WorldWideScience

Sample records for clic interaction point

  1. Interaction Point Backgrounds from the CLIC Post Collision Line

    OpenAIRE

    Salt, Michael David

    2012-01-01

    The proposed CLIC accelerator is designed to collide electrons and positrons ata centre of mass energy of 3 TeV, and a luminosity of 5.9 x 10^(34) cm^(−2) s^(−1) at the interactionpoint (IP). Being a single-pass machine, luminosity must be maximised byminimising the beam spot size to the order of a few nanometres. The effects of the finalfocussing and the intense beam-beam effects lead to a high production cross sectionof beamstrahlung photons, and highly divergent outgoing beams, both spatia...

  2. An Experimental Approach to Simulations of the CLIC Interaction Point

    DEFF Research Database (Denmark)

    Esberg, Jakob

    2012-01-01

    Since this thesis covers a relatively wide range of topics, the abstract is best split into sections that describe the scope of each chapter: The chapter on future colliders gives an introduction to key concepts of future high-energy, high-luminosity linear collider experiments. The chapter...... crystalline matter. The 6th chapter briefly introduces basic theoretical aspects that are natural for understanding the processes occurring at the interaction points of a future collider and in fixed target experiments. It is the purpose of this chapter to give basic formulas but also to give the reader...... experiments conducted at MAMI will be presented. Furthermore the chapter discusses the performance of new CMOS based detectors to be used in future experiments by the NA63 collaboration. The chapter on collider simulations introduces the beam-beam simulation codes GUINEA-PIG and GUINEA-PIG++, their methods...

  3. Interaction point feedback design and integrated simulations to stabilize the CLIC final focus

    CERN Document Server

    Balik, G; Deleglise, G; Jeremie, A; Pacquet, L; Badel, A; Caron, B; Le Breton, R; Latina, A; Pfingstner, J; Schulte, D; Snuverink, J

    2011-01-01

    The Compact Linear Collider (CLIC) accelerator has strong precision requirements on the offset position between the beams. Sensitive to ground motion (GM), the beam needs to be stabilized to unprecedented requirements. Different Beam Based Feedback (BBF) algorithms such as Orbit Feedback (OFB) and Interaction Point Feedback (IPFB) have been designed. This paper focuses on the IPFB control which could be added to the CLIC baseline. IPFB control has been tested for different GM models in presence of noises or disturbances and it uses digital linear control with an adaptive loop. The simulations demonstrate that it is possible to achieve the required performances and quantify the maximum allowed noise level. This amount of admitted noises and disturbances is given in terms of an equivalent disturbance on the position of the magnet that controls the beam offset. Due to the limited sampling frequency of the process, the control loop is in a very small bandwidth. The study shows that these disturbances have to be l...

  4. Background at the Interaction Point from the CLIC Post-Collision Line

    CERN Document Server

    Salt, M D; Apyan, A; Elsener, K; Gschwendtner, E; Ferrari, A

    2010-01-01

    The 1.5 TeV electron/positron CLIC beams, with a total power of 14 MW per beam, are disrupted at the interaction point (IP) due to the very strong beam-beam effect. The resulting spent beam products are transported to suitable dumps by the post-collision beam line, which generates beam losses and causes the production of secondary cascades towards the interaction region. In this paper the electromagnetic backgrounds at the IP are presented, which were calculated using biasing Monte Carlo techniques. Also, a first estimate is made of neutron backshine from the main beam dump.

  5. Photon backgrounds at the CLIC interaction point due to losses in the post-collision extraction line

    CERN Document Server

    Salt, M D; Elsener, K; Ferrari, A

    2010-01-01

    The CLIC beam delivery system focuses 1.5~TeV electron and positron beams to a nanometre-sized cross section when colliding them at the interaction point (IP). The intense focusing leads to large beam-beam effects, causing the production of beamstrahlung photons, coherent and incoherent $e^+e^-$ pairs, as well as a significant disruption of the main beam. The transport of the post-collision beams requires a minimal loss extraction line, with high acceptance for energy deviation and divergence. The current design includes vertical bends close to the IP in order to separate the charged particles with a sign opposite to the main beam into a diagnostic-equipped intermediate dump, whilst transporting the photons and the main beam to the final dump. Photon and charged particle losses on magnet masks and dumps result in a complex radiation field and IP background particle fluxes. In this paper, the electromagnetic backgrounds at the IP arising from the losses occurring closest to the collision point are calculated.

