a heavy-ion collider.

PubMed

Bruce, R; Jowett, J M; Gilardoni, S; Drees, A; Fischer, W; Tepikian, S; Klein, S R

2007-10-05

We report the first observations of beam losses due to bound-free pair production at the interaction point of a heavy-ion collider. This process is expected to be a major luminosity limit for the CERN Large Hadron Collider when it operates with (208)Pb(82+) ions because the localized energy deposition by the lost ions may quench superconducting magnet coils. Measurements were performed at the BNL Relativistic Heavy Ion Collider (RHIC) during operation with 100 GeV/nucleon (63)Cu(29+) ions. At RHIC, the rate, energy and magnetic field are low enough so that magnet quenching is not an issue. The hadronic showers produced when the single-electron ions struck the RHIC beam pipe were observed using an array of photodiodes. The measurement confirms the order of magnitude of the theoretical cross section previously calculated by others.

RF pulse shape control in the compact linear collider test facility

NASA Astrophysics Data System (ADS)

Kononenko, Oleksiy; Corsini, Roberto

2018-07-01

The Compact Linear Collider (CLIC) is a study for an electron-positron machine aiming at accelerating and colliding particles at the next energy frontier. The CLIC concept is based on the novel two-beam acceleration scheme, where a high-current low-energy drive beam generates RF in series of power extraction and transfer structures accelerating the low-current main beam. To compensate for the transient beam-loading and meet the energy spread specification requirements for the main linac, the RF pulse shape must be carefully optimized. This was recently modelled by varying the drive beam phase switch times in the sub-harmonic buncher so that, when combined, the drive beam modulation translates into the required voltage modulation of the accelerating pulse. In this paper, the control over the RF pulse shape with the phase switches, that is crucial for the success of the developed compensation model, is studied. The results on the experimental verification of this control method are presented and a good agreement with the numerical predictions is demonstrated. Implications for the CLIC beam-loading compensation model are also discussed.

Model identification of new heavy Z‧ bosons at ILC with polarized beams

NASA Astrophysics Data System (ADS)

Pankov, A. A.; Tsytrinov, A. V.

2017-12-01

Extra neutral gauge bosons, Z‧s, are predicted by many theoretical scenarios of physics beyond the Standard Model, and intensive searches for their signatures will be performed at present and future high energy colliders. It is quite possible that Z‧s are heavy enough to lie beyond the discovery reach expected at the CERN Large Hadron Collider LHC, in which case only indirect signatures of Z‧ exchanges may occur at future colliders, through deviations of the measured cross sections from the Standard Model predictions. We here discuss in this context the expected sensitivity to Z‧ parameters of fermion-pair production cross sections at the planned International Linear Collider (ILC), especially as regards the potential of distinguishing different Z‧ models once such deviations are observed. Specifically, we evaluate the discovery and identification reaches on Z‧ gauge bosons pertinent to the E 6, LR, ALR, and SSM classes of models at the ILC.

Gravitational mass of relativistic matter and antimatter

DOE PAGES

Kalaydzhyan, Tigran

2015-10-13

The universality of free fall, the weak equivalence principle (WEP), is a cornerstone of the general theory of relativity, the most precise theory of gravity confirmed in all experiments up to date. The WEP states the equivalence of the inertial, m, and gravitational, m g, masses and was tested in numerous occasions with normal matter at relatively low energies. However, there is no confirmation for the matter and antimatter at high energies. For the antimatter the situation is even less clear – current direct observations of trapped antihydrogen suggest the limits -65 < m g/m <110 not excluding the so-calledmore » antigravity phenomenon, i.e. repulsion of the antimatter by Earth. Here we demonstrate an indirect bound 0.96 < m g/m < 1.04 on the gravitational mass of relativistic electrons and positrons coming from the absence of the vacuum Cherenkov radiation at the Large Electron–Positron Collider (LEP) and stability of photons at the Tevatron collider in presence of the annual variations of the solar gravitational potential. Our result clearly rules out the speculated antigravity. By considering the absolute potential of the Local Supercluster (LS), we also predict the bounds 1 -4 ×10 -7 < m g/m <1 +2 ×10 -7 for an electron and positron. Lastly, we comment on a possibility of performing complementary tests at the future International Linear Collider (ILC) and Compact Linear Collider (CLIC).« less

Gravitational mass of relativistic matter and antimatter

NASA Astrophysics Data System (ADS)

Kalaydzhyan, Tigran

2015-12-01

The universality of free fall, the weak equivalence principle (WEP), is a cornerstone of the general theory of relativity, the most precise theory of gravity confirmed in all experiments up to date. The WEP states the equivalence of the inertial, m, and gravitational, mg, masses and was tested in numerous occasions with normal matter at relatively low energies. However, there is no confirmation for the matter and antimatter at high energies. For the antimatter the situation is even less clear - current direct observations of trapped antihydrogen suggest the limits - 65

Big data analytics for the Future Circular Collider reliability and availability studies

NASA Astrophysics Data System (ADS)

Begy, Volodimir; Apollonio, Andrea; Gutleber, Johannes; Martin-Marquez, Manuel; Niemi, Arto; Penttinen, Jussi-Pekka; Rogova, Elena; Romero-Marin, Antonio; Sollander, Peter

2017-10-01

Responding to the European Strategy for Particle Physics update 2013, the Future Circular Collider study explores scenarios of circular frontier colliders for the post-LHC era. One branch of the study assesses industrial approaches to model and simulate the reliability and availability of the entire particle collider complex based on the continuous monitoring of CERN’s accelerator complex operation. The modelling is based on an in-depth study of the CERN injector chain and LHC, and is carried out as a cooperative effort with the HL-LHC project. The work so far has revealed that a major challenge is obtaining accelerator monitoring and operational data with sufficient quality, to automate the data quality annotation and calculation of reliability distribution functions for systems, subsystems and components where needed. A flexible data management and analytics environment that permits integrating the heterogeneous data sources, the domain-specific data quality management algorithms and the reliability modelling and simulation suite is a key enabler to complete this accelerator operation study. This paper describes the Big Data infrastructure and analytics ecosystem that has been put in operation at CERN, serving as the foundation on which reliability and availability analysis and simulations can be built. This contribution focuses on data infrastructure and data management aspects and presents case studies chosen for its validation.

Accelerator Science: Circular vs. Linear

ScienceCinema

Lincoln, Don

2018-06-12

Particle accelerator are scientific instruments that allow scientists to collide particles together at incredible energies to study the secrets of the universe. However, there are many manners in which particle accelerators can be constructed. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of circular and linear accelerators.

Cavity beam position monitor system for the Accelerator Test Facility 2

NASA Astrophysics Data System (ADS)

Kim, Y. I.; Ainsworth, R.; Aryshev, A.; Boogert, S. T.; Boorman, G.; Frisch, J.; Heo, A.; Honda, Y.; Hwang, W. H.; Huang, J. Y.; Kim, E.-S.; Kim, S. H.; Lyapin, A.; Naito, T.; May, J.; McCormick, D.; Mellor, R. E.; Molloy, S.; Nelson, J.; Park, S. J.; Park, Y. J.; Ross, M.; Shin, S.; Swinson, C.; Smith, T.; Terunuma, N.; Tauchi, T.; Urakawa, J.; White, G. R.

2012-04-01

The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for final focus beam lines of linear high energy colliders. This paper describes the high resolution cavity beam position monitor (BPM) system, which is a part of the ATF2 diagnostics. Two types of cavity BPMs are used, C-band operating at 6.423 GHz, and S-band at 2.888 GHz with an increased beam aperture. The cavities, electronics, and digital processing are described. The resolution of the C-band system with attenuators was determined to be approximately 250 nm and 1μm for the S-band system. Without attenuation the best recorded C-band cavity resolution was 27 nm.

The ATLAS Experiment at the CERN Large Hadron Collider

NASA Astrophysics Data System (ADS)

ATLAS Collaboration; Aad, G.; Abat, E.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B. A.; Abolins, M.; Abramowicz, H.; Acerbi, E.; Acharya, B. S.; Achenbach, R.; Ackers, M.; Adams, D. L.; Adamyan, F.; Addy, T. N.; Aderholz, M.; Adorisio, C.; Adragna, P.; Aharrouche, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahmed, H.; Aielli, G.; Åkesson, P. F.; Åkesson, T. P. A.; Akimov, A. V.; Alam, S. M.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Aleppo, M.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alimonti, G.; Aliyev, M.; Allport, P. P.; Allwood-Spiers, S. E.; Aloisio, A.; Alonso, J.; Alves, R.; Alviggi, M. G.; Amako, K.; Amaral, P.; Amaral, S. P.; Ambrosini, G.; Ambrosio, G.; Amelung, C.; Ammosov, V. V.; Amorim, A.; Amram, N.; Anastopoulos, C.; Anderson, B.; Anderson, K. J.; Anderssen, E. C.; Andreazza, A.; Andrei, V.; Andricek, L.; Andrieux, M.-L.; Anduaga, X. S.; Anghinolfi, F.; Antonaki, A.; Antonelli, M.; Antonelli, S.; Apsimon, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Archambault, J. P.; Arguin, J.-F.; Arik, E.; Arik, M.; Arms, K. E.; Armstrong, S. R.; Arnaud, M.; Arnault, C.; Artamonov, A.; Asai, S.; Ask, S.; Åsman, B.; Asner, D.; Asquith, L.; Assamagan, K.; Astbury, A.; Athar, B.; Atkinson, T.; Aubert, B.; Auerbach, B.; Auge, E.; Augsten, K.; Aulchenko, V. M.; Austin, N.; Avolio, G.; Avramidou, R.; Axen, A.; Ay, C.; Azuelos, G.; Baccaglioni, G.; Bacci, C.; Bachacou, H.; Bachas, K.; Bachy, G.; Badescu, E.; Bagnaia, P.; Bailey, D. C.; Baines, J. T.; Baker, O. K.; Ballester, F.; Baltasar Dos Santos Pedrosa, F.; Banas, E.; Banfi, D.; Bangert, A.; Bansal, V.; Baranov, S. P.; Baranov, S.; Barashkou, A.; Barberio, E. L.; Barberis, D.; Barbier, G.; Barclay, P.; Bardin, D. Y.; Bargassa, P.; Barillari, T.; Barisonzi, M.; Barnett, B. M.; Barnett, R. M.; Baron, S.; Baroncelli, A.; Barone, M.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Barrillon, P.; Barriuso Poy, A.; Barros, N.; Bartheld, V.; Bartko, H.; Bartoldus, R.; Basiladze, S.; Bastos, J.; Batchelor, L. E.; Bates, R. L.; Batley, J. R.; Batraneanu, S.; Battistin, M.; Battistoni, G.; Batusov, V.; Bauer, F.; Bauss, B.; Baynham, D. E.; Bazalova, M.; Bazan, A.; Beauchemin, P. H.; Beaugiraud, B.; Beccherle, R. B.; Beck, G. A.; Beck, H. P.; Becks, K. H.; Bedajanek, I.; Beddall, A. J.; Beddall, A.; Bednár, P.; Bednyakov, V. A.; Bee, C.; Behar Harpaz, S.; Belanger, G. A. N.; Belanger-Champagne, C.; Belhorma, B.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellachia, F.; Bellagamba, L.; Bellina, F.; Bellomo, G.; Bellomo, M.; Beltramello, O.; Belymam, A.; Ben Ami, S.; Ben Moshe, M.; Benary, O.; Benchekroun, D.; Benchouk, C.; Bendel, M.; Benedict, B. H.; Benekos, N.; Benes, J.; Benhammou, Y.; Benincasa, G. P.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Beretta, M.; Berge, D.; Bergeaas, E.; Berger, N.; Berghaus, F.; Berglund, S.; Bergsma, F.; Beringer, J.; Bernabéu, J.; Bernardet, K.; Berriaud, C.; Berry, T.; Bertelsen, H.; Bertin, A.; Bertinelli, F.; Bertolucci, S.; Besson, N.; Beteille, A.; Bethke, S.; Bialas, W.; Bianchi, R. M.; Bianco, M.; Biebel, O.; Bieri, M.; Biglietti, M.; Bilokon, H.; Binder, M.; Binet, S.; Bingefors, N.; Bingul, A.; Bini, C.; Biscarat, C.; Bischof, R.; Bischofberger, M.; Bitadze, A.; Bizzell, J. P.; Black, K. M.; Blair, R. E.; Blaising, J. J.; Blanch, O.; Blanchot, G.; Blocker, C.; Blocki, J.; Blondel, A.; Blum, W.; Blumenschein, U.; Boaretto, C.; Bobbink, G. J.; Bocci, A.; Bocian, D.; Bock, R.; Boehm, M.; Boek, J.; Bogaerts, J. A.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bondarenko, V. G.; Bonino, R.; Bonis, J.; Bonivento, W.; Bonneau, P.; Boonekamp, M.; Boorman, G.; Boosten, M.; Booth, C. N.; Booth, P. S. L.; Booth, P.; Booth, J. R. A.; Borer, K.; Borisov, A.; Borjanovic, I.; Bos, K.; Boscherini, D.; Bosi, F.; Bosman, M.; Bosteels, M.; Botchev, B.; Boterenbrood, H.; Botterill, D.; Boudreau, J.; Bouhova-Thacker, E. V.; Boulahouache, C.; Bourdarios, C.; Boutemeur, M.; Bouzakis, K.; Boyd, G. R.; Boyd, J.; Boyer, B. H.; Boyko, I. R.; Bozhko, N. I.; Braccini, S.; Braem, A.; Branchini, P.; Brandenburg, G. W.; Brandt, A.; Brandt, O.; Bratzler, U.; Braun, H. M.; Bravo, S.; Brawn, I. P.; Brelier, B.; Bremer, J.; Brenner, R.; Bressler, S.; Breton, D.; Brett, N. D.; Breugnon, P.; Bright-Thomas, P. G.; Brochu, F. M.; Brock, I.; Brock, R.; Brodbeck, T. J.; Brodet, E.; Broggi, F.; Broklova, Z.; Bromberg, C.; Brooijmans, G.; Brouwer, G.; Broz, J.; Brubaker, E.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruni, A.; Bruni, G.; Bruschi, M.; Buanes, T.; Buchanan, N. J.; Buchholz, P.; Budagov, I. A.; Büscher, V.; Bugge, L.; Buira-Clark, D.; Buis, E. J.; Bujor, F.; Buran, T.; Burckhart, H.; Burckhart-Chromek, D.; Burdin, S.; Burns, R.; Busato, E.; Buskop, J. J. F.; Buszello, K. P.; Butin, F.; Butler, J. M.; Buttar, C. M.; Butterworth, J.; Butterworth, J. M.; Byatt, T.; Cabrera Urbán, S.; Cabruja Casas, E.; Caccia, M.; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calderón Terol, D.; Callahan, J.; Caloba, L. P.; Caloi, R.; Calvet, D.; Camard, A.; Camarena, F.; Camarri, P.; Cambiaghi, M.; Cameron, D.; Cammin, J.; Campabadal Segura, F.; Campana, S.; Canale, V.; Cantero, J.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Caprio, M.; Caracinha, D.; Caramarcu, C.; Carcagno, Y.; Cardarelli, R.; Cardeira, C.; Cardiel Sas, L.; Cardini, A.; Carli, T.; Carlino, G.; Carminati, L.; Caron, B.; Caron, S.; Carpentieri, C.; Carr, F. S.; Carter, A. A.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Cascella, M.; Caso, C.; Castelo, J.; Castillo Gimenez, V.; Castro, N.; Castrovillari, F.; Cataldi, G.; Cataneo, F.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Caughron, S.; Cauz, D.; Cavallari, A.; Cavalleri, P.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerna, C.; Cernoch, C.; Cerqueira, A. S.; Cerri, A.; Cerutti, F.; Cervetto, M.; Cetin, S. A.; Cevenini, F.; Chalifour, M.; Chamizo llatas, M.; Chan, A.; Chapman, J. W.; Charlton, D. G.; Charron, S.; Chekulaev, S. V.; Chelkov, G. A.; Chen, H.; Chen, L.; Chen, T.; Chen, X.; Cheng, S.; Cheng, T. L.; Cheplakov, A.; Chepurnov, V. F.; Cherkaoui El Moursli, R.; Chesneanu, D.; Cheu, E.; Chevalier, L.; Chevalley, J. L.; Chevallier, F.; Chiarella, V.; Chiefari, G.; Chikovani, L.; Chilingarov, A.; Chiodini, G.; Chouridou, S.; Chren, D.; Christiansen, T.; Christidi, I. A.; Christov, A.; Chu, M. L.; Chudoba, J.; Chuguev, A. G.; Ciapetti, G.; Cicalini, E.; Ciftci, A. K.; Cindro, V.; Ciobotaru, M. 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A.; Van der Bij, H.; van der Graaf, H.; van der Kraaij, E.; Van Eijk, B.; van Eldik, N.; van Gemmeren, P.; van Kesteren, Z.; van Vulpen, I.; Van Berg, R.; Vandelli, W.; Vandoni, G.; Vaniachine, A.; Vannucci, F.; Varanda, M.; Varela Rodriguez, F.; Vari, R.; Varnes, E. W.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vassilakopoulos, V. I.; Vassilieva, L.; Vataga, E.; Vaz, L.; Vazeille, F.; Vedrine, P.; Vegni, G.; Veillet, J. J.; Vellidis, C.; Veloso, F.; Veness, R.; Veneziano, S.; Ventura, A.; Ventura, S.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vertogardov, L.; Vetterli, M. C.; Vichou, I.; Vickey, T.; Viehhauser, G. H. A.; Vigeolas, E.; Villa, M.; Villani, E. G.; Villate, J.; Villella, I.; Vilucchi, E.; Vincent, P.; Vincke, H.; Vincter, M. G.; Vinogradov, V. B.; Virchaux, M.; Viret, S.; Virzi, J.; Vitale, A.; Vivarelli, I.; Vives, R.; Vives Vaques, F.; Vlachos, S.; Vogt, H.; Vokac, P.; Vollmer, C. F.; Volpi, M.; Volpini, G.; von Boehn-Buchholz, R.; von der Schmitt, H.; von Toerne, E.; Vorobel, V.; Vorobiev, A. P.; Vorozhtsov, A. S.; Vorozhtsov, S. B.; Vos, M.; Voss, K. C.; Voss, R.; Vossebeld, J. H.; Vovenko, A. S.; Vranjes, N.; Vrba, V.; Vreeswijk, M.; Anh, T. Vu; Vuaridel, B.; Vudragovic, M.; Vuillemin, V.; Vuillermet, R.; Wänanen, A.; Wahlen, H.; Walbersloh, J.; Walker, R.; Walkowiak, W.; Wall, R.; Wallny, R. S.; Walsh, S.; Wang, C.; Wang, J. C.; Wappler, F.; Warburton, A.; Ward, C. P.; Warner, G. P.; Warren, M.; Warsinsky, M.; Wastie, R.; Watkins, P. M.; Watson, A. T.; Watts, G.; Waugh, A. T.; Waugh, B. M.; Weaverdyck, C.; Webel, M.; Weber, G.; Weber, J.; Weber, M.; Weber, P.; Weidberg, A. R.; Weilhammer, P. M.; Weingarten, J.; Weiser, C.; Wellenstein, H.; Wellisch, H. P.; Wells, P. S.; Wemans, A.; Wen, M.; Wenaus, T.; Wendler, S.; Wengler, T.; Wenig, S.; Wermes, N.; Werneke, P.; Werner, P.; Werthenbach, U.; Wheeler-Ellis, S. J.; Whitaker, S. P.; White, A.; White, M. J.; White, S.; Whittington, D.; Wicek, F.; Wicke, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiesmann, M.; Wiesmann, M.; Wijnen, T.; Wildauer, A.; Wilhelm, I.; Wilkens, H. G.; Williams, H. H.; Willis, W.; Willocq, S.; Wilmut, I.; Wilson, J. A.; Wilson, A.; Wingerter-Seez, I.; Winton, L.; Witzeling, W.; Wlodek, T.; Woehrling, E.; Wolter, M. W.; Wolters, H.; Wosiek, B.; Wotschack, J.; Woudstra, M. J.; Wright, C.; Wu, S. L.; Wu, X.; Wuestenfeld, J.; Wunstorf, R.; Xella-Hansen, S.; Xiang, A.; Xie, S.; Xie, Y.; Xu, G.; Xu, N.; Yamamoto, A.; Yamamoto, S.; Yamaoka, H.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, J. C.; Yang, S.; Yang, U. K.; Yang, Y.; Yang, Z.; Yao, W.-M.; Yao, Y.; Yarradoddi, K.; Yasu, Y.; Ye, J.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, H.; Yoshida, R.; Young, C.; Youssef, S. P.; Yu, D.; Yu, J.; Yu, M.; Yu, X.; Yuan, J.; Yurkewicz, A.; Zaets, V. G.; Zaidan, R.; Zaitsev, A. M.; Zajac, J.; Zajacova, Z.; Zalite, A. Yu; Zalite, Yo K.; Zanello, L.; Zarzhitsky, P.; Zaytsev, A.; Zdrazil, M.; Zeitnitz, C.; Zeller, M.; Zema, P. F.; Zendler, C.; Zenin, A. V.; Zenis, T.; Zenonos, Z.; Zenz, S.; Zerwas, D.; Zhang, H.; Zhang, J.; Zheng, W.; Zhang, X.; Zhao, L.; Zhao, T.; Zhao, X.; Zhao, Z.; Zhelezko, A.; Zhemchugov, A.; Zheng, S.; Zhichao, L.; Zhou, B.; Zhou, N.; Zhou, S.; Zhou, Y.; Zhu, C. G.; Zhu, H. Z.; Zhuang, X. A.; Zhuravlov, V.; Zilka, B.; Zimin, N. I.; Zimmermann, S.; Ziolkowski, M.; Zitoun, R.; Zivkovic, L.; Zmouchko, V. V.; Zobernig, G.; Zoccoli, A.; Zoeller, M. M.; Zolnierowski, Y.; Zsenei, A.; zur Nedden, M.; Zychacek, V.

2008-08-01

The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.

Beam dynamics issues in linear colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seeman, J.T.

1989-06-01

The primary goal of present and future linear colliders is to maximize the integrated luminosity for the experimental program. Beam dynamics plays a central role in the maximization of integrated luminosity. It is the major issue in the production of small beam sizes and low experimental backgrounds and is also an important factor in the production of particle numbers, in the acceleration process, and in the number of bunches. The beam dynamics effects on bunches which are extracted from the damping rings, accelerated in the linac, collimated, momentum analyzed, and finally delivered to the final focus are reviewed. The effectsmore » of bunch compression, transverse and longitudinal wakefields, BNS damping, energy definition, dispersion, emittance, bunch aspect ratio, feedback, and stability are all important. 11 refs., 1 tab.« less

Power supply and pulsing strategies for the future linear colliders

NASA Astrophysics Data System (ADS)

Brogna, A. S.; Göttlicher, P.; Weber, M.

2012-02-01

The concept of the power delivery systems of the future linear colliders exploits the pulsed bunch structure of the beam in order to minimize the average current in the cables and the electronics and thus to reduce the material budget and heat dissipation. Although modern integrated circuit technologies are already available to design a low-power system, the concepts on how to pulse the front-end electronics and further reduce the power are not yet well understood. We propose a possible implementation of a power pulsing system based on a DC/DC converter and we choose the Analog Hadron Calorimeter as a specific example. The model features large switching currents of electronic modules in short time intervals to stimulate the inductive components along the cables and interconnections.

Multipacting optimization of a 750 MHz rf dipole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delayen, Jean R.; Castillo, Alejandro

2014-12-01

Crab crossing schemes have been proposed to re-instate luminosity degradation due to crossing angles at the interaction points in next generation colliders to avoid the use of sharp bending magnets and their resulting large synchrotron radiation generation, highly undessirable in the detector region. The rf dipole has been considered for a different set of applications in several machines, both rings and linear colliders. We present in this paper a study of the effects on the multipacting levels and location depending on geometrical variations on the design for a crabbing/deflecting application in a high current (3/0.5 A), high repetition (750 MHz)more » electron/proton collider, as a matter to provide a comparison point for similar applications of rf dipoles.« less

Alignment of the Stanford Linear Collider Arcs: Concepts and results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pitthan, R.; Bell, B.; Friedsam, H.

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 themore » 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.« less

The XXth International Workshop High Energy Physics and Quantum Field Theory

NASA Astrophysics Data System (ADS)

The Workshop continues a series of workshops started by the Skobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University (SINP MSU) in 1985 and conceived with the purpose of presenting topics of current interest and providing a stimulating environment for scientific discussion on new developments in theoretical and experimental high energy physics and physical programs for future colliders. Traditionally the list of workshop attendees includes a great number of active young scientists and students from Russia and other countries. This year Workshop is organized jointly by the SINP MSU and the Southern Federal University (SFedU) and will take place in the holiday hotel "Luchezarniy" (Effulgent) situated on the Black Sea shore in a picturesque natural park in the suburb of the largest Russian resort city Sochi - the host city of the XXII Olympic Winter Games to be held in 2014. The main topics to be covered are: Experimental results from the LHC. Tevatron summary: the status of the Standard Model and the boundaries on BSM physics. Future physics at Linear Colliders and super B-factories. Extensions of the Standard Model and their phenomenological consequences at the LHC and Linear Colliders: SUSY extensions of the Standard Model; particle interactions in space-time with extra dimensions; strings, quantum groups and new ideas from modern algebra and geometry. Higher order corrections and resummations for collider phenomenology. Automatic calculations of Feynman diagrams and Monte Carlo simulations. LHC/LC and astroparticle/cosmology connections. Modern nuclear physics and relativistic nucleous-nucleous collisions.

Operational head-on beam-beam compensation with electron lenses in the Relativistic Heavy Ion Collider

DOE PAGES

Fischer, W.; Gu, X.; Altinbas, Z.; ...

2015-12-23

Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider (RHIC) in order to increase the luminosity delivered to the experiments. We discuss the principle of combining a lattice for resonance driving term compensation and an electron lens for tune spread compensation. We describe the electron lens technology and its operational use. As of this date the implemented compensation scheme approximately doubled the peak and average luminosities.

A First Assessment of Two-Beam Linear Colliders and Longer-Term Two-Beam R& D Issues at SLAC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loew, Greg

2001-06-05

The purpose of this document is to summarize the work that has been done at SLAC in the last three or four months to assess the possibilities of two-beam linear colliders proposed by Ron Ruth, and to compare these colliders to the current NLC designs and their costs. The work is based on general discussions with C. Adolphsen, D. Burke, J. Irwin, J. Paterson, R. Ruth, T. Lavine and T. Raubenheimer, with considerable work done by the latter two. Given the complexities of these machines, the fact that the designs are far from complete and that all cost estimates aremore » still in a state of flux, it is clear that the conclusions drawn in this report cannot be cast in concrete. On the other hand, it does not seem too early to present the results that have been gathered so far, even if the facts contain significant uncertainties and the costs have large error bars. Now that R. Ruth has returned to SLAC, he will be able to add his point of view to the discussion. At this time, the conclusions presented here are the sole responsibility of the author.« less

Studies for a Dedicated B Detector at the Fermilab Collider

NASA Astrophysics Data System (ADS)

McBride, Patricia

1996-06-01

The observation of CP violation in the B system is one of the great experimental challenges of the next decade. Several B factories are already planned, however, there will be many interesting measurements awaiting a second generation of B exeriments. Studies are being carried out to design a dedicated collider B experiment for the Tevatron at Fermilab. A dedicated B detector at a hadron collider will have a physics reach beyond that of experiments scheduled to begin operation before the end of the decade.

Optics measurement and correction for the Relativistic Heavy Ion Collider

NASA Astrophysics Data System (ADS)

Shen, Xiaozhe

The quality of beam optics is of great importance for the performance of a high energy accelerator like the Relativistic Heavy Ion Collider (RHIC). The turn-by-turn (TBT) beam position monitor (BPM) data can be used to derive beam optics. However, the accuracy of the derived beam optics is often limited by the performance and imperfections of instruments as well as measurement methods and conditions. Therefore, a robust and model-independent data analysis method is highly desired to extract noise-free information from TBT BPM data. As a robust signal-processing technique, an independent component analysis (ICA) algorithm called second order blind identification (SOBI) has been proven to be particularly efficient in extracting physical beam signals from TBT BPM data even in the presence of instrument's noise and error. We applied the SOBI ICA algorithm to RHIC during the 2013 polarized proton operation to extract accurate linear optics from TBT BPM data of AC dipole driven coherent beam oscillation. From the same data, a first systematic estimation of RHIC BPM noise performance was also obtained by the SOBI ICA algorithm, and showed a good agreement with the RHIC BPM configurations. Based on the accurate linear optics measurement, a beta-beat response matrix correction method and a scheme of using horizontal closed orbit bumps at sextupoles for arc beta-beat correction were successfully applied to reach a record-low beam optics error at RHIC. This thesis presents principles of the SOBI ICA algorithm and theory as well as experimental results of optics measurement and correction at RHIC.

Analysis and modeling of proton beam loss and emittance growth in the Relativistic Heavy Ion Collider

DOE PAGES

Luo, Y.; Fischer, W.; White, S.

2016-02-04

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we will present the operational observations at the routine proton physics stores. In addition, the mechanisms for the beam loss, transverse emittance growth, and bunch lengthening are analyzed. Lastly, numerical calculations and multiparticle tracking are used to model these observations.

Fermilab | Publications and Videos

Science.gov Websites

International Linear Collider Global Design Effort. Science Node The Science Node is a free online publication , viewers can catch a true behind-the-scenes look of the United States' premier particle physics laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Syphers, M. J.; Chattopadhyay, S.

An overview is provided of the currently envisaged landscape of charged particle accelerators at the energy and intensity frontiers to explore particle physics beyond the standard model via 1-100 TeV-scale lepton and hadron colliders and multi-Megawatt proton accelerators for short- and long- baseline neutrino experiments. The particle beam physics, associated technological challenges and progress to date for these accelerator facilities (LHC, HL-LHC, future 100 TeV p-p colliders, Tev-scale linear and circular electron-positron colliders, high intensity proton accelerator complex PIP-II for DUNE and future upgrade to PIP-III) are outlined. Potential and prospects for advanced “nonlinear dynamic techniques” at the multi-MW levelmore » intensity frontier and advanced “plasma- wakefield-based techniques” at the TeV-scale energy frontier and are also described.« less

Parallel computation of transverse wakes in linear colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhan, Xiaowei; Ko, Kwok

1996-11-01

SLAC has proposed the detuned structure (DS) as one possible design to control the emittance growth of long bunch trains due to transverse wakefields in the Next Linear Collider (NLC). The DS consists of 206 cells with tapering from cell to cell of the order of few microns to provide Gaussian detuning of the dipole modes. The decoherence of these modes leads to two orders of magnitude reduction in wakefield experienced by the trailing bunch. To model such a large heterogeneous structure realistically is impractical with finite-difference codes using structured grids. The authors have calculated the wakefield in the DSmore » on a parallel computer with a finite-element code using an unstructured grid. The parallel implementation issues are presented along with simulation results that include contributions from higher dipole bands and wall dissipation.« less

Coupling Correction and Beam Dynamics at Ultralow Vertical Emittance in the ALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steier, Christoph; Robin, D.; Wolski, A.

2008-03-17

For synchrotron light sources and for damping rings of linear colliders it is important to be able to minimize the vertical emittance and to correct the spurious vertical dispersion. This allows one to maximize the brightness and/or the luminosity. A commonly used tool to measure the skew error distribution is the analysis of orbit response matrices using codes like LOCO. Using the new Matlab version of LOCO and 18 newly installed power supplies for individual skew quadrupoles at the ALS the emittance ratio could be reduced below 0.1% at 1.9 GeV yielding a vertical emittance of about 5 pm. Atmore » those very low emittances, additional effects like intra beam scattering become more important, potentially limiting the minimum emittance for machine like the damping rings of linear colliders.« less

CCD-based vertex detector for ILC

NASA Astrophysics Data System (ADS)

Stefanov, Konstantin D.

2006-12-01

Charge Coupled Devices (CCDs) have been successfully used in several high-energy physics experiments over the last 20 years. Their small pixel size and excellent precision provide a superb tool for studying of short-lived particles and understanding the nature at fundamental level. Over the last few years the Linear Collider Flavour Identification (LCFI) collaboration has developed Column-Parallel CCDs (CPCCD) and CMOS readout chips, to be used for the vertex detector at the International Linear Collider (ILC). The CPCCDs are very fast devices capable of satisfying the challenging requirements imposed by the beam structure of the superconducting accelerator. The first set of prototype devices have been successfully designed, manufactured and tested, with second generation chips on the way. Another idea for CCD-based device, the In-situ Storage Image Sensor (ISIS) is also under development and the first prototype has been manufactured.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richter, B.

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 latemore » 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.« less

Right-handed charged currents in the era of the Large Hadron Collider

DOE PAGES

Alioli, Simone; Cirigliano, Vincenzo; Dekens, Wouter Gerard; ...

2017-05-16

We discuss the phenomenology of right-handed charged currents in the frame-work of the Standard Model Effective Field Theory, in which they arise due to a single gauge-invariant dimension-six operator. We study the manifestations of the nine complex couplings of the W to right-handed quarks in collider physics, flavor physics, and low-energy precision measurements. We first obtain constraints on the couplings under the assumption that the right-handed operator is the dominant correction to the Standard Model at observable energies. Here, we subsequently study the impact of degeneracies with other Beyond-the-Standard-Model effective interactions and identify observables, both at colliders and low-energy experiments,more » that would uniquely point to right-handed charged currents.« less

Detectors for Linear Colliders: Detector design for a Future Electron-Positron Collider (4/4)

ScienceCinema

Thomson, Mark

2018-05-21

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.

Precise measurement of the left-right cross section asymmetry in Z boson production by electron-positron collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frey, R.E.

1994-12-01

A precise measurement of the left-right cross section asymmetry (A{sub LR}) for Z boson production by e{sup +}e{sup {minus}} collisions has been attained at the SLAC Linear Collider with the SLD detector. The author describes this measurement for the 1993 data run, emphasizing the significant improvements in polarized beam operation which took place for this run, where the luminosity-weighted electron beam polarization averaged 62.6 {+-} 1.2%. Preliminary 1993 results for A{sub LR} are presented. When combined with the (less precise) 1992 result, the preliminary result for the effective weak mixing angle is sin{sup 2}{theta}{sub W}{sup eff} = 0.2290 {+-} 0.0010.

The upgraded data acquisition system for beam loss monitoring at the Fermilab Tevatron and Main Injector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumbaugh, A.; Briegel, C.; Brown, B.C.

2011-11-01

A VME-based data acquisition system for beam-loss monitors has been developed and is in use in the Tevatron and Main Injector accelerators at the Fermilab complex. The need for enhanced beam-loss protection when the Tevatron is operating in collider-mode was the main driving force for the new design. Prior to the implementation of the present system, the beam-loss monitor system was disabled during collider operation and protection of the Tevatron magnets relied on the quench protection system. The new Beam-Loss Monitor system allows appropriate abort logic and thresholds to be set over the full set of collider operating conditions. Themore » system also records a history of beam-loss data prior to a beam-abort event for post-abort analysis. Installation of the Main Injector system occurred in the fall of 2006 and the Tevatron system in the summer of 2007. Both systems were fully operation by the summer of 2008. In this paper we report on the overall system design, provide a description of its normal operation, and show a number of examples of its use in both the Main Injector and Tevatron.« less

The upgraded data acquisition system for beam loss monitoring at the Fermilab Tevatron and Main Injector

NASA Astrophysics Data System (ADS)

Baumbaugh, A.; Briegel, C.; Brown, B. C.; Capista, D.; Drennan, C.; Fellenz, B.; Knickerbocker, K.; Lewis, J. D.; Marchionni, A.; Needles, C.; Olson, M.; Pordes, S.; Shi, Z.; Still, D.; Thurman-Keup, R.; Utes, M.; Wu, J.

2011-11-01

A VME-based data acquisition system for beam-loss monitors has been developed and is in use in the Tevatron and Main Injector accelerators at the Fermilab complex. The need for enhanced beam-loss protection when the Tevatron is operating in collider-mode was the main driving force for the new design. Prior to the implementation of the present system, the beam-loss monitor system was disabled during collider operation and protection of the Tevatron magnets relied on the quench protection system. The new Beam-Loss Monitor system allows appropriate abort logic and thresholds to be set over the full set of collider operating conditions. The system also records a history of beam-loss data prior to a beam-abort event for post-abort analysis. Installation of the Main Injector system occurred in the fall of 2006 and the Tevatron system in the summer of 2007. Both systems were fully operation by the summer of 2008. In this paper we report on the overall system design, provide a description of its normal operation, and show a number of examples of its use in both the Main Injector and Tevatron.

Fermilab Tevatron and Pbar source status report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, H.

1986-08-01

The antiproton production cycle is enumerated, and the commissioning of the antiproton source is described, giving milestones and major obstacles. The Tevatron collider operation is described, including procedure to load the Tevatron with three bunches of protons and three bunches of antiprotons. Commissioning of the Main Ring and Tevatron for collider operation is described. Development and accelerator studies in four areas were necessary: main ring RF manipulations; controls and applications software support; Tevatron storage and low-beta squeeze sequence; and study of various beam transfers, storage steps, and sequences. Final tests are described. A long range upgrade program is presently undermore » evaluation to accomplish these goals: luminosity increase to 5 x 10/sup 31/ cm/sup -2/sec/sup -1/, production rates up to 4 x 10/sup 11/ antiprotons/hr, and intensity increase for fixed target operation. Beam quality is to be improved by the injector and main ring upgrades, and the luminosity goal is addressed by the Collider upgrade. (LEW)« less

Symposium on electron linear accelerators in honor of Richard B. Neal's 80th birthday: Proceedings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siemann, R.H.

The papers presented at the conference are: (1) the construction of SLAC and the role of R.B. Neal; (2) symposium speech; (3) lessons learned from the SLC; (4) alternate approaches to future electron-positron linear colliders; (5) the NLC technical program; (6) advanced electron linacs; (7) medical uses of linear accelerators; (8) linac-based, intense, coherent X-ray source using self-amplified spontaneous emission. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clendenin, James E

The International Committee supported the proposal of the Chairman of the XVIII International Linac Conference to issue a new Compendium of linear accelerators. The last one was published in 1976. The Local Organizing Committee of Linac96 decided to set up a sub-committee for this purpose. Contrary to the catalogues of the High Energy Accelerators which compile accelerators with energies above 1 GeV, we have not defined a specific limit in energy. Microtrons and cyclotrons are not in this compendium. Also data from thousands of medical and industrial linacs has not been collected. Therefore, only scientific linacs are listed in themore » present compendium. Each linac found in this research and involved in a physics context was considered. It could be used, for example, either as an injector for high energy accelerators, or in nuclear physics, materials physics, free electron lasers or synchrotron light machines. Linear accelerators are developed in three continents only: America, Asia, and Europe. This geographical distribution is kept as a basis. The compendium contains the parameters and status of scientific linacs. Most of these linacs are operational. However, many facilities under construction or design studies are also included. A special mention has been made at the end for the studies of future linear colliders.« less

Linear Collider project database

Science.gov Websites

&D projects circa 2005 List of who is thinking of working on what. At present this includes non SLAC, FNAL, and Cornell meetings. Ordered list of who is thinking of working on what. At present this

A Superstrong Adjustable Permanent Magnet for the Final Focus Quadrupole in a Linear Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mihara, T.

A super strong permanent magnet quadrupole (PMQ) was fabricated and tested. It has an integrated strength of 28.5T with overall length of 10 cm and a 7mm bore radius. The final focus quadrupole of a linear collider needs a variable focal length. This can be obtained by slicing the magnet into pieces along the beamline direction and rotating these slices. But this technique may lead to movement of the magnetic center and introduction of a skew quadrupole component when the strength is varied. A ''double ring structure'' can ease these effects. A second prototype PMQ, containing thermal compensation materials andmore » with a double ring structure, has been fabricated. Worm gear is selected as the mechanical rotating scheme because the double ring structure needs a large torque to rotate magnets. The structure of the second prototype PMQ is shown.« less

rf design of a pulse compressor with correction cavity chain for klystron-based compact linear collider

NASA Astrophysics Data System (ADS)

Wang, Ping; Zha, Hao; Syratchev, Igor; Shi, Jiaru; Chen, Huaibi

2017-11-01

We present an X-band high-power pulse compression system for a klystron-based compact linear collider. In this system design, one rf power unit comprises two klystrons, a correction cavity chain, and two SLAC Energy Doubler (SLED)-type X-band pulse compressors (SLEDX). An rf pulse passes the correction cavity chain, by which the pulse shape is modified. The rf pulse is then equally split into two ways, each deploying a SLEDX to compress the rf power. Each SLEDX produces a short pulse with a length of 244 ns and a peak power of 217 MW to power four accelerating structures. With the help of phase-to-amplitude modulation, the pulse has a dedicated shape to compensate for the beam loading effect in accelerating structures. The layout of this system and the rf design and parameters of the new pulse compressor are described in this work.

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).

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Candel, Arno; Kabel, Andreas; Lee, Lie-Quan

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) - wakefieldmore » damping in the Power Extraction and Transfer Structure (PETS) and power transfer to the main beam accelerating structures are investigated.« less

Enhanced Compton Backscattering in a Periodic Mirror System for Polarized Positron Beam Generation

NASA Astrophysics Data System (ADS)

Miyahara, Yoshikazu

2002-05-01

By colliding a circularly polarized high power laser beam with a high-energy electron beam, intense circularly polarized γ-rays can be generated, which in turn can be used to produce a longitudinally polarized positron beam for a linear collider. In the present paper, an optical mirror system with periodic focal points is considered to generate intense polarized γ-rays. A CO2 laser beam propagates back and forth in a series of holed mirrors in a straight line. The diffraction loss through the holes is negligibly small, so that the laser beam can be used repeatedly for the collision. The beam size is reduced to 22 μm at a minimum and kept the same in 20 unit cells, ten of which are combined in series. A 5.8 GeV electron beam is focused to 30 μm at a minimum in a series of triplets of permanent quadrupole magnets to generate γ-rays of 60 MeV at a maximum. A γ-ray yield required for a positron beam in a linear collider can be obtained by 10 laser sources with a power of 3.1 kW each, which is considerably lower than the total power assumed in a previous proposal.

Gravitational waves from dark first order phase transitions and dark photons

NASA Astrophysics Data System (ADS)

Addazi, Andrea; Marcianò, Antonino

2018-01-01

Cold Dark Matter particles may interact with ordinary particles through a dark photon, which acquires a mass thanks to a spontaneous symmetry breaking mechanism. We discuss a dark photon model in which the scalar singlet associated to the spontaneous symmetry breaking has an effective potential that induces a first order phase transition in the early Universe. Such a scenario provides a rich phenomenology for electron-positron colliders and gravitational waves interferometers, and may be tested in several different channels. The hidden first order phase transition implies the emission of gravitational waves signals, which may constrain the dark photon’s space of parameters. Compared limits from electron-positron colliders, astrophysics, cosmology and future gravitational waves interferometers such as eLISA, U-DECIGO and BBO are discussed. This highly motivates a cross-checking strategy of data arising from experiments dedicated to gravitational waves, meson factories, the International Linear Collider (ILC), the Circular Electron Positron Collider (CEPC) and other underground direct detection experiments of cold dark matter candidates. Supported by the Shanghai Municipality (KBH1512299) and Fudan University (JJH1512105)

Heavy Higgs boson production at colliders in the singlet-triplet scotogenic dark matter model

NASA Astrophysics Data System (ADS)

Díaz, Marco Aurelio; Rojas, Nicolás; Urrutia-Quiroga, Sebastián; Valle, José W. F.

2017-08-01

We consider the possibility that the dark matter particle is a scalar WIMP messenger associated to neutrino mass generation, made stable by the same symmetry responsible for the radiative origin of neutrino mass. We focus on some of the implications of this proposal as realized within the singlet-triplet scotogenic dark matter model. We identify parameter sets consistent both with neutrino mass and the observed dark matter abundance. Finally we characterize the expected phenomenological profile of heavy Higgs boson physics at the LHC as well as at future linear Colliders.

Overview of the CLIC detector and its physics potential

NASA Astrophysics Data System (ADS)

Ström, Rickard

2017-12-01

The CLIC detector and physics study (CLICdp) is an international collaboration that investigates the physics potential of the Compact Linear Collider (CLIC). CLIC is a high-energy electron-positron collider under development, aiming for centre-of-mass energies from a few hundred GeV to 3 TeV. In addition to physics studies based on full Monte Carlo simulations of signal and background processes, CLICdp performs cuttingedge hardware R&D. In this contribution CLICdp will present recent results from physics prospect studies, emphasising Higgs studies. Additionally the new CLIC detector model and the recently updated CLIC baseline staging scenario will be presented.

Conceptual Design for CLIC Gun Pulser

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Tao

The Compact Linear Collider (CLIC) is a proposed future electron-positron collider, designed to perform collisions at energies from 0.5 to 5 TeV, with a nominal design optimized for 3 TeV (Dannheim, 2012). The Drive Beam Accelerator consists of a thermionic DC gun, bunching section and an accelerating section. The thermionic gun needs deliver a long (~143us) pulse of current into the buncher. A pulser is needed to drive grid of the gun to generate a stable current output. This report explores the requirements of the gun pulser and potential solutions to regulate grid current.

When Waves Collide: Future Conflict

DTIC Science & Technology

1995-01-01

predictions merely guesswork, and forecasts often nothing more than co- herent fiction masquerading as fact.2 Trends and megatrends , which are linear...transportation, on-site inspection, and environmental cleanup—including radi- ological, chemical, and biological —as well as enforcement of the

International Linear Collider Technical Design Report (Volumes 1 through 4)

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Nuclear structure functions at a future electron-ion collider

DOE PAGES

Aschenauer, E. C.; Fazio, S.; Lamont, M. A. C.; ...

2017-12-07

The quantitative knowledge of heavy nuclei's partonic structure is currently limited to rather large values of momentum fraction x { robust experimental constraints below x ~ 10 -2 at low resolution scale Q 2 are particularly scarce. This is in sharp contrast to the free proton's structure which has been probed in deep inelastic scattering (DIS) measurements down to x ~ 10 -5 at perturbative resolution scales. The construction of an Electron-Ion Collider (EIC) with a possibility to operate with a wide variety of nuclei, will allow one to explore the low-x region in much greater detail. In the presentmore » paper we simulate the extraction of the nuclear structure functions from measurements of inclusive and charm reduced cross sections at an EIC. The potential constraints are studied by analyzing simulated data directly in a next-to-leading order global fit of nuclear parton distribution functions based on the recent EPPS16 analysis. A special emphasis is placed on studying the impact an EIC would have on extracting the nuclear gluon PDF, the partonic component most prone to non-linear e ects at low Q 2. In comparison to the current knowledge, we find that the gluon PDF can be measured at an EIC with significantly reduced uncertainties.« less

Nuclear structure functions at a future electron-ion collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aschenauer, E. C.; Fazio, S.; Lamont, M. A. C.

The quantitative knowledge of heavy nuclei's partonic structure is currently limited to rather large values of momentum fraction x { robust experimental constraints below x ~ 10 -2 at low resolution scale Q 2 are particularly scarce. This is in sharp contrast to the free proton's structure which has been probed in deep inelastic scattering (DIS) measurements down to x ~ 10 -5 at perturbative resolution scales. The construction of an Electron-Ion Collider (EIC) with a possibility to operate with a wide variety of nuclei, will allow one to explore the low-x region in much greater detail. In the presentmore » paper we simulate the extraction of the nuclear structure functions from measurements of inclusive and charm reduced cross sections at an EIC. The potential constraints are studied by analyzing simulated data directly in a next-to-leading order global fit of nuclear parton distribution functions based on the recent EPPS16 analysis. A special emphasis is placed on studying the impact an EIC would have on extracting the nuclear gluon PDF, the partonic component most prone to non-linear e ects at low Q 2. In comparison to the current knowledge, we find that the gluon PDF can be measured at an EIC with significantly reduced uncertainties.« less

Beyond the Large Hadron Collider: A First Look at Cryogenics for CERN Future Circular Colliders

NASA Astrophysics Data System (ADS)

Lebrun, Philippe; Tavian, Laurent

Following the first experimental discoveries at the Large Hadron Collider (LHC) and the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. The study, conducted with the collaborative participation of interested institutes world-wide, considers several options for very high energy hadron-hadron, electron-positron and hadron-electron colliders to be installed in a quasi-circular underground tunnel in the Geneva basin, with a circumference of 80 km to 100 km. All these machines would make intensive use of advanced superconducting devices, i.e. high-field bending and focusing magnets and/or accelerating RF cavities, thus requiring large helium cryogenic systems operating at 4.5 K or below. Based on preliminary sets of parameters and layouts for the particle colliders under study, we discuss the main challenges of their cryogenic systems and present first estimates of the cryogenic refrigeration capacities required, with emphasis on the qualitative and quantitative steps to be accomplished with respect to the present state-of-the-art.

Double side read-out technique for mitigation of radiation damage effects in PbWO 4 crystals

DOE PAGES

Lucchini, Marco Toliman; Auffray, E.; Benaglia, A.; ...

2016-04-18

Test beam results of a calorimetric module based on 3×3×22 cm 3 PbWO 4 crystals, identical to those used in the CMS ECAL Endcaps, read out by a pair of photodetectors coupled to the two opposite sides (front and rear) of each crystal are presented. Nine crystals with different level of induced absorption, from 0 to 20 m -1, have been tested using electrons in the 50–200 GeV energy range. Photomultiplier tubes have been chosen as photodetectors to allow for a precise measurement of highly damaged crystals. The information provided by this double side read-out configuration allows to correct formore » event-by-event fluctuations of the longitudinal development of electromagnetic showers. By strongly mitigating the effect of non-uniform light collection efficiency induced by radiation damage, the double side read-out technique significantly improves the energy resolution with respect to a single side read-out configuration. The non-linearity of the response arising in damaged crystals is also corrected by a double side read-out configuration and the response linearity of irradiated crystals is restored. In high radiation environments at future colliders, as it will be the case for detectors operating during the High Luminosity phase of the Large Hadron Collider, defects can be created inside the scintillator volume leading to a non-uniform response of the calorimetric cell. As a result, the double side read-out technique presented in this study provides a valuable way to improve the performance of calorimeters based on scintillators whose active volumes are characterized by high aspect ratio cells similar to those used in this study.« less

Double side read-out technique for mitigation of radiation damage effects in PbWO 4 crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lucchini, Marco Toliman; Auffray, E.; Benaglia, A.

Test beam results of a calorimetric module based on 3×3×22 cm 3 PbWO 4 crystals, identical to those used in the CMS ECAL Endcaps, read out by a pair of photodetectors coupled to the two opposite sides (front and rear) of each crystal are presented. Nine crystals with different level of induced absorption, from 0 to 20 m -1, have been tested using electrons in the 50–200 GeV energy range. Photomultiplier tubes have been chosen as photodetectors to allow for a precise measurement of highly damaged crystals. The information provided by this double side read-out configuration allows to correct formore » event-by-event fluctuations of the longitudinal development of electromagnetic showers. By strongly mitigating the effect of non-uniform light collection efficiency induced by radiation damage, the double side read-out technique significantly improves the energy resolution with respect to a single side read-out configuration. The non-linearity of the response arising in damaged crystals is also corrected by a double side read-out configuration and the response linearity of irradiated crystals is restored. In high radiation environments at future colliders, as it will be the case for detectors operating during the High Luminosity phase of the Large Hadron Collider, defects can be created inside the scintillator volume leading to a non-uniform response of the calorimetric cell. As a result, the double side read-out technique presented in this study provides a valuable way to improve the performance of calorimeters based on scintillators whose active volumes are characterized by high aspect ratio cells similar to those used in this study.« less

Using Linear Gluon Polarization Inside an Unpolarized Proton to Determine the Higgs Spin and Parity

NASA Astrophysics Data System (ADS)

den Dunnen, Wilco J.

2014-06-01

Gluons inside an unpolarized proton are in general linearly polarized in the direction of their transverse momentum, rendering the LHC effectively a polarized gluon collider. This polarization can be utilized in the determination of the spin and parity of the newly found Higgs-like boson. We focus here on the determination of the spin using the azimuthal Collins-Soper angle distribution.

Neutron dosimetry at a high-energy electron-positron collider

NASA Astrophysics Data System (ADS)

Bedogni, Roberto

Electron-positron colliders with energy of hundreds of MeV per beam have been employed for studies in the domain of nuclear and sub-nuclear physics. The typical structure of such a collider includes an LINAC, able to produce both types of particles, an accumulator ring and a main ring, whose diameter ranges from several tens to hundred meters and allows circulating particle currents of several amperes per beam. As a consequence of the interaction of the primary particles with targets, shutters, structures and barriers, a complex radiation environment is produced. This paper addresses the neutron dosimetry issues associated with the operation of such accelerators, referring in particular to the DAΦ NE complex, operative since 1997 at INFN-Frascati National Laboratory (Italy). Special attention is given to the active and passive techniques used for the spectrometric and dosimetric characterization of the workplace neutron fields, for radiation protection dosimetry purposes.

NNLO QCD corrections to production of a spin-2 particle with nonuniversal couplings in the Drell-Yan process

NASA Astrophysics Data System (ADS)

Banerjee, Pulak; Dhani, Prasanna K.; Kumar, M. C.; Mathews, Prakash; Ravindran, V.

2018-05-01

We study the phenomenological impact of the interaction of spin-2 fields with those of the Standard Model in a model independent framework up to next-to-next-to-leading order in perturbative quantum chromodynamics. We use the invariant mass distribution of the pair of leptons produced at the Large Hadron Collider to demonstrate this. A minimal scenario where the spin-2 fields couple to two gauge invariant operators with different coupling strengths has been considered. These operators not being conserved show very different ultraviolet behavior increasing the searches options of spin-2 particles at the colliders. We find that our results using the higher order quantum corrections stabilize the predictions with respect to renormalization and factorization scales. We also find that corrections are appreciable which need to be taken into account in such searches at the colliders.

Les Houches ''Physics at TeV Colliders 2003'' Beyond the Standard Model Working Group: Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allanach, B

2004-03-01

The work contained herein constitutes a report of the ''Beyond the Standard Model'' working group for the Workshop ''Physics at TeV Colliders'', Les Houches, France, 26 May-6 June, 2003. The research presented is original, and was performed specifically for the workshop. Tools for calculations in the minimal supersymmetric standard model are presented, including a comparison of the dark matter relic density predicted by public codes. Reconstruction of supersymmetric particle masses at the LHC and a future linear collider facility is examined. Less orthodox supersymmetric signals such as non-pointing photons and R-parity violating signals are studied. Features of extra dimensional modelsmore » are examined next, including measurement strategies for radions and Higgs', as well as the virtual effects of Kaluza Klein modes of gluons. Finally, there is an update on LHC Z' studies.« less

Operational experience with nanocoulomb bunch charges in the Cornell photoinjector

DOE PAGES

Bartnik, Adam; Gulliford, Colwyn; Bazarov, Ivan; ...

2015-08-19

Characterization of 9–9.5 MeV electron beams produced in the dc-gun based Cornell photoinjector is given for bunch charges ranging from 20 pC to 2 nC. Comparison of the measured emittances and longitudinal current profiles to optimized 3D space charge simulations yields excellent agreement for bunch charges up to 1 nC when the measured laser distribution is used to generate initial particle distributions in simulation. Analysis of the scaling of the measured emittance with bunch charge shows that the emittance scales roughly as the square root of the bunch charge up to 300 pC, above which the trend becomes linear. Furthermore,more » these measurements demonstrate that the Cornell photoinjector can produce cathode emittance dominated beams meeting the emittance and peak current specifications for next generation free electron lasers operating at high repetition rate. In addition, the 1 and 2 nC results are relevant to the electron ion collider community.« less

Radiation Requirements and Testing of Cryogenic Thermometers for the Ilc

NASA Astrophysics Data System (ADS)

Barnett, T.; Filippov, Yu. P.; Filippova, E. Yu.; Mokhov, N. V.; Nakao, N.; Klebaner, A. L.; Korenev, S. A.; Theilacker, J. C.; Trenikhina, J.; Vaziri, K.

2008-03-01

Large quantity of cryogenic temperature sensors will be used for operation of the International Linear Collider (ILC). Most of them will be subject to high radiation doses during the accelerator lifetime. Understanding of particle energy spectra, accumulated radiation dose in thermometers and its impact on performance are vital in establishing technical specification of cryogenic thermometry for the ILC. Realistic MARS15 computer simulations were performed to understand the ILC radiation environment. Simulation results were used to establish radiation dose requirements for commercially available cryogenic thermometers. Two types of thermometers, Cernox® and TVO, were calibrated prior to irradiation using different technique. The sensors were subjected then to up to 200 kGy electron beam irradiation with kinetic energy of 5 MeV, a representative of the situation at the ILC operation. A post-irradiation behavior of the sensors was studied. The paper describes the MARS15 model, simulation results, cryogenic test set-up, irradiation tests, and cryogenic test results.

Proceedings of the XXI International Workshop High Energy Physics and Quantum Field Theory (QFTHEP 2013). 23 30 June, 2013. Saint Petersburg Area, Russia

NASA Astrophysics Data System (ADS)

The Workshop continues a series of workshops started by the Skobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University (SINP MSU) in 1985 and conceived with the purpose of presenting topics of current interest and providing a stimulating environment for scientific discussion on new developments in theoretical and experimental high energy physics and physical programs for future colliders. Traditionally the list of workshop attendees includes a great number of active young scientists and students from Russia and other countries. This year the Workshop is organized jointly by the SINP MSU and the SPbSU and it will take place in the holiday hotel "Baltiets" situated in a picturesque place of the Karelian Isthmus on the shore of the Gulf of Finland in the suburb of the second largest Russian city Saint Petersburg. Scientific program, the main topics to be covered are: * Higgs searches and other experimental results from the LHC and the Tevatron; impact of the Higgs-like boson observed * Physics prospects at Linear Colliders and super B-factories * Extensions of the Standard Model and their phenomenological consequences at the LHC and Linear Colliders * Higher order corrections and resummations for collider phenomenology * Automatic calculations and Monte Carlo simulations in high energy physics * LHC/LC and astroparticle/cosmology connections * Modern nuclear physics and relativistic nucleous-nucleous collisions * Detectors for future experiments in high energy physics The Workshop will include plenary and two parallel afternoon sessions. The plenary sessions will consist of invited lectures. The afternoon sessions will include original talks. Further details are given at http://qfthep.sinp.msu.ru

Taking Energy to the Physics Classroom from the Large Hadron Collider at CERN

ERIC Educational Resources Information Center

Cid, Xabier; Cid, Ramon

2009-01-01

In 2008, the greatest experiment in history began. When in full operation, the Large Hadron Collider (LHC) at CERN will generate the greatest amount of information that has ever been produced in an experiment before. It will also reveal some of the most fundamental secrets of nature. Despite the enormous amount of information available on this…

Colliding wall-jets on a cylindrical surface

NASA Astrophysics Data System (ADS)

Tesař, Václav; Peszynski, Kazimierz

2015-05-01

Paper discusses aerodynamics and potential engineering applications of an unusual and in literature practically unknown fluid flow configuration, with two wall-jets attached to a cylindrical surface so that they collide head-on and by mutual conjunction generate a single jet directed away from the wall. Applications are envisaged in pneumatic sensors, particularly those operating at low Reynolds numbers. Performed experimental investigation, combined with numerical flowfield computations, revealed several interesting aspects. The most interesting among them is the discovery of symmetry-breaking existence of three different stable flow regimes. This opens a possibility for fluidic tristable amplifiers and systems operating with ternary logic.

LHC: The Large Hadron Collider

ScienceCinema

Lincoln, Don

2018-01-16

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.

Studies of nonlinear interactions between counter-propagating Alfv'en waves in the LAPD

NASA Astrophysics Data System (ADS)

Auerbach, D. W.; Perez, J. C.; Carter, T. A.; Boldyrev, S.

2007-11-01

From a weak turbulence point of view, nonlinear interactions between shear Alfv'en waves are fundamental to the energy cascade in low-frequency magnetic turbulence. We report here on an experimental study of counter-propagating Alfv'en wave interactions in the Large Plasma Device (LAPD) at UCLA. Colliding, orthogonally polarized kinetic Alfv'en waves are generated by two antennae, separated by 5m along the guide magnetic field. Magnetic field and langmuir probes record plasma behavior between the antennae. When each antenna is operated separately, linearly polarized Alfv'en waves propagate in opposite directions along the guide field. When two antennae simultaneously excite counter propagating waves, we observe multiple side bands in the frequency domain, whose amplitude scales quadratically with wave amplitude. In the spatial domain we observe non-linear superposition in the 2D structure of the waves and spectral broadening in the perpendicular wave-number spectrum. This indicates the presence of nonlinear interaction of the counter propagating Alfv'en waves, and opens the possiblity to investigate Alfv'enic plasma turbulence in controlled and reproducible laboratory experiments.

Matter, Energy, Space and Time: The International Linear Collider Physics Prospects and International Aspects

NASA Astrophysics Data System (ADS)

Wagner, Albrecht

2006-04-01

Over the past century, physicists have sought to explain the character of the matter and energy in our universe, to show how the basic forces of nature and the building blocks of matter come about, and to explore the fabric of space and time. In the past three decades, experiments at laboratories around the world have given us a precise confirmation of the underlying theory called the standard model. These particle physics advances have a direct impact for our understanding of the structure of the universe, both at its inception in the Big Bang, and in its evolution to the present and future. The final synthesis is not yet fully clear, but we know with confidence that major discoveries expanding the standard model framework will occur at the next generation of accelerators. The Large Hadron Collider (LHC) being built at CERN will take us into the discovery realm. The proposed International Linear Collider (ILC) will extend the discoveries and provide a wealth of precision measurements that are essential for giving deeper understanding of their meaning, and pointing the way to further evolution of particle physics in the future. A world-wide consensus has formed for a baseline ILC project at energies of 500 GeV and beyond. The choice of the superconducting technology as basis for the ILC has paved the way for a global design effort which has now taken full speed.

Introduction to Superconducting RF Structures and the Effect of High Pressure Rinsing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tajima, Tsuyoshi

2016-06-30

This presentation begins by describing RF superconductivity and SRF accelerating structures. Then the use of superconducting RF structures in a number of accelerators around the world is reviewed; for example, the International Linear Collider (ILC) will use ~16,000 SRF cavities with ~2,000 cryomodules to get 500 GeV e⁺/e⁻ colliding energy. Field emission control was (and still is) a very important practical issue for SRF cavity development. It has been found that high-pressure ultrapure water rinsing as a final cleaning step after chemical surface treatment resulted in consistent performance of single- and multicell superconducting cavities.

Energy Dependence of Elliptic Flow over a Large Pseudorapidity Range in Au+Au Collisions at the BNL Relativistic Heavy Ion Collider

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

2005-04-01

This Letter describes the measurement of the energy dependence of elliptic flow for charged particles in Au+Au collisions using the PHOBOS detector at the Relativistic Heavy Ion Collider. Data taken at collision energies of √(sNN)=19.6, 62.4, 130, and 200 GeV are shown over a wide range in pseudorapidity. These results, when plotted as a function of η'=|η|-ybeam, scale with approximate linearity throughout η', implying no sharp changes in the dynamics of particle production as a function of pseudorapidity or increasing beam energy.

Energy dependence of elliptic flow over a large pseudorapidity range in Au+Au collisions at the BNL relativistic heavy ion collider.

PubMed

Back, B B; Baker, M D; Ballintijn, M; Barton, D S; Betts, R R; Bickley, A A; Bindel, R; Budzanowski, A; Busza, W; Carroll, A; Chai, Z; Decowski, M P; García, E; Gburek, T; George, N; Gulbrandsen, K; Gushue, S; Halliwell, C; Hamblen, J; Hauer, M; Heintzelman, G A; Henderson, C; Hofman, D J; Hollis, R S; Hołyński, R; Holzman, B; Iordanova, A; Johnson, E; Kane, J L; Katzy, J; Khan, N; Kucewicz, W; Kulinich, P; Kuo, C M; Lin, W T; Manly, S; McLeod, D; Mignerey, A C; Nouicer, R; Olszewski, A; Pak, R; Park, I C; Pernegger, H; Reed, C; Remsberg, L P; Reuter, M; Roland, C; Roland, G; Rosenberg, L; Sagerer, J; Sarin, P; Sawicki, P; Seals, H; Sedykh, I; Skulski, W; Smith, C E; Stankiewicz, M A; Steinberg, P; Stephans, G S F; Sukhanov, A; Tang, J-L; Tonjes, M B; Trzupek, A; Vale, C; van Nieuwenhuizen, G J; Vaurynovich, S S; Verdier, R; Veres, G I; Wenger, E; Wolfs, F L H; Wosiek, B; Woźniak, K; Wuosmaa, A H; Wysłouch, B

2005-04-01

This Letter describes the measurement of the energy dependence of elliptic flow for charged particles in Au+Au collisions using the PHOBOS detector at the Relativistic Heavy Ion Collider. Data taken at collision energies of square root of s(NN)=19.6, 62.4, 130, and 200 GeV are shown over a wide range in pseudorapidity. These results, when plotted as a function of eta(')=|eta|-y(beam), scale with approximate linearity throughout eta('), implying no sharp changes in the dynamics of particle production as a function of pseudorapidity or increasing beam energy.

Model-independent determination of the triple Higgs coupling at e + e – colliders

DOE PAGES

Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon; ...

2018-03-20

Here, the observation of Higgs pair production at high-energy colliders can give evidence for the presence of a triple Higgs coupling. However, the actual determination of the value of this coupling is more difficult. In the context of general models for new physics, double Higgs production processes can receive contributions from many possible beyond-Standard-Model effects. This dependence must be understood if one is to make a definite statement about the deviation of the Higgs field potential from the Standard Model. In this paper, we study the extraction of the triple Higgs coupling from the process e +e –→Zhh. We showmore » that, by combining the measurement of this process with other measurements available at a 500 GeV e +e – collider, it is possible to quote model-independent limits on the effective field theory parameter c 6 that parametrizes modifications of the Higgs potential. We present precise error estimates based on the anticipated International Linear Collider physics program, studied with full simulation. Our analysis also gives new insight into the model-independent extraction of the Higgs boson coupling constants and total width from e +e – data.« less

Model-independent determination of the triple Higgs coupling at e + e – colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon

Here, the observation of Higgs pair production at high-energy colliders can give evidence for the presence of a triple Higgs coupling. However, the actual determination of the value of this coupling is more difficult. In the context of general models for new physics, double Higgs production processes can receive contributions from many possible beyond-Standard-Model effects. This dependence must be understood if one is to make a definite statement about the deviation of the Higgs field potential from the Standard Model. In this paper, we study the extraction of the triple Higgs coupling from the process e +e –→Zhh. We showmore » that, by combining the measurement of this process with other measurements available at a 500 GeV e +e – collider, it is possible to quote model-independent limits on the effective field theory parameter c 6 that parametrizes modifications of the Higgs potential. We present precise error estimates based on the anticipated International Linear Collider physics program, studied with full simulation. Our analysis also gives new insight into the model-independent extraction of the Higgs boson coupling constants and total width from e +e – data.« less

Model-independent determination of the triple Higgs coupling at e+e- colliders

NASA Astrophysics Data System (ADS)

Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon; Peskin, Michael E.; Tian, Junping

2018-03-01

The observation of Higgs pair production at high-energy colliders can give evidence for the presence of a triple Higgs coupling. However, the actual determination of the value of this coupling is more difficult. In the context of general models for new physics, double Higgs production processes can receive contributions from many possible beyond-Standard-Model effects. This dependence must be understood if one is to make a definite statement about the deviation of the Higgs field potential from the Standard Model. In this paper, we study the extraction of the triple Higgs coupling from the process e+e-→Z h h . We show that, by combining the measurement of this process with other measurements available at a 500 GeV e+e- collider, it is possible to quote model-independent limits on the effective field theory parameter c6 that parametrizes modifications of the Higgs potential. We present precise error estimates based on the anticipated International Linear Collider physics program, studied with full simulation. Our analysis also gives new insight into the model-independent extraction of the Higgs boson coupling constants and total width from e+e- data.

Analysis of the Laser Calibration System for the CMS HCAL at CERN's Large Hadron Collider

NASA Astrophysics Data System (ADS)

Lebolo, Luis

2005-11-01

The European Organization for Nuclear Physics' (CERN) Large Hadron Collider uses the Compact Muon Solenoid (CMS) detector to measure collision products from proton-proton interactions. CMS uses a hadron calorimeter (HCAL) to measure the energy and position of quarks and gluons by reconstructing their hadronic decay products. An essential component of the detector is the calibration system, which was evaluated in terms of its misalignment, linearity, and resolution. In order to analyze the data, the authors created scripts in ROOT 5.02/00 and C++. The authors also used Mathematica 5.1 to perform complex mathematics and AutoCAD 2006 to produce optical ray traces. The misalignment of the optical components was found to be satisfactory; the Hybrid Photodiodes (HPDs) were confirmed to be linear; the constant, noise and stochastic contributions to its resolution were analyzed; and the quantum efficiency of most HPDs was determined to be approximately 40%. With a better understanding of the laser calibration system, one can further understand and improve the HCAL.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graf, Norman A.; /SLAC

Maximizing the physics performance of detectors being designed for the International Linear Collider, while remaining sensitive to cost constraints, requires a powerful, efficient, and flexible simulation, reconstruction and analysis environment to study the capabilities of a large number of different detector designs. The preparation of Letters Of Intent for the International Linear Collider involved the detailed study of dozens of detector options, layouts and readout technologies; the final physics benchmarking studies required the reconstruction and analysis of hundreds of millions of events. We describe the Java-based software toolkit (org.lcsim) which was used for full event reconstruction and analysis. The componentsmore » are fully modular and are available for tasks from digitization of tracking detector signals through to cluster finding, pattern recognition, track-fitting, calorimeter clustering, individual particle reconstruction, jet-finding, and analysis. The detector is defined by the same xml input files used for the detector response simulation, ensuring the simulation and reconstruction geometries are always commensurate by construction. We discuss the architecture as well as the performance.« less

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.

Studies of beam position monitor stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tenenbaum, P.

1998-05-01

The authors present the results from two studies of the time stability between the mechanical center of a beam position monitor and its electrical/electronic center. In the first study, a group of 93 BPM processors was calibrated via Test Pulse Generator once per hour in order to measure the contribution of the readout electronics to offset drifts. In the second study, a triplet of stripline BPMs in the Final Focus Test Beam, separated only by drift spaces, was read out every 6 minutes during 1 week of beam operation. In both cases offset stability was observed to be on themore » order of microns over time spans ranging from hours to days, although during the beam study much worse performance was also observed. Implications for the beam position monitor system of future linear collider systems are discussed.« less

Progress with High-Field Superconducting Magnets for High-Energy Colliders

NASA Astrophysics Data System (ADS)

Apollinari, Giorgio; Prestemon, Soren; Zlobin, Alexander V.

2015-10-01

One of the possible next steps for high-energy physics research relies on a high-energy hadron or muon collider. The energy of a circular collider is limited by the strength of bending dipoles, and its maximum luminosity is determined by the strength of final focus quadrupoles. For this reason, the high-energy physics and accelerator communities have shown much interest in higher-field and higher-gradient superconducting accelerator magnets. The maximum field of NbTi magnets used in all present high-energy machines, including the LHC, is limited to ˜10 T at 1.9 K. Fields above 10 T became possible with the use of Nb3Sn superconductors. Nb3Sn accelerator magnets can provide operating fields up to ˜15 T and can significantly increase the coil temperature margin. Accelerator magnets with operating fields above 15 T require high-temperature superconductors. This review discusses the status and main results of Nb3Sn accelerator magnet research and development and work toward 20-T magnets.

Progress with high-field superconducting magnets for high-energy colliders

DOE PAGES

Apollinari, Giorgio; Prestemon, Soren; Zlobin, Alexander V.

2015-10-01

One of the possible next steps for high-energy physics research relies on a high-energy hadron or muon collider. The energy of a circular collider is limited by the strength of bending dipoles, and its maximum luminosity is determined by the strength of final focus quadrupoles. For this reason, the high-energy physics and accelerator communities have shown much interest in higher-field and higher-gradient superconducting accelerator magnets. The maximum field of NbTi magnets used in all present high-energy machines, including the LHC, is limited to ~10 T at 1.9 K. Fields above 10 T became possible with the use of Nbmore » $$_3$$Sn superconductors. Nb$$_3$$Sn accelerator magnets can provide operating fields up to ~15 T and can significantly increase the coil temperature margin. Accelerator magnets with operating fields above 15 T require high-temperature superconductors. Furthermore, this review discusses the status and main results of Nb$$_3$$Sn accelerator magnet research and development and work toward 20-T magnets.« less

Study of Higgs effective couplings at electron-proton colliders

NASA Astrophysics Data System (ADS)

Hesari, Hoda; Khanpour, Hamzeh; Najafabadi, Mojtaba Mohammadi

2018-05-01

We perform a search for beyond-the-Standard-Model (BSM) dimension-six operators relevant to the Higgs boson at the Large Hadron Electron Collider (LHeC) and the Future Circular Hadron Electron Collider (FCC-he). With a large amount of data (few ab-1 ) and collisions at the TeV scale, both LHeC and FCC-he provide excellent opportunities to search for the BSM effects. The study is done through the process e-p →h j νe , where the Higgs boson decays into a pair of b b ¯, and we consider the main sources of background processes, including a realistic simulation of detector effects. For the FCC-he case, in some signal scenarios, to obtain an efficient event reconstruction and to have a good background rejection, jet substructure techniques are employed to reconstruct the boosted Higgs boson in the final state. In order to assess the sensitivity to the dimension-six operators, a shape analysis on the differential cross sections is performed. Stringent bounds are found on the Wilson coefficients of dimension-six operators with the integrated luminosities of 1 ab-1 and 10 ab-1 , which in some cases show improvements with respect to the high-luminosity LHC results.

Recombinant Science: The Birth of the Relativistic Heavy Ion Collider (431st Brookhaven Lecture)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crease, Robert P.

2007-12-12

As part of the celebration of Brookhaven Lab's 60th anniversary, Robert P. Crease, the Chair of the Philosophy Department at Stony Brook University and BNL's historian, will present the second of two talks on the Lab's history. In "Recombinant Science: The Birth of the Relativistic Heavy Ion Collider," Dr. Crease will focus on the creation of the world's most powerful colliding accelerator for nuclear physics. Known as RHIC, the collider, as Dr. Crease will recount, was formally proposed in 1984, received initial construction funding from the U.S. Department of Energy in 1991, and started operating in 2000. In 2005, themore » discovery at RHIC of the world's most perfect liquid, a state of matter that last existed just moments after the Big Bang, was announced, and, since then, this perfect liquid of quarks and gluons has been the subject of intense study.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aranda, J. I.; Tututi, E. S.; Flores-Tlalpa, A.

Higgs mediated flavor violating electromagnetic interactions, induced at the one-loop level by a nondiagonal Hf{sub i}f{sub j} vertex, with f{sub i} and f{sub j} charged leptons or quarks, are studied within the context of a completely general effective Yukawa sector that comprises SU{sub L}(2)xU{sub Y}(1)-invariant operators of up to dimension-six. Exact formulae for the one-loop {gamma}f{sub i}f{sub j} and {gamma}{gamma}f{sub i}f{sub j} couplings are presented and their related processes used to study the phenomena of Higgs mediated lepton flavor violation. The experimental limit on the {mu}{yields}e{gamma} decay is used to derive a bound on the branching ratio of the {mu}{yields}e{gamma}{gamma}more » transition, which is 6 orders of magnitude stronger than the current experimental limit. Previous results on the {tau}{yields}{mu}{gamma} and {tau}{yields}{mu}{gamma}{gamma} decays are reproduced. The possibility of detecting signals of lepton flavor violation at {gamma}{gamma} colliders is explored through the {gamma}{gamma}{yields}l{sub i}l{sub j} reaction, putting special emphasis on the {tau}{mu} final state. Using the bound imposed on the H{tau}{mu} vertex by the current experimental data on the muon anomalous magnetic moment, it is found that about half a hundred events may be produced in the International Linear Collider.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abeyratne, S; Ahmed, S; Barber, D

2012-08-01

Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectivelymore » utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very beginning, the design studies at Jefferson Lab have focused on achieving high collider performance, particularly ultrahigh luminosities up to 10{sup 34} cm{sup -2}s{sup -1} per detector with large acceptance, while maintaining high polarization for both the electron and light-ion beams. These are the two key performance requirements of a future electron-ion collider facility as articulated by the NSAC Long Range Plan. In MEIC, a new ion complex is designed specifically to deliver ion beams that match the high bunch repetition and highly polarized electron beam from CEBAF. During the last two years, both development of the science case and optimization of the machine design point toward a medium-energy electron-ion collider as the topmost goal for Jefferson Lab. The MEIC, with relatively compact collider rings, can deliver a luminosity above 10{sup 34} cm{sup -2}s{sup -1} at a center-of-mass energy up to 65 GeV. It offers an electron energy up to 11 GeV, a proton energy up to 100 GeV, and corresponding energies per nucleon for heavy ions with the same magnetic rigidity. This design choice balances the scope of the science program, collider capabilities, accelerator technology innovation, and total project cost. An energy upgrade could be implemented in the future by adding two large collider rings housed in another large tunnel to push the center-of-mass energy up to or exceeding 140 GeV. After careful consideration of an alternative electron energy recovery linac on ion storage ring approach, a ring-ring collider scenario at high bunch repetition frequency was found to offer fully competitive performance while eliminating the uncertainties of challenging R&D on ampere-class polarized electron sources and many-pass energy-recovery linacs (ERLs). The essential new elements of an MEIC facility at Jefferson Lab are an electron storage ring and an entirely new, modern ion acceleration and storage complex. For the high-current electron collider ring, the upgraded 12 GeV CEBAF SRF linac will serve as a full-energy injector, and, if needed, provide top-off refilling. The CEBAF fixed-target nuclear physics program can be simultaneously operated since the filling time of the electron ring is very short. The ion complex for MEIC consists of sources for polarized light ions and unpolarized light to heavy ions, an SRF ion linac with proton energy up to 280 MeV, a 3 GeV prebooster synchrotron, a large booster synchrotron for proton energy up to 20 GeV, and a medium-energy collider ring with energy up to 100 GeV. The ion complex can accelerate other species of ions with corresponding energies at each accelerating stage. There are three collision points planned for MEIC. Two of them are for collisions with medium-energy ions; the third is for low energy ion beams stored in a dedicated low-energy compact storage ring, as a possible follow-on project.« less

Connecting dark matter annihilation to the vertex functions of Standard Model fermions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Jason; Light, Christopher, E-mail: jkumar@hawaii.edu, E-mail: lightc@hawaii.edu

We consider scenarios in which dark matter is a Majorana fermion which couples to Standard Model fermions through the exchange of charged mediating particles. The matrix elements for various dark matter annihilation processes are then related to one-loop corrections to the fermion-photon vertex, where dark matter and the charged mediators run in the loop. In particular, in the limit where Standard Model fermion helicity mixing is suppressed, the cross section for dark matter annihilation to various final states is related to corrections to the Standard Model fermion charge form factor. These corrections can be extracted in a gauge-invariant manner frommore » collider cross sections. Although current measurements from colliders are not precise enough to provide useful constraints on dark matter annihilation, improved measurements at future experiments, such as the International Linear Collider, could improve these constraints by several orders of magnitude, allowing them to surpass the limits obtainable by direct observation.« less

First Operational Experience With a High-Energy Physics Run Control System Based on Web Technologies

NASA Astrophysics Data System (ADS)

Bauer, Gerry; Beccati, Barbara; Behrens, Ulf; Biery, Kurt; Branson, James; Bukowiec, Sebastian; Cano, Eric; Cheung, Harry; Ciganek, Marek; Cittolin, Sergio; Coarasa Perez, Jose Antonio; Deldicque, Christian; Erhan, Samim; Gigi, Dominique; Glege, Frank; Gomez-Reino, Robert; Gulmini, Michele; Hatton, Derek; Hwong, Yi Ling; Loizides, Constantin; Ma, Frank; Masetti, Lorenzo; Meijers, Frans; Meschi, Emilio; Meyer, Andreas; Mommsen, Remigius K.; Moser, Roland; O'Dell, Vivian; Oh, Alexander; Orsini, Luciano; Paus, Christoph; Petrucci, Andrea; Pieri, Marco; Racz, Attila; Raginel, Olivier; Sakulin, Hannes; Sani, Matteo; Schieferdecker, Philipp; Schwick, Christoph; Shpakov, Dennis; Simon, Michal; Sumorok, Konstanty; Yoon, Andre Sungho

2012-08-01

Run control systems of modern high-energy particle physics experiments have requirements similar to those of today's Internet applications. The Compact Muon Solenoid (CMS) collaboration at CERN's Large Hadron Collider (LHC) therefore decided to build the run control system for its detector based on web technologies. The system is composed of Java Web Applications distributed over a set of Apache Tomcat servlet containers that connect to a database back-end. Users interact with the system through a web browser. The present paper reports on the successful scaling of the system from a small test setup to the production data acquisition system that comprises around 10.000 applications running on a cluster of about 1600 hosts. We report on operational aspects during the first phase of operation with colliding beams including performance, stability, integration with the CMS Detector Control System and tools to guide the operator.

Status Of the ILC Main Linac Design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saini, Arun; Kapin, Valery; Solyak, Nikolay

2017-05-01

International Linear collider (ILC) is a proposed accelerator facility which is primarily based on two 11-km long superconducting main linacs. In this paper we present recent updates on the main linac design and discuss changes made in order to meet specification outlined in the technical design report (TDR).

Measurement of IR optics with linear coupling's action-angle parametrization

NASA Astrophysics Data System (ADS)

Luo, Y.; Bai, M.; Pilat, F.; Satogata, T.; Trbojevic, D.

2005-08-01

Linear coupling’s action-angle parametrization is convenient for interpretation of turn-by-turn beam position monitor (BPM) data. We demonstrate how to apply this parametrization to extract Twiss and coupling parameters in interaction regions (IRs), using BPMs on each side of a long IR drift region. Example data were acquired at the Relativistic Heavy Ion Collider, using an ac dipole to excite a single transverse eigenmode. We have measured the waist of the β function and its Twiss and coupling parameters.

Emittance preservation in plasma-based accelerators with ion motion

DOE PAGES

Benedetti, C.; Schroeder, C. B.; Esarey, E.; ...

2017-11-01

In a plasma-accelerator-based linear collider, the density of matched, low-emittance, high-energy particle bunches required for collider applications can be orders of magnitude above the background ion density, leading to ion motion, perturbation of the focusing fields, and, hence, to beam emittance growth. By analyzing the response of the background ions to an ultrahigh density beam, analytical expressions, valid for nonrelativistic ion motion, are derived for the transverse wakefield and for the final (i.e., after saturation) bunch emittance. Analytical results are validated against numerical modeling. Initial beam distributions are derived that are equilibrium solutions, which require head-to-tail bunch shaping, enabling emittancemore » preservation with ion motion.« less

Protection of the CERN Large Hadron Collider

NASA Astrophysics Data System (ADS)

Schmidt, R.; Assmann, R.; Carlier, E.; Dehning, B.; Denz, R.; Goddard, B.; Holzer, E. B.; Kain, V.; Puccio, B.; Todd, B.; Uythoven, J.; Wenninger, J.; Zerlauth, M.

2006-11-01

The Large Hadron Collider (LHC) at CERN will collide two counter-rotating proton beams, each with an energy of 7 TeV. The energy stored in the superconducting magnet system will exceed 10 GJ, and each beam has a stored energy of 362 MJ which could cause major damage to accelerator equipment in the case of uncontrolled beam loss. Safe operation of the LHC will therefore rely on a complex system for equipment protection. The systems for protection of the superconducting magnets in case of quench must be fully operational before powering the magnets. For safe injection of the 450 GeV beam into the LHC, beam absorbers must be in their correct positions and specific procedures must be applied. Requirements for safe operation throughout the cycle necessitate early detection of failures within the equipment, and active monitoring of the beam with fast and reliable beam instrumentation, mainly beam loss monitors (BLM). When operating with circulating beams, the time constant for beam loss after a failure extends from apms to a few minutes—failures must be detected sufficiently early and transmitted to the beam interlock system that triggers a beam dump. It is essential that the beams are properly extracted on to the dump blocks at the end of a fill and in case of emergency, since the beam dump blocks are the only elements of the LHC that can withstand the impact of the full beam.

Collider shot setup for Run 2 observations and suggestions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Annala, J.; Joshel, B.

1996-01-31

This note is intended to provoke discussion on Collider Run II shot setup. We hope this is a start of activities that will converge on a functional description of what is needed for shot setups in Collider Run II. We will draw on observations of the present shot setup to raise questions and make suggestions for the next Collider run. It is assumed that the reader has some familiarity with the Collider operational issues. Shot setup is defined to be the time between the end of a store and the time the Main Control Room declares colliding beams. This ismore » the time between Tevatron clock events SCE and SCB. This definition does not consider the time experiments use to turn on their detectors. This analysis was suggested by David Finley. The operational scenarios for Run II will require higher levels of reliability and speed for shot setup. See Appendix I and II. For example, we estimate that a loss of 3 pb{sup {minus}1}/week (with 8 hour stores) will occur if shot setups take 90 minutes instead of 30 minutes. In other words: If you do 12 shots for one week and accept an added delay of one minute in each shot, you will loose more than 60 nb{sup {minus}1} for that week alone (based on a normal shot setup of 30 minutes). These demands should lead us to be much more pedantic about all the factors that affect shot setups. Shot setup will be viewed as a distinct process that is composed of several inter- dependent `components`: procedures, hardware, controls, and sociology. These components don`t directly align with the different Accelerator Division departments, but are topical groupings of the needed accelerator functions. Defining these components, and categorizing our suggestions within them, are part of the goal of this document. Of course, some suggestions span several of these components.« less

240 GHz pedestal-free colliding-pulse mode-locked laser with a wide operation range

NASA Astrophysics Data System (ADS)

Hou, L.; Haji, M.; Marsh, J. H.

2014-11-01

A 240 GHz, sixth-harmonic monolithic ~1.55 μm colliding-pulse mode-locked laser is reported using a three-quantum-well active layer design and a passive far-field reduction layer. The device emits 0.88 ps pulses with a peak power of 65 mW and intermediate longitudinal modes suppressed by >30 dB. The device demonstrates a wide operation range compared to the conventional five-quantum-well design as well as having a low divergence angle (12.7° × 26.3°), granting a twofold improvement in butt-coupling efficiency into a flat cleaved single-mode fibre.

Linear momentum, angular momentum and energy in the linear collision between two balls

NASA Astrophysics Data System (ADS)

Hanisch, C.; Hofmann, F.; Ziese, M.

2018-01-01

In an experiment of the basic physics laboratory, kinematical motion processes were analysed. The motion was recorded with a standard video camera having frame rates from 30 to 240 fps the videos were processed using video analysis software. Video detection was used to analyse the symmetric one-dimensional collision between two balls. Conservation of linear and angular momentum lead to a crossover from rolling to sliding directly after the collision. By variation of the rolling radius the system could be tuned from a regime in which the balls move away from each other after the collision to a situation in which they re-collide.

The Lhc Collider:. Status and Outlook to Operation

NASA Astrophysics Data System (ADS)

Schmidt, Rüdiger

2006-04-01

For the LHC to provide particle physics with proton-proton collisions at the centre of mass energy of 14 TeV with a luminosity of 1034 cm-2s-1, the machine will operate with high-field dipole magnets using NbTi superconductors cooled to below the lambda point of helium. In order to reach design performance, the LHC requires both, the use of existing technologies pushed to the limits as well as the application of novel technologies. The construction follows a decade of intensive R&D and technical validation of major collider sub-systems. This paper will focus on the required LHC performance, and on the implications on the used technologies. The consequences of the unprecedented quantity of energy stored in both magnets and beams will be discussed. A brief outlook to operation and its consequences for machine protection will be given.

Dynamic imperfections and optimized feedback design in the Compact Linear Collider main linac

NASA Astrophysics Data System (ADS)

Eliasson, Peder

2008-05-01

The Compact Linear Collider (CLIC) main linac is sensitive to dynamic imperfections such as element jitter, injected beam jitter, and ground motion. These effects cause emittance growth that, in case of ground motion, has to be counteracted by a trajectory feedback system. The feedback system itself will, due to jitter effects and imperfect beam position monitors (BPMs), indirectly cause emittance growth. Fast and accurate simulations of both the direct and indirect effects are desirable, but due to the many elements of the CLIC main linac, simulations may become very time consuming. In this paper, an efficient way of simulating linear (or nearly linear) dynamic effects is described. The method is also shown to facilitate the analytic determination of emittance growth caused by the different dynamic imperfections while using a trajectory feedback system. Emittance growth expressions are derived for quadrupole, accelerating structure, and beam jitter, for ground motion, and for noise in the feedback BPMs. Finally, it is shown how the method can be used to design a feedback system that is optimized for the optics of the machine and the ground motion spectrum of the particular site. This feedback system gives an emittance growth rate that is approximately 10 times lower than that of traditional trajectory feedbacks. The robustness of the optimized feedback system is studied for a number of additional imperfections, e.g., dipole corrector imperfections and faulty knowledge about the machine optics, with promising results.

An EUDET/AIDA Pixel Beam Telescope for Detector Development

NASA Astrophysics Data System (ADS)

Rubinskiy, I.; EUDET Consortium; AIDA Consortium

Ahigh resolution(σ< 2 μm) beam telescope based on monolithic active pixel sensors (MAPS) was developed within the EUDET collaboration. EUDET was a coordinated detector R&D programme for the future International Linear Collider providing test beam infrastructure to detector R&D groups. The telescope consists of six sensor planes with a pixel pitch of either 18.4 μm or 10 μmand canbe operated insidea solenoidal magnetic fieldofupto1.2T.Ageneral purpose cooling, positioning, data acquisition (DAQ) and offine data analysis tools are available for the users. The excellent resolution, readout rate andDAQintegration capabilities made the telescopea primary beam tests tool also for several CERN based experiments. In this report the performance of the final telescope is presented. The plans for an even more flexible telescope with three differentpixel technologies(ATLASPixel, Mimosa,Timepix) withinthenew European detector infrastructure project AIDA are presented.

Challenges And Concepts for Design of An Interaction Region With Push-Pull Arrangement of Detectors - An Interface Document

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, B.; /Brookhaven; Herve, Alain

2011-10-14

Two experimental detectors working in a push-pull mode has been considered for the Interaction Region of the International Linear Collider. The push-pull mode of operation sets specific requirements and challenges for many systems of detector and machine, in particular for the IR magnets, for the cryogenics and alignment system, for beamline shielding, for detector design and overall integration, and so on. These challenges and the identified conceptual solutions discussed in the paper intend to form a draft of the Interface Document which will be developed further in the nearest future. The authors of the present paper include the organizers andmore » conveners of working groups of the workshop on engineering design of interaction region IRENG07, the leaders of the IR Integration within Global Design Effort Beam Delivery System, and the representatives from each detector concept submitting the Letters Of Intent.« less

Design and performance of a high resolution, low latency stripline beam position monitor system

NASA Astrophysics Data System (ADS)

Apsimon, R. J.; Bett, D. R.; Blaskovic Kraljevic, N.; Burrows, P. N.; Christian, G. B.; Clarke, C. I.; Constance, B. D.; Dabiri Khah, H.; Davis, M. R.; Perry, C.; Resta López, J.; Swinson, C. J.

2015-03-01

A high-resolution, low-latency beam position monitor (BPM) system has been developed for use in particle accelerators and beam lines that operate with trains of particle bunches with bunch separations as low as several tens of nanoseconds, such as future linear electron-positron colliders and free-electron lasers. The system was tested with electron beams in the extraction line of the Accelerator Test Facility at the High Energy Accelerator Research Organization (KEK) in Japan. It consists of three stripline BPMs instrumented with analogue signal-processing electronics and a custom digitizer for logging the data. The design of the analogue processor units is presented in detail, along with measurements of the system performance. The processor latency is 15.6 ±0.1 ns . A single-pass beam position resolution of 291 ±10 nm has been achieved, using a beam with a bunch charge of approximately 1 nC.

The Next Linear Collider Program

Science.gov Websites

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The Next Linear Collider Program

Science.gov Websites

posted to the new SLAC ILC web site http://www-project.slac.stanford.edu/ilc/. Also, see the new site for . The NLC web site will remain accessible as an archive of important work done on the many systems | Navbar || || Documentation | NLC Playpen | Web Comments & Suggestions | Desktop Trouble Call | LC

The Next Linear Collider Program

Science.gov Websites

. Records including program management records, financial records, technical and R&D data needed to international collaboration including BINP (Protvino), DESY, FNAL, KEK, LAL d'Orsay, MPI (Munich) and SLAC. SLAC scientific records for proper NLC documentation. Both paper and electronic files are archived in conjunction

Analog VS Digital Hadron Calorimetry at a Future Electron-Positron Linear Collider

NASA Astrophysics Data System (ADS)

Magill, Stephen R.

2005-02-01

Precision jet measurements at a future e+e- linear collider may only be possible using so-called Particle Flow Algorithms (PFAs). While there are many possible implementations of P-flow techniques, they all have in common separation of induced calorimeter showers from charged and neutral hadrons (as well as photons) within a jet. Shower reconstruction in the calorimeter becomes more important than energy measurement of hadrons. The calorimeter cells must be highly granular both transverse to the particle trajectory and in longitudinal segmentation. It is probable that as the cell size decreases, it will be harder to get an energy measure from each cell (analog calorimetry). Using only the hit information (digital calorimetry) may be the best way to measure the neutral hadron energy contribution to jets. In this paper, comparisons of analog and digital methods of measuring the contributions of neutral hadrons to jets are made in simulation and in the context of a particular PFA, indicating that the digital method is at least equal to the analog case in jet energy resolution.

Modulators for the S-band test linac at DESY

NASA Astrophysics Data System (ADS)

Bieler, M.; Choroba, S.; Hameister, J.; Lewin, H.-Ch.

1995-07-01

The development of adequate modulators for high peak power klystrons is one of the focus points for linear collider R&D programs. For the DESY/THD S-band linear collider study 150 MW rf-pulse power at 50 Hz repetition rate and 3 μs pulse duration is required [1]. Two different modulator schemes are under investigation. One is the conventional line type pulser, using a pulse forming network and a step up transformer, the other one is a hard tube pulser, using a dc power source at the full klystron voltage and a switch tube. This paper is focused on the modulator development for the S-band Test Linac at DESY. After a short overview over the test linac and a brief description of the 150 MW S-band klystron the circuitry of the line type pulse (LTP) is given. A hard tube pulser (HTP), which switches the high voltage directly from a storage capacitor to the klystron, has been built up at DESY. Circuitry and the results of the commissioning of the switch tube are reported.

Using Spin Correlations to Distinguish Zh from ZA at the International Linear Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahlon, Gregory; /Penn State U., Mont Alto; Parke, Stephen J.

2006-06-01

We investigate how to exploit the spin information imparted to the Z boson in associated Higgs production at a future linear collider as an aid in distinguishing between CP-even and CP-odd Higgs bosons. We apply a generalized spin-basis analysis which allows us to study the possibilities offered by non-traditional choices of spin projection axis. In particular, we find that the Z bosons produced in association with a CP-even Higgs via polarized collisions are in a single transverse spin-state (> 90% purity) when we use the Zh-transverse basis, provided that the Z bosons are not ultra-relativistic (speed < 0.9c). This samemore » basis applied to the associated production of a CP-odd Higgs yields Z's that are an approximately equal mixture of longitudinal and transverse polarizations. We present a decay angular distribution which could be used to distinguish between the CP-even and CP-odd cases. Finally, we make a few brief remarks about how this distribution would be affected if the Higgs boson turns out to not be a CP-eigenstate.« less

Standard model effective field theory: Integrating out neutralinos and charginos in the MSSM

NASA Astrophysics Data System (ADS)

Han, Huayong; Huo, Ran; Jiang, Minyuan; Shu, Jing

2018-05-01

We apply the covariant derivative expansion method to integrate out the neutralinos and charginos in the minimal supersymmetric Standard Model. The results are presented as set of pure bosonic dimension-six operators in the Standard Model effective field theory. Nontrivial chirality dependence in fermionic covariant derivative expansion is discussed carefully. The results are checked by computing the h γ γ effective coupling and the electroweak oblique parameters using the Standard Model effective field theory with our effective operators and direct loop calculation. In global fitting, the proposed lepton collider constraint projections, special phenomenological emphasis is paid to the gaugino mass unification scenario (M2≃2 M1) and anomaly mediation scenario (M1≃3.3 M2). These results show that the precision measurement experiments in future lepton colliders will provide a very useful complementary job in probing the electroweakino sector, in particular, filling the gap of the soft lepton plus the missing ET channel search left by the traditional collider, where the neutralino as the lightest supersymmetric particle is very degenerated with the next-to-lightest chargino/neutralino.

Heavy-ion physics with the ALICE experiment at the CERN Large Hadron Collider.

PubMed

Schukraft, J

2012-02-28

After close to 20 years of preparation, the dedicated heavy-ion experiment A Large Ion Collider Experiment (ALICE) took first data at the CERN Large Hadron Collider (LHC) accelerator with proton collisions at the end of 2009 and with lead nuclei at the end of 2010. After a short introduction into the physics of ultra-relativistic heavy-ion collisions, this article recalls the main design choices made for the detector and summarizes the initial operation and performance of ALICE. Physics results from this first year of operation concentrate on characterizing the global properties of typical, average collisions, both in proton-proton (pp) and nucleus-nucleus reactions, in the new energy regime of the LHC. The pp results differ, to a varying degree, from most quantum chromodynamics-inspired phenomenological models and provide the input needed to fine tune their parameters. First results from Pb-Pb are broadly consistent with expectations based on lower energy data, indicating that high-density matter created at the LHC, while much hotter and larger, still behaves like a very strongly interacting, almost perfect liquid.

Exotic decays of the 125 GeV Higgs boson at future e +e – colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Zhen; Wang, Lian -Tao; Zhang, Hao

Discovery of unexpected properties of the Higgs boson offers an intriguing opportunity of shedding light on some of the most profound puzzles in particle physics. The Beyond Standard Model (BSM) decays of the Higgs boson could reveal new physics in a direct manner. Future electron-positron lepton colliders operating as Higgs factories, including CEPC, FCC-ee and ILC, with the advantages of a clean collider environment and large statistics, could greatly enhance the sensitivity in searching for these BSM decays. In this work, we perform a general study of Higgs exotic decays at futuremore » $e^+e^-$ lepton colliders, focusing on the Higgs decays with hadronic final states and/or missing energy, which are very challenging for the High-Luminosity program of the Large Hadron Collider (HL-LHC). We show that with simple selection cuts, $$O(10^{-3}\\sim10^{-5})$$ limits on the Higgs exotic decay branching fractions can be achieved using the leptonic decaying spectator $Z$ boson in the associated production mode $$e^+e^-\\rightarrow Z H$$. We further discuss the interplay between the detector performance and Higgs exotic decay, and other possibilities of exotic decays. Finally, our work is a first step in a comprehensive study of Higgs exotic decays at future lepton colliders, which is a key ingredient of Higgs physics that deserves further investigation.« less

Exotic decays of the 125 GeV Higgs boson at future e +e – colliders

DOE PAGES

Liu, Zhen; Wang, Lian -Tao; Zhang, Hao

2017-06-01

Discovery of unexpected properties of the Higgs boson offers an intriguing opportunity of shedding light on some of the most profound puzzles in particle physics. The Beyond Standard Model (BSM) decays of the Higgs boson could reveal new physics in a direct manner. Future electron-positron lepton colliders operating as Higgs factories, including CEPC, FCC-ee and ILC, with the advantages of a clean collider environment and large statistics, could greatly enhance the sensitivity in searching for these BSM decays. In this work, we perform a general study of Higgs exotic decays at futuremore » $e^+e^-$ lepton colliders, focusing on the Higgs decays with hadronic final states and/or missing energy, which are very challenging for the High-Luminosity program of the Large Hadron Collider (HL-LHC). We show that with simple selection cuts, $$O(10^{-3}\\sim10^{-5})$$ limits on the Higgs exotic decay branching fractions can be achieved using the leptonic decaying spectator $Z$ boson in the associated production mode $$e^+e^-\\rightarrow Z H$$. We further discuss the interplay between the detector performance and Higgs exotic decay, and other possibilities of exotic decays. Finally, our work is a first step in a comprehensive study of Higgs exotic decays at future lepton colliders, which is a key ingredient of Higgs physics that deserves further investigation.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hand, L.N.

Some proposed techniques for using laser beams to accelerate charged particles are reviewed. Two specific ideas for 'grating-type' accelerating structures are discussed. Speculations are presented about how a successful laser accelerator could be used in a 'multi-pass collider', a type of machine which would have characteristics intermediate between those of synchrotrons and linear (single-pass) colliders. No definite conclusions about practical structures for laser accelerators are reached, but it is suggested that a serious effort be made to design a small prototype machine. Achieving a reasonable luminosity demands that the accelerator either be a cw machine or that laser peak powermore » requirements be much higher than those presently available. Use of superconducting gratings requires a wavelength in the sub-millimeter range.« less

The laser accelerator-another unicorn in the garden

NASA Astrophysics Data System (ADS)

Hand, L. N.

1981-07-01

Some proposed techniques for using laser beams to accelerate charged particles was reviewed. Two specific ideas for grating type accelerating structures are discussed. Speculations are presented about how a successful laser accelerator could be used in a multipass collider; a type of machine which would have characteristics intermediate between those of synchrotrons and linear (single pass) colliders. No definite conclusions about practical structures for laser accelerators are reached, but it is suggested that a serious effort be made to design a small prototype machine. Achieving a reasonable luminosity demands that the accelerator either be a cw machine or that laser peak power requirements to be much higher than those presently available. Use of superconducting gratings requires a wavelength in the sub-millimeter range.

Type IIB Colliding Plane Waves

NASA Astrophysics Data System (ADS)

Gutperle, M.; Pioline, B.

2003-09-01

Four-dimensional colliding plane wave (CPW) solutions have played an important role in understanding the classical non-linearities of Einstein's equations. In this note, we investigate CPW solutions in 2n+2-dimensional Einstein gravity with a n+1-form flux. By using an isomorphism with the four-dimensional problem, we construct exact solutions analogous to the Szekeres vacuum solution in four dimensions. The higher-dimensional versions of the Khan-Penrose and Bell-Szekeres CPW solutions are studied perturbatively in the vicinity of the light-cone. We find that under small perturbations, a curvature singularity is generically produced, leading to both space-like and time-like singularities. For n = 4, our results pertain to the collision of two ten-dimensional type-IIB Blau-Figueroa o'Farrill-Hull-Papadopoulos plane waves.

Neurosurgery simulation using non-linear finite element modeling and haptic interaction

NASA Astrophysics Data System (ADS)

Lee, Huai-Ping; Audette, Michel; Joldes, Grand R.; Enquobahrie, Andinet

2012-02-01

Real-time surgical simulation is becoming an important component of surgical training. To meet the realtime requirement, however, the accuracy of the biomechancial modeling of soft tissue is often compromised due to computing resource constraints. Furthermore, haptic integration presents an additional challenge with its requirement for a high update rate. As a result, most real-time surgical simulation systems employ a linear elasticity model, simplified numerical methods such as the boundary element method or spring-particle systems, and coarse volumetric meshes. However, these systems are not clinically realistic. We present here an ongoing work aimed at developing an efficient and physically realistic neurosurgery simulator using a non-linear finite element method (FEM) with haptic interaction. Real-time finite element analysis is achieved by utilizing the total Lagrangian explicit dynamic (TLED) formulation and GPU acceleration of per-node and per-element operations. We employ a virtual coupling method for separating deformable body simulation and collision detection from haptic rendering, which needs to be updated at a much higher rate than the visual simulation. The system provides accurate biomechancial modeling of soft tissue while retaining a real-time performance with haptic interaction. However, our experiments showed that the stability of the simulator depends heavily on the material property of the tissue and the speed of colliding objects. Hence, additional efforts including dynamic relaxation are required to improve the stability of the system.

Participation in the ARGUS experiment at the DORIS Collider at Desy, Hamburg, Germany and participation in the AMY experiment at the TRISTAN Collider in Tsukuba, Japan: 1986 progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darden, C.

1987-01-01

Progress is reported on the AMY and ARGUS detectors, as well as plans for the next funding period. The AMY detector is reported as well on the way to completion, but not yet ready to take data. The ARGUS detector is reported to have completed its fourth year of operation. Some upsilon 1S decay data are discussed. 37 refs. (LEW)

Physics Accomplishments and Future Prospects of the BES Experiments at the Beijing Electron-Positron Collider

NASA Astrophysics Data System (ADS)

Briere, Roy A.; Harris, Frederick A.; Mitchell, Ryan E.

2016-10-01

The cornerstone of the Chinese experimental particle physics program is a series of experiments performed in the τ-charm energy region. China began building e+e- colliders at the Institute for High Energy Physics in Beijing more than three decades ago. Beijing Electron Spectrometer (BES) is the common root name for the particle physics detectors operated at these machines. We summarize the development of the BES program and highlight the physics results across several topical areas.

Managing operational documentation in the ALICE Detector Control System

NASA Astrophysics Data System (ADS)

Lechman, M.; Augustinus, A.; Bond, P.; Chochula, P.; Kurepin, A.; Pinazza, O.; Rosinsky, P.

2012-12-01

ALICE (A Large Ion Collider Experiment) is one of the big LHC (Large Hadron Collider) experiments at CERN in Geneve, Switzerland. The experiment is composed of 18 sub-detectors controlled by an integrated Detector Control System (DCS) that is implemented using the commercial SCADA package PVSSII. The DCS includes over 1200 network devices, over 1,000,000 monitored parameters and numerous custom made software components that are prepared by over 100 developers from all around the world. This complex system is controlled by a single operator via a central user interface. One of his/her main tasks is the recovery of anomalies and errors that may occur during operation. Therefore, clear, complete and easily accessible documentation is essential to guide the shifter through the expert interfaces of different subsystems. This paper describes the idea of the management of the operational documentation in ALICE using a generic repository that is built on a relational database and is integrated with the control system. The experience gained and the conclusions drawn from the project are also presented.

Testing the electroweak phase transition in scalar extension models at lepton colliders

NASA Astrophysics Data System (ADS)

Cao, Qing-Hong; Huang, Fa-Peng; Xie, Ke-Pan; Zhang, Xinmin

2018-01-01

We study the electroweak phase transition in three scalar extension models beyond the Standard Model. Assuming new scalars are decoupled at some heavy scale, we use the covariant derivative expansion method to derive all of the dimension-6 effective operators, whose coefficients are highly correlated in a specific model. We provide bounds to the complete set of dimension-6 operators by including the electroweak precision test and recent Higgs measurements. We find that the parameter space of strong first-order phase transitions (induced by the | H{| }6 operator) can be probed extensively in Zh production at future electron-positron colliders. QHC and KPX are supported in part by the National Science Foundation of China(11175069, 11275009, 11422545), XZ and FPH are supported by the NSFC (11121092, 11033005, 11375202) and also by the CAS Pilot-B program. FPH is also supported by the China Postdoctoral Science Foundation (2016M590133, 2017T100108)

Drell-Yan process as an avenue to test a noncommutative standard model at the Large Hadron Collider

NASA Astrophysics Data System (ADS)

J, Selvaganapathy; Das, Prasanta Kumar; Konar, Partha

2016-06-01

We study the Drell-Yan process at the Large Hadron Collider in the presence of the noncommutative extension of the standard model. Using the Seiberg-Witten map, we calculate the production cross section to first order in the noncommutative parameter Θμ ν . Although this idea has been evolving for a long time, only a limited amount of phenomenological analysis has been completed, and this was mostly in the context of the linear collider. An outstanding feature from this nonminimal noncommutative standard model not only modifies the couplings over the SM production channel but also allows additional nonstandard vertices which can play a significant role. Hence, in the Drell-Yan process, as studied in the present analysis, one also needs to account for the gluon fusion process at the tree level. Some of the characteristic signatures, such as oscillatory azimuthal distributions, are an outcome of the momentum-dependent effective couplings. We explore the noncommutative scale ΛNC≥0.4 TeV , considering different machine energy ranging from 7 to 13 TeV.

Aberration compensation in a Skew parametric-resonance ionization cooling channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sy, Amy V.; Derbenev, Yaroslav S.; Morozov, Vasiliy

Skew Parametric-resonance Ionization Cooling (Skew PIC) represents a novel method for focusing of highly divergent particle beams, as in the final 6D cooling stage of a high-luminosity muon collider. In the muon collider concept, the resultant equilibrium transverse emittances from cooling with Skew PIC are an order of magnitude smaller than in conventional ionization cooling. The concept makes use of coupling of the transverse dynamic behavior, and the linear dynamics are well-behaved with good agreement between analytic solutions and simulation results. Compared to the uncoupled system, coupling of the transverse dynamic behavior purports to reduce the number of multipoles requiredmore » for aberration compensation while also avoiding unwanted resonances. Aberration compensation is more complicated in the coupled case, especially in the high-luminosity muon collider application where equilibrium angular spreads in the cooling channel are on the order of 200 mrad. We present recent progress on aberration compensation for control of highly divergent muon beams in the coupled correlated optics channel, and a simple cooling model to test the transverse acceptance of the channel.« less

Discrepant Results in a 2-D Marble Collision

ERIC Educational Resources Information Center

Kalajian, Peter

2013-01-01

Video analysis of 2-D collisions is an excellent way to investigate conservation of linear momentum. The often-desired experimental design goal is to minimize the momentum loss in order to demonstrate the conservation law. An air table with colliding pucks is an ideal medium for this experiment, but such equipment is beyond the budget of many…

Implementation of depolarization due to beam-beam effects in the beam-beam interaction simulation tool GUINEA-PIG++

NASA Astrophysics Data System (ADS)

Rimbault, C.; Le Meur, G.; Blampuy, F.; Bambade, P.; Schulte, D.

2009-12-01

Depolarization is a new feature in the beam-beam simulation tool GUINEA-PIG++ (GP++). The results of this simulation are studied and compared with another beam-beam simulation tool, CAIN, considering different beam parameters for the International Linear Collider (ILC) with a centre-of-mass energy of 500 GeV.

The Next Linear Collider Program

Science.gov Websites

/graphics.htm Snowmass 2001 http://snowmass2001.org/ Electrical Systems Modulators http://www -project.slac.stanford.edu/lc/local/electrical/e_home.htm DC Magnet Power http://www-project.slac.stanford.edu/lc/local /electrical/e_home.htm Global Systems http://www-project.slac.stanford.edu/lc/local/electrical/e_home.htm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bower, G.

We summarize the current status and future developments of the North American Group's Java-based system for studying physics and detector design issues at a linear collider. The system is built around Java Analysis Studio (JAS) an experiment-independent Java-based utility for data analysis. Although the system is an integrated package running in JAS, many parts of it are also standalone Java utilities.

List of Posters

NASA Astrophysics Data System (ADS)

List of Posters: Dark matter annihilation in the Galactic galo, by Dokuchaev Vyacheslav, et al. NEMO developments towards km3 telescope in the Mediterranean Sea. The NEMO project. Neutrino Mediterranean Observatory By Antonio Capone, NEMO Collaboration. Alignment as a result from QCD jet production or new still unknown physics at LHC? By Alexander Snigirev. Small-scale fluctuations of extensive air showers: systematics in energy and muon density estimation By Grigory Rubtsov. SHINIE: Simulation of High-Energy Neutrino Interacting with the Earth By Lin Guey-Lin, et al.. Thermodynamics of rotating solutions in n+1 dimensional Einstein - Maxwell -dilation gravity By Ahmad Sheykhi, et al.. Supernova neutrino physics with future large Cherenkov detectors By Daniele Montanino. Crossing of the Cosmological Constant Barrier in the string Inspired Dark Energy Model By S. Yu. Vernov. Calculations of radio signals produced by ultra-high and extremely high energy neutrino induced cascades in Antarctic ice By D. Besson, et al.. Inflation, Cosmic Acceleration and string Gravity By Ischwaree Neupane. Neutrino Physics: Charm and J/Psi production in the atmosphere By Liudmila Volkova. Three generation flavor transitions and decays of supernova relic neutrinos By Daniele Montanino. Lattice calculations & computational quantum field theory: Sonification of Quark and Baryon Spectra By Markum Harald, et al.. Generalized Kramers-Wannier Duality for spin systems with non-commutative symmetry By V. M. Buchstaber, et al.. Heavy ion collisions & quark matter: Nuclear matter jets and multifragmentation By Danut Argintaru, et al.. QCD hard interactions: The qT-spectrum of the Higgs and Slepton-pairs at the LHC By Guiseppe Bozzi. QCD soft interactions: Nonperturbative effects in Single-Spin Asymmetries: Instantons and TMD-parton distributions By Igor Cherednikov, et al.. Gluon dominance model and high multiplicity By Elena Kokoulina. Resonances in eta pi- pi- pi+ system By Dmitry Ryabchikov. Saturation effects in diffractive scattering at LHC By Oleg Selugin. A nonperturbative expansion method in QCD and R-related quantities By Igor Solovtsov. Z-scaling and high multiplicity particle Production in bar pp/pp & AA collisions at Tevatron and RHIC By Mikhail Tokarev. Scaling behaviour of the reactionsdd - > p↑ /3H and pd - > pd with pT at energy I-2 GeV By Yuri Uzikov. [ADS Note: Title formula can not be rendered correctly in ASCII.] CP violation, rare decays, CKM: Precision Measurements of the Mass of the Top Quark at CDF (Precision Top Mass Measurements at CDF) By Daniel Whiteson. Measurement of the Bs Oscillation at CDF By Luciano Ristori. The Bs mixing phase at LHCb By J. J. van Hunen. ATLAS preparations for precise measurements of semileptonic rare B decays By K. Toms. Hadron spectroscopy & exotics: Searches for radial excited states of charmonium in experiments using cooled antiproton beams By M. Yu. Barabanov. Retardation effects in the rotating string model By Fabien Buisseret and Claude Semay. Final results from VEPP-2M (CMD-2 and SND) By G. V. Fedotovich. Heavy Quark Physics: Prospects for B physics measurements using the CMS detector at the LHC By Andreev Valery. Heavy flavour production at HERA-B By Andrey Bogatyrev. B-Meson subleading form factors in the Heavy Quark Effective Theory (HQET) By Frederic Jugeau. Beyond the Standard Model: Monopole Decay in a Variable External Field By Andrey Zayakin. Two-Loop matching coefficients for the strong coupling in the MSSM By Mihaila Luminita. Test of lepton flavour violation at LHC By Hidaka Keisho. Looking at New Physics through 4 jets and no ET By Maity Manas. Are Preons Dyons? Naturalness of Three Generations By Das Chitta Ranjan. SUSY Dark Matter at Linear Collider By Sezen Sekmen, Mehmet Zeyrek. MSSM light Higgs boson scenario and its test at hadron colliders By Alexander Belyaev. Antiscalar Approach to Gravity and Standard Model By E. Mychelkin. GRID distributed analysis in high energy physics: PAX: Physics Analysis Design and Application on the GRID By Martin Erdmann, et al.. D0 and the (SAM) GRID: An ongoing success story DO Collaboration. R & D for future accelerators, detectors & new facilities: High Level Trigger Selection in the CMS experiment By Monica Vazquez Acosta. R&D for a Helical Undulator Based Positron Source for the International Linear Collider By Phil Allport. Muon Detection, Reconstruction and Identification in CMS By Ivan Belotelov. Acoustic Measurements for EeV Neutrino Detection at the South Pole By Sebastian Böser. The PSI source of ultracold neutrons (UCN) By Manfred Daum. The LHCb Pixel Hybrid Photon Detectors (Characterization of Nybrig Photon Detectors for the LHCb experiment) By Neville Harnew, et al.. Semi-Insulating GaN-radiation hard semiconductor for ionizing radiation detectors By Juozas Vaitkus. Monitored Drift Tube end-cap spectrometer for the ATLAS detector By Dmitri Kotchetkov. Development of Focusing Aerogel RICH By Sergey Kononov, et al.. Electromagnetic Calibration of the Hadronic Tile Calorimeter Modules of the ATLAS detector at the LHC By Iouri Koultchitski. A Study of Proximity focusing RICH with Multiple Refractive Index Aerogel Radiator By Peter Krizan. The Heavy Flavor Tracker (HFT) for STAR By Vasil Kuspil. ATLAS Liquid Argon Calorimeter ATLAS Collaboration: Field Emission in HEP Colliders Initiated by a Relativistic Positively Charged Bunch of Particles By Boris Levchenko. MICE: the international Muon Ionization Cooling Experiment By Kenneth Long. In situ calibration of the CMS electromagnetic calorimeter By Augustino Lorenzo. The Transition Radiation Tracker for the ATLAS experiment at the LHC By Victor Maleev. Resonance depolarization and Compton-Backscattering technique for beam energy measurement of VEPP-4M collider By Ivan Nikolaev, et al.. CCD - based Pixel Detectors by LCFI By Andrei Nomerotski. The SiD Detector Concept for the International Linear Collider By Dmitry Onoprienko. CMS Hadron Calorimetry, Calibration, and Jets/Missing Transverse Energy Measurements By Sergey Petrushanko. The CMS Silicon Tracker By Oliver Pooth. Drift Chamber for CMD-3 detector By Alexandr Popov, et al.. Vacuum Phototriods for the CMS ECAL Endcap crystal calorimeter By Vladimir Postoev. CMS Silicon Tracker: Track Reconstruction and Alignment By Frank-Peter Schilling. eRHIC - A precision electron-proton/ion collider facility at Brookhaven National Laboratory By Bernd Surrow. Development of tracking detectors with industrially produced GEM foils By Bernd Surrow, et al.. A Linear Collider Facility with High Intensity e+e- beams (A high intensity e+e- Linear Collider Facility at low energy) By Andre Schoening. Construction of the BESIII detector for tau-charm physics By Yifang Wang. The HERMES Recoil Detector By Sergey Yashchenko. Simulation of MICE in G4 MICE MICE Experiment: The new DO Layer O silicon detector The DO trigger upgrade for RUNIIb The Do Collaboration. Operational experiences with the silicon detector at CDF By Jeannine Wagner. Mathematical aspects of QFT & string theory: Electron in superstrong Coulomb field By D. Gitman. Stability of a non-commutative Jackiw-Teitelboim gravity By Fresneda Rodrigo, et al.. 4d gravity localized on thick branes: the complete mass spectrum By Alfredo Herrera-Aguilar. On Emergence of Quantum Mechanics By L. V. Prokhorov.

3D Boolean operations in virtual surgical planning.

PubMed

Charton, Jerome; Laurentjoye, Mathieu; Kim, Youngjun

2017-10-01

Boolean operations in computer-aided design or computer graphics are a set of operations (e.g. intersection, union, subtraction) between two objects (e.g. a patient model and an implant model) that are important in performing accurate and reproducible virtual surgical planning. This requires accurate and robust techniques that can handle various types of data, such as a surface extracted from volumetric data, synthetic models, and 3D scan data. This article compares the performance of the proposed method (Boolean operations by a robust, exact, and simple method between two colliding shells (BORES)) and an existing method based on the Visualization Toolkit (VTK). In all tests presented in this article, BORES could handle complex configurations as well as report impossible configurations of the input. In contrast, the VTK implementations were unstable, do not deal with singular edges and coplanar collisions, and have created several defects. The proposed method of Boolean operations, BORES, is efficient and appropriate for virtual surgical planning. Moreover, it is simple and easy to implement. In future work, we will extend the proposed method to handle non-colliding components.

Performance of the PHOBOS silicon sensors

NASA Astrophysics Data System (ADS)

Decowski, M. P.; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hołyński, R.; Hofman, D. J.; Holzman, B.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Mülmenstädt, J.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Stephans, G. S. F.; Steinberg, P.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

2002-02-01

The PHOBOS detector is designed to study the physics of Au+Au collisions at the Relativistic Heavy Ion Collider. The detector is almost entirely made of silicon pad detectors and was fully operational during the first year of operation. The detector is described, and key performance characteristics are summarized.

Optimization of the beam crossing angle at the ILC for e+e‑ and γ γ collisions

NASA Astrophysics Data System (ADS)

Telnov, V. I.

2018-03-01

At this time, the design of the International Linear Collider (ILC) is optimized for e+e‑ collisions; the photon collider (γ γ and >=) is considered as an option. Unexpected discoveries, such as the diphoton excess digamma(750) seen at the LHC, could strongly motivate the construction of a photon collider. In order to enable the γ γ collision option, the ILC design should be compatible with it from the very beginning. In this paper, we discuss the problem of the beam crossing angle. In the ILC technical design [1], this angle is 14 mrad, which is just enough to provide enough space for the final quadrupoles and outgoing beams. For γ γ collisions, the crossing angle must be larger because the low-energy electrons that result from multiple Compton scattering get large disruption angles in collisions with the opposing electron beam and some deflection in the solenoidal detector field. For a 2E0=500 GeV collider, the required crossing angle is about 25 mrad. In this paper, we consider the factors that determine the crossing angle as well as its minimum permissible value that does not yet cause a considerable reduction of the γ γ luminosity. It is shown that the best solution is to increase the laser wavelength from the current 1 μm (which is optimal for 2E0=500 GeV) to 2 μm as this makes possible achieving high γ γ luminosities at a crossing angle of 20 mrad, which is also quite comfortable for e+e‑ collisions, does not cause any degradation of the e+e‑ luminosity and opens the possibility for a more energetic future collider in the same tunnel (e.g., CLIC). Moreover, the 2 μm wavelength is optimal for a 2E0 = 1 TeV collider, e.g., a possible ILC energy upgrade. Please consider this paper an appeal to increase the ILC crossing angle from 14 to 20 mrad.

Exotic decays of the 125 GeV Higgs boson at future e+e- colliders

NASA Astrophysics Data System (ADS)

Liu, Zhen; Wang, Lian-Tao; Zhang, Hao

2017-06-01

The discovery of unexpected properties of the Higgs boson would offer an intriguing opportunity to shed light on some of the most profound puzzles in particle physics. Beyond Standard Model (BSM) decays of the Higgs boson could reveal new physics in a direct manner. Future electron-positron lepton colliders operating as Higgs factories, including CEPC, FCC-ee and ILC, with the advantages of a clean collider environment and large statistics, could greatly enhance sensitivity in searching for these BSM decays. In this work, we perform a general study of Higgs exotic decays at future e+e- lepton colliders, focusing on the Higgs decays with hadronic final states and/or missing energy, which are very challenging for the High-Luminosity program of the Large Hadron Collider (HL-LHC). We show that with simple selection cuts, (10-3-10-5) limits on the Higgs exotic decay branching fractions can be achieved using the leptonic decaying spectator Z boson in the associated production mode e+e-→ ZH. We further discuss the interplay between detector performance and Higgs exotic decays, and other possibilities of exotic decays. Our work is a first step in a comprehensive study of Higgs exotic decays at future lepton colliders, which is a key area of Higgs physics that deserves further investigation. Supported by Fermi Research Alliance, LLC (DE-AC02-07CH11359) with the U.S. Department of Energy, DOE (DE-SC0013642), IHEP(Y6515580U1), and IHEP Innovation (Y4545171Y2)

Beam dynamics studies at DAΦNE: from ideas to experimental results

NASA Astrophysics Data System (ADS)

Zobov, M.; DAΦNE Team

2017-12-01

DAΦNE is the electron-positron collider operating at the energy of Φ-resonance, 1 GeV in the center of mass. The presently achieved luminosity is by about two orders of magnitude higher than that obtained at other colliders ever operated at this energy. Careful beam dynamic studies such as the vacuum chamber design with low beam coupling impedance, suppression of different kinds of beam instabilities, investigation of beam-beam interaction, optimization of the beam nonlinear motion have been the key ingredients that have helped to reach this impressive result. Many novel ideas in accelerator physics have been proposed and/or tested experimentally at DAΦNE for the first time. In this paper we discuss the advanced accelerator physics studies performed at DAΦNE.

Status of the NICA project at JINR

NASA Astrophysics Data System (ADS)

Kekelidze, Vladimir; Kovalenko, Alexandr; Lednicky, Rihard; Matveev, Viktor; Meshkov, Igor; Sorin, Alexandr; Trubnikov, Grigory

2017-03-01

The NICA (Nuclotron-based Ion Collider fAcility) project is now under active realization at the Joint Institute for Nuclear Research (JINR, Dubna). The main goal of the project is a study of hot and dense strongly interacting matter in heavy-ion (up to Au) collisions at the center-of-mass energies up to 11 GeV per nucleon. Two modes of operation are foreseen, collider mode and extracted beams, with two detectors: MPD and BM@N. The both experiments are in preparation stage. An average luminosity in the collider mode is expected to be 1027 cm-2 s-1 for Au (79+). Extracted beams of various nuclei with maximum momenta of 13 GeV/c (for protons) will be available. A study of spin physics with extracted and colliding beams of polarized deuterons and protons at energies up to 27 GeV (for protons) is foreseen with the NICA facility. The proposed program allows one to search for possible signs of phase transitions and critical phenomena as well as to shed light on the problem of the nucleon spin structure.

Optics measurement and correction during beam acceleration in the Relativistic Heavy Ion Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, C.; Marusic, A.; Minty, M.

2014-09-09

To minimize operational complexities, setup of collisions in high energy circular colliders typically involves acceleration with near constant β-functions followed by application of strong focusing quadrupoles at the interaction points (IPs) for the final beta-squeeze. At the Relativistic Heavy Ion Collider (RHIC) beam acceleration and optics squeeze are performed simultaneously. In the past, beam optics correction at RHIC has taken place at injection and at final energy with some interpolation of corrections into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats which if corrected could minimize undesirable emittance dilutions and maximizemore » the spin polarization of polarized proton beams by avoidance of higher-order multipole fields sampled by particles within the bunch. In this report the methodology now operational at RHIC for beam optics corrections during acceleration with simultaneous beta-squeeze will be presented together with measurements which conclusively demonstrate the superior beam control. As a valuable by-product, the corrections have minimized the beta-beat at the profile monitors so reducing the dominant error in and providing more precise measurements of the evolution of the beam emittances during acceleration.« less

The PHOBOS experiment at the RHIC collider

NASA Astrophysics Data System (ADS)

Katzy, Judith M.; Back, B.; Baker, M. D.; Barton, D.; Betts, R.; Białas, A.; Budzanowski, A.; Busza, W.; Carroll, A.; Chang, Y.-H.; Chen, A. E.; Coghen, T.; Czyż, W.; Decowski, M. P.; Friedl, M.; Gałuszka, K.; Ganz, R.; Garcia-Solis, E.; George, N.; Godlewski, J.; Gulbrandsen, K. H.; Gushue, S.; Halliwell, C.; Hayes, A.; Heintzelman, G.; Hołyński, R.; Holzman, B.; Jagadish, U.; Johnson, E.; Kotuła, J.; Kucewicz, W.; Kulinich, P.; Lemler, M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A.; Mülmenstädt, J.; Neal, M.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I.; Pernegger, H.; Plesko, M.; Remsberg, L. P.; Reuter, M.; Roland, G.; Rosenberg, L.; Sarin, P.; Sawicki, P.; Stanskas, P. J.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Trzupek, A.; van Nieuwenhuizen, G.; Vale, C.; Verdier, R.; Wadsworth, B.; Wolfs, F.; Wosiek, B.; Woźniak, K.; Wuosmaa, A.; Wysłouch, B.; Zalewski, K.; Phobos Collaboration

1999-12-01

PHOBOS is one of four experiments at the Relativistic Heavy Ion Collider (RHIC), scheduled to start data collection in fall 1999. Its main goal is to collect events using minimum bias triggers. A search will then be made for interesting, and perhaps rare, classes of events that may indicate the formation of a quark gluon plasma (QGP) or the restoration of chiral symmetry. In this report we describe the PHOBOS detector design and present the first results in detector development. We will also present our expectations from the first year of operation.

A review of the Fermilab fixed-target program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rameika, R.

1994-12-01

All eyes are now on the Fermilab collider program as the intense search for the top quark continues. Nevertheless, Fermilab`s long tradition of operating a strong, diverse physics program depends not only on collider physics but also on effective use of the facilities the Laboratory was founded on, the fixed-target beamlines. In this talk the author presents highlights of the Fermilab fixed-target program from its (not too distant) past, (soon to be) present, and (hopefully, not too distant) future program. The author concentrates on those experiments which are unique to the fixed-target program, in particular hadron structure measurements which usemore » the varied beams and targets available in this mode and the physics results from kaon, hyperon and high statistics charm experiments which are not easily accessible in high p{sub T} hadron collider detectors.« less

The Next Linear Collider Program

Science.gov Websites

posted to the new SLAC ILC web site http://www-project.slac.stanford.edu/ilc/. Also, see the new site for . The NLC web site will remain accessible as an archive of important work done on the many systems to be complete by the end of the calendar year. NLC Website Search: Entire SLAC Web | Help Phonebook

LONG TERM STABILITY STUDY AT FNAL AND SLAC USING BINP DEVELOPED HYDROSTATIC LEVEL SYSTEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seryi, Andrei

2003-05-28

Long term ground stability is essential for achieving the performance goals of the Next Linear Collider. To characterize ground motion on relevant time scales, measurements have been performed at three geologically different locations using a hydrostatic level system developed specifically for these studies. Comparative results from the different sites are presented in this paper.

Measurements and simulations of MAPS (Monolithic Active Pixel Sensors) response to charged particles - a study towards a vertex detector at the ILC

NASA Astrophysics Data System (ADS)

Maczewski, Lukasz

2010-05-01

The International Linear Collider (ILC) is a project of an electron-positron (e+e-) linear collider with the centre-of-mass energy of 200-500 GeV. Monolithic Active Pixel Sensors (MAPS) are one of the proposed silicon pixel detector concepts for the ILC vertex detector (VTX). Basic characteristics of two MAPS pixel matrices MIMOSA-5 (17 μm pixel pitch) and MIMOSA-18 (10 μm pixel pitch) are studied and compared (pedestals, noises, calibration of the ADC-to-electron conversion gain, detector efficiency and charge collection properties). The e+e- collisions at the ILC will be accompanied by intense beamsstrahlung background of electrons and positrons hitting inner planes of the vertex detector. Tracks of this origin leave elongated clusters contrary to those of secondary hadrons. Cluster characteristics and orientation with respect to the pixels netting are studied for perpendicular and inclined tracks. Elongation and precision of determining the cluster orientation as a function of the angle of incidence were measured. A simple model of signal formation (based on charge diffusion) is proposed and tested using the collected data.

Cosmic bubble and domain wall instabilities II: fracturing of colliding walls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braden, Jonathan; Bond, J. Richard; Mersini-Houghton, Laura, E-mail: j.braden@ucl.ac.uk, E-mail: bond@cita.utoronto.ca, E-mail: mersini@physics.unc.edu

2015-08-01

We study collisions between nearly planar domain walls including the effects of small initial nonplanar fluctuations. These perturbations represent the small fluctuations that must exist in a quantum treatment of the problem. In a previous paper, we demonstrated that at the linear level a subset of these fluctuations experience parametric amplification as a result of their coupling to the planar symmetric background. Here we study the full three-dimensional nonlinear dynamics using lattice simulations, including both the early time regime when the fluctuations are well described by linear perturbation theory as well as the subsequent stage of fully nonlinear evolution. Wemore » find that the nonplanar fluctuations have a dramatic effect on the overall evolution of the system. Specifically, once these fluctuations begin to interact nonlinearly the split into a planar symmetric part of the field and the nonplanar fluctuations loses its utility. At this point the colliding domain walls dissolve, with the endpoint of this being the creation of a population of oscillons in the collision region. The original (nearly) planar symmetry has been completely destroyed at this point and an accurate study of the system requires the full three-dimensional simulation.« less

Cosmic bubble and domain wall instabilities II: fracturing of colliding walls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braden, Jonathan; Department of Physics, University of Toronto,60 St. George Street, Toronto, ON, M5S 3H8; Department of Physics and Astronomy, University College London,Gower Street, London, WC1E 6BT

2015-08-26

We study collisions between nearly planar domain walls including the effects of small initial nonplanar fluctuations. These perturbations represent the small fluctuations that must exist in a quantum treatment of the problem. In a previous paper, we demonstrated that at the linear level a subset of these fluctuations experience parametric amplification as a result of their coupling to the planar symmetric background. Here we study the full three-dimensional nonlinear dynamics using lattice simulations, including both the early time regime when the fluctuations are well described by linear perturbation theory as well as the subsequent stage of fully nonlinear evolution. Wemore » find that the nonplanar fluctuations have a dramatic effect on the overall evolution of the system. Specifically, once these fluctuations begin to interact nonlinearly the split into a planar symmetric part of the field and the nonplanar fluctuations loses its utility. At this point the colliding domain walls dissolve, with the endpoint of this being the creation of a population of oscillons in the collision region. The original (nearly) planar symmetry has been completely destroyed at this point and an accurate study of the system requires the full three-dimensional simulation.« less

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.

Consequences of bounds on longitudinal emittance growth for the design of recirculating linear accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berg, J. S.

2015-05-03

Recirculating linear accelerators (RLAs) are a cost-effective method for the acceleration of muons for a muon collider in energy ranges from a couple GeV to a few 10s of GeV. Muon beams generally have longitudinal emittances that are large for the RF frequency that is used, and it is important to limit the growth of that longitudinal emittance. This has particular consequences for the arc design of the RLAs. I estimate the longitudinal emittance growth in an RLA arising from the RF nonlinearity. Given an emittance growth limitation and other design parameters, one can then compute the maximum momentum compactionmore » in the arcs. I describe how to obtain an approximate arc design satisfying these requirements based on the deisgn in [1]. Longitudinal dynamics also determine the energy spread in the beam, and this has consequences on the transverse phase advance in the linac. This in turn has consequences for the arc design due to the need to match beta functions. I combine these considerations to discuss design parameters for the acceleration of muons for a collider in an RLA from 5 to 63 GeV.« less

Energy dependence of polarization across broad deexcitation gamma-ray line profiles

NASA Astrophysics Data System (ADS)

Werntz, Carl; Lang, F. L.

1998-04-01

The energy profiles of deexcitation gamma-ray lines from recoiling inelastically scattered nuclei exhibit detailed structure. MeV-wide gamma-ray lines from the direction of the Orion nebula have been detected (H. Bloemen, et al., Astr. and Astrophys. L5, 281 (1994).) by COMPTEL whose source is postulated to be cosmic ray carbon and oxygen nuclei shock accelerated near supernova remnants colliding with ambient hydrogen and helium. Even when the heavy ion velocity distributions are isotropic, structure characteristic of the multipolarity of the gamma transition remains (A. M. Bykov et al, Astr. and Astrophys. 607, L37 (1996); B. Kozlovsky et al, Astrophys. J. 484, (1997).). In experiments in which the energy dependent structure of the deexcitation gamma-ray profiles is not resolved, the gammas display a high degree of linear polarization that rapidly changes with gamma-beam angle. We calculate the polarization, both linear and circular, as a function of gamma-ray energy across the laboratory line profiles of C12*(4.44) and O16*(6.13) inelastically excited by protons and alphas. We then investigate the polarization in the surviving structures for isotropic energetic ions colliding with ^1H and ^4He.

Experimental Verification of Predicted Oscillations near a Spin Resonance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolanoski, Hermann; /Humboldt U., Berlin

2011-12-05

The E166 experiment at the Stanford Linear Accelerator Center (SLAC) has demonstrated a scheme for the production of polarized positrons which is suitable for implementation in a future Linear Collider. A multi-GeV electron beam passed through a helical undulator to generate multi-MeV, circularly polarized photons which were then converted in a thin target to produce positrons (and electrons) with longitudinal polarization above 80% at 6 MeV. The results are in agreement with GEANT4 simulations that include the dominant polarization-dependent interactions of electrons, positrons and photons in matter.

Design and performance of the SLD vertex detector: a 307 Mpixel tracking system

NASA Astrophysics Data System (ADS)

Abe, K.; Arodzero, A.; Baltay, C.; Brau, J. E.; Breidenbach, M.; Burrows, P. N.; Chou, A. S.; Crawford, G.; Damerell, C. J. S.; Dervan, P. J.; Dong, D. N.; Emmet, W.; English, R. L.; Etzion, E.; Foss, M.; Frey, R.; Haller, G.; Hasuko, K.; Hertzbach, S. S.; Hoeflich, J.; Huffer, M. E.; Jackson, D. J.; Jaros, J. A.; Kelsey, J.; Lee, I.; Lia, V.; Lintern, A. L.; Liu, M. X.; Manly, S. L.; Masuda, H.; McKemey, A. K.; Moore, T. B.; Nichols, A.; Nagamine, T.; Oishi, N.; Osborne, L. S.; Russell, J. J.; Ross, D.; Serbo, V. V.; Sinev, N. B.; Sinnott, J.; Skarpaas, K. Viii; Smy, M. B.; Snyder, J. A.; Strauss, M. G.; Dong, S.; Suekane, F.; Taylor, F. E.; Trandafir, A. I.; Usher, T.; Verdier, R.; Watts, S. J.; Weiss, E. R.; Yashima, J.; Yuta, H.; Zapalac, G.

1997-02-01

This paper describes the design, construction, and initial operation of SLD's upgraded vertex detector which comprises 96 two-dimensional charge-coupled devices (CCDs) with a total of 307 Mpixel. Each pixel functions as an independent particle detecting element, providing space point measurements of charged particle tracks with a typical precision of 4 μm in each co-ordinate. The CCDs are arranged in three concentric cylinders just outside the beam-pipe which surrounds the e +e - collision point of the SLAC Linear Collider (SLC). The detector is a powerful tool for distinguishing displaced vertex tracks, produced by decay in flight of heavy flavour hadrons or tau leptons, from tracks produced at the primary event vertex. The requirements for this detector include a very low mass structure (to minimize multiple scattering) both for mechanical support and to provide signal paths for the CCDs; operation at low temperature with a high degree of mechanical stability; and high speed CCD readout, signal processing, and data sparsification. The lessons learned in achieving these goals should be useful for the construction of large arrays of CCDs or active pixel devices in the future in a number of areas of science and technology.

Every Heavenly Body When Created Will Have No Motion, Linear, Rotational and/or Vibratory Motion, Singly or in Some Combination

NASA Astrophysics Data System (ADS)

Brekke, Stewart

2010-02-01

Each galaxy, star and planet is in a state of no motion, linear, rotational and/or vibratory motion. Orbital motion is linear motion in a force field such as gravity. These motions were created in the formation of the galaxy, star or planet unless modified by external events such as colliding galaxies or impacts such as meteors. Some motions, such as rotations and vibrations may be differential such as in the cases of our sun and the Milky Way galaxy. The basic equation for each heavenly body is as follows. E = mc^2 + 1/2mv^2 + 1/2I2̂+ 1/2Kx^2 + WG+ WE+ WM. )

THE RHIC SEQUENCER.

DOE Office of Scientific and Technical Information (OSTI.GOV)

VAN ZEIJTS,J.; DOTTAVIO,T.; FRAK,B.

The Relativistic Heavy Ion Collider (RHIC) has a high level asynchronous time-line driven by a controlling program called the ''Sequencer''. Most high-level magnet and beam related issues are orchestrated by this system. The system also plays an important task in coordinated data acquisition and saving. We present the program, operator interface, operational impact and experience.

Rise time analysis of pulsed klystron-modulator for efficiency improvement of linear colliders

NASA Astrophysics Data System (ADS)

Oh, J. S.; Cho, M. H.; Namkung, W.; Chung, K. H.; Shintake, T.; Matsumoto, H.

2000-04-01

In linear accelerators, the periods during the rise and fall of a klystron-modulator pulse cannot be used to generate RF power. Thus, these periods need to be minimized to get high efficiency, especially in large-scale machines. In this paper, we present a simplified and generalized voltage rise time function of a pulsed modulator with a high-power klystron load using the equivalent circuit analysis method. The optimum pulse waveform is generated when this pulsed power system is tuned with a damping factor of ˜0.85. The normalized rise time chart presented in this paper allows one to predict the rise time and pulse shape of the pulsed power system in general. The results can be summarized as follows: The large distributed capacitance in the pulse tank and operating parameters, Vs× Tp , where Vs is load voltage and Tp is the pulse width, are the main factors determining the pulse rise time in the high-power RF system. With an RF pulse compression scheme, up to ±3% ripple of the modulator voltage is allowed without serious loss of compressor efficiency, which allows the modulator efficiency to be improved as well. The wiring inductance should be minimized to get the fastest rise time.

Gauge bosons and heavy quarks: Proceedings of Summer Institute on Particle Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hawthorne, J.F.

1991-01-01

This report contains papers on the following topics: Z decays and tests of the standard model; future possibilities for LEP; studies of the interactions of electroweak gauge bosons; top quark topics; the next linear collider; electroweak processes in hadron colliders; theoretical topics in B-physics; experimental aspects of B-physics; B-factory storage ring design; rare kaon decays; CP violation in K{sup 0} decays at CERN; recent K{sup 0} decay results from Fermilab E-731; results from LEP on heavy quark physics; review of recent results on heavy flavor production; weak matrix elements and the determination of the weak mixing angles; recent results frommore » CLEO I and a glance at CLEO II data; recent results from ARGUS; neutrino lepton physics with the CHARM 2 detector; recent results from the three TRISTAN experiments; baryon number violation at high energy in the standard model: fact or fiction New particle searches at LEP; review of QCD at LEP; electroweak interactions at LEP; recent results on W physics from the UA2 experiment at the CERN {rho}{bar {rho}} collider; B physics at CDF; and review of particle astrophysics.« less

Instrumentation status of the low-b magnet systems at the Large Hadron Collider (LHC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darve, C.; /Fermilab; Balle, C.

2011-05-01

The low-{beta} magnet systems are located in the Large Hadron Collider (LHC) insertion regions around the four interaction points. They are the key elements in the beams focusing/defocusing process allowing proton collisions at luminosity up to 10{sup 34}cm{sup -2}s{sup -1}. Those systems are a contribution of the US-LHC Accelerator project. The systems are mainly composed of the quadrupole magnets (triplets), the separation dipoles and their respective electrical feed-boxes (DFBX). The low-{beta} magnet systems operate in an environment of extreme radiation, high gradient magnetic field and high heat load to the cryogenic system due to the beam dynamic effect. Due tomore » the severe environment, the robustness of the diagnostics is primordial for the operation of the triplets. The hardware commissioning phase of the LHC was completed in February 2010. In the sake of a safer and more user-friendly operation, several consolidations and instrumentation modifications were implemented during this commissioning phase. This paper presents the instrumentation used to optimize the engineering process and operation of the final focusing/defocusing quadrupole magnets for the first years of operation.« less

Low Emittance Tuning Studies for SuperB

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liuzzo, Simone; /INFN, Pisa; Biagini, Maria

2012-07-06

SuperB[1] is an international project for an asymmetric 2 rings collider at the B mesons cm energy to be built in the Rome area in Italy. The two rings will have very small beam sizes at the Interaction Point and very small emittances, similar to the Linear Collider Damping Rings ones. In particular, the ultra low vertical emittances, 7 pm in the LER and 4 pm in the HER, need a careful study of the misalignment errors effects on the machine performances. Studies on the closed orbit, vertical dispersion and coupling corrections have been carried out in order to specifymore » the maximum allowed errors and to provide a procedure for emittance tuning. A new tool which combines MADX and Matlab routines has been developed, allowing for both corrections and tuning. Results of these studies are presented.« less

The SLAC linac as used in the SLC collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seeman, J.T.; Abrams, G.; Adolphsen, C.

The linac of the SLAC Linear Collider (SLC) must accelerate three high intensity bunches on each linac pulse from 1.2 GeV to 50 GeV with minimal increase of the small transverse emittance. The procedures and adjustments used to obtain this goal are outlined. Some of the accelerator parameters and components which interact are the beam energy, transverse position, component alignment, RF manipulation, feedback systems, quadrupole lattice, BNS damping, energy spectra, phase space matching, collimation, instrumentation and modelling. The method to bring these interdependent parameters collectively into specification has evolved over several years. This review is ordered in the sequence whichmore » is used to turn on the linac from a cold start and produce acceptable beams for the final focus and collisions. Approximate time estimates for the various activities are given. 21 refs.« less

Fission and fusion scenarios for magnetic microswimmer clusters

PubMed Central

Guzmán-Lastra, Francisca; Kaiser, Andreas; Löwen, Hartmut

2016-01-01

Fission and fusion processes of particle clusters occur in many areas of physics and chemistry from subnuclear to astronomic length scales. Here we study fission and fusion of magnetic microswimmer clusters as governed by their hydrodynamic and dipolar interactions. Rich scenarios are found that depend crucially on whether the swimmer is a pusher or a puller. In particular a linear magnetic chain of pullers is stable while a pusher chain shows a cascade of fission (or disassembly) processes as the self-propulsion velocity is increased. Contrarily, magnetic ring clusters show fission for any type of swimmer. Moreover, we find a plethora of possible fusion (or assembly) scenarios if a single swimmer collides with a ringlike cluster and two rings spontaneously collide. Our predictions are obtained by computer simulations and verifiable in experiments on active colloidal Janus particles and magnetotactic bacteria. PMID:27874006

Making beam splitters with dark soliton collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steiglitz, Ken

2010-10-15

We show with numerical simulations that for certain simple choices of parameters, the waveguides induced by colliding dark solitons in a Kerr medium yield a complete family of beam splitters for trapped linear waves, ranging from total transmission to total deflection. The way energy is transferred from one waveguide to another is similar to that of a directional coupler, but no special fabrication is required. Dark soliton beam splitters offer potential advantages over their bright soliton counterparts: Their transfer characteristics do not depend on the relative phase or speed of the colliding solitons; dark solitons are generally more robust thanmore » bright solitons; and the probe peaks at nulls of the pump, enhancing the signal-to-noise ratio for probe detection. The last factor is especially important for possible application to quantum information processing.« less

Pursuing the Secrets of Matter, Space and Time at the Energy Frontier

NASA Astrophysics Data System (ADS)

Grannis, Paul

2003-04-01

Particle physicists have made good progress in characterizing the fundamental forces of Nature and the elementary constituents of matter, and these phenomena shaped the universe in its earliest moments. However, what we know now is likely quite incomplete, and new ingredients are expected to surface in accelerator experiments over the coming twenty years. The new results are expected to give us insights into the nature of physics at much higher energies, and thus at earlier epochs in the universe, than are probed directly and may reveal new complexity in the nature of space and time. We will discuss the nature of the new results to be expected at the expanding energy frontier from experimental programs at the Fermilab Tevatron, the CERN Large Hadron Collider, and a TeV scale electron-positron linear collider.

Exploring the Universe Within

ScienceCinema

John Marburger

2017-12-09

A guided tour of Brookhaven's Relativistic Heavy Ion Collider (RHIC) conducted by past Laboratory Director John Marburger. RHIC is a world-class scientific research facility that began operation in 2000, following 10 years of development and construction.

Passive detection of subpixel obstacles for flight safety

NASA Astrophysics Data System (ADS)

Nixon, Matthew D.; Loveland, Rohan C.

2001-12-01

Military aircraft fly below 100 ft. above ground level in support of their missions. These aircraft include fixed and rotary wing and may be manned or unmanned. Flying at these low altitudes presents a safety hazard to the aircrew and aircraft, due to the occurrences of obstacles within the aircraft's flight path. The pilot must rely on eyesight and in some cases, infrared sensors to see obstacles. Many conditions can exacerbate visibility creating a situation in which obstacles are essentially invisible, creating a safety hazard, even to an alerted aircrew. Numerous catastrophic accidents have occurred in which aircraft have collided with undetected obstacles. Accidents of this type continue to be a problem for low flying military and commercial aircraft. Unmanned Aerial Vehicles (UAVs) have the same problem, whether operating autonomously or under control of a ground operator. Boeing-SVS has designed a passive, small, low- cost (under $100k) gimbaled, infrared imaging based system with advanced obstacle detection algorithms. Obstacles are detected in the infrared band, and linear features are analyzed by innovative cellular automata based software. These algorithms perform detection and location of sub-pixel linear features. The detection of the obstacles is performed on a frame by frame basis, in real time. Processed images are presented to the aircrew on their display as color enhanced features. The system has been designed such that the detected obstacles are displayed to the aircrew in sufficient time to react and maneuver the aircraft to safety. A patent for this system is on file with the US patent office, and all material herein should be treated accordingly.

Beyond the Standard Model IV

NASA Astrophysics Data System (ADS)

Gunion, John F.; Han, Tao; Ohnemus, James

1995-08-01

The Table of Contents for the book is as follows: * Preface * Organizing and Advisory Committees * PLENARY SESSIONS * Looking Beyond the Standard Model from LEP1 and LEP2 * Virtual Effects of Physics Beyond the Standard Model * Extended Gauge Sectors * CLEO's Views Beyond the Standard Model * On Estimating Perturbative Coefficients in Quantum Field Theory and Statistical Physics * Perturbative Corrections to Inclusive Heavy Hadron Decay * Some Recent Developments in Sphalerons * Searching for New Matter Particles at Future Colliders * Issues in Dynamical Supersymmetry Breaking * Present Status of Fermilab Collider Accelerator Upgrades * The Extraordinary Scientific Opportunities from Upgrading Fermilab's Luminosity ≥ 1033 cm-2 sec-1 * Applications of Effective Lagrangians * Collider Phenomenology for Strongly Interacting Electroweak Sector * Physics of Self-Interacting Electroweak Bosons * Particle Physics at a TeV-Scale e+e- Linear Collider * Physics at γγ and eγ Colliders * Challenges for Non-Minimal Higgs Searchers at Future Colliders * Physics Potential and Development of μ+μ- Colliders * Beyond Standard Quantum Chromodynamics * Extracting Predictions from Supergravity/Superstrings for the Effective Theory Below the Planck Scale * Non-Universal SUSY Breaking, Hierarchy and Squark Degeneracy * Supersymmetric Phenomenology in the Light of Grand Unification * A Survey of Phenomenological Constraints on Supergravity Models * Precision Tests of the MSSM * The Search for Supersymmetry * Neutrino Physics * Neutrino Mass: Oscillations and Hot Dark Matter * Dark Matter and Large-Scale Structure * Electroweak Baryogenesis * Progress in Searches for Non-Baryonic Dark Matter * Big Bang Nucleosynthesis * Flavor Tests of Quark-Lepton * Where are We Coming from? What are We? Where are We Going? * Summary, Perspectives * PARALLEL SESSIONS * SUSY Phenomenology I * Is Rb Telling us that Superpartners will soon be Discovered? * Dark Matter in Constrained Minimal Supersymmetry * A Fourth Family in the MSSM? * Multi-channel Search for Supergravity at the Large Hadron Collider * Precise Predictions for Masses and Couplings in the Minimal Supersymmetric Standard Model * Radiative b Decays and the Detection of Supersymmetric Dark Matter * Bounds on ΔB = 1 Couplings in the Supersymmetric Standard Model * Testing Supersymmetry at the Next Linear Collider * SUSY Phenomenology II * Is There a Light Gluino Window? * Soft Supersymmetry Breaking and Finiteness * Consequences of Low Energy Dynamical Supersymmetry Breaking * String Model Theory and Phenomenology * Z2 × Z2 Orbifold Compactification - the Origin of Realistic Free Fermionic Models * Effective Supergravity from 4-D Fermionic Strings * String Models Featuring Direct Product Unification * Hadronic and Non-Perturbative Physics * Salient Features of High-Energy Multiparticle Distributions: 1-d Ising Model Captures Them All * Pion Fusion in the Equivalent Pion Approximation * Deterministic Theory of Atomic Structure * Disoriented Chiral Condensate * Higgs Physics * The LHC Phenomenology of the CP-Odd Scalar in Two-Doublet Models * Detection of Minimal Supersymmetric Model Higgs Bosons in γγ Collisions: Influence of SUSY Decay Modes * Electroweak Corrections to the Charged Higgs Production Cross-Section * A Comparison of Higgs Mass Bounds in the SM and the MSSM * Searching for Higgs Bosons on LHC Using b-Tagging * Top Quark and Flavor Physics * Flavor Mixing, CP Violation and a Heavy Top * New Fermion Families and Precision Electroweak Data * Dipole Operator Phenomenology and Quark Mass Generation: An Update * Possible Higgs Boson Effects on the Running of Third and Fourth Generation Quark Masses and Mixings * How the Top Family Differs * Fermion Masses in Extended Technicolour * New Developments in Perturbative QCD * Efficient Analytic Computation of Higher-Order QCD Amplitudes * Use of Recursion Relations to Compute One-Loop Helicity Amplitudes * Gluon Radiation Patterns in Hard Scattering Events * B Physics * Inclusive Hadronic Production of the Bc Meson via Heavy Quark Fragmentation * Helicity Probabilities for Heavy Quark Fragmentation into Heavy-Light Excited Mesons * Hadronic Penguins in B Decays and Extraction of α, β and γ * CP Violation Physics * Maximum Likelihood Method for New Physics Mixing Angles, and Projections to Using B Factory Results * CP Violation in Fermionic Decays of Higgs Bosons * Test of CP Violation in Non-Leptonic Hyperon Decays * CP Violation in the Weinberg Multi-Higgs Model * Triple-Product Spin-Momentum Correlations in Polarized Z Decays to Three Jets * Radiative CP Violation * HERA Results * A Search for Leptoquarks and Squarks in H1 at HERA * Search for Leptoquarks in ep Collisions at √ {s}=296; {GeV} * Search for Excited Fermions in ep Collisions at √ {s}=296; {GeV} * Tevatron Results * Measurement of Diboson Production at the Tevatron Collider with D0 * Search for SUSY in D0 * Search for SUSY at CDF * Search for First and Second Generation Leptoquarks with the D0 Detector * Search for Exotic Particles at CDF * e+e- and μ+μ- Physics * Aspects of Higgs Boson Searches * Measurements of the Forward-Backward Asymmetry of Quarks in the DELPHI Experiment at LEP * Astrophysics, Dark Matter, Cosmology and Neutrino Physics * A Model Independent Approach to Future Solar Neutrino Experiments * Neutrino Oscillations with Beams from AGN's and GRB's * Implication of Macho Detections for Dark Matter Searches * Chiral Restoration in the Early Universe: Pion Halo in the Sky * SEWS, Anomalous Couplings, and Precision EW * Do WL and H form a P-Wave Bound State? * An Update on Strong WLWL Scattering at the LHC * The Difficulties Involved in Calculating δρ * What Can We Learn from the Measurement R_{b}≡Γ(Z → bbar{b}/Γ(Z → Hadrons)? * Gauge Invariance and Anomalous Gauge Boson Couplings * Probing the Standard Model with Hadronic WZ Production * Consequences of Recent Electroweak Data and W-Mass for the Top Quark and Higgs Masses * Equivalence Theorem as a Criterion for Probing the Electroweak Symmetry Breaking Mechanism * Conference Schedule * Schedule of the Parallel Sessions * List of Participants

High-Energy QCD Asymptotics of Photon-Photon Collisions

NASA Astrophysics Data System (ADS)

Brodsky, S. J.; Fadin, V. S.; Kim, V. T.; Lipatov, L. N.; Pivovarov, G. B.

2002-07-01

The high-energy behaviour of the total cross section for highly virtual photons, as predicted by the BFKL equation at next-to-leading order (NLO) in QCD, is discussed. The NLO BFKL predictions, improved by the BLM optimal scale setting, are in good agreement with recent OPAL and L3 data at CERN LEP2. NLO BFKL predictions for future linear colliders are presented.

CARE activities on superconducting RF cavities at INFN Milano

NASA Astrophysics Data System (ADS)

Bosotti, A.; Pierini, P.; Michelato, P.; Pagani, C.; Paparella, R.; Panzeri, N.; Monaco, L.; Paulon, R.; Novati, M.

2005-09-01

The SC RF group at INFN Milano-LASA is involved both in the TESLA/TTF collaboration and in the research and design activity on superconducting cavities for proton accelerators. Among these activities, some are supported by the European community within the CARE project. In the framework of the JRASRF collaboration we are developing a coaxial blade tuner for ILC (International Linear Collider) cavities, integrated with piezoelectric actuators for the compensation of the Lorenz force detuning and microphonics perturbation. Another activity, regarding the improved component design on SC technology, based on the information retrieving about the status of art on ancillaries and experience of various laboratories involved in SCRF, has started in our laboratory. Finally, in the framework of the HIPPI collaboration, we are testing two low beta superconducting cavities, built for the Italian TRASCO project, to verify the possibility to use them for pulsed operation. All these activities will be described here, together with the main results and the future perspectives.

Numerical evaluation of mobile robot navigation in static indoor environment via EGAOR Iteration

NASA Astrophysics Data System (ADS)

Dahalan, A. A.; Saudi, A.; Sulaiman, J.; Din, W. R. W.

2017-09-01

One of the key issues in mobile robot navigation is the ability for the robot to move from an arbitrary start location to a specified goal location without colliding with any obstacles while traveling, also known as mobile robot path planning problem. In this paper, however, we examined the performance of a robust searching algorithm that relies on the use of harmonic potentials of the environment to generate smooth and safe path for mobile robot navigation in a static known indoor environment. The harmonic potentials will be discretized by using Laplacian’s operator to form a system of algebraic approximation equations. This algebraic linear system will be computed via 4-Point Explicit Group Accelerated Over-Relaxation (4-EGAOR) iterative method for rapid computation. The performance of the proposed algorithm will then be compared and analyzed against the existing algorithms in terms of number of iterations and execution time. The result shows that the proposed algorithm performed better than the existing methods.

Improving Higgs coupling measurements through ZZ Fusion at the ILC

DOE PAGES

Han, Tao; Liu, Zhen; Qian, Zhuoni; ...

2015-06-17

In this study, we evaluate the e -e + → e -e + + h process through the ZZ fusion channel at the International Linear Collider operating at 500 GeV and 1 TeV center-of-mass energies. We perform realistic simulations on the signal process and background processes. With judicious kinematic cuts, we find that the inclusive cross section can be measured to 2.9% after combining the 500 GeV at 500 fb -1 and 1 TeV at 1 ab -1 runs. A multivariate log-likelihood analysis further improves the precision of the cross section measurement to 2.3%. We discuss the overall improvement to model-independent Higgs width andmore » coupling determinations and demonstrate the use of different channels in distinguishing new physics effects in Higgs physics. Our study demonstrates the importance of the ZZ fusion channel to Higgs precision physics, which has often been neglected in the literature.« less

New physics at the TeV scale

NASA Astrophysics Data System (ADS)

Chakdar, Shreyashi

The Standard Model of particle physics is assumed to be a low-energy effective theory with new physics theoretically motivated to be around TeV scale. The thesis presents theories with new physics beyond the Standard Model in the TeV scale testable in the colliders. Work done in chapters 2, 3 and 5 in this thesis present some models incorporating different approaches of enlarging the Standard Model gauge group to a grand unified symmetry with each model presenting its unique signatures in the colliders. The study on leptoquarks gauge bosons in reference to TopSU(5) model in chapter 2 showed that their discovery mass range extends up to 1.5 TeV at 14 TeV LHC with luminosity of 100 fb--1. On the other hand, in chapter 3 we studied the collider phenomenology of TeV scale mirror fermions in Left-Right Mirror model finding that the reaches for the mirror quarks goes upto 750 GeV at the 14 TeV LHC with 300 fb--1 luminosity. In chapter 4 we have enlarged the bosonic symmetry to fermi-bose symmetry e.g. supersymmetry and have shown that SUSY with non-universalities in gaugino or scalar masses within high scale SUGRA set up can still be accessible at LHC with 14 TeV. In chapter 5, we performed a study in respect to the e+e-- collider and find that precise measurements of the higgs boson mass splittings up to ˜ 100 MeV may be possible with high luminosity in the International Linear Collider (ILC). In chapter 6 we have shown that the experimental data on neutrino masses and mixings are consistent with the proposed 4/5 parameter Dirac neutrino models yielding a solution for the neutrino masses with inverted mass hierarchy and large CP violating phase delta and thus can be tested experimentally. Chapter 7 of the thesis incorporates a warm dark matter candidate in context of two Higgs doublet model. The model has several testable consequences at colliders with the charged scalar and pseudoscalar being in few hundred GeV mass range. This thesis presents an endeavor to study beyond standard model physics at the TeV scale with testable signals in the Colliders.

Proceedings of the Eleventh International Conference on Calorimetry in Particle Physics

NASA Astrophysics Data System (ADS)

Cecchi, Claudia

The Pamela silicon tungsten calorimeter / G. Zampa -- Design and development of a dense, fine grained silicon tungsten calorimeter with integrated electronics / D. Strom -- High resolution silicon detector for 1.2-3.1 eV (400-1000 nm) photons / D. Groom -- The KLEM high energy cosmic rays collector for the NUCLEON satellite mission / M. Merkin (contribution not received) -- The electromagnetic calorimeter of the Hera-b experiment / I. Matchikhilian -- The status of the ATLAS tile calorimeter / J. Mendes Saraiva -- Design and mass production of Scintillator Pad Detector (SPD) / Preshower (PS) detector for LHC-b experiment / E. Gushchin -- Study of new FNAL-NICADD extruded scintillator as active media of large EMCal of ALICE at LHC / O. Grachov -- The CMS hadron calorimeter / D. Karmgard (contribution not received) -- Test beam study of the KOPIO Shashlyk calorimeter prototype / A. Poblaguev -- The Shashlik electro-magnetic calorimeter for the LHCb experiment / S. Barsuk -- Quality of mass produced lead-tungstate crystals / R. Zhu -- Status of the CMS electromagnetic calorimeter / J. Fay -- Scintillation detectors for radiation-hard electromagnetic calorimeters / H. Loehner -- Energy, timing and two-photon invariant mass resolution of a 256-channel PBWO[symbol] calorimeter / M. Ippolitov -- A high performance hybrid electromagnetic calorimeter at Jefferson Lab / A. Gasparian -- CsI(Tl) calorimetry on BESHI / T. Hu (contribution not received) -- The crystal ball and TAPS detectors at the MAMI electron beam facility / D. Watts -- Front-end electronics of the ATLAS tile calorimeter / R. Teuscher -- The ATLAS tilecal detector control system / A. Gomes -- Performance of the liquid argon final calibration board / C. de la Taille -- Overview of the LHCb calorimeter electronics / F. Machefert -- LHCb preshower photodetector and electronics / S. Monteil -- The CMS ECAL readout architecture and the clock and control system / K. Kloukinas -- Test of the CMS-ECAL trigger primitive generation / N. Regnault -- Optical data links for the CMS ECAL / J. Grahl (contribution not received) -- CMS ECAL off-detector electronics / R. Alemany Fernandez -- Performance of a low noise readout ASIC for the W-Si calorimeter physics prototype for the future linear collider / C. de la Taille -- Properties of a sampling calorimeter with warm-liquid ionization chambers / S. Plewnia -- Calorimetry and the DO experiment / R. Zitoun (contribution not received) -- Data quality monitoring for the DØ calorimeter / V. Shary -- Status of the construction of the ATLAS electromagnetic liquid argon calorimeter, overview of beam test performance studies / L. Serin -- Uniformity of response of ATLAS liquid argon EM calorimeter / O. Gaunter -- Status of the ATLAS liquid argon hadronic endcap calorimeter construction / M. Vincter -- Results from particle beam tests of the ATLAS liquid argon endcap calorimeters / M. Lefebvre -- First results of the DREAM project / R. Wigmans -- Electron and muon detection with a dual-readout (DREAM) calorimeter / N. Akchurin -- The neutron zero degree calorimeter for the ALICE experiment / M. Gallio -- The liquid xenon scintillation calorimeter of the MEG experiment: operation of a large prototype / G. Signorelli -- Detection of high energy particles using radio frequency signals / C. Hebert -- Hadronic shower simulation / J.-P. Wellisch -- E.M. and hadronic shower simulation with FLUKA / G. Battistoni -- Simulation of the LHCb electromagnetic calorimeter response with GEANT4 / P. Robbe -- Comparison of beam test results of the combined ATLAS liquid argon endcap calorimeters with GEANT3 and GEANT4 simulations / D. Salihagić -- GEANT4 hadronic physics validation with LHC test-beam data / C. Alexa -- The full simulation of the GLAST LAT high energy gamma ray telescope / F. Longo -- Response of the KLOE electromagnetic calorimeter to low-energy particles / T. Spadaro -- Calorimeter algorithms for DØ; / S. Trincaz-Duvoid -- Identification of low P[symbol] muon with the ATLAS tile calorimeter / G. Usai -- Electron and photon reconstruction with fully simulated events in the CMS experiment / G. Daskalakis -- Expected performance of Jet, [symbol] and [symbol] reconstruction in ATLAS / I. Vivarelli -- LHCb calorimeter from trigger to physics / O. Deschamps -- The calibration strategy of CMS electromagnetic calorimeter / P. Meridiani -- Energy and impact point reconstruction in the CMS ECAL (testbeam results from 2003) / I. B. van Vulpen -- The jet energy scale and resolution in the DO calorimeter / A. Kupco (contribution not received) -- Precision linearity studies of the ATLAS liquid argon EM calorimeter / G. Graziani -- Calibration of the ATLAS tile calorimeter / F. Sarri -- Performance of the CMS ECAL laser monitoring source in the test beam / A. Bornheim -- Energy reconstruction algorithms and their influence on the ATLAS tile calorimeter / E. Fullana -- Study of the biological effectiveness of ionizing radiations for a more realistic evaluation of the radiation quality in hadrontherapy / R. Cherubini (contribution not received) -- New dosimetry technologies for IMRT (Intensity Modulated Radio Therapy) / A. Piermattei -- Photon neutron radiotherapy / G. Giannini (contribution not received) -- Recent developments in molecular imaging / G. Zavattini (contribution not received) -- Performance goals and design considerations for a linear collider calorimeter / F. Sefkow -- Improving the jet reconstruction with the particle flow method; an introduction / J.-C. Brient -- Fine grained SiW ECAL for a linear collider detector / D. Strom (in the silicon session) -- Silicon-tungsten sampling electromagnetic calorimeter for the TeV electron-positron linear collider / J.-C. Brient -- LCCAL: a calorimeter prototype for future linear colliders / S. Miscetti -- Analog vs digital hadron calorimetry at a future electron-positron linear collider / S. Magill -- Toward a scintillator based heal and tail catcher for the LC calorimeter / M. Martin (contribution not received) -- Minical options, description in MC, calibration, plans for test beam prototype / G. Eigen (contribution not received) -- Photodetector options for a scintillator heal / E. Popova (contribution not received) -- Very low background scintillators in DAMA project: results and perspectives / R. Bernabei -- EDELWEISS Ge cryogenics detectors: main performance and physics results / X. Navick (contribution not received) -- Review of massive underground detectors / A. Rubbia -- Review of neutrino telescopes underwater and under ice / A. Capone (contribution not received) -- The fluorescence detector of the Pierre Auger Observatory / R. Caruso -- The EUSO mission for the observation of ultra high energy cosmic rays from space / A. Petrolini -- Performance of a 3D imaging electromagnetic calorimeter for the AMSO2 space experiment / C. Adloff -- Beam test calibration of the balloon borne imaging calorimeter for the CREAM experiment / P. Maestro.

Compensation of head-on beam-beam induced resonance driving terms and tune spread in the Relativistic Heavy Ion Collider

DOE PAGES

Fischer, W.; Gu, X.; Drees, K. A.; ...

2017-09-13

A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory [Phys. Rev. Lett. 115, 264801 (2015)]. The compensation consists of electron lenses for the reduction of the beam-beam induced tune spread, and a lattice for the minimization of beam-beam generated resonance driving terms. We describe the implementations of the lattice and electron lenses, and report on measurements of lattice properties and the effect of the electron lenses on the hadron beam.

Compensation of head-on beam-beam induced resonance driving terms and tune spread in the Relativistic Heavy Ion Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, W.; Gu, X.; Drees, K. A.

A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory [Phys. Rev. Lett. 115, 264801 (2015)]. The compensation consists of electron lenses for the reduction of the beam-beam induced tune spread, and a lattice for the minimization of beam-beam generated resonance driving terms. We describe the implementations of the lattice and electron lenses, and report on measurements of lattice properties and the effect of the electron lenses on the hadron beam.

Thermal issues at the SSC

NASA Technical Reports Server (NTRS)

Ranganathan, Raj P.; Dao, Bui V.

1992-01-01

A variety of heat transfer problems arise in the design of the Superconducting Super Collider (SSC). One class of problems is to minimize heat leak from the ambient to the SSC rings, since the rings contain superconducting magnets maintained at a temperature of 4 K. Another arises from the need to dump the beam of protrons (traveling around the SSC rings) on to absorbers during an abort of the collider. Yet another category of problems is the cooling of equipment to dissipate the heat generated during operation. An overview of these problems and sample heat transfer results are given in this paper.

10 CFR 605.5 - The Office of Energy Research Financial Assistance Program.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) Scientific Computing Staff (7) Superconducting Super Collider (8) University and Science Education Programs... appendix A of this part. (b) The Program areas are: (1) Basic Energy Sciences (2) Field Operations...

10 CFR 605.5 - The Office of Energy Research Financial Assistance Program.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) Scientific Computing Staff (7) Superconducting Super Collider (8) University and Science Education Programs... appendix A of this part. (b) The Program areas are: (1) Basic Energy Sciences (2) Field Operations...

10 CFR 605.5 - The Office of Energy Research Financial Assistance Program.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) Scientific Computing Staff (7) Superconducting Super Collider (8) University and Science Education Programs... appendix A of this part. (b) The Program areas are: (1) Basic Energy Sciences (2) Field Operations...

10 CFR 605.5 - The Office of Energy Research Financial Assistance Program.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) Scientific Computing Staff (7) Superconducting Super Collider (8) University and Science Education Programs... appendix A of this part. (b) The Program areas are: (1) Basic Energy Sciences (2) Field Operations...

Probing the Higgs with angular observables at future e +e – colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Zhen

In this paper, I summarize our recent works on using differential observables to explore the physics potential of future e +e – colliders in the framework of Higgs effective field theory. This proceeding is based upon Refs. 1 and 2. We study angular observables in the e +e – → ZHℓ +ℓ –bmore » $$\\bar{b}$$ channel at future circular e +e – colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy √s = 240 GeV and 5 (30) ab –1 integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for the Higgsstrahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of constraining the “blind spot” in indirect limits on supersymmetric scalar top partners. Finally, we also discuss the possibility of using ZZ-fusion at e +e – machines at different energies to probe new operators.« less

Probing the Higgs with angular observables at future e +e – colliders

DOE PAGES

Liu, Zhen

2016-10-24

In this paper, I summarize our recent works on using differential observables to explore the physics potential of future e +e – colliders in the framework of Higgs effective field theory. This proceeding is based upon Refs. 1 and 2. We study angular observables in the e +e – → ZHℓ +ℓ –bmore » $$\\bar{b}$$ channel at future circular e +e – colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy √s = 240 GeV and 5 (30) ab –1 integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for the Higgsstrahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of constraining the “blind spot” in indirect limits on supersymmetric scalar top partners. Finally, we also discuss the possibility of using ZZ-fusion at e +e – machines at different energies to probe new operators.« less

Progress towards next generation hadron colliders: FCC-hh, HE-LHC, and SPPC

NASA Astrophysics Data System (ADS)

Zimmermann, Frank; EuCARD-2 Extreme Beams Collaboration; Future Circular Collider (FCC) Study Collaboration

2017-01-01

A higher-energy circular proton collider is generally considered to be the only path available in this century for exploring energy scales well beyond the reach of the Large Hadron Collider (LHC) presently in operation at CERN. In response to the 2013 Update of the European Strategy for Particle Physics and aligned with the 2014 US ``P5'' recommendations, the international Future Circular Collider (FCC) study, hosted by CERN, is designing such future frontier hadron collider. This so-called FCC-hh will provide proton-proton collisions at a centre-of-mass energy of 100 TeV, with unprecedented luminosity. The FCC-hh energy goal is reached by combining higher-field, 16 T magnets, based on Nb3Sn superconductor, and a new 100 km tunnel connected to the LHC complex. In addition to the FCC-hh proper, the FCC study is also exploring the possibility of a High-Energy LHC (HE-LHC), with a centre-of-mass energy of 25-27 TeV, as could be achieved in the existing 27 km LHC tunnel using the FCC-hh magnet technology. A separate design effort centred at IHEP Beijing aims at developing and constructing a similar collider in China, with a smaller circumference of about 54 km, called SPPC. Assuming even higher-field 20 T magnets, by relying on high-temperature superconductor, the SPPC could reach a c.m. energy of about 70 TeV. This presentation will report the motivation and the present status of the R&D for future hadron colliders, a comparison of the three designs under consideration, the major challenges, R&D topics, the international technology programs, and the emerging global collaboration. Work supported by the European Commission under Capacities 7th Framework Programme project EuCARD-2, Grant Agreement 312453, and the HORIZON 2020 project EuroCirCol, Grant Agreement 654305.

Etude Experimentale du Photo-Injecteur de Fermilab (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carneiro, Jean-Paul

2001-01-01

TESLA (TeV Superconducting Linear Accelerator) is an international collaboration which is studying the feasibility of anmore » $e^+e^-$ collider of energy 0.8 TeV in the center of mass. One of the first goals of this collaboration was to construct a prototype linear accelerator at the DESY Laboratory in Hamburg, the TESLA Test Facility (TTF), in order to establish the technical basis for the collider. Two injectors were developed for TTF: a thermionic injector (developed by LAL-Orsay, IPN-Orsay, and CEA-Saclay) and a photo-injector (developed by Fermilab). The thermionic injector was used from February 1997 to October 1998, and then it was replaced by the photo-injector, which was first operated in December 1998. Another photo-injector, identical to the one delivered to TTF, was installed at Fermilab in the $$A{\\emptyset}$$ Building. The first beam from the latter was produced on 3 March 1999. The photo-injector consists of an RF gun, followed by a superconducting cavity. The RF gun is a 1.625-cell copper cavity with a resonant frequency of 1.3 GHz. The gun contains a cesium telluride ($$C_{s_2}$$Te) photo-cathode, which is illuminated by UV pulses from a Nd:YLF laser. The system can produce trains of 800 bunches of photo-electrons of charge 8 nC per bunch with spacing between bunches of 1$$\\mu$$s and 10 Hz repetition rate. Upon emerging from the RF gun, the beam energy is 4 to 5 MeV; the beam is then rapidly accelerated by the superconducting cavity to an energy of 17 to 20 MeV. Finally, a magnetic chicane, consisting of 4 dipoles, produces longitudinal compression of the electron bunches. This thesis describes the installation of the photo-injector at Fermilab and presents the experimentally-measured characteristics of the injector. The principal measurements were quantum eciency, dark current, transverse emittance, and bunch length. The conclusion from these studies is that the quality of the photo-injector beam fullls the design goals. The photo-injector at Fermilab is presently available for user experiments, including the production of at beams and plasma wake eld acceleration.« less

AMY trigger system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakai, Yoshihide

1989-04-01

A trigger system of the AMY detector at TRISTAN e{sup +}e{sup -} collider is described briefly. The system uses simple track segment and shower cluster counting scheme to classify events to be triggered. It has been operating successfully since 1987.

Study of cluster shapes in a monolithic active pixel detector

NASA Astrophysics Data System (ADS)

Maçzewski, ł.; Adamus, M.; Ciborowski, J.; Grzelak, G.; łużniak, P.; Nieżurawski, P.; Żarnecki, A. F.

2009-11-01

Beamstrahlung will constitute an important source of background in a pixel vertex detector at the future International Linear Collider. Electron and positron tracks of this origin impact the pixel planes at angles generally larger than those of secondary hadrons and the corresponding clusters are elongated. We report studies of cluster characteristics using test beam electron tracks incident at various angles on a MIMOSA-5 monolithic active pixel sensor matrix.

Signals for Extra Dimensions at CLIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rizzo, Thomas G.

A brief overview is presented of the signatures for several different models with extra dimensions at CLIC, an e{sup +}e{sup -} linear collider with a center of mass energy of 3-5 TeV and an integrated luminosity of order 1 ab{sup -1}. In all cases the search reach for the resulting new physic signatures is found to be in the range of {approx} 15-80 TeV.

Evaluation of an Integrated Read-Out Layer Prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abu-Ajamieh, Fayez

2011-07-01

This thesis presents evaluation results of an Integrated Read-out Layer (IRL), a proposed concept in scintillator-based calorimetry intended to meet the exceptional calorimetric requirements of the envisaged International Linear Collider (ILC). This study presents a full characterization of the prototype IRL, including exploration of relevant parameters, calibration performance, and the uniformity of response. The study represents proof of the IRL concept. Finally, proposed design enhancements are presented.

Evaluation of an Integrated Read-Out Layer Prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abu-Ajamieh, Fayez; /NIU

2011-08-18

This thesis presents evaluation results of an Integrated Read-out Layer (IRL), a proposed concept in scintillator-based calorimetry intended to meet the exceptional calorimetric requirements of the envisaged International Linear Collider (ILC). This study presents a full characterization of the prototype IRL, including exploration of relevant parameters, calibration performance, and the uniformity of response. The study represents proof of the IRL concept. Finally, proposed design enhancements are presented.

Characteristics of compound multiplicity in 84Kr36 with various light and heavy targets at 1 GeV per nucleon

NASA Astrophysics Data System (ADS)

Chouhan, N. S.; Singh, M. K.; Singh, V.; Pathak, R.

2013-12-01

Interactions of 84Kr36 having kinetic energy around 1 GeV per nucleon with NIKFI BR-2 nuclear emulsion detector's target reveal some of the important features of compound multiplicity. Present article shows that width of compound multiplicity distributions and value of mean compound multiplicity have linear relationship with mass number of the projectile colliding system.

Detectors for Linear Colliders: Tracking and Vertexing (2/4)

ScienceCinema

Battaglia, Marco

2018-04-16

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.

Repeated crossing of two concentric spherical thin-shells with charge

NASA Astrophysics Data System (ADS)

Mazharimousavi, S. Habib; Halilsoy, M.

Interaction/collision of two concentric spherical thin-shells of linear fluid resulting in collapse has been considered recently. We show that addition of finely tuned electric charges on the shells apart from the cosmological constant serves to delay the collapse indefinitely, yielding an ever colliding system of two concentric fluid shells. Given the finely tuned charges, this provides an example of a perpetual two-body motion in general relativity.

Electron cloud buildup driving spontaneous vertical instabilities of stored beams in the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Romano, Annalisa; Boine-Frankenheim, Oliver; Buffat, Xavier; Iadarola, Giovanni; Rumolo, Giovanni

2018-06-01

At the beginning of the 2016 run, an anomalous beam instability was systematically observed at the CERN Large Hadron Collider (LHC). Its main characteristic was that it spontaneously appeared after beams had been stored for several hours in collision at 6.5 TeV to provide data for the experiments, despite large chromaticity values and high strength of the Landau-damping octupole magnet. The instability exhibited several features characteristic of those induced by the electron cloud (EC). Indeed, when LHC operates with 25 ns bunch spacing, an EC builds up in a large fraction of the beam chambers, as revealed by several independent indicators. Numerical simulations have been carried out in order to investigate the role of the EC in the observed instabilities. It has been found that the beam intensity decay is unfavorable for the beam stability when LHC operates in a strong EC regime.

Heavy quarkonium production at collider energies: Factorization and evolution

NASA Astrophysics Data System (ADS)

Kang, Zhong-Bo; Ma, Yan-Qing; Qiu, Jian-Wei; Sterman, George

2014-08-01

We present a perturbative QCD factorization formalism for inclusive production of heavy quarkonia of large transverse momentum, pT at collider energies, including both leading power (LP) and next-to-leading power (NLP) behavior in pT. We demonstrate that both LP and NLP contributions can be factorized in terms of perturbatively calculable short-distance partonic coefficient functions and universal nonperturbative fragmentation functions, and derive the evolution equations that are implied by the factorization. We identify projection operators for all channels of the factorized LP and NLP infrared safe short-distance partonic hard parts, and corresponding operator definitions of fragmentation functions. For the NLP, we focus on the contributions involving the production of a heavy quark pair, a necessary condition for producing a heavy quarkonium. We evaluate the first nontrivial order of evolution kernels for all relevant fragmentation functions, and discuss the role of NLP contributions.

Implications of the 750 GeV γγ Resonance as a Case Study for the International Linear Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujii, Keisuke; Grojean, Christophe; Peskin, Michael E.

If the γγ resonance at 750 GeV suggested by 2015 LHC data turns out to be a real effect, what are the implications for the physics case and upgrade path of the International Linear Collider? Whether or not the resonance is confirmed, this question provides an interesting case study testing the robustness of the ILC physics case. In this note, we address this question with two points: (1) Almost all models proposed for the new 750 GeV particle require additional new particles with electroweak couplings. The key elements of the 500 GeV ILC physics program - precision measurements of themore » Higgs boson, the top quark, and 4-fermion interactions - will powerfully discriminate among these models. This information will be important in conjunction with new LHC data, or alone, if the new particles accompanying the 750 GeV resonance are beyond the mass reach of the LHC. (2) Over a longer term, the energy upgrade of the ILC to 1 TeV already discussed in the ILC TDR will enable experiments in γγ and e +e - collisions to directly produce and study the 750 GeV particle from these unique initial states.« less

Cryogenic system configuration for the International Linear Collider (ILC) at mountainous site

NASA Astrophysics Data System (ADS)

Nakai, H.; Okamura, T.; Delikaris, D.; Peterson, T.; Yamamoto, A.

2017-02-01

The International Linear Collider (ILC) plans to make use of ten cryoplants for its main linacs, each providing 19 kW at 4.5 K equivalent and among of it 3.6 kW at 2 K. Each cryoplant will consist of various cryogenic components such as a 4.5 K refrigerator cold box, a 2 K refrigerator cold box, and helium compressors and so on. In the technical design report (TDR) of the ILC, due to the mountainous topology, almost all cryogenic components would be installed in underground cryogenic caverns next to the main linac tunnels and only cooling towers on surface area. However, we would like to find a more effective and sophisticated configuration of the cryoplant components (cryogenic configuration). Under several constraints of technical, geographical, and environmental points of view, the cryogenic configuration should be considered carefully to satisfy such various conditions. After discussions on this topic conducted at various workshops and conferences, an updated cryogenic configuration is suggested. The proposed updated configuration may affect the total construction cost of the ILC and the entire structure of the ILC conventional facilities. The updated cryogenic configuration is presented and the on-going discussions with the conventional facilities and siting (CFS) colleagues for further improvement of the cryogenic configuration is introduced.

Acceleration of a trailing positron bunch in a plasma wakefield accelerator

DOE PAGES

Doche, A.; Beekman, C.; Corde, S.; ...

2017-10-27

High gradients of energy gain and high energy efficiency are necessary parameters for compact, cost-efficient and high-energy particle colliders. Plasma Wakefield Accelerators (PWFA) offer both, making them attractive candidates for next-generation colliders. Here in these devices, a charge-density plasma wave is excited by an ultra-relativistic bunch of charged particles (the drive bunch). The energy in the wave can be extracted by a second bunch (the trailing bunch), as this bunch propagates in the wake of the drive bunch. While a trailing electron bunch was accelerated in a plasma with more than a gigaelectronvolt of energy gain, accelerating a trailing positronmore » bunch in a plasma is much more challenging as the plasma response can be asymmetric for positrons and electrons. We report the demonstration of the energy gain by a distinct trailing positron bunch in a plasma wakefield accelerator, spanning nonlinear to quasi-linear regimes, and unveil the beam loading process underlying the accelerator energy efficiency. A positron bunch is used to drive the plasma wake in the experiment, though the quasi-linear wake structure could as easily be formed by an electron bunch or a laser driver. Finally, the results thus mark the first acceleration of a distinct positron bunch in plasma-based particle accelerators.« less

Trajectory measurements and correlations in the final focus beam line at the KEK Accelerator Test Facility

NASA Astrophysics Data System (ADS)

Renier, Y.; Bambade, P.; Tauchi, T.; White, G. R.; Boogert, S.

2013-06-01

The Accelerator Test Facility 2 (ATF2) commissioning group aims to demonstrate the feasibility of the beam delivery system of the next linear colliders (ILC and CLIC) as well as to define and to test the tuning methods. As the design vertical beam sizes of the linear colliders are about few nanometers, the stability of the trajectory as well as the control of the aberrations are very critical. ATF2 commissioning started in December 2008, and thanks to submicron resolution beam position monitors (BPMs), it has been possible to measure the beam position fluctuation along the final focus of ATF2 during the 2009 runs. The optics was not the nominal one yet, with a lower focusing to make the tuning easier. In this paper, a method to measure the noise of each BPM every pulse, in a model-independent way, will be presented. A method to reconstruct the trajectory’s fluctuations is developed which uses the previously determined BPM resolution. As this reconstruction provides a measurement of the beam energy fluctuations, it was also possible to measure the horizontal and vertical dispersion function at each BPMs parasitically. The spatial and angular dispersions can be fitted from these measurements with uncertainties comparable with usual measurements.

Acceleration of a trailing positron bunch in a plasma wakefield accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doche, A.; Beekman, C.; Corde, S.

High gradients of energy gain and high energy efficiency are necessary parameters for compact, cost-efficient and high-energy particle colliders. Plasma Wakefield Accelerators (PWFA) offer both, making them attractive candidates for next-generation colliders. Here in these devices, a charge-density plasma wave is excited by an ultra-relativistic bunch of charged particles (the drive bunch). The energy in the wave can be extracted by a second bunch (the trailing bunch), as this bunch propagates in the wake of the drive bunch. While a trailing electron bunch was accelerated in a plasma with more than a gigaelectronvolt of energy gain, accelerating a trailing positronmore » bunch in a plasma is much more challenging as the plasma response can be asymmetric for positrons and electrons. We report the demonstration of the energy gain by a distinct trailing positron bunch in a plasma wakefield accelerator, spanning nonlinear to quasi-linear regimes, and unveil the beam loading process underlying the accelerator energy efficiency. A positron bunch is used to drive the plasma wake in the experiment, though the quasi-linear wake structure could as easily be formed by an electron bunch or a laser driver. Finally, the results thus mark the first acceleration of a distinct positron bunch in plasma-based particle accelerators.« less

Construction of the DHCAL

NASA Astrophysics Data System (ADS)

Francis, Kurt; CALICE Collaboration

Particle Flow Algorithms (PFAs) have been proposed as a method of improving the jet energy resolution of future colliding beam detectors. PFAs require calorimeters with high granularity to enable three-dimensional imaging of events. The Calorimeter for the Linear Collider Collaboration (CALICE) is developing and testing prototypes of such highly segmented calorimeters. In this context, a large prototype of a Digital Hadron Calorimeter (DHCAL) was developed and constructed by a group led by Argonne National Laboratory. The DHCAL consists of 52 layers, instrumented with Resistive Plate Chambers (RPCs) and interleaved with steel absorber plates. The RPCs are read out by 1 x 1 cm2 pads with a 1-bit resolution (digital readout). The DHCAL prototype has approximately 480,000 readout channels. This talk reports on the design, construction and commissioning of the DHCAL. The DHCAL was installed at the Fermilab Test Beam Facility in fall 2010 and data was collected through the summer 2011.

Fission and fusion scenarios for magnetic microswimmer clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guzmán-Lastra, Francisca; Kaiser, Andreas; Löwen, Hartmut

Fission and fusion processes of particle clusters occur in many areas of physics and chemistry from subnuclear to astronomic length scales. Here we study fission and fusion of magnetic microswimmer clusters as governed by their hydrodynamic and dipolar interactions. Rich scenarios are found that depend crucially on whether the swimmer is a pusher or a puller. In particular a linear magnetic chain of pullers is stable while a pusher chain shows a cascade of fission (or disassembly) processes as the self-propulsion velocity is increased. Contrarily, magnetic ring clusters show fission for any type of swimmer. Moreover, we find a plethoramore » of possible fusion (or assembly) scenarios if a single swimmer collides with a ringlike cluster and two rings spontaneously collide. Lastly, our predictions are obtained by computer simulations and verifiable in experiments on active colloidal Janus particles and magnetotactic bacteria.« less

Simulation of radiation damping in rings, using stepwise ray-tracing methods

DOE PAGES

Meot, F.

2015-06-26

The ray-tracing code Zgoubi computes particle trajectories in arbitrary magnetic and/or electric field maps or analytical field models. It includes a built-in fitting procedure, spin tracking many Monte Carlo processes. The accuracy of the integration method makes it an efficient tool for multi-turn tracking in periodic machines. Energy loss by synchrotron radiation, based on Monte Carlo techniques, had been introduced in Zgoubi in the early 2000s for studies regarding the linear collider beam delivery system. However, only recently has this Monte Carlo tool been used for systematic beam dynamics and spin diffusion studies in rings, including eRHIC electron-ion collider projectmore » at the Brookhaven National Laboratory. Some beam dynamics aspects of this recent use of Zgoubi capabilities, including considerations of accuracy as well as further benchmarking in the presence of synchrotron radiation in rings, are reported here.« less

Electrons and Mirror Symmetry

ScienceCinema

Kumar, Krishna

2017-12-09

The neutral weak force between an electron and a target particle, mediated by the Z boson, can be isolated by measuring the fractional change under a mirror reflection of the scattering probability of relativistic longitudinally polarized electrons off unpolarized targets. This technique yields neutral weak force measurements at a length scale of 1 femtometer, in contrast to high energy collider measurements that probe much smaller length scales. Study of the variation of the weak force over a range of length scales provides a stringent test of theory, complementing collider measurements. We describe a recent measurement of the neutral weak force between two electrons by the E158 experiment at the Stanford Linear Accelerator Center. While the weak force between an electron and positron has been extensively studied, that between two electrons had never directly been measured. We conclude by discussing prospects for even more precise measurements at future facilities.

Fission and fusion scenarios for magnetic microswimmer clusters

DOE PAGES

Guzmán-Lastra, Francisca; Kaiser, Andreas; Löwen, Hartmut

2016-11-22

Fission and fusion processes of particle clusters occur in many areas of physics and chemistry from subnuclear to astronomic length scales. Here we study fission and fusion of magnetic microswimmer clusters as governed by their hydrodynamic and dipolar interactions. Rich scenarios are found that depend crucially on whether the swimmer is a pusher or a puller. In particular a linear magnetic chain of pullers is stable while a pusher chain shows a cascade of fission (or disassembly) processes as the self-propulsion velocity is increased. Contrarily, magnetic ring clusters show fission for any type of swimmer. Moreover, we find a plethoramore » of possible fusion (or assembly) scenarios if a single swimmer collides with a ringlike cluster and two rings spontaneously collide. Lastly, our predictions are obtained by computer simulations and verifiable in experiments on active colloidal Janus particles and magnetotactic bacteria.« less

Epicyclic helical channels for parametric resonance ionization cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johson, Rolland Paul; Derbenev, Yaroslav

Proposed next-generation muon colliders will require major technical advances to achieve rapid muon beam cooling requirements. Parametric-resonance Ionization Cooling (PIC) is proposed as the final 6D cooling stage of a high-luminosity muon collider. In PIC, a half-integer parametric resonance causes strong focusing of a muon beam at appropriately placed energy absorbers while ionization cooling limits the beam’s angular spread. Combining muon ionization cooling with parametric resonant dynamics in this way should then allow much smaller final transverse muon beam sizes than conventional ionization cooling alone. One of the PIC challenges is compensation of beam aberrations over a sufficiently wide parametermore » range while maintaining the dynamical stability with correlated behavior of the horizontal and vertical betatron motion and dispersion. We explore use of a coupling resonance to reduce the dimensionality of the problem and to shift the dynamics away from non-linear resonances. PIC simulations are presented.« less

Systematic study of the isotopic dependence of fusion dynamics for neutron- and proton-rich nuclei using a proximity formalism

NASA Astrophysics Data System (ADS)

Ghodsi, O. N.; Gharaei, R.; Lari, F.

2012-08-01

The behaviors of barrier characteristics and fusion cross sections are analyzed by changing neutrons over a wide range of colliding systems. For this purpose, we have extended our previous study [Ghodsi and Gharaei, Eur. Phys. J. AEPJAFV1434-600110.1140/epja/i2012-12021-x 48, 21 (2012), it is devoted to the colliding systems with neutron-rich nuclei] to 125 isotopic systems with the condition of 0.5⩽N/Z⩽1.6 for their compound nuclei. The AW 95, Bass 80, Denisov DP, and Prox. 2010 potentials are used to calculate the nuclear part of the interacting potential. The obtained results show that the trend of barrier heights VB and positions RB as well as nuclear VN and Coulomb VC potentials (at R=RB) as a function of (N/Z-1) quantity are nonlinear (second order) whereas the fusion cross sections follow a linear dependence.

What Will the Neighbors Think? Building Large-Scale Science Projects Around the World

ScienceCinema

Jones, Craig; Mrotzek, Christian; Toge, Nobu; Sarno, Doug

2017-12-22

Public participation is an essential ingredient for turning the International Linear Collider into a reality. Wherever the proposed particle accelerator is sited in the world, its neighbors -- in any country -- will have something to say about hosting a 35-kilometer-long collider in their backyards. When it comes to building large-scale physics projects, almost every laboratory has a story to tell. Three case studies from Japan, Germany and the US will be presented to examine how community relations are handled in different parts of the world. How do particle physics laboratories interact with their local communities? How do neighbors react to building large-scale projects in each region? How can the lessons learned from past experiences help in building the next big project? These and other questions will be discussed to engage the audience in an active dialogue about how a large-scale project like the ILC can be a good neighbor.

Probing triple-Higgs productions via 4 b 2 γ decay channel at a 100 TeV hadron collider

DOE PAGES

Chen, Chien-Yi; Yan, Qi-Shu; Zhao, Xiaoran; ...

2016-01-11

We report that the quartic self-coupling of the Standard Model Higgs boson can only be measured by observing the triple-Higgs production process, but it is challenging for the LHC Run 2 or International Linear Collider (ILC) at a few TeV because of its extremely small production rate. In this paper, we present a detailed Monte Carlo simulation study of the triple-Higgs production through gluon fusion at a 100 TeV hadron collider and explore the feasibility of observing this production mode. We focus on the decay channel HHH →more » $$b\\bar{b}$$$b\\bar{b}$$γγ, investigating detector effects and optimizing the kinematic cuts to discriminate the signal from the backgrounds. Our study shows that, in order to observe the Standard Model triple-Higgs signal, the integrated luminosity of a 100 TeV hadron collider should be greater than 1.8×10 4 ab ₋1. We also explore the dependence of the cross section upon the trilinear (λ 3) and quartic (λ 4) self-couplings of the Higgs. Ultimately, we find that, through a search in the triple-Higgs production, the parameters λ 3 and λ 4 can be restricted to the ranges [₋1,5] and [₋20,30], respectively. We also examine how new physics can change the production rate of triple-Higgs events. For example, in the singlet extension of the Standard Model, we find that the triple-Higgs production rate can be increased by a factor of O(10).« less

Particle Tracking on the BNL Relativistic Heavy Ion Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dell, G. F.

1986-08-07

Tracking studies including the effects of random multipole errors as well as the effects of random and systematic multipole errors have been made for RHIC. Initial results for operating at an off diagonal working point are discussed.

Physics Goals and Experimental Challenges of the Proton-Proton High-Luminosity Operation of the LHC

NASA Astrophysics Data System (ADS)

Campana, P.; Klute, M.; Wells, P. S.

2016-10-01

The completion of Run 1 of the Large Hadron Collider (LHC) at CERN has seen the discovery of the Higgs boson and an unprecedented number of precise measurements of the Standard Model, and Run 2 has begun to provide the first data at higher energy. The high-luminosity upgrade of the LHC (HL-LHC) and the four experiments (ATLAS, CMS, ALICE, and LHCb) will exploit the full potential of the collider to discover and explore new physics beyond the Standard Model. We review the experimental challenges and the physics opportunities in proton-proton collisions at the HL-LHC.

Design Studies and Optimization of High-Field Nb$$_3$$Sn Dipole Magnets for a Future Very High Energy PP Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kashikhin, V. V.; Novitski, I.; Zlobin, A. V.

2017-05-01

High filed accelerator magnets with operating fields of 15-16 T based on themore » $$Nb_3Sn$$ superconductor are being considered for the LHC energy upgrade or a future Very High Energy pp Collider. Magnet design studies are being conducted in the U.S., Europe and Asia to explore the limits of the $$Nb_3Sn$$ accelerator magnet technology while optimizing the magnet design and performance parame-ters, and reducing magnet cost. The first results of these studies performed at Fermilab in the framework of the US-MDP are reported in this paper.« less

Unveiling the top secrets with the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Chierici, R.

2013-12-01

Top quark physics is one of the pillars of fundamental research in the field of high energy physics. It not only gives access to precision measurements for constraining the Standard Model of particles and interactions but also it represents a privileged domain for new physics searches. This contribution summarizes the main results in top quark physics obtained with the two general-purpose detectors ATLAS and CMS during the first two years of operations of the Large Hadron Collider (LHC) at CERN. It covers the 2010 and 2011 data taking periods, where the LHC ran at a centre-of-mass energy of 7 TeV.

High Energy Colliding Beams; What Is Their Future?

NASA Astrophysics Data System (ADS)

Richter, Burton

The success of the first few years of LHC operations at CERN, and the expectation of more to come as the LHC's performance improves, are already leading to discussions of what should be next for both proton-proton and electron-positron colliders. In this discussion I see too much theoretical desperation caused by the so-far-unsuccessful hunt for what is beyond the Standard Model, and too little of the necessary interaction of the accelerator, experimenter, and theory communities necessary for a scientific and engineering success. Here, I give my impressions of the problem, its possible solution, and what is needed to have both a scientifically productive and financially viable future.

High Energy Colliding Beams; What Is Their Future?

NASA Astrophysics Data System (ADS)

Richter, Burton

2014-04-01

The success of the first few years of LHC operations at CERN, and the expectation of more to come as the LHC's performance improves, are already leading to discussions of what should be next for both proton-proton and electron-positron colliders. In this discussion I see too much theoretical desperation caused by the so-far-unsuccessful hunt for what is beyond the Standard Model, and too little of the necessary interaction of the accelerator, experimenter, and theory communities necessary for a scientific and engineering success. Here, I give my impressions of the problem, its possible solution, and what is needed to have both a scientifically productive and financially viable future.

High Energy Colliding Beams; What Is Their Future?

NASA Astrophysics Data System (ADS)

Richter, Burton

2015-02-01

The success of the first few years of LHC operations at CERN, and the expectation of more to come as the LHC's performance improves, are already leading to discussions of what should be next for both proton-proton and electron-positron colliders. In this discussion I see too much theoretical desperation caused by the so-far-unsuccessful hunt for what is beyond the Standard Model, and too little of the necessary interaction of the accelerator, experimenter, and theory communities necessary for a scientific and engineering success. Here, I give my impressions of the problem, its possible solution, and what is needed to have both a scientifically productive and financially viable future.

Longitudinal asymmetry and its effect on pseudorapidity distributions in Pb-Pb collisions at √{sNN } = 2.76 TeV

NASA Astrophysics Data System (ADS)

Acharya, S.; Adam, J.; Adamová, D.; Adolfsson, J.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Al-Turany, M.; Alam, S. N.; Alba, J. L. B.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altenkamper, L.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andreou, D.; Andrews, H. A.; Andronic, A.; Anguelov, V.; Anson, C.; Antičić, T.; Antinori, F.; Antonioli, P.; Anwar, R.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Ball, M.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barioglio, L.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Batigne, G.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Beltran, L. G. E.; Belyaev, V.; Bencedi, G.; Beole, S.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, A.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Blair, J. T.; Blau, D.; Blume, C.; Boca, G.; Bock, F.; Bogdanov, A.; Boldizsár, L.; Bombara, M.; Bonomi, G.; Bonora, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Botta, E.; Bourjau, C.; Bratrud, L.; Braun-Munzinger, P.; Bregant, M.; Broker, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buhler, P.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caffarri, D.; Caines, H.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Capon, A. A.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Ceballos Sanchez, C.; Cerello, P.; Chandra, S.; Chang, B.; Chapeland, S.; Chartier, M.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Cho, S.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Chowdhury, T.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Concas, M.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Costanza, S.; Crkovská, J.; Crochet, P.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; de, S.; de Caro, A.; de Cataldo, G.; de Conti, C.; de Cuveland, J.; de Falco, A.; de Gruttola, D.; De Marco, N.; de Pasquale, S.; de Souza, R. D.; Degenhardt, H. F.; Deisting, A.; Deloff, A.; Deplano, C.; Dhankher, P.; di Bari, D.; di Mauro, A.; di Nezza, P.; di Ruzza, B.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Doremalen, L. V. R.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Duggal, A. K.; Dukhishyam, M.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erhardt, F.; Espagnon, B.; Esumi, S.; Eulisse, G.; Eum, J.; Evans, D.; Evdokimov, S.; Fabbietti, L.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Fernández Téllez, A.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Francisco, A.; Frankenfeld, U.; Fronze, G. G.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gajdosova, K.; Gallio, M.; Galvan, C. D.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Garg, K.; Gargiulo, C.; Gasik, P.; Gauger, E. F.; Gay Ducati, M. B.; Germain, M.; Ghosh, J.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; Gonzalez, A. S.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Graham, K. L.; Greiner, L.; Grelli, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Gronefeld, J. M.; Grosa, F.; Grosse-Oetringhaus, J. F.; Grosso, R.; Gruber, L.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Guzman, I. B.; Haake, R.; Hadjidakis, C.; Hamagaki, H.; Hamar, G.; Hamon, J. C.; Haque, M. R.; Harris, J. W.; Harton, A.; Hassan, H.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Hellbär, E.; Helstrup, H.; Herghelegiu, A.; Hernandez, E. G.; Herrera Corral, G.; Herrmann, F.; Hess, B. A.; Hetland, K. F.; Hillemanns, H.; Hills, C.; Hippolyte, B.; Hladky, J.; Hohlweger, B.; Horak, D.; Hornung, S.; Hosokawa, R.; Hristov, P.; Hughes, C.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Iga Buitron, S. A.; Ilkaev, R.; Inaba, M.; Ippolitov, M.; Irfan, M.; Islam, M. S.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacak, B.; Jacazio, N.; Jacobs, P. M.; Jadhav, M. B.; Jadlovsky, J.; Jaelani, S.; Jahnke, C.; Jakubowska, M. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jercic, M.; Jimenez Bustamante, R. T.; Jones, P. G.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karayan, L.; Karczmarczyk, P.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Ketzer, B.; Khabanova, Z.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Khatun, A.; Khuntia, A.; Kielbowicz, M. M.; Kileng, B.; Kim, B.; Kim, D.; Kim, D. J.; Kim, H.; Kim, J. S.; Kim, J.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Bösing, C.; Klewin, S.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Köhler, M. K.; Kollegger, T.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Konyushikhin, M.; Kopcik, M.; Kour, M.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.; Koyithatta Meethaleveedu, G.; Králik, I.; Kravčáková, A.; Kreis, L.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kuhn, C.; Kuijer, P. G.; Kumar, A.; Kumar, J.; Kumar, L.; Kumar, S.; Kundu, S.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Lagana Fernandes, C.; Lai, Y. S.; Lakomov, I.; Langoy, R.; Lapidus, K.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lavicka, R.; Lea, R.; Leardini, L.; Lee, S.; Lehas, F.; Lehner, S.; Lehrbach, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; Lévai, P.; Li, X.; Lien, J.; Lietava, R.; Lim, B.; Lindal, S.; Lindenstruth, V.; Lindsay, S. W.; Lippmann, C.; Lisa, M. A.; Litichevskyi, V.; Llope, W. J.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Loncar, P.; Lopez, X.; López Torres, E.; Lowe, A.; Luettig, P.; Luhder, J. R.; Lunardon, M.; Luparello, G.; Lupi, M.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martin, N. A.; Martinengo, P.; Martinez, J. A. L.; Martínez, M. I.; Martínez García, G.; Martinez Pedreira, M.; Masciocchi, S.; Masera, M.; Masoni, A.; Masson, E.; Mastroserio, A.; Mathis, A. M.; Matuoka, P. F. T.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzilli, M.; Mazzoni, M. A.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Mhlanga, S.; Miake, Y.; Mieskolainen, M. M.; Mihaylov, D. L.; Mikhaylov, K.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Mohisin Khan, M.; Moreira de Godoy, D. A.; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Münning, K.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Myers, C. J.; Myrcha, J. W.; Nag, D.; Naik, B.; Nair, R.; Nandi, B. K.; Nania, R.; Nappi, E.; Narayan, A.; Naru, M. U.; Natal da Luz, H.; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Negrao de Oliveira, R. A.; Nellen, L.; Nesbo, S. V.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Ohlson, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Oravec, M.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Pachmayer, Y.; Pacik, V.; Pagano, D.; Pagano, P.; Paić, G.; Palni, P.; Pan, J.; Pandey, A. K.; Panebianco, S.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, J.; Parmar, S.; Passfeld, A.; Pathak, S. P.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.; Peng, X.; Pereira, L. G.; Pereira da Costa, H.; Peresunko, D.; Perez Lezama, E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Pezzi, R. P.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pliquett, F.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Poppenborg, H.; Porteboeuf-Houssais, S.; Pozdniakov, V.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Rana, D. B.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Ratza, V.; Ravasenga, I.; Read, K. F.; Redlich, K.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rodríguez Cahuantzi, M.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Rokita, P. S.; Ronchetti, F.; Rosas, E. D.; Rosnet, P.; Rossi, A.; Rotondi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rueda, O. V.; Rui, R.; Rumyantsev, B.; Rustamov, A.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Saarinen, S.; Sadhu, S.; Sadovsky, S.; Šafařík, K.; Saha, S. K.; Sahlmuller, B.; Sahoo, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sandoval, A.; Sarkar, D.; Sarkar, N.; Sarma, P.; Sas, M. H. P.; Scapparone, E.; Scarlassara, F.; Schaefer, B.; Scharenberg, R. P.; Scheid, H. S.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schmidt, M. O.; Schmidt, M.; Schmidt, N. V.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Šefčík, M.; Seger, J. E.; Sekiguchi, Y.; Sekihata, D.; Selyuzhenkov, I.; Senosi, K.; Senyukov, S.; Serradilla, E.; Sett, P.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shahoyan, R.; Shaikh, W.; Shangaraev, A.; Sharma, A.; Sharma, A.; Sharma, M.; Sharma, M.; Sharma, N.; Sheikh, A. I.; Shigaki, K.; Shou, Q.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silaeva, S.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singhal, V.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Song, J.; Song, M.; Soramel, F.; Sorensen, S.; Sozzi, F.; Spiriti, E.; Sputowska, I.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stankus, P.; Stenlund, E.; Stocco, D.; Storetvedt, M. M.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Suljic, M.; Sultanov, R.; Šumbera, M.; Sumowidagdo, S.; Suzuki, K.; Swain, S.; Szabo, A.; Szarka, I.; Tabassam, U.; Takahashi, J.; Tambave, G. J.; Tanaka, N.; Tarhini, M.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thakur, D.; Thakur, S.; Thomas, D.; Thoresen, F.; Tieulent, R.; Tikhonov, A.; Timmins, A. R.; Toia, A.; Torres, S. R.; Tripathy, S.; Trogolo, S.; Trombetta, G.; Tropp, L.; Trubnikov, V.; Trzaska, W. H.; Trzeciak, B. A.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Umaka, E. N.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vala, M.; van der Maarel, J.; van Hoorne, J. W.; van Leeuwen, M.; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vázquez Doce, O.; Vechernin, V.; Veen, A. M.; Velure, A.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Vértesi, R.; Vickovic, L.; Vigolo, S.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Villatoro Tello, A.; Vinogradov, A.; Vinogradov, L.; Virgili, T.; Vislavicius, V.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Voscek, D.; Vranic, D.; Vrláková, J.; Wagner, B.; Wang, H.; Wang, M.; Watanabe, D.; Watanabe, Y.; Weber, M.; Weber, S. G.; Weiser, D. F.; Wenzel, S. C.; Wessels, J. P.; Westerhoff, U.; Whitehead, A. M.; Wiechula, J.; Wikne, J.; Wilk, G.; Wilkinson, J.; Willems, G. A.; Williams, M. C. S.; Willsher, E.; Windelband, B.; Witt, W. E.; Yalcin, S.; Yamakawa, K.; Yang, P.; Yano, S.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yoon, J. H.; Yurchenko, V.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zardoshti, N.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhang, C.; Zhang, Z.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zmeskal, J.; Zou, S.; Alice Collaboration

2018-06-01

First results on the longitudinal asymmetry and its effect on the pseudorapidity distributions in Pb-Pb collisions at √{sNN } = 2.76 TeV at the Large Hadron Collider are obtained with the ALICE detector. The longitudinal asymmetry arises because of an unequal number of participating nucleons from the two colliding nuclei, and is estimated for each event by measuring the energy in the forward neutron-Zero-Degree-Calorimeters (ZNs). The effect of the longitudinal asymmetry is measured on the pseudorapidity distributions of charged particles in the regions | η | < 0.9, 2.8 < η < 5.1 and - 3.7 < η < - 1.7 by taking the ratio of the pseudorapidity distributions from events corresponding to different regions of asymmetry. The coefficients of a polynomial fit to the ratio characterise the effect of the asymmetry. A Monte Carlo simulation using a Glauber model for the colliding nuclei is tuned to reproduce the spectrum in the ZNs and provides a relation between the measurable longitudinal asymmetry and the shift in the rapidity (y0) of the participant zone formed by the unequal number of participating nucleons. The dependence of the coefficient of the linear term in the polynomial expansion, c1, on the mean value of y0 is investigated.

Test of Relativistic Gravity for Propulsion at the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Felber, Franklin

2010-01-01

A design is presented of a laboratory experiment that could test the suitability of relativistic gravity for propulsion of spacecraft to relativistic speeds. An exact time-dependent solution of Einstein's gravitational field equation confirms that even the weak field of a mass moving at relativistic speeds could serve as a driver to accelerate a much lighter payload from rest to a good fraction of the speed of light. The time-dependent field of ultrarelativistic particles in a collider ring is calculated. An experiment is proposed as the first test of the predictions of general relativity in the ultrarelativistic limit by measuring the repulsive gravitational field of bunches of protons in the Large Hadron Collider (LHC). The estimated `antigravity beam' signal strength at a resonant detector of each proton bunch is 3 nm/s2 for 2 ns during each revolution of the LHC. This experiment can be performed off-line, without interfering with the normal operations of the LHC.

Participation in the ARGUS experiment at the DORIS Collider at DESY, Hamburg, Germany and participation in the AMY experiment at the Tristan Collider in Tsukuba, Japan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darden, C.; Rosenfeld, C.

1990-01-01

This paper discusses electron-positron annihilation at high energy. This work began in 1977 with the DASP II Collaboration at the DORIS storage ring of the DESY Laboratory in Hamburg. The collaboration's first publication reported the observation of the narrow {Upsilon} resonance at 9.46 GeV, confirming the original observation of this state in proton-nucleus collisions at Fermilab. To enable investigations of the {Upsilon} family of resonances the DORIS ring was rebuilt for reliable operation at the top of its energy range where the {Upsilon} states are accessible. In addition a new detector, ARGUS, was installed at one interaction region. This papermore » also discusses the AMY Collaboration which investigates electron-positron annihilation at energies from 50 to 65 GeV. The AMY detector is in the beam of the TRISTAN collider of the KEK Laboratory in Tsukuba, Japan.« less

Design criteria for prompt radiation limits on the relativistic heavy ion collider site.

PubMed

Stevens, A; Musolino, S; Harrison, M

1994-03-01

The Relativistic Heavy Ion Collider (RHIC) is a superconducting colliding beam accelerator facility that is currently under construction. Relatively small amounts of energy depositing in the coils of superconducting magnets can result in a "quench," the irreversible transition to the normal resistive state. The quench limit of superconducting magnets, therefore, constrains local beam loss throughout the injection, acceleration, and storage cycles to extremely low levels. From a practical standpoint, it follows that there is essentially no prompt radiation in most regions due to normal operations. The design of shielding is, therefore, principally driven by the consequences of a single pulse fault at full energy in one of the two storage rings. Since there are no regulatory requirements or guidance documents that prescribe radiological performance goals for this situation, the RHIC Project has proposed a scheme to classify the various areas of the RHIC complex based on Design Basis Accident faults. The criteria is then compared to existing regulatory requirements and guidance recommendations.

DEPFET detectors for future electron-positron colliders

NASA Astrophysics Data System (ADS)

Marinas, C.

2015-11-01

The DEPFET Collaboration develops highly granular, ultra-thin pixel detectors for outstanding vertex reconstruction at future electron-positron collider experiments. A DEPFET sensor, by the integration of a field effect transistor on a fully depleted silicon bulk, provides simultaneous position sensitive detector capabilities and in pixel amplification. The characterization of the latest DEPFET prototypes has proven that a adequate signal-to-noise ratio and excellent single point resolution can be achieved for a sensor thickness of 50 micrometers. The close to final auxiliary ASICs have been produced and found to operate a DEPFET pixel detector of the latest generation with the required read-out speed. A complete detector concept is being developed for the Belle II experiment at the new Japanese super flavor factory. DEPFET is not only the technology of choice for the Belle II vertex detector, but also a prime candidate for the ILC. Therefore, in this contribution, the status of DEPFET R&D project is reviewed in the light of the requirements of the vertex detector at a future electron-positron collider.

Impact of beam-beam effects on precision luminosity measurements at the ILC

NASA Astrophysics Data System (ADS)

Rimbault, C.; Bambade, P.; Mönig, K.; Schulte, D.

2007-09-01

In this paper, the impact of beam-beam effects on the precision luminosity measurement at the International Linear Collider is investigated quantitatively for the first time. GUINEA-PIG, a beam-beam interaction simulation tool, is adapted to treat the space charge effects affecting the Bhabha events used in this measurement. The biases due to the resulting changes in kinematics are evaluated for different center-of-mass energies and beam parameters.

Zee-Babu type model with U (1 )Lμ-Lτ gauge symmetry

NASA Astrophysics Data System (ADS)

Nomura, Takaaki; Okada, Hiroshi

2018-05-01

We extend the Zee-Babu model, introducing local U (1 )Lμ-Lτ symmetry with several singly charged bosons. We find a predictive neutrino mass texture in a simple hypothesis in which mixings among singly charged bosons are negligible. Also, lepton-flavor violations are less constrained compared with the original model. Then, we explore the testability of the model, focusing on doubly charged boson physics at the LHC and the International Linear Collider.

Neutrino Mass Generation at TeV Scale and New Physics Signatures from Charged Higgs at the LHC for Photon Initiated Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Kirtiman; Homi Bhabha National Institute, Mumbai; Jana, Sudip

We consider the collider phenomenology of a simple extension of the Standard Model (SM), which consists of an EW isospinmore » $3/2$ scalar, $$\\Delta$$ and a pair of EW isospin $1$ vector like fermions, $$\\Sigma$$ and $$\\bar{\\Sigma}$$, responsible for generating tiny neutrino mass via the effective dimension seven operator. This scalar quadruplet with hypercharge Y = 3 has a plethora of implications at the collider experiments. Its signatures at TeV scale colliders are expected to be seen, if the quadruplet masses are not too far above the electroweak symmetry breaking scale. In this article, we study the phenomenology of multi-charged quadruplet scalars. In particular, we study the multi-lepton signatures at the Large Hadron Collider (LHC) experiment, arising from the production and decays of triply and doubly charged scalars. We studied Drell-Yan (DY) pair production as well as pair production of the charged scalars via photon-photon fusion. For doubly and triply charged scalars, photon fusion contributes significantly for large scalar masses. We also studied LHC constraints on the masses of doubly charged scalars in this model. We derive a lower mass limit of 725 GeV on doubly charged quadruplet scalar.« less

Neutrino Mass Generation at TeV Scale and New Physics Signatures from Charged Higgs at the LHC for Photon Initiated Processes

DOE PAGES

Ghosh, Kirtiman; Homi Bhabha National Institute, Mumbai; Jana, Sudip; ...

2018-03-29

We consider the collider phenomenology of a simple extension of the Standard Model (SM), which consists of an EW isospinmore » $3/2$ scalar, $$\\Delta$$ and a pair of EW isospin $1$ vector like fermions, $$\\Sigma$$ and $$\\bar{\\Sigma}$$, responsible for generating tiny neutrino mass via the effective dimension seven operator. This scalar quadruplet with hypercharge Y = 3 has a plethora of implications at the collider experiments. Its signatures at TeV scale colliders are expected to be seen, if the quadruplet masses are not too far above the electroweak symmetry breaking scale. In this article, we study the phenomenology of multi-charged quadruplet scalars. In particular, we study the multi-lepton signatures at the Large Hadron Collider (LHC) experiment, arising from the production and decays of triply and doubly charged scalars. We studied Drell-Yan (DY) pair production as well as pair production of the charged scalars via photon-photon fusion. For doubly and triply charged scalars, photon fusion contributes significantly for large scalar masses. We also studied LHC constraints on the masses of doubly charged scalars in this model. We derive a lower mass limit of 725 GeV on doubly charged quadruplet scalar.« less

Modal interaction in linear dynamic systems near degenerate modes

NASA Technical Reports Server (NTRS)

Afolabi, D.

1991-01-01

In various problems in structural dynamics, the eigenvalues of a linear system depend on a characteristic parameter of the system. Under certain conditions, two eigenvalues of the system approach each other as the characteristic parameter is varied, leading to modal interaction. In a system with conservative coupling, the two eigenvalues eventually repel each other, leading to the curve veering effect. In a system with nonconservative coupling, the eigenvalues continue to attract each other, eventually colliding, leading to eigenvalue degeneracy. Modal interaction is studied in linear systems with conservative and nonconservative coupling using singularity theory, sometimes known as catastrophe theory. The main result is this: eigenvalue degeneracy is a cause of instability; in systems with conservative coupling, it induces only geometric instability, whereas in systems with nonconservative coupling, eigenvalue degeneracy induces both geometric and elastic instability. Illustrative examples of mechanical systems are given.

Observation of Rayleigh-Taylor-instability evolution in a plasma with magnetic and viscous effects

DOE PAGES

Adams, Colin S.; Moser, Auna L.; Hsu, Scott C.

2015-11-06

We present time-resolved observations of Rayleigh-Taylor-instability (RTI) evolution at the interface between an unmagnetized plasma jet colliding with a stagnated, magnetized plasma. The observed instability growth time (~10μs) is consistent with the estimated linear RTI growth rate calculated using experimentally inferred values of density (~10 14cm–3) and deceleration (~10 9 m/s 2). The observed mode wavelength (≳1 cm) nearly doubles within a linear growth time. Furthermore, theoretical estimates of magnetic and viscous stabilization and idealized magnetohydrodynamic simulations including a physical viscosity model both suggest that the observed instability evolution is subject to magnetic and/or viscous effects.

Crabbing System for an Electron-Ion Collider

NASA Astrophysics Data System (ADS)

Castilla, Alejandro

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

Rotations in the actively colliding Finisterre Arc Terrane: paleomagnetic constraints on Plio-Pleistocene evolution of the South Bismarck microplate, northeastern Papua New Guinea

NASA Astrophysics Data System (ADS)

Weiler, P. D.; Coe, R. S.

2000-01-01

We report paleomagnetic results from 12 Plio-Pleistocene localities in the actively colliding Finisterre Arc Terrane of northeastern Papua New Guinea (PNG). Calcareous, hemipelagic cover rocks possess a stable, syn-collisional remagnetization indicating a clockwise rotation of the colliding terrane through about 40° in post-Miocene time. A decrease in paleomagnetic declination anomalies as a function of along-strike distance in the Finisterre Arc Terrane, analyzed by our preferred model of a linear remagnetization and a migrating Euler pole, suggests an average rotation rate of 8° Ma -1, in good agreement with the instantaneous rate from global positioning system geodesy. Thus, we propose that this rotation results from a coherent, rigid-body rotation of the Finisterre Terrane rather than from sequential docking of independently colliding blocks of the terrane. Moreover, we conclude that these paleomagnetic declinations result mainly from South Bismarck Plate motion, and not decoupled rotation of the crustal terrane independent of the underlying lithosphere. We examine models of a syn-collisional remagnetization with both fixed and migrating Euler poles of South Bismarck/Australia plate relative motion, and suggest that the Euler pole describing South Bismarck Plate motion has migrated southwestward to its present location on the collision suture in response to the propagating collision. This plate kinematic model agrees with the variability in depth of the seismogenic slab beneath the collision zone. Our best-fit model of pole migration describes South Bismarck/Australia relative motion producing a highly oblique collision in its early stages, with the Finisterre Arc Terrane converging along a left-lateral Ramu-Markham suture, gradually changing to the nearly orthogonal convergence observed today.

Anisotropic flow of thermal photons at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

NASA Astrophysics Data System (ADS)

Chatterjee, Rupa; Dasgupta, Pingal; Srivastava, Dinesh K.

2017-07-01

We calculate elliptic and triangular flow parameters of thermal photons using an event-by-event hydrodynamic model with fluctuating initial conditions at 200 A GeV Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and at 2.76 A TeV Pb+Pb collisions at the Cern Large Hadron Collider (LHC) for three different centrality bins. The photon elliptic flow shows strong centrality dependence where v2(pT) increases towards peripheral collisions both at RHIC and at the LHC energies. However, the triangular flow parameter does not show significant dependence on the collision centrality. The elliptic as well as the triangular flow parameters found to underestimate the PHENIX data at RHIC by a large margin for all three centrality bins. We calculate pT spectrum and anisotropic flow of thermal photons from 200 A GeV Cu+Cu collisions at RHIC for a 0-20% centrality bin and compare with the results with those from Au+Au collisions. The production of thermal photons is found to decrease significantly for Cu+Cu collisions compared to Au+Au collisions. However, the effect of initial state fluctuation is found to be more pronounced for anisotropic flow, resulting in larger v2 and v3 for Cu+Cu collisions. We study the correlation between the anisotropic flow parameters and the corresponding initial spatial anisotropies from their event-by-event distributions at RHIC and at the LHC energies. The linear correlation between v2 and ɛ2 is found be stronger compared to the correlation between v3 and ɛ3. In addition, the correlation coefficient is found to be larger at LHC than at RHIC.

Big Science and the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Giudice, Gian Francesco

2012-03-01

The Large Hadron Collider (LHC), the particle accelerator operating at CERN, is probably the most complex and ambitious scientific project ever accomplished by humanity. The sheer size of the enterprise, in terms of financial and human resources, naturally raises the question whether society should support such costly basic-research programs. I address this question by first reviewing the process that led to the emergence of Big Science and the role of large projects in the development of science and technology. I then compare the methodologies of Small and Big Science, emphasizing their mutual linkage. Finally, after examining the cost of Big Science projects, I highlight several general aspects of their beneficial implications for society.

Development of Resistive Micromegas for Sampling Calorimetry

NASA Astrophysics Data System (ADS)

Geralis, T.; Fanourakis, G.; Kalamaris, A.; Nikas, D.; Psallidas, A.; Chefdeville, M.; Karyotakis, I.; Koletsou, I.; Titov, M.

2018-02-01

Resistive micromegas is proposed as an active element for sampling calorimetry. Future linear collider experiments or the HL-LHC experiments can profit from those developments for Particle Flow Calorimetry. Micromegas possesses remarkable properties concerning gain stability, reduced ion feedback, response linearity, adaptable sensitive element granularity, fast response and high rate capability. Recent developments on Micromegas with a protective resistive layer present excellent results, resolving the problem of discharges caused by local high charge deposition, thanks to its RC-slowed charge evacuation. Higher resistivity though, may cause loss of the response linearity at high rates. We have scanned a wide range of resistivities and performed laboratory tests with X-rays that demonstrate excellent response linearity up to rates of (a few) times 10MHz/cm2, with simultaneous mitigation of discharges. Beam test studies at SPS/CERN with hadrons have also shown a remarkable stability of the resistive Micromegas and low currents for rates up to 15MHz/cm2. We present results from the aforementioned studies confronted with MC simulation

A Fast Monte Carlo Simulation for the International Linear Collider Detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Furse, D.; /Georgia Tech

2005-12-15

The following paper contains details concerning the motivation for, implementation and performance of a Java-based fast Monte Carlo simulation for a detector designed to be used in the International Linear Collider. This simulation, presently included in the SLAC ILC group's org.lcsim package, reads in standard model or SUSY events in STDHEP file format, stochastically simulates the blurring in physics measurements caused by intrinsic detector error, and writes out an LCIO format file containing a set of final particles statistically similar to those that would have found by a full Monte Carlo simulation. In addition to the reconstructed particles themselves, descriptionsmore » of the calorimeter hit clusters and tracks that these particles would have produced are also included in the LCIO output. These output files can then be put through various analysis codes in order to characterize the effectiveness of a hypothetical detector at extracting relevant physical information about an event. Such a tool is extremely useful in preliminary detector research and development, as full simulations are extremely cumbersome and taxing on processor resources; a fast, efficient Monte Carlo can facilitate and even make possible detector physics studies that would be very impractical with the full simulation by sacrificing what is in many cases inappropriate attention to detail for valuable gains in time required for results.« less

Detector Outline Document for the Fourth Concept Detector ("4th") at the International Linear Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbareschi, Daniele; et al.

We describe a general purpose detector ( "Fourth Concept") at the International Linear Collider (ILC) that can measure with high precision all the fundamental fermions and bosons of the standard model, and thereby access all known physics processes. The 4th concept consists of four basic subsystems: a pixel vertex detector for high precision vertex definitions, impact parameter tagging and near-beam occupancy reduction; a Time Projection Chamber for robust pattern recognition augmented with three high-precision pad rows for precision momentum measurement; a high precision multiple-readout fiber calorimeter, complemented with an EM dual-readout crystal calorimeter, for the energy measurement of hadrons, jets,more » electrons, photons, missing momentum, and the tagging of muons; and, an iron-free dual-solenoid muon system for the inverse direction bending of muons in a gas volume to achieve high acceptance and good muon momentum resolution. The pixel vertex chamber, TPC and calorimeter are inside the solenoidal magnetic field. All four subsytems separately achieve the important scientific goal to be 2-to-10 times better than the already excellent LEP detectors, ALEPH, DELPHI, L3 and OPAL. All four basic subsystems contribute to the identification of standard model partons, some in unique ways, such that consequent physics studies are cogent. As an integrated detector concept, we achieve comprehensive physics capabilities that puts all conceivable physics at the ILC within reach.« less

High Reliability Prototype Quadrupole for the Next Linear Collider

NASA Astrophysics Data System (ADS)

Spencer, C. M.

2001-01-01

The Next Linear Collider (NLC) will require over 5600 magnets, each of which must be highly reliable and/or quickly repairable in order that the NLC reach its 85/ overall availability goal. A multidiscipline engineering team was assembled at SLAC to develop a more reliable electromagnet design than historically had been achieved at SLAC. This team carried out a Failure Mode and Effects Analysis (FMEA) on a standard SLAC quadrupole magnet system. They overcame a number of longstanding design prejudices, producing 10 major design changes. This paper describes how a prototype magnet was constructed and the extensive testing carried out on it to prove full functionality with an improvement in reliability. The magnet's fabrication cost will be compared to the cost of a magnet with the same requirements made in the historic SLAC way. The NLC will use over 1600 of these 12.7 mm bore quadrupoles with a range of integrated strengths from 0.6 to 132 Tesla, a maximum gradient of 135 Tesla per meter, an adjustment range of 0 to -20/ and core lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micron during the 20/ adjustment. A magnetic measurement set-up has been developed that can measure sub-micron shifts of a magnetic center. The prototype satisfied the center shift requirement over the full range of integrated strengths.

Impact of large beam-induced heat loads on the transient operation of the beam screens and the cryogenic plants of the Future Circular Collider (FCC)

NASA Astrophysics Data System (ADS)

Correia Rodrigues, H.; Tavian, L.

2017-12-01

The Future Circular Collider (FCC) under study at CERN will produce 50-TeV high-energy proton beams. The high-energy particle beams are bent by 16-T superconducting dipole magnets operating at 1.9 K and distributed over a circumference of 80 km. The circulating beams induce 5 MW of dynamic heat loads by several processes such as synchrotron radiation, resistive dissipation of beam image currents and electron clouds. These beam-induced heat loads will be intercepted by beam screens operating between 40 and 60 K and induce transients during beam injection. Energy ramp-up and beam dumping on the distributed beam-screen cooling loops, the sector cryogenic plants and the dedicated circulators. Based on the current baseline parameters, numerical simulations of the fluid flow in the cryogenic distribution system during a beam operation cycle were performed. The effects of the thermal inertia of the headers on the helium flow temperature at the cryogenic plant inlet as well as the temperature gradient experienced by the beam screen has been assessed. Additionally, this work enabled a thorough exergetic analysis of different cryogenic plant configurations and laid the building-block for establishing design specification of cold and warm circulators.

Safety recommendation : right wing separation

DOT National Transportation Integrated Search

1999-05-28

On April 19, 1999, at about 12:46 p.m. eastern daylight time, a Beech T-34A, N140SW, operated by Sky Warriors, Inc., collided with the ground near Rydall, Georgia, following an inflight separation of the right wing. Both the air transport pilot and t...

Beam position monitoring system at CESR

NASA Astrophysics Data System (ADS)

Billing, M. G.; Bergan, W. F.; Forster, M. J.; Meller, R. E.; Rendina, M. C.; Rider, N. T.; Sagan, D. C.; Shanks, J.; Sikora, J. P.; Stedinger, M. G.; Strohman, C. R.; Palmer, M. A.; Holtzapple, R. L.

2017-09-01

The Cornell Electron-positron Storage Ring (CESR) has been converted from a High Energy Physics electron-positron collider to operate as a dedicated synchrotron light source for the Cornell High Energy Synchrotron Source (CHESS) and to conduct accelerator physics research as a test accelerator, capable of studying topics relevant to future damping rings, colliders and light sources. Some of the specific topics that were targeted for the initial phase of operation of the storage ring in this mode, labeled CESRTA (CESR as a Test Accelerator), included 1) tuning techniques to produce low emittance beams, 2) the study of electron cloud development in a storage ring and 3) intra-beam scattering effects. The complete conversion of CESR to CESRTA occurred over a several year period and is described elsewhere. As a part of this conversion the CESR beam position monitoring (CBPM) system was completely upgraded to provide the needed instrumental capabilities for these studies. This paper describes the new CBPM system hardware, its function and representative measurements performed by the upgraded system.

Submicron multi-bunch BPM for CLIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmickler, H.; Soby, L.; /CERN

2010-08-01

A common-mode free cavity BPM is currently under development at Fermilab within the ILC-CLIC collaboration. This monitor will be operated in a CLIC Main Linac multi-bunch regime, and needs to provide both, high spatial and time resolution. We present the design concept, numerical analysis, investigation on tolerances and error effects, as well as simulations on the signal response applying a multi-bunch stimulus. The proposed CERN linear collider (CLIC) requires a very precise measurement of beam trajectory to preserve the low emittance when transporting the beam through the Main Linac. An energy chirp within the bunch train will be applied tomore » measure and minimize the dispersion effects, which require high resolution (in both, time and space) beam position monitors (BPM) along the beam-line. We propose a low-Q waveguide loaded TM{sub 110} dipole mode cavity as BPM, which is complemented by a TM{sub 010} monopole mode resonator of same resonant frequency for reference signal purposes. The design is based on a well known TM{sub 110} selective mode coupling idea.« less

An ultra-low power self-timed column-level ADC for a CMOS pixel sensor based vertex detector

NASA Astrophysics Data System (ADS)

Zhang, L.; Wang, M.

2014-11-01

The International Large Detector (ILD) is a detector concept for the future linear collider experiment. The vertex detector is the key tool to achieve high precision measurements for flavor tagging, which puts stringent requirements on the CMOS pixel sensors. Due to the cooling systems which deteriorate the material budget and increase the multiple scattering, it is important to reduce the power consumption. This paper presents an ultra-low power self-timed column-level ADC for the CMOS pixel sensors, aiming to equip the outer layers of the vertex detector. The ADC was designed to operate in two modes (active and idle) adapted to the low hit density in the outer layers. The architecture employs an enhanced sample-and-hold circuit and a self-timed technique. The total power consumption with a 3-V supply is 225μW during idle mode, which is the most frequent situation. This value rises to 425μW in the case of the active mode. It occupies an area of 35 × 590μm2.

High Frequency, High Gradient Dielectric Wakefield Acceleration Experiments at SLAC and BNL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenzweig, James; /UCLA; Travish, Gil

Given the recent success of >GV/m dielectric wakefield accelerator (DWA) breakdown experiments at SLAC, and follow-on coherent Cerenkov radiation production at the UCLA Neptune, a UCLA-USC-SLAC collaboration is now implementing a new set of experiments that explore various DWA scenarios. These experiments are motivated by the opportunities presented by the approval of FACET facility at SLAC, as well as unique pulse-train wakefield drivers at BNL. The SLAC experiments permit further exploration of the multi-GeV/m envelope in DWAs, and will entail investigations of novel materials (e.g. CVD diamond) and geometries (Bragg cylindrical structures, slab-symmetric DWAs), and have an over-riding goal ofmore » demonstrating >GeV acceleration in {approx}33 cm DWA tubes. In the nearer term before FACET's commissioning, we are planning measurements at the BNL ATF, in which we drive {approx}50-200 MV/m fields with single pulses or pulse trains. These experiments are of high relevance to enhancing linear collider DWA designs, as they will demonstrate potential for efficient operation with pulse trains.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cullinan, F. J.; Boogert, S. T.; Farabolini, W.

2015-11-19

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 referencemore » 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. Lastly, 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.« less

High Resolution BPM Upgrade for the ATF Damping Ring at KEK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eddy, N.; Briegel, C.; Fellenz, B.

2011-08-17

A beam position monitor (BPM) upgrade at the KEK Accelerator Test Facility (ATF) damping ring has been accomplished, carried out by a KEK/FNAL/SLAC collaboration under the umbrella of the global ILC R&D effort. The upgrade consists of a high resolution, high reproducibility read-out system, based on analog and digital down-conversion techniques, digital signal processing, and also implements a new automatic gain error correction schema. The technical concept and realization as well as results of beam studies are presented. The next generation of linear colliders require ultra-low vertical emittance of <2 pm-rad. The damping ring at the KEK Accelerator Test Facilitymore » (ATF) is designed to demonstrate this mission critical goal. A high resolution beam position monitor (BPM) system for the damping ring is one of the key tools for realizing this goal. The BPM system needs to provide two distnict measurements. First, a very high resolution ({approx}100-200nm) closed-orbit measurement which is averaged over many turns and realized with narrowband filter techniques - 'narrowband mode'. This is needed to monitor and steer the beam along an optimum orbit and to facilitate beam-based alignment to minimize non-linear field effects. Second, is the ability to make turn by turn (TBT) measurements to support optics studies and corrections necessary to achieve the design performance. As the TBT measurement necessitates a wider bandwidth, it is often referred to as 'wideband mode'. The BPM upgrade was initiated as a KEK/SLAC/FNAL collaboration in the frame of the Global Design Initiative of the International Linear Collider. The project was realized and completed using Japan-US funds with Fermilab as the core partner.« less

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.

Recording the synchrotron radiation by a picosecond streak camera for bunch diagnostics in cyclic accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vereshchagin, A K; Vorob'ev, N S; Gornostaev, P B

2016-02-28

A PS-1/S1 picosecond streak camera with a linear sweep is used to measure temporal characteristics of synchrotron radiation pulses on a damping ring (DR) at the Budker Institute of Nuclear Physics (BINP) of the Siberian Branch of the Russian Academy of Sciences (Novosibirsk). The data obtained allow a conclusion as to the formation processes of electron bunches and their 'quality' in the DR after injection from the linear accelerator. The expediency of employing the streak camera as a part of an optical diagnostic accelerator complex for adjusting the injection from a linear accelerator is shown. Discussed is the issue ofmore » designing a new-generation dissector with a time resolution up to a few picoseconds, which would allow implementation of a continuous bunch monitoring in the DR during mutual work with the electron-positron colliders at the BINP. (acoustooptics)« less

Light flavon signals at electron-photon colliders

NASA Astrophysics Data System (ADS)

Muramatsu, Yu; Nomura, Takaaki; Shimizu, Yusuke; Yokoya, Hiroshi

2018-01-01

Flavor symmetries are useful to realize fermion flavor structures in the standard model (SM). In particular, the discrete A4 symmetry is used to realize lepton flavor structures, and some scalars—called flavons—are introduced to break this symmetry. In many models, flavons are assumed to be much heavier than the electroweak scale. However, our previous work showed that a flavon mass around 100 GeV is allowed by experimental constraints in the A4 symmetric model with a residual Z3 symmetry. In this paper, we discuss collider searches for such a light flavon φT. We find that electron-photon collisions at the International Linear Collider have advantages for searching for these signals. In electron-photon collisions, flavons are produced as e-γ →l-φT and decay into two charged leptons. Then, we analyze signals of the flavor-conserving final state τ+τ-e- and the flavor-violating final states τ+μ-μ- and μ+τ-τ- by carrying out numerical simulations. For the former final state, SM background can be strongly suppressed by imposing cuts on the invariant masses of final-state leptons. For the latter final states, SM background is extremely small, because in the SM there are no such flavor-violating final states. We then find that sufficient discovery significance can be obtained, even if flavons are heavier than the lower limits from flavor physics.

Probing top-Z dipole moments at the LHC and ILC

DOE PAGES

Röntsch, Raoul; Schulze, Markus

2015-08-11

We investigate the weak electric and magnetic dipole moments of top quark-Z boson interactions at the Large Hadron Collider (LHC) and the International Linear Collider (ILC). Their vanishingly small magnitude in the Standard Model makes these couplings ideal for probing New Physics interactions and for exploring the role of top quarks in electroweak symmetry breaking. In our analysis, we consider the production of two top quarks in association with a Z boson at the LHC, and top quark pairs mediated by neutral gauge bosons at the ILC. These processes yield direct sensitivity to top quark-Z boson interactions and complement indirectmore » constraints from electroweak precision data. Our computation is accurate to next-to-leading order in QCD, we include the full decay chain of top quarks and the Z boson, and account for theoretical uncertainties in our constraints. Furthermore, we find that LHC experiments will soon be able to probe weak dipole moments for the first time.« less

Laboratory Directed Research and Development Program: Annual report to the Department of Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogeka, G.J.; Romano, A.J.

1994-12-01

Project program summaries are presented for: effect of bacterial spore protein on mutagenesis; cellular toxicity of coaine and cocaethylene; calcinfication in marine alga (global carbon cycling); advanced permanent magnet materials; a high flux neutron source; genetics of drug addiction; microdialysis; analysis of powder diffraction data; accelerator technology; nucleic acids and proteins and their interactions, by small-angle XRD; enhancement of microplanar beam radiation therapy of gliosarcoma; relaxographic and functional MRI; low-temperature infrared laser absorption spectroscopy; photodesorption of H{sub 2}; helical magnet for RHIC; novel microporous solids; chemistry and physics of stratospheric aerosols (ozone depletion); rf source for linear colliders; resonance Ramanmore » detection of VOCs; synthesis of plant fatty acids with unusual double bond positions; outer surface proteins of the Lyme disease spirochete; multiwire proportional chambers for collider muons; self-organized criticality; PCR-SSCP detection of genetic changes at single cell level; proton facility for cancer therapy; and visible free-electron laser experiment.« less

First a tragedy, then farce

NASA Astrophysics Data System (ADS)

Foster, Brian

2008-09-01

It is impossible to think about the problems in the UK over the last 10 months arising from the £80m shortfall in the budget of the Science and Technology Facilities Council (STFC) without recalling Marx's famous aphorism: "History repeats itself, first as tragedy, then as farce." Certainly the repetition of a funding crisis in UK particle physics and astronomy is hardly unexpected; they seem to occur every decade or so with unwelcome regularity. The consequent loss of morale, jobs and opportunities in the UK for the brightest young people to pursue their dreams in what is widely acknowledged to be world-class science is a tragedy. What perhaps marks the uniqueness of the funding crisis this time round is the level of farce. The sums that did not add up; the consultations without interlocutors; and the truculent and damaging statements about withdrawal from the Gemini telescopes based in Hawaii and Chile, and the International Linear Collider (ILC) - the next big particle-physics project after the Large Hadron Collider (LHC) at CERN.

Plasma lens experiments at the Final Focus Test Beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barletta, B.; Chattopadhyay, S.; Chen, P.

1993-04-01

We intend to carry out a series of plasma lens experiments at the Final Focus Test Beam facility at SLAC. These experiments will be the first to study the focusing of particle beams by plasma focusing devices in the parameter regime of interest for high energy colliders, and is expected to lead to plasma lens designs capable of unprecedented spot sizes. Plasma focusing of positron beams will be attempted for the first time. We will study the effects of lens aberrations due to various lens imperfections. Several approaches will be applied to create the plasma required including laser ionization andmore » beam ionization of a working gas. At an increased bunch population of 2.5 {times} 10{sup 10}, tunneling ionization of a gas target by an electron beam -- an effect which has never been observed before -- should be significant. The compactness of our device should prove to be of interest for applications at the SLC and the next generation linear colliders.« less

X-ray observations of the colliding wind binary WR 25

NASA Astrophysics Data System (ADS)

Arora, Bharti; Pandey, Jeewan Chandra

2018-04-01

Using the archival data obtained from Chandra and Suzaku spanning over '8 years, we present an analysis of a WN6h+O4f Wolf-Rayet binary, WR 25. The X-ray light curves folded over a period of '208 d in the 0.3 - 10.0 keV energy band showed phase-locked variability where the count rates were found to be maximum near the periastron passage. The X-ray spectra of WR 25 were well explained by a two-temperature plasma model with temperatures of 0.64 ± 0.01 and 2.96 ± 0.05 keV and are consistent with previous results. The orbital phase dependent local hydrogen column density was found to be maximum just after the periastron passage, when the WN type star is in front of the O star. The hard (2.0 - 10.0 keV) X-ray luminosity was linearly dependent on the inverse of binary separation which confirms that WR 25 is a colliding wind binary.

Dissipative models of colliding stellar winds - I. Effects of thermal conduction in wide binary systems

NASA Astrophysics Data System (ADS)

Myasnikov, A. V.; Zhekov, S. A.

1998-11-01

The influence of electron thermal conduction on the 2D gas dynamics of colliding stellar winds is investigated. It is shown that, as a result of the non-linear dependence of the electron thermal flux on the temperature, the pre-heating zones (in which the hot gas in the interaction region heats the cool winds in front of the shocks) have finite sizes. The dependence of the problem of the structure of the flow in the interaction region on the dimensionless parameters is studied, and a simple expression is derived for the size of the pre-heating zones at the axis of symmetry. It is shown that small values of the thermal conductivity do not suppress the Kelvin-Helmholtz instability if the adiabatic flow is subject to it. Further studies, both numerical and analytical, in this direction will be of great interest. The influence of thermal conduction on the X-ray emission from the interaction region is also estimated.

Generating Low Beta Regions with Quadrupoles for Final Muon Cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acosta, J. G.; Cremaldi, L. M.; Hart, T. L.

2017-05-01

Muon beams and colliders are rich sources of new physics, if muons can be cooled. A normalized rms transverse muon emittance of 280 microns has been achieved in simulation with short solenoids and a betatron function of 3 cm. Here we use ICOOL, G4beamline, and MAD-X to explore using a 400 MeV/c muon beam and strong focusing quadrupoles to approach a normalized transverse emittance of 100 microns and finish 6D muon cooling. The low beta regions produced by the quadrupoles are occupied by dense, low Z absorbers, such as lithium hydride or beryllium, that cool the beam. Equilibrium transverse emittancemore » is linearly proportional to the beta function. Reverse emittance exchange with septa and/or wedges is then used to decrease transverse emittance from 100 to 25 microns at the expense of longitudinal emittance for a high energy lepton collider. Work remains to be done on chromaticity correction.« less

Construction and response of a highly granular scintillator-based electromagnetic calorimeter

NASA Astrophysics Data System (ADS)

Repond, J.; Xia, L.; Eigen, G.; Price, T.; Watson, N. K.; Winter, A.; Thomson, M. A.; Cârloganu, C.; Blazey, G. C.; Dyshkant, A.; Francis, K.; Zutshi, V.; Gadow, K.; Göttlicher, P.; Hartbrich, O.; Kotera, K.; Krivan, F.; Krüger, K.; Lu, S.; Lutz, B.; Reinecke, M.; Sefkow, F.; Sudo, Y.; Tran, H. L.; Kaplan, A.; Schultz-Coulon, H.-Ch.; Bilki, B.; Northacker, D.; Onel, Y.; Wilson, G. W.; Kawagoe, K.; Sekiya, I.; Suehara, T.; Yamashiro, H.; Yoshioka, T.; Alamillo, E. Calvo; Fouz, M. C.; Marin, J.; Navarrete, J.; Pelayo, J. Puerta; Verdugo, A.; Chadeeva, M.; Danilov, M.; Gabriel, M.; Goecke, P.; Graf, C.; Israeli, Y.; Kolk, N. Van Der; Simon, F.; Szalay, M.; Windel, H.; Bilokin, S.; Bonis, J.; Pöschl, R.; Thiebault, A.; Richard, F.; Zerwas, D.; Balagura, V.; Boudry, V.; Brient, J.-C.; Cornat, R.; Cvach, J.; Janata, M.; Kovalcuk, M.; Kvasnicka, J.; Polak, I.; Smolik, J.; Vrba, V.; Zalesak, J.; Zuklin, J.; Choi, W.; Kotera, K.; Nishiyama, M.; Sakuma, T.; Takeshita, T.; Tozuka, S.; Tsubokawa, T.; Uozumi, S.; Jeans, D.; Ootani, W.; Liu, L.; Chang, S.; Khan, A.; Kim, D. H.; Kong, D. J.; Oh, Y. D.; Ikuno, T.; Sudo, Y.; Takahashi, Y.; Götze, M.; Calice Collaboration

2018-04-01

A highly granular electromagnetic calorimeter with scintillator strip readout is being developed for future linear collider experiments. A prototype of 21.5 X0 depth and 180 × 180mm2 transverse dimensions was constructed, consisting of 2160 individually read out 10 × 45 × 3mm3 scintillator strips. This prototype was tested using electrons of 2-32 GeV at the Fermilab Test Beam Facility in 2009. Deviations from linear energy response were less than 1.1%, and the intrinsic energy resolution was determined to be (12 . 5 ± 0 . 1(stat.) ± 0 . 4(syst.)) % /√{ E [ GeV ] } ⊕(1.2 ± 0.1 (stat.)-0.7+0.6 (syst.)) %, where the uncertainties correspond to statistical and systematic sources, respectively.

Numerical Calculations of Short-Range Wakefields of Collimators

NASA Astrophysics Data System (ADS)

Ng, C. K.

2001-12-01

The performance of future linear colliders are limited by the effect of short-range collimator wakefields on the beam. The beam quality is sensitive to the positioning of collimators at the end of the linac. The determination of collimator wakefields has been difficult, largely because of the scarcity of measurement data, and of the limitation of applicability of analytical results to realistic structures. In this paper, numerical methods using codes such as MAFIA are used to determine a series of tapered collimators with rectangular apertures that have been built for studies at SLAC (Stanford Linear Accelerator Center). We will study the dependences of the wakefield on the collimator taper angle, the collimator gap as well as the bunch length. Calculations are also compared with measurements.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cornuelle, John C.

In March, 2001, the TESLA Collaboration published its Technical Design Report (TDR, see references and links in Appendix), the first sentence of which stated ''...TESLA (TeV-Energy Superconducting Linear Collider) (will be) a superconducting electron-positron collider of initially 500 GeV total energy, extendable to 800 GeV, and an integrated X-ray laser laboratory.'' The TDR included cost and manpower estimates for a 500 GeV e{sup +}e{sup -} collider (250 on 250 GeV) based on superconducting RF cavity technology. This was submitted as a proposal to the German government. The government asked the German Science Council to evaluate this proposal. The recommendation frommore » this body is anticipated to be available by November 2002. The government has indicated that it will react on this recommendation by mid-2003. In June 2001, Steve Holmes, Fermilab's Associate Director for Accelerators, commissioned Helen Edwards and Peter Garbincius to organize a study of the TESLA Technical Design Report and the associated cost and manpower estimates. Since the elements and methodology used in producing the TESLA cost estimate were somewhat different from those used in preparing similar estimates for projects within the U.S., it is important to understand the similarities, differences, and equivalences between the TESLA estimate and U.S. cost estimates. In particular, the project cost estimate includes only purchased equipment, materials, and services, but not manpower from DESY or other TESLA collaborating institutions, which is listed separately. It does not include the R&D on the TESLA Test Facility (TTF) nor the costs of preparing the TDR nor the costs of performing the conceptual studies so far. The manpower for the pre-operations commissioning program (up to beam) is included in the estimate, but not the electrical power or liquid Nitrogen (for initial cooldown of the cryogenics plant). There is no inclusion of any contingency or management reserve. If the U.S. were to become involved with the TESLA project, either as a collaborator for an LC in Germany, or as host country for TESLA in the U.S., it is important to begin to understand the scope and technical details of the project, what R&D still needs to be done, and how the U.S. can contribute. The charge for this study is included in the Appendix to this report.« less

Superconducting Magnet Technology for Future High Energy Proton Colliders

NASA Astrophysics Data System (ADS)

Gourlay, Stephen

2017-01-01

Interest in high field dipoles has been given a boost by new proposals to build a high-energy proton-proton collider to follow the LHC and programs around the world are taking on the task to answer the need. Studies aiming toward future high-energy proton-proton colliders at the 100 TeV scale are now being organized. The LHC and current cost models are based on technology close to four decades old and point to a broad optimum of operation using dipoles with fields between 5 and 12T when site constraints, either geographical or political, are not a factor. Site geography constraints that limit the ring circumference can drive the required dipole field up to 20T, which is more than a factor of two beyond state-of-the-art. After a brief review of current progress, the talk will describe the challenges facing future development and present a roadmap for moving high field accelerator magnet technology forward. This work was supported by the Director, Office of Science, High Energy Physics, US Department of Energy, under contract No. DE-AC02-05CH11231.

Higgs portal dark matter in non-standard cosmological histories

NASA Astrophysics Data System (ADS)

Hardy, Edward

2018-06-01

A scalar particle with a relic density set by annihilations through a Higgs portal operator is a simple and minimal possibility for dark matter. However, assuming a thermal cosmological history this model is ruled out over most of parameter space by collider and direct detection constraints. We show that in theories with a non-thermal cosmological history Higgs portal dark matter is viable for a wide range of dark matter masses and values of the portal coupling, evading existing limits. In particular, we focus on the string theory motivated scenario of a period of matter domination due to a light modulus with a decay rate that is suppressed by the Planck scale. Dark matter with a mass ≲ GeV is possible without additional hidden sector states, and this can have astrophysically relevant self-interactions. We also study the signatures of such models at future direct, indirect, and collider experiments. Searches for invisible Higgs decays at the high luminosity LHC or an e + e - collider could cover a significant proportion of the parameter space for low mass dark matter, and future direct detection experiments will play a complementary role.

Collider effects of unparticle interactions in multiphoton signals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aliev, T. M.; Frank, Mariana; Turan, Ismail

2009-12-01

A new model of physics, with a hidden conformal sector which manifests itself as an unparticle coupling to standard model particles effectively through higher dimensional operators, predicts strong collider signals due to unparticle self-interactions. We perform a complete analysis of the most spectacular of these signals at the hadron collider, pp(p){yields}{gamma}{gamma}{gamma}{gamma} and {gamma}{gamma}gg. These processes can go through the three-point unparticle self-interactions as well as through some s and t channel diagrams with one and/or two unparticle exchanges. We study the contributions of individual diagrams classified with respect to the number of unparticle exchanges and discuss their effect on themore » cross sections at the Tevatron and the LHC. We also restrict the Tevatron bound on the unknown coefficient of the three-point unparticle correlator. With the availability of data from the Tevatron, and the advent of the data emerging from the LHC, these interactions can provide a clear and strong indication of unparticle physics and distinguish this model from other beyond the standard model scenarios.« less

Simulation of secondary emission calorimeter for future colliders

NASA Astrophysics Data System (ADS)

Yetkin, E. A.; Yetkin, T.; Ozok, F.; Iren, E.; Erduran, M. N.

2018-03-01

We present updated results from a simulation study of a conceptual sampling electromagnetic calorimeter based on secondary electron emission process. We implemented the secondary electron emission process in Geant4 as a user physics list and produced the energy spectrum and yield of secondary electrons. The energy resolution of the SEE calorimeter was σ/E = (41%) GeV1/2/√E and the response linearity to electromagnetic showers was to within 1.5%. The simulation results were also compared with a traditional scintillator calorimeter.

Physics experiments with Nintendo Wii controllers

NASA Astrophysics Data System (ADS)

Wheeler, Martyn D.

2011-01-01

This article provides a detailed description of the use of Nintendo Wii game controllers in physics demonstrations. The main features of the controller relevant to physics are outlined and the procedure for communicating with a PC is described. A piece of software written by the author is applied to gathering data from a controller suspended from a spring undergoing simple harmonic motion, a pair of controllers mounted on colliding gliders on a linear air track, and a person jumping from a balance board.

Bremsstrahlung from colour charges as a source of soft particle production in hadronic collisions

NASA Astrophysics Data System (ADS)

Bialas, A.; Jezabek, M.

2004-06-01

It is proposed that soft particle production in hadronic collisions is dominated by multiple gluon exchanges between partons from the colliding hadrons, followed by radiation of hadronic clusters from the coloured partons distributed uniformly in rapidity. This explains naturally two dominant features of the data: (a) the linear increase of rapidity spectra in the regions of limiting fragmentation and, (b) the proportionality between the increasing width of the limiting fragmentation region and the height of the central plateau.

ATCA for Machines-- Advanced Telecommunications Computing Architecture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larsen, R.S.; /SLAC

2008-04-22

The Advanced Telecommunications Computing Architecture is a new industry open standard for electronics instrument modules and shelves being evaluated for the International Linear Collider (ILC). It is the first industrial standard designed for High Availability (HA). ILC availability simulations have shown clearly that the capabilities of ATCA are needed in order to achieve acceptable integrated luminosity. The ATCA architecture looks attractive for beam instruments and detector applications as well. This paper provides an overview of ongoing R&D including application of HA principles to power electronics systems.

Accelerating Into the Future: From 0 to GeV in a Few Centimeters (LBNL Summer Lecture Series)

ScienceCinema

Leemans, Wim [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Accelerator and Fusion Research Division (AFRD) and Laser Optics and Accelerator Systems Integrated Studies (LOASIS)

2018-05-04

Summer Lecture Series 2008: By exciting electric fields in plasma-based waveguides, lasers accelerate electrons in a fraction of the distance conventional accelerators require. The Accelerator and Fusion Research Division's LOASIS program, headed by Wim Leemans, has used 40-trillion-watt laser pulses to deliver billion-electron-volt (1 GeV) electron beams within centimeters. Leemans looks ahead to BELLA, 10-GeV accelerating modules that could power a future linear collider.

Accelerating Into the Future: From 0 to GeV in a Few Centimeters (LBNL Summer Lecture Series)

ScienceCinema

Leemans, Wim [LOASIS Program, AFRD

2017-12-09

July 8, 2008 Berkeley Lab lecture: By exciting electric fields in plasma-based waveguides, lasers accelerate electrons in a fraction of the distance conventional accelerators require. The Accelerator and Fusion Research Division's LOASIS program, headed by Wim Leemans, has used 40-trillion-watt laser pulses to deliver billion-electron-volt (1 GeV) electron beams within centimeters. Leemans looks ahead to BELLA, 10-GeV accelerating modules that could power a future linear collider.

Wakefield Simulation of CLIC PETS Structure Using Parallel 3D Finite Element Time-Domain Solver T3P

DOE Office of Scientific and Technical Information (OSTI.GOV)

Candel, A.; Kabel, A.; Lee, L.

In recent years, SLAC's Advanced Computations Department (ACD) has developed the parallel 3D Finite Element electromagnetic time-domain code T3P. Higher-order Finite Element methods on conformal unstructured meshes and massively parallel processing allow unprecedented simulation accuracy for wakefield computations and simulations of transient effects in realistic accelerator structures. Applications include simulation of wakefield damping in the Compact Linear Collider (CLIC) power extraction and transfer structure (PETS).

The FONT5 Bunch-by-Bunch Position and Angle Feedback System at ATF2

NASA Astrophysics Data System (ADS)

Apsimon, R. J.; Bett, D. R.; Burrows, P. N.; Christian, G. B.; Constance, B.; Davis, M. R.; Gerbershagen, A.; Perry, C.; Resta-Lopez, J.

The FONT5 upstream beam-based feedback system at ATF2 is designed to correct the position and angle jitter at the entrance to the ATF2 final-focus system, and also to demonstrate a prototype intra-train feedback system for the International Linear Collider interaction point. We discuss the hardware, from stripline BPMs to kickers, and RF and digital signal processing, as well as presenting results from the latest beam tests at ATF2.

SLC injector modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanerfeld, H; Herrmannsfeldt, W.B.; James, M.B.

1985-03-01

The injector for the Stanford Linear Collider is being studied using the fully electromagnetic particle-in-cell program MASK. The program takes account of cylindrically symmetrical rf fields from the external source, as well as fields produced by the beam and dc magnetic fields. It calculates the radial and longitudinal motion of electrons and plots their positions in various planes in phase space. Bunching parameters can be optimized and insights into the bunching process and emittance growth have been gained. The results of the simulations are compared to the experimental results.

Next-to-leading order predictions for WW + jet production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campbell, John M.; Miller, David J.; Robens, Tania

2015-07-28

In this study we report on a next-to-leading order calculation of WW + jet production at hadron colliders, with subsequent leptonic decays of the W bosons included. The calculation of the one-loop contributions is performed using generalized unitarity methods in order to derive analytic expressions for the relevant amplitudes. These amplitudes have been implemented in the parton-level Monte Carlo generator mcfm, which we use to provide a complete next-to-leading order calculation. Predictions for total cross sections, as well as differential distributions for several key observables, are computed both for the LHC operating at 14 TeV as well as for amore » possible future 100 TeV proton-proton collider.« less

New Experiments with Antiprotons

NASA Astrophysics Data System (ADS)

Kaplan, D. M.

2011-12-01

Fermilab operates the world's most intense antiproton source. Recently proposed experiments can use those antiprotons either parasitically during Teva-tron Collider running or after the Tevatron Collider finishes in about 2011. For example, the annihilation of 8 GeV antiprotons might make the world's most intense source of tagged D0 mesons, and thus the best near-term opportunity to study charm mixing and search for new physics via its CP-violation signature. Other possible precision measurements include properties of the X(3872) and the charmonium system. An experiment using a Penning trap and an atom interferometer could make the world's first measurement of the gravitational force on antimatter. These and other potential measurements using antiprotons could yield a broad physics program at Fermilab in the post-Tevatron era.

Precision constraints on the top-quark effective field theory at future lepton colliders

NASA Astrophysics Data System (ADS)

Durieux, G.

We examine the constraints that future lepton colliders would impose on the effective field theory describing modifications of top-quark interactions beyond the standard model, through measurements of the $e^+e^-\\to bW^+\\:\\bar bW^-$ process. Statistically optimal observables are exploited to constrain simultaneously and efficiently all relevant operators. Their constraining power is sufficient for quadratic effective-field-theory contributions to have negligible impact on limits which are therefore basis independent. This is contrasted with the measurements of cross sections and forward-backward asymmetries. An overall measure of constraints strength, the global determinant parameter, is used to determine which run parameters impose the strongest restriction on the multidimensional effective-field-theory parameter space.

Beam energy scan with asymmetric collision at RHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, C.; Alessi, J.; Beebe, E.

A beam energy scan of deuteron-gold collision, with center-of-mass energy at 19.6, 39, 62.4 and 200.7 GeV/n, was performed at the Relativistic Heavy Ion Collider in 2016 to study the threshold for quark-gluon plasma (QGP) production. The lattice, RF, stochastic cooling and other subsystems were in different configurations for the various energies. The operational challenges changed with every new energy. The operational experience at each energy, the operation performance, highlights and lessons of the beam energy scan are reviewed in this report.

Highway Accident Summary Report: Bus Collision With Pedestrians, Normandy, Missouri, June 11, 1997

DOT National Transportation Integrated Search

1998-02-19

On June 11, 1997, a transit bus collided with seven pedestrians at a "park and ride" transit facility in Normandy, Missouri. The bus was being operated by a driver trainee who had just completed a routine stop at the station. After allowing the passe...

Crabbing system for an electron-ion collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castilla, Alejandro

2017-05-01

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

Measuring the Magnetic Center Behavior of an ILC Superconducting Quadrupole Prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spencer, Cherrill M.; Adolphsen, Chris; Berndt, Martin

2011-02-07

The main linacs of the proposed International Linear Collider (ILC) consist of superconducting cavities operated at 2K. The accelerating cavities are contained in a contiguous series of cryogenic modules that also house the main linac quadrupoles, thus the quadrupoles also need to be superconducting. In an early ILC design, these magnets are about 0.6 m long, have cos (2{theta}) coils, and operate at constant field gradients up to 60 T/m. In order to preserve the small beam emittances in the ILC linacs, the e+ and e- beams need to traverse the quadrupoles near their magnetic centers. A quadrupole shunting techniquemore » is used to measure the quadrupole alignment with the beams; this process requires the magnetic centers move by no more than about 5 micrometers when their strength is changed. To determine if such tight stability is achievable in a superconducting quadrupole, we at SLAC measured the magnetic center motions in a prototype ILC quadrupole built at CIEMAT in Spain. A rotating coil technique was used with a better than 0.1 micrometer precision in the relative field center position, and less than a 2 micrometer systematic error over 30 minutes. This paper describes the warm-bore cryomodule that houses the quadrupole in its Helium vessel, the magnetic center measurement system, the measured center data and strength and harmonics magnetic data.« less

Linear and non-linear flow mode in Pb-Pb collisions at √{sNN} = 2.76 TeV

NASA Astrophysics Data System (ADS)

Acharya, S.; Adamová, D.; Adolfsson, J.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Alba, J. L. B.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altenkamper, L.; Altsybeev, I.; Alves Garcia Prado, C.; An, M.; Andrei, C.; Andreou, D.; Andrews, H. A.; Andronic, A.; Anguelov, V.; Anson, C.; Antičić, T.; Antinori, F.; Antonioli, P.; Anwar, R.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Ball, M.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barioglio, L.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Beltran, L. G. E.; Belyaev, V.; Bencedi, G.; Beole, S.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Blair, J. T.; Blau, D.; Blume, C.; Boca, G.; Bock, F.; Bogdanov, A.; Boldizsár, L.; Bombara, M.; Bonomi, G.; Bonora, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buhler, P.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caffarri, D.; Caines, H.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Capon, A. A.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Ceballos Sanchez, C.; Cerello, P.; Chandra, S.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Cho, S.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Chowdhury, T.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Concas, M.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Costanza, S.; Crkovská, J.; Crochet, P.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; de, S.; de Caro, A.; de Cataldo, G.; de Conti, C.; de Cuveland, J.; de Falco, A.; de Gruttola, D.; De Marco, N.; de Pasquale, S.; de Souza, R. D.; Degenhardt, H. F.; Deisting, A.; Deloff, A.; Deplano, C.; Dhankher, P.; di Bari, D.; di Mauro, A.; di Nezza, P.; di Ruzza, B.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Doremalen, L. V. V.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Duggal, A. K.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erhardt, F.; Espagnon, B.; Esumi, S.; Eulisse, G.; Eum, J.; Evans, D.; Evdokimov, S.; Fabbietti, L.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Francisco, A.; Frankenfeld, U.; Fronze, G. G.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gajdosova, K.; Gallio, M.; Galvan, C. D.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Garg, K.; Garg, P.; Gargiulo, C.; Gasik, P.; Gauger, E. F.; Gay Ducati, M. B.; Germain, M.; Ghosh, J.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; Gonzalez, A. S.; Gonzalez, V.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Graham, K. L.; Greiner, L.; Grelli, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grion, N.; Gronefeld, J. M.; Grosa, F.; Grosse-Oetringhaus, J. F.; Grosso, R.; Gruber, L.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Guzman, I. B.; Haake, R.; Hadjidakis, C.; Hamagaki, H.; Hamar, G.; Hamon, J. C.; Harris, J. W.; Harton, A.; Hassan, H.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Hellbär, E.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Herrmann, F.; Hess, B. A.; Hetland, K. F.; Hillemanns, H.; Hills, C.; Hippolyte, B.; Hladky, J.; Hohlweger, B.; Horak, D.; Hornung, S.; Hosokawa, R.; Hristov, P.; Hughes, C.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Iga Buitron, S. A.; Ilkaev, R.; Inaba, M.; Ippolitov, M.; Irfan, M.; Isakov, V.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacak, B.; Jacazio, N.; Jacobs, P. M.; Jadhav, M. B.; Jadlovska, S.; Jadlovsky, J.; Jaelani, S.; Jahnke, C.; Jakubowska, M. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jercic, M.; Jimenez Bustamante, R. T.; Jones, P. G.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karayan, L.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Ketzer, B.; Khabanova, Z.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Khatun, A.; Khuntia, A.; Kielbowicz, M. M.; Kileng, B.; Kim, D.; Kim, D. W.; Kim, D. J.; Kim, H.; Kim, J. S.; Kim, J.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Bösing, C.; Klewin, S.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Konyushikhin, M.; Kopcik, M.; Kour, M.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.; Koyithatta Meethaleveedu, G.; Králik, I.; Kravčáková, A.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kuhn, C.; Kuijer, P. G.; Kumar, A.; Kumar, J.; Kumar, L.; Kumar, S.; Kundu, S.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Lagana Fernandes, C.; Lai, Y. S.; Lakomov, I.; Langoy, R.; Lapidus, K.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lavicka, R.; Lazaridis, L.; Lea, R.; Leardini, L.; Lee, S.; Lehas, F.; Lehner, S.; Lehrbach, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lim, B.; Lindal, S.; Lindenstruth, V.; Lindsay, S. W.; Lippmann, C.; Lisa, M. A.; Litichevskyi, V.; Ljunggren, H. M.; Llope, W. J.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Loncar, P.; Lopez, X.; López Torres, E.; Lowe, A.; Luettig, P.; Lunardon, M.; Luparello, G.; Lupi, M.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martin, N. A.; Martinengo, P.; Martinez, J. A. L.; Martínez, M. I.; Martínez García, G.; Martinez Pedreira, M.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Masson, E.; Mastroserio, A.; Mathis, A. M.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzilli, M.; Mazzoni, M. A.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Mhlanga, S.; Miake, Y.; Mieskolainen, M. M.; Mihaylov, D.; Mihaylov, D. L.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Mohisin Khan, M.; Montes, E.; Moreira de Godoy, D. A.; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Münning, K.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Myers, C. J.; Myrcha, J. W.; Naik, B.; Nair, R.; Nandi, B. K.; Nania, R.; Nappi, E.; Narayan, A.; Naru, M. U.; Natal da Luz, H.; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Negrao de Oliveira, R. A.; Nellen, L.; Nesbo, S. V.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Nobuhiro, A.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Ohlson, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Oravec, M.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Pachmayer, Y.; Pacik, V.; Pagano, D.; Pagano, P.; Paić, G.; Palni, P.; Pan, J.; Pandey, A. K.; Panebianco, S.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, J.; Parmar, S.; Passfeld, A.; Pathak, S. P.; Paticchio, V.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.; Peng, X.; Pereira, L. G.; Pereira da Costa, H.; Peresunko, D.; Perez Lezama, E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Pezzi, R. P.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pliquett, F.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Poppenborg, H.; Porteboeuf-Houssais, S.; Porter, J.; Pozdniakov, V.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Rana, D. B.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Ratza, V.; Ravasenga, I.; Read, K. F.; Redlich, K.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rodríguez Cahuantzi, M.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Rokita, P. S.; Ronchetti, F.; Rosas, E. D.; Rosnet, P.; Rossi, A.; Rotondi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rueda, O. V.; Rui, R.; Russo, R.; Rustamov, A.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Saarinen, S.; Sadhu, S.; Sadovsky, S.; Šafařík, K.; Saha, S. K.; Sahlmuller, B.; Sahoo, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sandoval, A.; Sarkar, D.; Sarkar, N.; Sarma, P.; Sas, M. H. P.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Scheid, H. S.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schmidt, M. O.; Schmidt, M.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Šefčík, M.; Seger, J. E.; Sekiguchi, Y.; Sekihata, D.; Selyuzhenkov, I.; Senosi, K.; Senyukov, S.; Serradilla, E.; Sett, P.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shahoyan, R.; Shaikh, W.; Shangaraev, A.; Sharma, A.; Sharma, A.; Sharma, M.; Sharma, M.; Sharma, N.; Sheikh, A. I.; Shigaki, K.; Shou, Q.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singhal, V.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Song, J.; Song, M.; Soramel, F.; Sorensen, S.; Sozzi, F.; Spiriti, E.; Sputowska, I.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stankus, P.; Stenlund, E.; Stocco, D.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Suljic, M.; Sultanov, R.; Šumbera, M.; Sumowidagdo, S.; Suzuki, K.; Swain, S.; Szabo, A.; Szarka, I.; Szczepankiewicz, A.; Tabassam, U.; Takahashi, J.; Tambave, G. J.; Tanaka, N.; Tarhini, M.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thakur, D.; Thakur, S.; Thomas, D.; Tieulent, R.; Tikhonov, A.; Timmins, A. R.; Toia, A.; Tripathy, S.; Trogolo, S.; Trombetta, G.; Tropp, L.; Trubnikov, V.; Trzaska, W. H.; Trzeciak, B. A.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Umaka, E. N.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vala, M.; van der Maarel, J.; van Hoorne, J. W.; van Leeuwen, M.; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vázquez Doce, O.; Vechernin, V.; Veen, A. M.; Velure, A.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Vértesi, R.; Vickovic, L.; Vigolo, S.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Villatoro Tello, A.; Vinogradov, A.; Vinogradov, L.; Virgili, T.; Vislavicius, V.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Voscek, D.; Vranic, D.; Vrláková, J.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Watanabe, D.; Watanabe, Y.; Weber, M.; Weber, S. G.; Weiser, D. F.; Wenzel, S. C.; Wessels, J. P.; Westerhoff, U.; Whitehead, A. M.; Wiechula, J.; Wikne, J.; Wilk, G.; Wilkinson, J.; Willems, G. A.; Williams, M. C. S.; Willsher, E.; Windelband, B.; Witt, W. E.; Yalcin, S.; Yamakawa, K.; Yang, P.; Yano, S.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yoon, J. H.; Yurchenko, V.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zardoshti, N.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhang, C.; Zhang, Z.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zmeskal, J.; Zou, S.; Alice Collaboration

2017-10-01

The second and the third order anisotropic flow, V2 and V3, are mostly determined by the corresponding initial spatial anisotropy coefficients, ε2 and ε3, in the initial density distribution. In addition to their dependence on the same order initial anisotropy coefficient, higher order anisotropic flow, Vn (n > 3), can also have a significant contribution from lower order initial anisotropy coefficients, which leads to mode-coupling effects. In this Letter we investigate the linear and non-linear modes in higher order anisotropic flow Vn for n = 4, 5, 6 with the ALICE detector at the Large Hadron Collider. The measurements are done for particles in the pseudorapidity range | η | < 0.8 and the transverse momentum range 0.2

Linear and non-linear flow mode in Pb–Pb collisions at s NN = 2.76  TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acharya, S.; Adamová, D.; Adolfsson, J.

The second and the third order anisotropic flow, V 2 and V 3, are mostly determined by the corresponding initial spatial anisotropy coefficients, and , in the initial density distribution. In addition to their dependence on the same order initial anisotropy coefficient, higher order anisotropic flow, V n (n > 3), can also have a significant contribution from lower order initial anisotropy coefficients, which leads to mode-coupling effects. In this Letter we investigate the linear and non-linear modes in higher order anisotropic flow V n for n = 4, 5, 6 with the ALICE detector at the Large Hadron Collider.more » The measurements are done for particles in the pseudorapidity range |η| < 0.8 and the transverse momentum range 0.2 < p T < 5.0 GeV/c as a function of collision centrality. The results are compared with theoretical calculations and provide important constraints on the initial conditions, including initial spatial geometry and its fluctuations, as well as the ratio of the shear viscosity to entropy density of the produced system.« less

Linear and non-linear flow mode in Pb–Pb collisions at s NN = 2.76  TeV

DOE PAGES

Acharya, S.; Adamová, D.; Adolfsson, J.; ...

2017-08-04

The second and the third order anisotropic flow, V 2 and V 3, are mostly determined by the corresponding initial spatial anisotropy coefficients, and , in the initial density distribution. In addition to their dependence on the same order initial anisotropy coefficient, higher order anisotropic flow, V n (n > 3), can also have a significant contribution from lower order initial anisotropy coefficients, which leads to mode-coupling effects. In this Letter we investigate the linear and non-linear modes in higher order anisotropic flow V n for n = 4, 5, 6 with the ALICE detector at the Large Hadron Collider.more » The measurements are done for particles in the pseudorapidity range |η| < 0.8 and the transverse momentum range 0.2 < p T < 5.0 GeV/c as a function of collision centrality. The results are compared with theoretical calculations and provide important constraints on the initial conditions, including initial spatial geometry and its fluctuations, as well as the ratio of the shear viscosity to entropy density of the produced system.« less

Linear microbunching analysis for recirculation machines

DOE PAGES

Tsai, C. -Y.; Douglas, D.; Li, R.; ...

2016-11-28

Microbunching instability (MBI) has been one of the most challenging issues in designs of magnetic chicanes for short-wavelength free-electron lasers or linear colliders, as well as those of transport lines for recirculating or energy-recovery-linac machines. To quantify MBI for a recirculating machine and for more systematic analyses, we have recently developed a linear Vlasov solver and incorporated relevant collective effects into the code, including the longitudinal space charge, coherent synchrotron radiation, and linac geometric impedances, with extension of the existing formulation to include beam acceleration. In our code, we semianalytically solve the linearized Vlasov equation for microbunching amplification factor formore » an arbitrary linear lattice. In this study we apply our code to beam line lattices of two comparative isochronous recirculation arcs and one arc lattice preceded by a linac section. The resultant microbunching gain functions and spectral responses are presented, with some results compared to particle tracking simulation by elegant (M. Borland, APS Light Source Note No. LS-287, 2002). These results demonstrate clearly the impact of arc lattice design on the microbunching development. Lastly, the underlying physics with inclusion of those collective effects is elucidated and the limitation of the existing formulation is also discussed.« less

Performance of the first prototype of the CALICE scintillator strip electromagnetic calorimeter

NASA Astrophysics Data System (ADS)

Francis, K.; Repond, J.; Schlereth, J.; Smith, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S. T.; Sosebee, M.; White, A. P.; Yu, J.; Eigen, G.; Mikami, Y.; Watson, N. K.; Thomson, M. A.; Ward, D. R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Dotti, A.; Folger, G.; Ivantchenko, V.; Ribon, A.; Uzhinskiy, V.; Cârloganu, C.; Gay, P.; Manen, S.; Royer, L.; Tytgat, M.; Zaganidis, N.; Blazey, G. C.; Dyshkant, A.; Lima, J. G. R.; Zutshi, V.; Hostachy, J.-Y.; Morin, L.; Cornett, U.; David, D.; Ebrahimi, A.; Falley, G.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krüger, K.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubüser, C.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Garutti, E.; Laurien, S.; Lu, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Schultz-Coulon, H.-Ch.; Shen, W.; Stamen, R.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; Wilson, G. W.; Kawagoe, K.; Sudo, Y.; Yoshioka, T.; Dauncey, P. D.; Wing, M.; Salvatore, F.; Cortina Gil, E.; Mannai, S.; Baulieu, G.; Calabria, P.; Caponetto, L.; Combaret, C.; Della Negra, R.; Grenier, G.; Han, R.; Ianigro, J.-C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Vander Donckt, M.; Zoccarato, Y.; Calvo Alamillo, E.; Fouz, M.-C.; Puerta-Pelayo, J.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Besson, D.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Karakash, A.; Popova, E.; Tikhomirov, V.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Weuste, L.; Amjad, M. S.; Bonis, J.; Callier, S.; Conforti di Lorenzo, S.; Cornebise, P.; Doublet, Ph.; Dulucq, F.; Fleury, J.; Frisson, T.; van der Kolk, N.; Li, H.; Martin-Chassard, G.; Richard, F.; de la Taille, Ch.; Pöschl, R.; Raux, L.; Rouëné, J.; Seguin-Moreau, N.; Anduze, M.; Balagura, V.; Boudry, V.; Brient, J.-C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Magniette, F.; Musat, G.; Ruan, M.; Tran, T. H.; Videau, H.; Bulanek, B.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Kotera, K.; Ono, H.; Takeshita, T.; Uozumi, S.; Jeans, D.; Chang, S.; Khan, A.; Kim, D. H.; Kong, D. J.; Oh, Y. D.; Götze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.

2014-11-01

A first prototype of a scintillator strip-based electromagnetic calorimeter was built, consisting of 26 layers of tungsten absorber plates interleaved with planes of 45×10×3 mm3 plastic scintillator strips. Data were collected using a positron test beam at DESY with momenta between 1 and 6 GeV/c. The prototype's performance is presented in terms of the linearity and resolution of the energy measurement. These results represent an important milestone in the development of highly granular calorimeters using scintillator strip technology. A number of possible design improvements were identified, which should be implemented in a future detector of this type. This technology is being developed for a future linear collider experiment, aiming at the precise measurement of jet energies using particle flow techniques.

Status and commissioning of the CMS experiment

NASA Astrophysics Data System (ADS)

Wulz, C.-E.

2008-05-01

The construction status of the CMS experiment at the Large Hadron Collider and strategies for commissioning the subdetectors, the magnet, the trigger and the data acquisition are described. The first operations of CMS as a unified system, using either cosmic rays or test data, and the planned activities until the startup of the LHC are presented.

When Physical and Digital Worlds Collide: A Tool for Early Childhood Learners

ERIC Educational Resources Information Center

Parton, Becky Sue; Hancock, Robert

2008-01-01

Very young children learn by exploring their surroundings, mostly by playing, during which they construct mental representations of the world. In fact, prior to Piaget's formal operational stage, children need concrete, hands-on experiences rather than abstract concepts to support more natural learning, developing, and thinking. In terms of…

Review of physics results from the Tevatron: Heavy flavor physics

DOE PAGES

Lewis, Jonathan; van Kooten, Rick

2015-02-28

In this study, we present a review of heavy flavor physics results from the CDF and DØ Collaborations operating at the Fermilab Tevatron Collider. A summary of results from Run 1 is included, but we concentrate on legacy results of charm and b physics from Run 2, including results up to Summer 2014.

Antiproton acceleration in the Fermilab Main Ring and Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, P.; Dinkel, J.; Ducar, R.

1987-03-01

The operation of the Fermilab Main Ring and Tevatron rf systems for colliding beams physics is discussed. The changes in the rf feedback system required for the accelration of antiprotons, and the methods for achieving proper transfer of both protons and antiprotons are described. Data on acceleration and transfer efficiencies are presented.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benson, Stephen V.; Derbenev, Yaroslav S.; Douglas, David R.

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

Testing beam-induced quench levels of LHC superconducting magnets

NASA Astrophysics Data System (ADS)

Auchmann, B.; Baer, T.; Bednarek, M.; Bellodi, G.; Bracco, C.; Bruce, R.; Cerutti, F.; Chetvertkova, V.; Dehning, B.; Granieri, P. P.; Hofle, W.; Holzer, E. B.; Lechner, A.; Nebot Del Busto, E.; Priebe, A.; Redaelli, S.; Salvachua, B.; Sapinski, M.; Schmidt, R.; Shetty, N.; Skordis, E.; Solfaroli, M.; Steckert, J.; Valuch, D.; Verweij, A.; Wenninger, J.; Wollmann, D.; Zerlauth, M.

2015-06-01

In the years 2009-2013 the Large Hadron Collider (LHC) has been operated with the top beam energies of 3.5 and 4 TeV per proton (from 2012) instead of the nominal 7 TeV. The currents in the superconducting magnets were reduced accordingly. To date only seventeen beam-induced quenches have occurred; eight of them during specially designed quench tests, the others during injection. There has not been a single beam-induced quench during normal collider operation with stored beam. The conditions, however, are expected to become much more challenging after the long LHC shutdown. The magnets will be operating at near nominal currents, and in the presence of high energy and high intensity beams with a stored energy of up to 362 MJ per beam. In this paper we summarize our efforts to understand the quench levels of LHC superconducting magnets. We describe beam-loss events and dedicated experiments with beam, as well as the simulation methods used to reproduce the observable signals. The simulated energy deposition in the coils is compared to the quench levels predicted by electrothermal models, thus allowing one to validate and improve the models which are used to set beam-dump thresholds on beam-loss monitors for run 2.

Spool pieces at the SSCL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clayton, T.; Cai, Y.; Smellie, R.

1993-05-01

The basic features of the Superconducting Super Collider lattice are the two beamlines formed by superconducting dipoles (7736) and quadrupoles (1564). The dipoles constraint two 20 TeV proton beams into counterrotating closed orbits of 86.2 km. The quadrupoles (FODO) require cryogenic cooling the LHe temperatures. This requirement isolates the main magnets from the outside world. The interface required, the spool, is a crucial component of superconducting lattice design and machine operation. There are over 1588 spools in the Super Collider. We present hear SSCL spool designs which consist of (1) housing for superconducting closed orbit and multipole correction magnets, (2)more » cryogenic function, magnet quench protection, system power, and instrumentation interfaces, and (3) cold to warm transitions for ware magnet and warm instrumentation drift spaces.« less

Prospects for colliders and collider physics to the 1 PeV energy scale

NASA Astrophysics Data System (ADS)

King, Bruce J.

2000-08-01

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

A new bipolar Qtrim power supply system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mi, C.; Bruno, D.; Drozd, J.

2015-05-03

This year marks the 15th run of RHIC (Relativistic Heavy Ion Collider) operations. The reliability of superconducting magnet power supplies is one of the essential factors in the entire accelerator complex. Besides maintaining existing power supplies and their associated equipment, newly designed systems are also required based on the physicist’s latest requirements. A bipolar power supply was required for this year’s main quadruple trim power supply. This paper will explain the design, prototype, testing, installation and operation of this recently installed power supply system.

Project Nuclotron-based Ion Collider fAcility at JINR

NASA Astrophysics Data System (ADS)

Kekelidze, V. D.; Matveev, V. A.; Meshkov, I. N.; Sorin, A. S.; Trubnikov, G. V.

2017-09-01

The project of Nuclotron-based Ion Collider fAcility (NICA) that is under development at JINR (Dubna) is presented. The general goals of the project are experimental studies of both hot and dense baryonic matter and spin physics (in collisions of polarized protons and deuterons). The first program requires providing of heavy ion collisions in the energy range of √ {{s_{NN}}} = 4-11 Gev at average luminosity of L = 1 × 1027 cm-2 s-1 for 197Au79+ nuclei. The polarized beams mode is proposed to be used in energy range of √ {{s_{NN}}} = 12-27 Gev (protons at luminosity of L ≥ 1 × 1030 cm-2 s-1. The report contains description of the facility scheme and its characteristics in heavy ion operation mode. The Collider will be equipped with two detectors—MultiPurpose Detector (MPD), which is in an active stage of construction, and Spin Physics Detector (SPD) that is in the stage of conceptual design. Fixed target experiment "Baryonic matter at Nuclotron" (BM@N) will be performed in very beginning of the project. The wide program of applied researches at NICA facility is being developed as well.

Network Upgrade for the SLC: Control System Modifications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crane, M.; Mackenzie, R.; Sass, R.

2011-09-09

Current communications between the SLAC Linear Collider control system central host and the SLCmicros is built upon the SLAC developed SLCNET communication hardware and protocols. We will describe how the Internet Suite of protocols (TCP/IP) are used to replace the SLCNET protocol interface. The major communication pathways and their individual requirements are described. A proxy server is used to reduce the number of total system TCP/IP connections. The SLCmicros were upgraded to use Ethernet and TCP/IP as well as SLCNET. Design choices and implementation experiences are addressed.

Unique Identification of Lee-Wick Gauge Bosons at Linear Colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rizzo, Thomas G.

2007-12-14

Grinstein, O'Connell and Wise have recently presented an extension of the Standard Model (SM), based on the ideas of Lee and Wick (LW), which demonstrates an interesting way to remove the quadratically divergent contributions to the Higgs mass induced by radiative corrections. This model predicts the existence of negative-norm copies of the usual SM fields at the TeV scale with ghost-like propagators and negative decay widths, but with otherwise SM-like couplings. In earlier work, it was demonstrated that the LW states in the gauge boson sector of these models, though easy to observe, cannot be uniquely identified as such atmore » the LHC. In this paper, we address the issue of whether or not this problem can be resolved at an e{sup +}e{sup -} collider with a suitable center of mass energy range. We find that measurements of the cross section and the left-right polarization asymmetry associated with Bhabha scattering can lead to a unique identification of the neutral electroweak gauge bosons of the Lee-Wick type.« less

Charged-particle pseudorapidity distributions in Au+Au collisions at sNN=62.4 GeV

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; Nieuwenhuizen, G. J. Van; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.

2006-08-01

The charged-particle pseudorapidity density for Au+Au collisions at sNN=62.4 GeV has been measured over a wide range of impact parameters and compared to results obtained at other energies. As a function of collision energy, the pseudorapidity distribution grows systematically both in height and width. The midrapidity density is found to grow approximately logarithmically between BNL Alternating Gradient Synchrotron (AGS) energies and the top BNL Relativistic Heavy Ion Collider (RHIC) energy. There is also an approximate factorization of the centrality and energy dependence of the midrapidity yields. The new results at sNN=62.4 GeV confirm the previously observed phenomenon of “extended longitudinal scaling” in the pseudorapidity distributions when viewed in the rest frame of one of the colliding nuclei. It is also found that the evolution of the shape of the distribution with centrality is energy independent, when viewed in this reference frame. As a function of centrality, the total charged particle multiplicity scales linearly with the number of participant pairs as it was observed at other energies.

The Coming Revolutions in Particle Physics

ScienceCinema

Quigg, Chris

2017-12-09

Wonderful opportunities await particle physics over the next decade, with new instruments and experiments poised to explore the frontiers of high energy, infinitesimal distances, and exquisite rarity. We look forward to the Large Hadron Collider at CERN to explore the 1-TeV scale (extending efforts at LEP and the Tevatron to unravel the nature of electroweak symmetry breaking) and many initiatives to develop our understanding of the problem of identity: what makes a neutrino a neutrino and a top quark a top quark. We suspect that the detection of proton decay is only a few orders of magnitude away in sensitivity. Astronomical observations should help to tell us what kinds of matter and energy make up the universe. We might even learn to read experiment for clues about the dimensionality of spacetime. If we are inventive enough, we may be able to follow this rich menu with the physics opportunities offered by a linear electron-positron collider and a (muon storage ring) neutrino factory. I expect a remarkable flowering of experimental particle physics, and of theoretical physics that engages with experiment.

Final 6D Muon Ionization Colling using Strong Focusing Quadrupoles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hart, T. L.; Acosta, J. G.; Cremaldi, L. M.

2016-11-15

Abstract Low emittance muon beam lines and muon colliders are potentially a rich source of BSM physics for future exper- imenters. A muon beam normalized emittance of ax,y,z = (280, 280, 1570)µm has been achieved in simulation with short solenoids and a betatron function of 3 cm. Here we use ICOOL and MAD-X to explore using a 400 MeV/c muon beam and strong focusing quadrupoles to achieve a normalized transverse emittance of 100 µm and complete 6D cooling. The low beta regions, as low as 5 mm, produced by the quadrupoles are occupied by dense, low Z absorbers, such asmore » lithium hydride or beryllium, that cool the beam transversely. Equilibrium transverse emittance is linearly proportional to the transverse betatron function. Reverse emittance exchange with septa and/or wedges is then used to decrease transverse emittance from 100 to 25 µm at the expense of longitudinal emittance for a high energy lepton collider. Cooling challenges include chromaticity correction, ssband overlap, quadrupole acceptance, and staying in phase with RF.« less

Loaded delay lines for future RF pulse compression systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, R.M.; Wilson, P.B.; Kroll, N.M.

1995-05-01

The peak power delivered by the klystrons in the NLCRA (Next Linear Collider Test Accelerator) now under construction at SLAC is enhanced by a factor of four in a SLED-II type of R.F. pulse compression system (pulse width compression ratio of six). To achieve the desired output pulse duration of 250 ns, a delay line constructed from a 36 m length of circular waveguide is used. Future colliders, however, will require even higher peak power and larger compression factors, which favors a more efficient binary pulse compression approach. Binary pulse compression, however, requires a line whose delay time is approximatelymore » proportional to the compression factor. To reduce the length of these lines to manageable proportions, periodically loaded delay lines are being analyzed using a generalized scattering matrix approach. One issue under study is the possibility of propagating two TE{sub o} modes, one with a high group velocity and one with a group velocity of the order 0.05c, for use in a single-line binary pulse compression system. Particular attention is paid to time domain pulse degradation and to Ohmic losses.« less

Characterization and Comparison of Control Units for Piezo Actuators to be used for Lorentz Force Compensation inth ILC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattacharyya, Sampriti; Pilipenko, Roman; /Fermilab

2010-01-01

Superconducting accelerators, such as the International Linear Collider (ILC), rely on very high Q accelerating cavities to achieve high electric fields at low RF power. Such cavities have very narrow resonances: a few kHz with a 1.3GHz resonance frequency for the ILC. Several mechanical factors cause tune shifts much larger than this: pressure variations in the liquid helium bath; microphonics from pumps and other mechanical devices; and for a pulsed machine such as the ILC, Lorentz force detuning (pressure from the contained RF field). Simple passive stiffening is limited by many manufacturing and material considerations. Therefore, active tuning using piezomore » actuators is needed. Here we study a supply for their operation. Since commercial power amplifiers are expensive, we analyzed the characteristics of four power amplifiers: (iPZD) built by Istituto Nazionale di Fisica Nucleare (Sezione di Pisa); and a DC-DC converter power supply built in Fermilab (Piezo Master); and two commercial amplifiers, Piezosystem jena and Piezomechanik. This paper presents an analysis and characterization of these amplifiers to understand the cost benefit and reliability when using in a large scale, pulsed beam accelerator like the ILC.« less

Measuring B{sup {+-}}{yields}{tau}{sup {+-}}{nu} and B{sub c}{sup {+-}}{yields}{tau}{sup {+-}}{nu} at the Z peak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akeroyd, A. G.; Chen, C.H.; National Center for Theoretical Sciences, Taiwan

2008-06-01

The measurement of B{sup {+-}}{yields}{tau}{sup {+-}}{nu}{sub {tau}} at the B factories provides important constraints on the parameter tan{beta}/m{sub H{sup {+-}}} in the context of models with two Higgs doublets. Limits on this decay from e{sup +}e{sup -} collisions at the Z peak were sensitive to the sum of B{sup {+-}}{yields}{tau}{sup {+-}}{nu}{sub {tau}} and B{sub c}{sup {+-}}{yields}{tau}{sup {+-}}{nu}{sub {tau}}. Because of the possibly sizeable contribution from B{sub c}{sup {+-}}{yields}{tau}{sup {+-}}{nu}{sub {tau}} we suggest that a signal for this combination might be observed if the CERN LEP L3 Collaboration used its total data of {approx}3.6x10{sup 6} hadronic decays of the Z boson.more » Moreover, we point out that a future linear collider operating at the Z peak (Giga Z option) could constrain tan{beta}/m{sub H{sup {+-}}} from the sum of these processes with a precision comparable to that anticipated at proposed high luminosity B factories from B{sup {+-}}{yields}{tau}{sup {+-}}{nu}{sub {tau}} alone.« less

Dark current and radiation shielding studies for the ILC main linac

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mokhov, Nikolai V.; Rakhno, I. L.; Solyak, N. A.

2016-12-05

Electrons of dark current (DC), generated in high-gradient superconducting RF cavities (SRF) due to field emission, can be accelerated up to very high energies—19 GeV in the case of the International Linear Collider (ILC) main linac—before they are removed by focusing and steering magnets. Electromagnetic and hadron showers generated by such electrons can represent a significant radiation threat to the linac equipment and personnel. In our study, an operational scenario is analysed which is believed can be considered as the worst case scenario for the main linac regarding the DC contribution to the radiation environment in the main linac tunnel.more » A detailed modelling is performed for the DC electrons which are emitted from the surface of the SRF cavities and can be repeatedly accelerated in the high-gradient fields in many SRF cavities. Results of MARS15 Monte Carlo calculations, performed for the current main linac tunnel design, reveal that the prompt dose design level of 25 μSv/hr in the service tunnel can be provided by a 2.3-m thick concrete wall between the main and service ls.« less

Pair production processes and flavor in gauge-invariant perturbation theory

NASA Astrophysics Data System (ADS)

Egger, Larissa; Maas, Axel; Sondenheimer, René

2017-12-01

Gauge-invariant perturbation theory is an extension of ordinary perturbation theory which describes strictly gauge-invariant states in theories with a Brout-Englert-Higgs effect. Such gauge-invariant states are composite operators which have necessarily only global quantum numbers. As a consequence, flavor is exchanged for custodial quantum numbers in the Standard Model, recreating the fermion spectrum in the process. Here, we study the implications of such a description, possibly also for the generation structure of the Standard Model. In particular, this implies that scattering processes are essentially bound-state-bound-state interactions, and require a suitable description. We analyze the implications for the pair-production process e+e-→f¯f at a linear collider to leading order. We show how ordinary perturbation theory is recovered as the leading contribution. Using a PDF-type language, we also assess the impact of sub-leading contributions. To lowest order, we find that the result is mainly influenced by how large the contribution of the Higgs at large x is. This gives an interesting, possibly experimentally testable, scenario for the formal field theory underlying the electroweak sector of the Standard Model.

Introducing the LHC in the Classroom: An Overview of Education Resources Available

ERIC Educational Resources Information Center

Wiener, Gerfried J.; Woithe, Julia; Brown, Alexander; Jende, Konrad

2016-01-01

In the context of the recent re-start of CERN's Large Hadron Collider (LHC) and the challenge presented by unidentified falling objects (UFOs), we seek to facilitate the introduction of high energy physics in the classroom. Therefore, this paper provides an overview of the LHC and its operation, highlighting existing education resources, and…

Large-Area Plasma-Panel Radiation Detectors for Nuclear Medicine Imaging to Homeland Security and the Super Large Hadron Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friedman, Dr. Peter S.; Ball, Robert; Chapman, J. Wehrley

2010-01-01

A new radiation sensor derived from plasma panel display technology is introduced. It has the capability to detect ionizing and non-ionizing radiation over a wide energy range and the potential for use in many applications. The principle of operation is described and some early results presented.

A novel in situ trigger combination method

DOE PAGES

Buzatu, Adrian; Warburton, Andreas; Krumnack, Nils; ...

2013-01-30

Searches for rare physics processes using particle detectors in high-luminosity colliding hadronic beam environments require the use of multi-level trigger systems to reject colossal background rates in real time. In analyses like the search for the Higgs boson, there is a need to maximize the signal acceptance by combining multiple different trigger chains when forming the offline data sample. In such statistically limited searches, datasets are often amassed over periods of several years, during which the trigger characteristics evolve and system performance can vary significantly. Reliable production cross-section measurements and upper limits must take into account a detailed understanding ofmore » the effective trigger inefficiency for every selected candidate event. We present as an example the complex situation of three trigger chains, based on missing energy and jet energy, that were combined in the context of the search for the Higgs (H) boson produced in association with a $W$ boson at the Collider Detector at Fermilab (CDF). We briefly review the existing techniques for combining triggers, namely the inclusion, division, and exclusion methods. We introduce and describe a novel fourth in situ method whereby, for each candidate event, only the trigger chain with the highest a priori probability of selecting the event is considered. We compare the inclusion and novel in situ methods for signal event yields in the CDF $WH$ search. This new combination method, by virtue of its scalability to large numbers of differing trigger chains and insensitivity to correlations between triggers, will benefit future long-running collider experiments, including those currently operating on the Large Hadron Collider.« less

Beam Induced Hydrodynamic Tunneling in the Future Circular Collider Components

NASA Astrophysics Data System (ADS)

Tahir, N. A.; Burkart, F.; Schmidt, R.; Shutov, A.; Wollmann, D.; Piriz, A. R.

2016-08-01

A future circular collider (FCC) has been proposed as a post-Large Hadron Collider accelerator, to explore particle physics in unprecedented energy ranges. The FCC is a circular collider in a tunnel with a circumference of 80-100 km. The FCC study puts an emphasis on proton-proton high-energy and electron-positron high-intensity frontier machines. A proton-electron interaction scenario is also examined. According to the nominal FCC parameters, each of the 50 TeV proton beams will carry an amount of 8.5 GJ energy that is equivalent to the kinetic energy of an Airbus A380 (560 t) at a typical speed of 850 km /h . Safety of operation with such extremely energetic beams is an important issue, as off-nominal beam loss can cause serious damage to the accelerator and detector components with a severe impact on the accelerator environment. In order to estimate the consequences of an accident with the full beam accidently deflected into equipment, we have carried out numerical simulations of interaction of a FCC beam with a solid copper target using an energy-deposition code (fluka) and a 2D hydrodynamic code (big2) iteratively. These simulations show that, although the penetration length of a single FCC proton and its shower in solid copper is about 1.5 m, the full FCC beam will penetrate up to about 350 m into the target because of the "hydrodynamic tunneling." These simulations also show that a significant part of the target is converted into high-energy-density matter. We also discuss this interesting aspect of this study.

A novel in situ trigger combination method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buzatu, Adrian; Warburton, Andreas; Krumnack, Nils

Searches for rare physics processes using particle detectors in high-luminosity colliding hadronic beam environments require the use of multi-level trigger systems to reject colossal background rates in real time. In analyses like the search for the Higgs boson, there is a need to maximize the signal acceptance by combining multiple different trigger chains when forming the offline data sample. In such statistically limited searches, datasets are often amassed over periods of several years, during which the trigger characteristics evolve and system performance can vary significantly. Reliable production cross-section measurements and upper limits must take into account a detailed understanding ofmore » the effective trigger inefficiency for every selected candidate event. We present as an example the complex situation of three trigger chains, based on missing energy and jet energy, that were combined in the context of the search for the Higgs (H) boson produced in association with a $W$ boson at the Collider Detector at Fermilab (CDF). We briefly review the existing techniques for combining triggers, namely the inclusion, division, and exclusion methods. We introduce and describe a novel fourth in situ method whereby, for each candidate event, only the trigger chain with the highest a priori probability of selecting the event is considered. We compare the inclusion and novel in situ methods for signal event yields in the CDF $WH$ search. This new combination method, by virtue of its scalability to large numbers of differing trigger chains and insensitivity to correlations between triggers, will benefit future long-running collider experiments, including those currently operating on the Large Hadron Collider.« less

Performance of the first prototype of the CALICE scintillator strip electromagnetic calorimeter

DOE PAGES

Francis, K.; Repond, J.; Schlereth, J.; ...

2014-11-01

A first prototype of a scintillator strip-based electromagnetic calorimeter was built, consisting of 26 layers of tungsten absorber plates interleaved with planes of 45 × 10 × 3 mm³ plastic scintillator strips. Data were collected using a positron test beam at DESY with momenta between 1 and 6 GeV/c. The prototype's performance is presented in terms of the linearity and resolution of the energy measurement. These results represent an important milestone in the development of highly granular calorimeters using scintillator strip technology. A number of possible design improvements were identified, which should be implemented in a future detector of thismore » type. This technology is being developed for a future linear collider experiment, aiming at the precise measurement of jet energies using particle flow techniques.« less

High-temperature superconductor coating for coupling impedance reduction in the FCC-hh beam screen

NASA Astrophysics Data System (ADS)

Krkotić, Patrick; Niedermayer, Uwe; Boine-Frankenheim, Oliver

2018-07-01

The international Future Circular Collider study develops a conceptual design for a post Large Hadron Collider particle accelerator using 16 T superconducting dipoles for achieving p-p center-of-mass collision energies up to 100 TeV. One concern for this project is the beam coupling impedance especially at injection energy. A copper coated beam screen as in the LHC is planned, but preliminary studies indicate that copper at the high operating temperature of 50 K might not provide a sufficiently low impedance for a stable beam. In order to reduce the coupling impedance, we investigate high-temperature superconductors as a possible coating material in combination with copper as a hybrid system. The effect of different coating combinations are estimated through numerical calculations to identify the best hybrid beam screen coating system.

The discovery of the Higgs boson at the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Nisati, A.; Tonelli, G.

2015-11-01

This paper summarises the work done by the ATLAS and CMS collaborations, and by the teams of the Large Hadron Collider at CERN, that led to the discovery of a new particle, with mass near 125GeV and properties consistent with the ones predicted for the Standard Model Higgs boson. An overview of the Standard Model, with a description of the role of the Higgs boson in the theory, and a summary of the searches for this particle prior to the LHC operations is also given. The paper presents the results obtained by ATLAS and CMS from the analysis of the full data set produced in the first physics run of LHC. After a short discussion on the implications of the discovery, the future prospects for the precision study of the new particle are lastly discussed.

The LHC magnet system and its status of development

NASA Technical Reports Server (NTRS)

Bona, Maurizio; Perin, Romeo; Vlogaert, Jos

1995-01-01

CERN is preparing for the construction of a new high energy accelerator/collider, the Large Hadron Collider (LHC). This new facility will mainly consist of two superconducting magnetic beam channels, 27 km long, to be installed in the existing LEP tunnel. The magnetic system comprises about 1200 twin-aperture dipoles, 13.145 m long, with an operational field of 8.65 T, about 600 quadrupoles, 3 m long, and a very large number of other superconducting magnetic components. A general description of the system is given together with the main features of the design of the regular lattice magnets. The paper also describes the present state of the magnet R & D program. Results from short model work, as well as from full scale prototypes will be presented, including the recently tested 10 m long full-scale prototype dipole manufactured in industry.

Aerosol counterflow two-jets unit for continuous measurement of the soluble fraction of atmospheric aerosols.

PubMed

Mikuska, Pavel; Vecera, Zbynek

2005-09-01

A new type of aerosol collector employing a liquid at laboratory temperature for continuous sampling of atmospheric particles is described. The collector operates on the principle of a Venturi scrubber. Sampled air flows at high linear velocity through two Venturi nozzles "atomizing" the liquid to form two jets of a polydisperse aerosol of fine droplets situated against each other. Counterflow jets of droplets collide, and within this process, the aerosol particles are captured into dispersed liquid. Under optimum conditions (air flow rate of 5 L/min and water flow rate of 2 mL/min), aerosol particles down to 0.3 microm in diameter are quantitatively collected in the collector into deionized water while the collection efficiency of smaller particles decreases. There is very little loss of fine aerosol within the aerosol counterflow two-jets unit (ACTJU). Coupling of the aerosol collector with an annular diffusion denuder located upstream of the collector ensures an artifact-free sampling of atmospheric aerosols. Operation of the ACTJU in combination with on-line detection devices allows in situ automated analysis of water-soluble aerosol species (e.g., NO2-, NO3-)with high time resolution (as high as 1 s). Under the optimum conditions, the limit of detection for particulate nitrite and nitrate is 28 and 77 ng/m(3), respectively. The instrument is sufficiently rugged for its application at routine monitoring of aerosol composition in the real time.

High duty factor plasma generator for CERN's Superconducting Proton Linac.

PubMed

Lettry, J; Kronberger, M; Scrivens, R; Chaudet, E; Faircloth, D; Favre, G; Geisser, J-M; Küchler, D; Mathot, S; Midttun, O; Paoluzzi, M; Schmitzer, C; Steyaert, D

2010-02-01

CERN's Linac4 is a 160 MeV linear accelerator currently under construction. It will inject negatively charged hydrogen ions into CERN's PS-Booster. Its ion source is a noncesiated rf driven H(-) volume source directly inspired from the one of DESY and is aimed to deliver pulses of 80 mA of H(-) during 0.4 ms at a 2 Hz repetition rate. The Superconducting Proton Linac (SPL) project is part of the luminosity upgrade of the Large Hadron Collider. It consists of an extension of Linac4 up to 5 GeV and is foreseen to deliver protons to a future 50 GeV synchrotron (PS2). For the SPL high power option (HP-SPL), the ion source would deliver pulses of 80 mA of H(-) during 1.2 ms and operate at a 50 Hz repetition rate. This significant upgrade motivates the design of the new water cooled plasma generator presented in this paper. Its engineering is based on the results of a finite element thermal study of the Linac4 H(-) plasma generator that identified critical components and thermal barriers. A cooling system is proposed which achieves the required heat dissipation and maintains the original functionality. Materials with higher thermal conductivity are selected and, wherever possible, thermal barriers resulting from low pressure contacts are removed by brazing metals on insulators. The AlN plasma chamber cooling circuit is inspired from the approach chosen for the cesiated high duty factor rf H(-) source operating at SNS.

Soft Fusion Energy Path: Isotope Production in Energy Subcritical/Economy Hypercritical D +D Colliding-Beam Mini Fusion Reactor `Exyder'

NASA Astrophysics Data System (ADS)

Hester, Tim; Maglich, Bogdan; Calsec Collaboration

2015-03-01

Bethe1 and Sakharov2 argued for soft fusion energy path via isotope production, substantiated by Manheimer3. - Copious T and 3He production4 , 5 from D(d, p) T and D(d, n) 3He reactions in 725 KeV D +D colliding beams was measured in weak-focusing Self-Collider6 , 7 radius 0.15 m, in B = 3.12 T, non-linearly stabilized by electron cloud oscillations8 to confinement time = 24 s. Simulations6 predict that by switching to strong focusing9, 10 deuterons 0.75 MeV each, generate 1 3He +1T +1p + 1n at total input energy cost 10.72 MeV. Economic value of T and 3He is 65 and 120 MeV/atom, respectively. We obtain economic gain 205MeV/10.72 MeV ~ 2,000% i.e. 3He production funds cost of T. If first wall is made of Thorium n's will breed 233U releasing 200 MeV/fission, at neutron cost 5.36 MeV versus 160 MeV in beam on target, resulting in no cost 3He production, valued 75K/g. 1. Physics Today, May 1979, p.44; 2. Memoirs, Vintage Books, (1992); 3. Phys. Today, May 2012 p. 12; 4. Phys. Rev. Lett. 54, 796 (1985); 5. Bull. APS, 57, No. 3 (2012); 6. Part. Acc.1, (1970); 7. ANEUTRONIC FUSION NIM A 271 1-167 (1988); 8. Phys. Rev. Lett. 70, 1818 (1993); 9. Part. Acc. 34, 13 (1990).

STAR FORMATION IN TURBULENT MOLECULAR CLOUDS WITH COLLIDING FLOW

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsumoto, Tomoaki; Dobashi, Kazuhito; Shimoikura, Tomomi, E-mail: matsu@hosei.ac.jp

2015-03-10

Using self-gravitational hydrodynamical numerical simulations, we investigated the evolution of high-density turbulent molecular clouds swept by a colliding flow. The interaction of shock waves due to turbulence produces networks of thin filamentary clouds with a sub-parsec width. The colliding flow accumulates the filamentary clouds into a sheet cloud and promotes active star formation for initially high-density clouds. Clouds with a colliding flow exhibit a finer filamentary network than clouds without a colliding flow. The probability distribution functions (PDFs) for the density and column density can be fitted by lognormal functions for clouds without colliding flow. When the initial turbulence ismore » weak, the column density PDF has a power-law wing at high column densities. The colliding flow considerably deforms the PDF, such that the PDF exhibits a double peak. The stellar mass distributions reproduced here are consistent with the classical initial mass function with a power-law index of –1.35 when the initial clouds have a high density. The distribution of stellar velocities agrees with the gas velocity distribution, which can be fitted by Gaussian functions for clouds without colliding flow. For clouds with colliding flow, the velocity dispersion of gas tends to be larger than the stellar velocity dispersion. The signatures of colliding flows and turbulence appear in channel maps reconstructed from the simulation data. Clouds without colliding flow exhibit a cloud-scale velocity shear due to the turbulence. In contrast, clouds with colliding flow show a prominent anti-correlated distribution of thin filaments between the different velocity channels, suggesting collisions between the filamentary clouds.« less

Hollow Electron Beam Collimation for HL-LHC - Effects on the Beam Core

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fitterer, M.; Stancari, G.; Valishev, A.

2017-06-13

Collimation with hollow electron beams is currently one of the most promising concepts for active halo control in the High Luminosity Large Hadron Collider (HL-LHC). To ensure the successful operation of the hollow beam collimator the unwanted effects on the beam core, which might arise from the operation with a pulsed electron beam, must be minimized. This paper gives a summary of the effect of hollow electron lenses on the beam core in terms of sources, provides estimates for HL-LHC and discusses the possible mitigation methods.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, C. -Y.; Douglas, D.; Li, R.

Microbunching instability (MBI) has been one of the most challenging issues in designs of magnetic chicanes for short-wavelength free-electron lasers or linear colliders, as well as those of transport lines for recirculating or energy-recovery-linac machines. To quantify MBI for a recirculating machine and for more systematic analyses, we have recently developed a linear Vlasov solver and incorporated relevant collective effects into the code, including the longitudinal space charge, coherent synchrotron radiation, and linac geometric impedances, with extension of the existing formulation to include beam acceleration. In our code, we semianalytically solve the linearized Vlasov equation for microbunching amplification factor formore » an arbitrary linear lattice. In this study we apply our code to beam line lattices of two comparative isochronous recirculation arcs and one arc lattice preceded by a linac section. The resultant microbunching gain functions and spectral responses are presented, with some results compared to particle tracking simulation by elegant (M. Borland, APS Light Source Note No. LS-287, 2002). These results demonstrate clearly the impact of arc lattice design on the microbunching development. Lastly, the underlying physics with inclusion of those collective effects is elucidated and the limitation of the existing formulation is also discussed.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, W.; Gu, X.; Altinbas, Z.

Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider (RHIC) in order to increase the luminosity delivered to the experiments. We discuss the principle of combining a lattice for resonance driving term compensation and an electron lens for tune spread compensation. We describe the electron lens technology and its operational use. As of this date the implemented compensation scheme approximately doubled the peak and average luminosities.

46 CFR 185.230 - Report of accident to aid to navigation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Report of accident to aid to navigation. 185.230 Section 185.230 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Marine Casualties and Voyage Records § 185.230 Report of accident to aid to navigation. Whenever a vessel collides...

Cryogenics for the MuCool Test Area (MTA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darve, Christine; Norris, Barry; Pei, Liu-Jin

2005-09-01

MuCool Test Area (MTA) is a complex of buildings at Fermi National Accelerator Laboratory, which are dedicated to operate components of a cooling cell to be used for Muon Collider and Neutrino Factory R&D. The long-term goal of this facility is to test ionization cooling principles by operating a 25-liter liquid hydrogen (LH{sub 2}) absorber embedded in a 5 Tesla superconducting solenoid magnet. The MTA solenoid magnet will be used with RF cavities exposed to a high intensity beam. Cryogens used at the MTA include LHe, LN{sub 2} and LH{sub 2}. The latter dictates stringent system design for hazardous locations.more » The cryogenic plant is a modified Tevatron refrigerator based on the Claude cycle. The implementation of an in-house refrigerator system and two 300 kilowatt screw compressors is under development. The helium refrigeration capacity is 500 W at 14 K. In addition the MTA solenoid magnet will be batch-filled with LHe every 2 days using the same cryo-plant. This paper reviews cryogenic systems used to support the Muon Collider and Neutrino Factory R&D programs and emphasizes the feasibility of handling cryogenic equipment at MTA in a safe manner.« less

Cryogenics for the MuCool Test Area (MTA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darve, Christine; Norris, Barry; Pei, Liujin

2006-03-20

MuCool Test Area (MTA) is a complex of buildings at Fermi National Accelerator Laboratory, which are dedicated to operate components of a cooling cell to be used for Muon Collider and Neutrino Factory R and D. The long-term goal of this facility is to test ionization cooling principles by operating a 25-liter liquid hydrogen (LH2) absorber embedded in a 5 Tesla superconducting solenoid magnet. The MTA solenoid magnet will be used with RF cavities exposed to a high intensity beam. Cryogens used at the MTA include LHe, LN2 and LH2. The latter dictates stringent system design for hazardous locations. Themore » cryogenic plant is a modified Tevatron refrigerator based on the Claude cycle. The implementation of an in-house refrigerator system and two 300 kilowatt screw compressors is under development. The helium refrigeration capacity is 500 W at 14 K. In addition the MTA solenoid magnet will be batch-filled with LHe every 2 days using the same cryo-plant. This paper reviews cryogenic systems used to support the Muon Collider and Neutrino Factory R and D programs and emphasizes the feasibility of handling cryogenic equipment at MTA in a safe manner.« less

Design of a synchrotron radiation detector for the test beam lines at the Superconducting Super Collider Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hutton, R.D.

1994-01-01

As part of the particle- and momentum-tagging instrumentation required for the test beam lines of the Superconducting Super Collider (SSC), the synchrotron radiation detector (SRD) was designed to provide electron tagging at momentum above 75 GeV. In a parallel effort to the three test beam lines at the SSC, schedule demands required testing and calibration operations to be initiated at Fermilab. Synchrotron radiation detectors also were to be installed in the NM and MW beam lines at Femilab before the test beam lines at the SSC would become operational. The SRD is the last instrument in a series of threemore » used in the SSC test beam fines. It follows a 20-m drift section of beam tube downstream of the last silicon strip detector. A bending dipole just in of the last silicon strip detector produces the synchrotron radiation that is detected in a 50-mm-square cross section NaI crystal. A secondary scintillator made of Bicron BC-400 plastic is used to discriminate whether it is synchrotron radiation or a stray particle that causes the triggering of the NaI crystal`s photo multiplier tube (PMT).« less

Potential for luminosity improvement for low-energy RHIC operation with long bunches

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fedotov, A.; Blaskiewicz, M.

Electron cooling was proposed to increase luminosity of the RHIC collider for heavy ion beams at low energies. Luminosity decreases as the square of bunch intensity due to the beam loss from the RF bucket as a result of the longitudinal intra beam scattering (IBS), as well as due to the transverse emittance growth because of the transverse IBS. Both transverse and longitudinal IBS can be counteracted with electron cooling. This would allow one to keep the initial peak luminosity close to constant throughout the store essentially without the beam loss. In addition, the phase-space density of the hadron beamsmore » can be further increased by providing stronger electron cooling. Unfortunately, the defining limitation for low energies in RHIC is expected to be the space charge. Here we explore an idea of additional improvement in luminosity, on top of the one coming from just IBS compensation and longer stores, which may be expected if one can operate with longer bunches at the space-charge limit in a collider. This approach together with electron cooling may result in about 10-fold improvement in total luminosity for low-energy RHIC program.« less

Radiation protection and environmental management at the relativistic heavy ion collider.

PubMed

Musolino, S V; Briggs, S L; Stevens, A J

2001-01-01

The Relativistic Heavy Ion Collider (RHIC) is a high energy hadron accelerator built to study basic nuclear physics. It consists of two counter-rotating beams of fully stripped gold ions that are accelerated in two rings to an energy of 100 GeV/nucleon or protons at 250 GeV/c. The beams can be stored for a period of five to ten hours and brought into collision for experiments during that time. The first major physics objective is to recreate a state of matter, the quark-gluon plasma, that has been predicted to have existed at a short time after the creation of the universe. Because there are only a few other high energy particle accelerators like RHIC in the world, the rules promulgated in the US Code of Federal Regulations under the Atomic Energy Act, State regulations, or international guidance documents do not cover prompt radiation from accelerators to govern directly the design and operation of a superconducting collider. Special design criteria for prompt radiation were developed to provide guidance tor the design of radiation shielding. Environmental Management at RHIC is accomplished through the ISO 14001 Environmental Management System. The applicability, benefits, and implementation of ISO 14001 within the framework of a large research accelerator complex are discussed in the paper.

Experimental investigation of adiabatic compression and heating using collision of an MHD-driven jet with a gas target cloud for magnetized target fusion

NASA Astrophysics Data System (ADS)

Seo, Byonghoon; Li, Hui; Bellan, Paul

2017-10-01

We are studying magnetized target fusion using an experimental method where an imploding liner compressing a plasma is simulated by a high-speed MHD-driven plasma jet colliding with a gas target cloud. This has the advantage of being non-destructive so orders of magnitude more shots are possible. Since the actual density and temperature are much more modest than fusion-relevant values, the goal is to determine the scaling of the increase in density and temperature when an actual experimental plasma is adiabatically compressed. Two new-developed diagnostics are operating and providing data. The first new diagnostic is a fiber-coupled interferometer which measures line-integrated electron density not only as a function of time, but also as a function of position along the jet. The second new diagnostic is laser Thomson scattering which measures electron density and temperature at the location where the jet collides with the cloud. These diagnostics show that when the jet collides with a target cloud the jet slows down substantially and both the electron density and temperature increase. The experimental measurements are being compared with 3D MHD and hybrid kinetic numerical simulations that model the actual experimental geometry.

Performance study of SKIROC2/A ASIC for ILD Si-W ECAL

NASA Astrophysics Data System (ADS)

Suehara, T.; Sekiya, I.; Callier, S.; Balagura, V.; Boudry, V.; Brient, J.-C.; de la Taille, C.; Kawagoe, K.; Irles, A.; Magniette, F.; Nanni, J.; Pöschl, R.; Yoshioka, T.

2018-03-01

The ILD Si-W ECAL is a sampling calorimeter with tungsten absorber and highly segmented silicon layers for the International Large Detector (ILD), one of the two detector concepts for the International Linear Collider. SKIROC2 is an ASIC for the ILD Si-W ECAL. To investigate the issues found in prototype detectors, we prepared dedicated ASIC evaluation boards with either BGA sockets or directly soldered SKIROC2. We report a performance study with the evaluation boards, including signal-to-noise ratio and TDC performance with comparing SKIROC2 and an updated version, SKIROC2A.

Dust coagulation in ISM

NASA Technical Reports Server (NTRS)

Chokshi, Arati; Tielens, Alexander G. G. M.; Hollenbach, David

1989-01-01

Coagulation is an important mechanism in the growth of interstellar and interplanetary dust particles. The microphysics of the coagulation process was theoretically analyzed as a function of the physical properties of the coagulating grains, i.e., their size, relative velocities, temperature, elastic properties, and the van der Waal interaction. Numerical calculations of collisions between linear chains provide the wave energy in individual particles and the spectrum of the mechanical vibrations set up in colliding particles. Sticking probabilities are then calculated using simple estimates for elastic deformation energies and for the attenuation of the wave energy due to absorption and scattering processes.

Analysis and measurement of the transfer matrix of a 9-cell, 1.3-GHz superconducting cavity

DOE PAGES

Halavanau, A.; Eddy, N.; Edstrom, D.; ...

2017-04-13

Superconducting linacs are capable of producing intense, stable, high-quality electron beams that have found widespread applications in science and industry. Here, the 9-cell, 1.3-GHz superconducting standing-wave accelerating rf cavity originally developed for e +/e - linear-collider applications has been broadly employed in various superconducting-linac designs. In this paper we discuss the transfer matrix of such a cavity and present its measurement performed at the Fermilab Accelerator Science and Technology (FAST) facility. Finally, the experimental results are found to be in agreement with analytical calculations and numerical simulations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clancey, P.; Logg, C.

DEPOT has been developed to provide tracking for the Stanford Linear Collider (SLC) control system equipment. For each piece of equipment entered into the database, complete location, service, maintenance, modification, certification, and radiation exposure histories can be maintained. To facilitate data entry accuracy, efficiency, and consistency, barcoding technology has been used extensively. DEPOT has been an important tool in improving the reliability of the microsystems controlling SLC. This document describes the components of the DEPOT database, the elements in the database records, and the use of the supporting programs for entering data, searching the database, and producing reports from themore » information.« less

Estimates of dispersive effects in a bent NLC Main Linac

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael Syphers and Leo Michelotti

2000-10-31

An alternative being considered for the Next Linear Collider (NLC) is not to tunnel in a straight line but to bend the Main Linac into an arc so as to follow a gravitational equipotential. The authors begin here an examination of the effects that this would have on vertical dispersion, with its attendant consequences on synchrotron radiation and emittance growth by looking at two scenarios: a gentle continuous bending of the beam to follow an equipotential surface, and an introduction of sharp bends at a few sites in the linac so as to reduce the maximum sagitta produced.

Governance of the International Linear Collider Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foster, B.; /Oxford U.; Barish, B.

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 describesmore » 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 apportioned at both a national and global level, is essential if the project is to be realised. Finally, models for running costs and decommissioning at the conclusion of the ILC project are proposed. This document represents an interim report of the bodies and individuals studying these questions inside the structure set up and supervised by the International Committee for Future Accelerators (ICFA). It represents a request for comment to the international community in all relevant disciplines, scientific, technical and most importantly, political. Many areas require further study and some, in particular the site selection process, have not yet progressed sufficiently to be addressed in detail in this document. Discussion raised by this document will be vital in framing the final proposals due to be published in 2012 in the Technical Design Report being prepared by the Global Design Effort of the ILC.« less

CEPC booster design study

DOE PAGES

Bian, Tianjian; Gao, Jie; Zhang, Chuang; ...

2017-12-10

In September 2012, Chinese scientists proposed a Circular Electron Positron Collider (CEPC) in China at 240 GeV center-of-mass energy for Higgs studies. The booster provides 120 GeV electron and positron beams to the CEPC collider for top-up injection at 0.1 Hz. The design of the full energy booster ring of the CEPC is a challenge. The ejected beam energy is 120 GeV and the injected beam energy is 6 GeV. Here in this paper we describe two alternative schemes, the wiggler bend scheme and the normal bend scheme. For the wiggler bend scheme, we propose to operate the booster ringmore » as a large wiggler at low energy and as a normal ring at high energy to avoid the problem of very low dipole magnet fields. Finally, for the normal bend scheme, we implement the orbit correction to correct the earth field.« less

Beyond Higgs couplings: Probing the Higgs with angular observables at future e$$^{+}$$e$$^{-}$$ colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craig, Nathaniel; Gu, Jiayin; Liu, Zhen

Here, we study angular observables in themore » $$ {e}^{+}{e}^{-}\\to ZH\\to {\\ell}^{+}{\\ell}^{-}b\\overline{b} $$ channel at future circular e$$^{+}$$ e$$^{-}$$ colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy $$ \\sqrt{s}=240 $$ GeV and 5 (30) ab$$^{-1}$$ integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for he Higgs-strahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of both probing BSM corrections to the HZγ coupling and constraining the “blind spot” in indirect limits on supersymmetric scalar top partners.« less

Probing the fermionic Higgs portal at lepton colliders

DOE PAGES

Fedderke, Michael A.; Lin, Tongyan; Wang, Lian -Tao

2016-04-26

Here, we study the sensitivity of future electron-positron colliders to UV completions of the fermionic Higgs portal operator H †Hχ¯χ. Measurements of precision electroweak S and T parameters and the e +e – → Zh cross-section at the CEPC, FCC-ee, and ILC are considered. The scalar completion of the fermionic Higgs portal is closely related to the scalar Higgs portal, and we summarize existing results. We devote the bulk of our analysis to a singlet-doublet fermion completion. Assuming the doublet is sufficiently heavy, we construct the effective field theory (EFT) at dimension-6 in order to compute contributions to the observables.more » We also provide full one-loop results for S and T in the general mass parameter space. In both completions, future precision measurements can probe the new states at the (multi-)TeV scale, beyond the direct reach of the LHC.« less

Beyond Higgs couplings: Probing the Higgs with angular observables at future e$$^{+}$$e$$^{-}$$ colliders

DOE PAGES

Craig, Nathaniel; Gu, Jiayin; Liu, Zhen; ...

2016-03-09

Here, we study angular observables in themore » $$ {e}^{+}{e}^{-}\\to ZH\\to {\\ell}^{+}{\\ell}^{-}b\\overline{b} $$ channel at future circular e$$^{+}$$ e$$^{-}$$ colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy $$ \\sqrt{s}=240 $$ GeV and 5 (30) ab$$^{-1}$$ integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for he Higgs-strahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of both probing BSM corrections to the HZγ coupling and constraining the “blind spot” in indirect limits on supersymmetric scalar top partners.« less

Probing the fermionic Higgs portal at lepton colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fedderke, Michael A.; Lin, Tongyan; Wang, Lian -Tao

Here, we study the sensitivity of future electron-positron colliders to UV completions of the fermionic Higgs portal operator H †Hχ¯χ. Measurements of precision electroweak S and T parameters and the e +e – → Zh cross-section at the CEPC, FCC-ee, and ILC are considered. The scalar completion of the fermionic Higgs portal is closely related to the scalar Higgs portal, and we summarize existing results. We devote the bulk of our analysis to a singlet-doublet fermion completion. Assuming the doublet is sufficiently heavy, we construct the effective field theory (EFT) at dimension-6 in order to compute contributions to the observables.more » We also provide full one-loop results for S and T in the general mass parameter space. In both completions, future precision measurements can probe the new states at the (multi-)TeV scale, beyond the direct reach of the LHC.« less

The Effects of Space-Charge on the Dynamics of the Ion Booster in the Jefferson Lab EIC (JLEIC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bogacz, Alex; Nissen, Edward

Optimization of the booster synchrotron design to operate in the extreme space-charge dominated regime is proposed. This study is motivated by the ultra-high luminosity promised by the JLEIC accelerator complex, which poses several beam dynamics and lattice design challenges for its individual components. We examine the effects of space charge on the dynamics of the booster synchrotron for the proposed JLEIC electron ion collider. This booster will inject and accumulate protons and heavy ions at an energy of 280 MeV and then engage in a process of acceleration and electron cooling to bring it to its extraction energy of 8more » GeV. This would then be sent into the ion collider ring part of JLEIC. In order to examine the effects of space charge on the dynamics of this process we use the software SYNERGIA.« less

Hot Quark Soup Produced at RHIC

ScienceCinema

None

2018-01-16

The Relativistic Heavy Ion Collider (RHIC, http://www.bnl.gov/rhic) is a 2.4-mile-circumference particle accelerator/collider that has been operating at Brookhaven Lab since 2000, delivering collisions of heavy ions, protons, and other particles to an international team of physicists investigating the basic structure and fundamental forces of matter. In 2005, RHIC physicists announced that the matter created in RHICs most energetic collisions behaves like a nearly perfect liquid in that it has extraordinarily low viscosity, or resistance to flow. Since then, the scientists have been taking a closer look at this remarkable form of matter, which last existed some 13 billion years ago, a mere fraction of a second after the Big Bang. Scientists have revealed new findings, including the first measurement of temperature very early in the collision events, and their implications for the nature of this early-universe matter.

CEPC booster design study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bian, Tianjian; Gao, Jie; Zhang, Chuang

In September 2012, Chinese scientists proposed a Circular Electron Positron Collider (CEPC) in China at 240 GeV center-of-mass energy for Higgs studies. The booster provides 120 GeV electron and positron beams to the CEPC collider for top-up injection at 0.1 Hz. The design of the full energy booster ring of the CEPC is a challenge. The ejected beam energy is 120 GeV and the injected beam energy is 6 GeV. Here in this paper we describe two alternative schemes, the wiggler bend scheme and the normal bend scheme. For the wiggler bend scheme, we propose to operate the booster ringmore » as a large wiggler at low energy and as a normal ring at high energy to avoid the problem of very low dipole magnet fields. Finally, for the normal bend scheme, we implement the orbit correction to correct the earth field.« less

Design and Simulation of a Matching System into the Helical Cooling Channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshikawa, C.; Ankenbrandt, C.; Johnson, R. P.

2014-07-01

Muon colliders could provide the most sensitive measurement of the Higgs mass and return the US back to the Energy Frontier. Central to the capabilities of muon colliders are the cooling channels that provide the extraordinary reduction in emittance required for the precise Higgs mass measurement and increased luminosity for enhanced discovery potential of an Energy Frontier Machine. The Helical Cooling Channel (HCC) is able to achieve such emittance reduction and matching sections within the HCC have been successfully designed in the past with lossless transmission and no emittance growth. However, matching into the HCC from a straight solenoid posesmore » a challenge, since a large emittance beam must cross transition. We elucidate on the challenge and present evaluations of two solutions, along with concepts to integrate the operations of a Charge Separator and match into the HCC.« less

Collisionless shock formation, spontaneous electromagnetic fluctuations, and streaming instabilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bret, A.; Instituto de Investigaciones Energeticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real; Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51 Cambridge, Massachusetts 02138

2013-04-15

Collisionless shocks are ubiquitous in astrophysics and in the lab. Recent numerical simulations and experiments have shown how they can arise from the encounter of two collisionless plasma shells. When the shells interpenetrate, the overlapping region turns unstable, triggering the shock formation. As a first step towards a microscopic understanding of the process, we analyze here in detail the initial instability phase. On the one hand, 2D relativistic Particle-In-Cell simulations are performed where two symmetric initially cold pair plasmas collide. On the other hand, the instabilities at work are analyzed, as well as the field at saturation and the seedmore » field which gets amplified. For mildly relativistic motions and onward, Weibel modes govern the linear phase. We derive an expression for the duration of the linear phase in good agreement with the simulations. This saturation time constitutes indeed a lower-bound for the shock formation time.« less

Instrumentation for the study of low emittance tuning and beam dynamics at CESR

NASA Astrophysics Data System (ADS)

Billing, M. G.; Dobbins, J. A.; Forster, M. J.; Kreinick, D. L.; Meller, R. E.; Peterson, D. P.; Ramirez, G. A.; Rendina, M. C.; Rider, N. T.; Sagan, D. C.; Shanks, J.; Sikora, J. P.; Stedinger, M. G.; Strohman, C. R.; Williams, H. A.; Palmer, M. A.; Holtzapple, R. L.; Flanagan, J.

2017-11-01

The Cornell Electron-positron Storage Ring (CESR) has been converted from a High Energy Physics electron-positron collider to operate as a dedicated synchrotron light source for the Cornell High Energy Synchrotron Source (CHESS) and to conduct accelerator physics research as a test accelerator, capable of studying topics relevant to future damping rings, colliders and light sources. Some of the specific topics that were targeted for the initial phase of operation of the storage ring in this mode for CESR as a Test Accelerator (CesrTA) included 1) tuning techniques to produce low emittance beams, 2) the study of electron cloud development in a storage ring and 3) intra-beam scattering effects. The complete conversion of CESR to CesrTA occurred over a several year period, described elsewhere [1-3]. In addition to instrumentation for the storage ring, which was created for CesrTA, existing instrumentation was modified to facilitate the entire range of investigations to support these studies. Procedures were developed, often requiring coordinated measurements among different instruments [4]. This paper describes the instruments utilized for the study of beam dynamics during the operation of CesrTA. The treatment of these instruments will remain fairly general in this paper as it focusses on an overview of the instruments themselves. Their interaction and inter-relationships during sequences of observations is found in a companion paper describing the associated measurement techniques. More detailed descriptions and detailed operational performance for some of the instrumentation may be found elsewhere and these will be referenced in the related sections of this paper.

Exploring triplet-quadruplet fermionic dark matter at the LHC and future colliders

NASA Astrophysics Data System (ADS)

Wang, Jin-Wei; Bi, Xiao-Jun; Xiang, Qian-Fei; Yin, Peng-Fei; Yu, Zhao-Huan

2018-02-01

We study the signatures of the triplet-quadruplet dark matter model at the LHC and future colliders, including the 100 TeV Super Proton-Proton Collider and the 240 GeV Circular Electron Positron Collider. The dark sector in this model contains one fermionic electroweak triplet and two fermionic quadruplets, which have two kinds of Yukawa couplings to the Higgs doublet. Electroweak production signals of the dark sector fermions in the monojet+ ET, disappearing track, and multilepton+ET channels at the LHC and the Super Proton-Proton Collider are investigated. Moreover, we study the loop effects of this model on the Circular Electron Positron Collider precision measurements of e+e-→Z h and h →γ γ . We find that most of the parameter regions allowed by the observed dark matter relic density will be well explored by such direct and indirect searches at future colliders.

Flavorful Z‧ signatures at LHC and ILC

NASA Astrophysics Data System (ADS)

Chen, Shao-Long; Okada, Nobuchika

2008-10-01

There are lots of new physics models which predict an extra neutral gauge boson, referred as Z‧-boson. In a certain class of these new physics models, the Z‧-boson has flavor-dependent couplings with the fermions in the Standard Model (SM). Based on a simple model in which couplings of the SM fermions in the third generation with the Z‧-boson are different from those of the corresponding fermions in the first two generations, we study the signatures of Z‧-boson at the Large Hadron Collider (LHC) and the International Linear Collider (ILC). We show that at the LHC, the Z‧-boson with mass around 1 TeV can be produced through the Drell-Yan processes and its dilepton decay modes provide us clean signatures not only for the resonant production of Z‧-boson but also for flavor-dependences of the production cross sections. We also study fermion pair productions at the ILC involving the virtual Z‧-boson exchange. Even though the center-of-energy of the ILC is much lower than a Z‧-boson mass, the angular distributions and the forward-backward asymmetries of fermion pair productions show not only sizable deviations from the SM predictions but also significant flavor-dependences.

Latest R&D news and beam test performance of the highly granular SiW-ECAL technological prototype for the ILC

NASA Astrophysics Data System (ADS)

Irles, A.

2018-02-01

High precision physics at future colliders as the International Linear Collider (ILC) require unprecedented high precision in the determination of the energy of final state particles. The needed precision will be achieved thanks to the Particle Flow algorithms (PF) which require highly granular and hermetic calorimeters systems. The physical proof of concept of the PF was performed in the previous campaign of beam tests of physic prototypes within the CALICE collaboration. One of these prototypes was the physics prototype of the Silicon-Tungsten Electromagnetic Calorimeter (SiW-ECAL) for the ILC. In this document we present the latest news on R&D of the next generation prototype, the technological prototype with fully embedded very front-end (VFE) electronics, of the SiW-ECAL. Special emphasis is given to the presentation and discussion of the first results from the beam test done at DESY in June 2017. The physics program for such beam test consisted in the calibration and commissioning of the current set of available SiW ECAL modules; the test of performance of individual slabs under 1T magnetic fields; and the study of electromagnetic showers events.

Exploring the BWCA (Bino-Wino co-annihilation) scenario for neutralino dark matter

NASA Astrophysics Data System (ADS)

Baer, Howard; Krupovnickas, Tadas; Mustafayev, Azar; Park, Eun-Kyung; Profumo, Stefano; Tata, Xerxes

2005-12-01

In supersymmetric models with non-universal gaugino masses, it is possible to have opposite-sign SU(2) and U(1) gaugino mass terms. In these models, the gaugino eigenstates experience little mixing so that the lightest SUSY particle remains either pure bino or pure wino. The neutralino relic density can only be brought into accord with the WMAP measured value when bino-wino co-annihilation (BWCA) acts to enhance the dark matter annihilation rate. We map out parameter space regions and mass spectra which are characteristic of the BWCA scenario. Direct and indirect dark matter detection rates are shown to be typically very low. At collider experiments, the BWCA scenario is typified by a small mass gap mtilde Z2-mtilde Z1 ~ 20-80 GeV, so that tree level two body decays of tilde Z2 are not allowed. However, in this case the second lightest neutralino has an enhanced loop decay branching fraction to photons. While the photonic neutralino decay signature looks difficult to extract at the Fermilab Tevatron, it should lead to distinctive events at the CERN LHC and at a linear e+e- collider.

DOE-HEP Final Report for 2013-2016: Studies of plasma wakefields for high repetition-rate plasma collider, and Theoretical study of laser-plasma proton and ion acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katsouleas, Thomas C.; Sahai, Aakash A.

2016-08-08

There were two goals for this funded project: 1. Studies of plasma wakefields for high repetition-rate plasma collider, and 2. Theoretical study of laser-plasma proton and ion acceleration. For goal 1, an analytical model was developed to determine the ion-motion resulting from the interaction of non-linear “blow-out” wakefields excited by beam-plasma and laser-plasma interactions. This is key to understanding the state of the plasma at timescales of 1 picosecond to a few 10s of picoseconds behind the driver-energy pulse. More information can be found in the document. For goal 2, we analytically and computationally analyzed the longitudinal instabilities of themore » laser-plasma interactions at the critical layer. Specifically, the process of “Doppler-shifted Ponderomotive bunching” is significant to eliminate the very high-energy spread and understand the importance of chirping the laser pulse frequency. We intend to publish the results of the mixing process in 2-D. We intend to publish Chirp-induced transparency. More information can be found in the document.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerns, Q.A.; Jackson, G.; Kerns, C.R.

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

Exotic Signals of Vectorlike Quarks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dobrescu, Bogdan A.; Yu, Felix

2016-12-06

Vectorlike fermions are an important target for hadron collider searches. We show that the vectorlike quarks may predominantly decay via higher-dimensional operators into a quark plus a couple of other Standard Model fermions. Pair production of vectorlike quarks of charge 2/3 at the LHC would then lead to a variety of possible final states, includingmore » $$t\\bar t + 4\\tau$$, $$t\\bar b\

Capture, acceleration and bunching rf systems for the MEIC booster and storage rings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Shaoheng; Guo, Jiquan; Lin, Fanglei

2015-09-01

The Medium-energy Electron Ion Collider (MEIC), proposed by Jefferson Lab, consists of a series of accelerators. The electron collider ring accepts electrons from CEBAF at energies from 3 to 12 GeV. Protons and ions are delivered to a booster and captured in a long bunch before being ramped and transferred to the ion collider ring. The ion collider ring accelerates a small number of long ion bunches to colliding energy before they are re-bunched into a high frequency train of very short bunches for colliding. Two sets of low frequency RF systems are needed for the long ion bunch energymore » ramping in the booster and ion collider ring. Another two sets of high frequency RF cavities are needed for re-bunching in the ion collider ring and compensating synchrotron radiation energy loss in the electron collider ring. The requirements from energy ramping, ion beam bunching, electron beam energy compensation, collective effects, beam loading and feedback capability, RF power capability, etc. are presented. The preliminary designs of these RF systems are presented. Concepts for the baseline cavity and RF station configurations are described, as well as some options that may allow more flexible injection and acceleration schemes.« less

Perfect commuting-operator strategies for linear system games

NASA Astrophysics Data System (ADS)

Cleve, Richard; Liu, Li; Slofstra, William

2017-01-01

Linear system games are a generalization of Mermin's magic square game introduced by Cleve and Mittal. They show that perfect strategies for linear system games in the tensor-product model of entanglement correspond to finite-dimensional operator solutions of a certain set of non-commutative equations. We investigate linear system games in the commuting-operator model of entanglement, where Alice and Bob's measurement operators act on a joint Hilbert space, and Alice's operators must commute with Bob's operators. We show that perfect strategies in this model correspond to possibly infinite-dimensional operator solutions of the non-commutative equations. The proof is based around a finitely presented group associated with the linear system which arises from the non-commutative equations.

Theory and measurements of emittance preservation in plasma wakefield acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frederico, Joel

2016-12-01

In this dissertation, we examine the preservation and measurement of emittance in the plasma wakefield acceleration blowout regime. Plasma wakefield acceleration (PWFA) is a revolutionary approach to accelerating charged particles that has been demonstrated to have the potential for gradients orders of magnitude greater than traditional approaches. The application of PWFA to the design of a linear collider will make new high energy physics research possible, but the design parameters must first be shown to be competitive with traditional methods. Emittance preservation is necessary in the design of a linear collider in order to maximize luminosity. We examine the conditionsmore » necessary for circular symmetry in the PWFA blowout regime, and demonstrate that current proposals meet these bounds. We also present an application of beam lamentation which describes the process of beam parameter and emittance matching. We show that the emittance growth saturates as a consequence of energy spread in the beam. The initial beam parameters determine the amount of emittance growth, while the contribution of energy spread is negligible. We also present a model for ion motion in the presence of a beam that is much more dense than the plasma. By combining the model of ion motion and emittance growth, we find the emittance growth due to ion motion is minimal in the case of marginal ion motion. In addition, we present a simulation that validates the ion motion model, which is under further development to examine emittance growth of both marginal and pronounced ion motion. Finally, we present a proof-of-concept of an emittance measurement which may enable the analysis of emittance preservation in future PWFA experiments.« less

35th International Conference of High Energy Physics

NASA Astrophysics Data System (ADS)

The French particle physics community is particularly proud to have been selected to host the 35th ICHEP conference in 2010 in Paris. This conference is the focal point of all our field since more than fifty years and is the reference event where all important results in particle physics cosmology and astroparticles are presented and discussed. This alone suffices to make this event very important. But in 2010, a coincidence of exceptional events will make this conference even more attractive! What is then so special about ICHEP 2010 conference? It will be the first ICHEP conference where physics results obtained at the LHC will be presented! New results about the elusive Higgs boson, or signals of physics beyond the standard model might therefore be announced at this conference! Major discoveries in other domains such as gravitational waves, neutrino telescopes, neutrino oscillations, dark matter or in the flavour sector are also possible, just to name a few. In addition , 2010 will be an important date to shape up the future of our field. Several major projects will present the status of their Conceptual or Engineering Design Reports during the conference. The International Linear Collider (ILC) Global Design Effort team will present the report corresponding to the end of their Technical Design Phase 1. The Compact Linear Collider (CLIC) will also report on its Conceptual Design Report. Other major projects such as Super B factories will also be presented. These reports together with LHC physics results will form the basis for key political decisions needed to be taken in the years to come. In summary, there can be no doubt that Paris is the place to be in summer 2010 for anyone interested in High Energy Physics and we will make every effort to make your stay as interesting and enjoyable as possible.

Physics and Analysis at a Hadron Collider - An Introduction (1/3)

ScienceCinema

None

2018-05-11

This is the first lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This first lecture provides a brief introduction to hadron collider physics and collider detector experiments as well as offers some analysis guidelines. The lectures are aimed at graduate students.

Extraordinary Tools for Extraordinary Science: The Impact ofSciDAC on Accelerator Science&Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryne, Robert D.

2006-08-10

Particle accelerators are among the most complex and versatile instruments of scientific exploration. They have enabled remarkable scientific discoveries and important technological advances that span all programs within the DOE Office of Science (DOE/SC). The importance of accelerators to the DOE/SC mission is evident from an examination of the DOE document, ''Facilities for the Future of Science: A Twenty-Year Outlook''. Of the 28 facilities listed, 13 involve accelerators. Thanks to SciDAC, a powerful suite of parallel simulation tools has been developed that represent a paradigm shift in computational accelerator science. Simulations that used to take weeks or more now takemore » hours, and simulations that were once thought impossible are now performed routinely. These codes have been applied to many important projects of DOE/SC including existing facilities (the Tevatron complex, the Relativistic Heavy Ion Collider), facilities under construction (the Large Hadron Collider, the Spallation Neutron Source, the Linac Coherent Light Source), and to future facilities (the International Linear Collider, the Rare Isotope Accelerator). The new codes have also been used to explore innovative approaches to charged particle acceleration. These approaches, based on the extremely intense fields that can be present in lasers and plasmas, may one day provide a path to the outermost reaches of the energy frontier. Furthermore, they could lead to compact, high-gradient accelerators that would have huge consequences for US science and technology, industry, and medicine. In this talk I will describe the new accelerator modeling capabilities developed under SciDAC, the essential role of multi-disciplinary collaboration with applied mathematicians, computer scientists, and other IT experts in developing these capabilities, and provide examples of how the codes have been used to support DOE/SC accelerator projects.« less

Extraordinary tools for extraordinary science: the impact of SciDAC on accelerator science and technology

NASA Astrophysics Data System (ADS)

Ryne, Robert D.

2006-09-01

Particle accelerators are among the most complex and versatile instruments of scientific exploration. They have enabled remarkable scientific discoveries and important technological advances that span all programs within the DOE Office of Science (DOE/SC). The importance of accelerators to the DOE/SC mission is evident from an examination of the DOE document, ''Facilities for the Future of Science: A Twenty-Year Outlook.'' Of the 28 facilities listed, 13 involve accelerators. Thanks to SciDAC, a powerful suite of parallel simulation tools has been developed that represent a paradigm shift in computational accelerator science. Simulations that used to take weeks or more now take hours, and simulations that were once thought impossible are now performed routinely. These codes have been applied to many important projects of DOE/SC including existing facilities (the Tevatron complex, the Relativistic Heavy Ion Collider), facilities under construction (the Large Hadron Collider, the Spallation Neutron Source, the Linac Coherent Light Source), and to future facilities (the International Linear Collider, the Rare Isotope Accelerator). The new codes have also been used to explore innovative approaches to charged particle acceleration. These approaches, based on the extremely intense fields that can be present in lasers and plasmas, may one day provide a path to the outermost reaches of the energy frontier. Furthermore, they could lead to compact, high-gradient accelerators that would have huge consequences for US science and technology, industry, and medicine. In this talk I will describe the new accelerator modeling capabilities developed under SciDAC, the essential role of multi-disciplinary collaboration with applied mathematicians, computer scientists, and other IT experts in developing these capabilities, and provide examples of how the codes have been used to support DOE/SC accelerator projects.

Dashboard Task Monitor for Managing ATLAS User Analysis on the Grid

NASA Astrophysics Data System (ADS)

Sargsyan, L.; Andreeva, J.; Jha, M.; Karavakis, E.; Kokoszkiewicz, L.; Saiz, P.; Schovancova, J.; Tuckett, D.; Atlas Collaboration

2014-06-01

The organization of the distributed user analysis on the Worldwide LHC Computing Grid (WLCG) infrastructure is one of the most challenging tasks among the computing activities at the Large Hadron Collider. The Experiment Dashboard offers a solution that not only monitors but also manages (kill, resubmit) user tasks and jobs via a web interface. The ATLAS Dashboard Task Monitor provides analysis users with a tool that is independent of the operating system and Grid environment. This contribution describes the functionality of the application and its implementation details, in particular authentication, authorization and audit of the management operations.

Robert R. Wilson Prize III: Applications of Intrabeam Scattering Formulae to a Myriad of Accelerator Systems

NASA Astrophysics Data System (ADS)

Mtingwa, Sekazi K.

2017-01-01

We discuss our entree into accelerator physics and the problem of intrabeam scattering in particular. We focus on the historical importance of understanding intrabeam scattering for the successful operation of Fermilab's Accumulator and Tevatron and the subsequent hunt for the top quark, and its importance for successful operation of CERN's Large Hadron Collider that discovered the Higgs boson. We provide details on intrabeam scattering formalisms for hadron and electron beams at high energies, concluding with an Ansatz by Karl Bane that has applications to electron damping rings and synchrotron light sources.

LHC Status and Upgrade Challenges

NASA Astrophysics Data System (ADS)

Smith, Jeffrey

2009-11-01

The Large Hadron Collider has had a trying start-up and a challenging operational future lays ahead. Critical to the machine's performance is controlling a beam of particles whose stored energy is equivalent to 80 kg of TNT. Unavoidable beam losses result in energy deposition throughout the machine and without adequate protection this power would result in quenching of the superconducting magnets. A brief overview of the machine layout and principles of operation will be reviewed including a summary of the September 2008 accident. The current status of the LHC, startup schedule and upgrade options to achieve the target luminosity will be presented.

IBS suppression lattice in RHIC: theory and experimental verification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fedotov,A.V.; Bai, M.; Bruno, D.

Intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for Relativistic Heavy Ion Collider (RHIC) operation with heavy ions. Over the last few years the process of IBS was carefully studied in RHIC with dedicated IBS measurements and their comparison with the theoretical models. A new lattice was recently designed and implemented in RHIC to suppress transverse IBS growth, which lowered the average arc dispersion by about 20% [1]. This lattice became operational during RHIC Run-8. We review the IBS suppression mechanism, IBS measurements before and after the lattice change, and comparisons with predictions.

How to measure the linear polarization of gluons in unpolarized proton using the heavy-quark pair leptoproduction

NASA Astrophysics Data System (ADS)

Efremov, A. V.; Ivanov, N. Ya.; Teryaev, O. V.

2018-02-01

We study the azimuthal cos ⁡ φ and cos ⁡ 2 φ asymmetries in heavy-quark pair leptoproduction, lN →l‧ Q Q bar X, as probes of linearly polarized gluons inside unpolarized proton, where the azimuth φ is the angle between the lepton scattering plane (l ,l‧) and the heavy quark production plane (N , Q). First, we determine the maximal values for the cos ⁡ φ and cos ⁡ 2 φ asymmetries allowed by the photon-gluon fusion with unpolarized gluons; these predictions are large, (√{ 3 } - 1) / 2 and 1/3, respectively. Then we calculate the contribution of the transverse-momentum dependent gluonic counterpart of the Boer-Mulders function, h1⊥g, describing the linear polarization of gluons inside unpolarized proton. Our analysis shows that the maximum values of the azimuthal distributions depend strongly on the gluon polarization; they vary from 0 to 1 depending on h1⊥g. We conclude that the azimuthal cos ⁡ φ and cos ⁡ 2 φ asymmetries in heavy-quark pair leptoproduction are predicted to be large and very sensitive to the contribution of linearly polarized gluons. For this reason, future measurements of the azimuthal distributions in charm and bottom production at the proposed EIC and LHeC colliders seem to be very promising for determination of the linear polarization of gluons inside unpolarized proton.

The ratio R = dσL/dσT in heavy-quark pair leptoproduction as a probe of linearly polarized gluons in unpolarized proton

NASA Astrophysics Data System (ADS)

Efremov, A. V.; Ivanov, N. Ya.; Teryaev, O. V.

2018-05-01

We study the Callan-Gross ratio R = dσL / dσT in heavy-quark pair leptoproduction, lN →l‧ Q Q bar X, as a probe of linearly polarized gluons inside unpolarized proton, where dσT (dσL) is the differential cross section of the γ* N → Q Q bar X process initiated by a transverse (longitudinal) virtual photon. Note first that the maximal value for the quantity R allowed by the photon-gluon fusion with unpolarized gluons is large, about 2. We calculate the contribution of the transverse-momentum dependent gluonic counterpart of the Boer-Mulders function, h1 ⊥g , describing the linear polarization of gluons inside unpolarized proton. Our analysis shows that the maximum value of the ratio R depends strongly on the gluon polarization; it varies from 0 to Q2/4m2 depending on h1⊥g . We conclude that the Callan-Gross ratio in heavy-quark pair leptoproduction is predicted to be large and very sensitive to the contribution of linearly polarized gluons. For this reason, future measurements of the longitudinal and transverse components of the charm and bottom production cross sections at the proposed EIC and LHeC colliders seem to be very promising for determination of the linear polarization of gluons inside unpolarized proton.