  6. Stabilisation and precision pointing quadrupole magnets in the Compact Linear Collider (CLIC)

    CERN Document Server

    Janssens, Stef; van den Brand, Jo; Bertolini, Alessandro; Artoos, Kurt

    This thesis describes the research done to provide stabilisation and precision positioning for the main beam quadrupole magnets of the Compact Linear Collider CLIC. The introduction describes why new particle accelerators are needed to further the knowledge of our universe and why they are linear. A proposed future accelerator is the Compact Linear Collider (CLIC) which consists of a novel two beam accelerator concept. Due to its linearity and subsequent single pass at the interaction point, this new accelerator requires a very small beam size at the interaction point, in order to increase collision effectiveness. One of the technological challenges, to obtain these small beam sizes at the interaction point, is to keep the quadrupole magnets aligned and stable to 1.5 nm integrated r.m.s. in vertical and 5 nm integrated root mean square (r.m.s.) in lateral direction. Additionally there is a proposal to create an intentional offset (max. 50 nm every 20 ms with a precision of +/- 1 nm), for several quadrupole ma...

  7. Interaction of Human Chloride Intracellular Channel Protein 1 (CLIC1) with Lipid Bilayers: A Fluorescence Study.

    Science.gov (United States)

    Hare, Joanna E; Goodchild, Sophia C; Breit, Samuel N; Curmi, Paul M G; Brown, Louise J

    2016-07-12

    Chloride intracellular channel protein 1 (CLIC1) is very unusual as it adopts a soluble glutathione S-transferase-like canonical fold but can also autoinsert into lipid bilayers to form an ion channel. The conversion between these forms involves a large, but reversible, structural rearrangement of the CLIC1 module. The only identified environmental triggers controlling the metamorphic transition of CLIC1 are pH and oxidation. Until now, there have been no high-resolution structural data available for the CLIC1 integral membrane state, and consequently, a limited understanding of how CLIC1 unfolds and refolds across the bilayer to form a membrane protein with ion channel activity exists. Here we show that fluorescence spectroscopy can be used to establish the interaction and position of CLIC1 in a lipid bilayer. Our method employs a fluorescence energy transfer (FRET) approach between CLIC1 and a dansyl-labeled lipid analogue to probe the CLIC1-lipid interface. Under oxidizing conditions, a strong FRET signal between the single tryptophan residue of CLIC1 (Trp35) and the dansyl-lipid analogue was detected. When considering the proportion of CLIC1 interacting with the lipid bilayer, as estimated by fluorescence quenching experiments, the FRET distance between Trp35 and the dansyl moiety on the membrane surface was determined to be ∼15 Å. This FRET-detected interaction provides direct structural evidence that CLIC1 associates with membranes. The results presented support the current model of an oxidation-driven interaction of CLIC1 with lipid bilayers and also propose a membrane anchoring role for Trp35. PMID:27299171

  8. Cholesterol Promotes Interaction of the Protein CLIC1 with Phospholipid Monolayers at the Air–Water Interface

    Science.gov (United States)

    Hossain, Khondker R.; Al Khamici, Heba; Holt, Stephen A.; Valenzuela, Stella M.

    2016-01-01

    CLIC1 is a Chloride Intracellular Ion Channel protein that exists either in a soluble state in the cytoplasm or as a membrane bound protein. Members of the CLIC family are largely soluble proteins that possess the intriguing property of spontaneous insertion into phospholipid bilayers to form integral membrane ion channels. The regulatory role of cholesterol in the ion-channel activity of CLIC1 in tethered lipid bilayers was previously assessed using impedance spectroscopy. Here we extend this investigation by evaluating the influence of cholesterol on the spontaneous membrane insertion of CLIC1 into Langmuir film monolayers prepared using 1-palmitoyl-2-oleoylphosphatidylcholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-ethanolamine and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine alone or in combination with cholesterol. The spontaneous membrane insertion of CLIC1 was shown to be dependent on the presence of cholesterol in the membrane. Furthermore, pre-incubation of CLIC1 with cholesterol prior to its addition to the Langmuir film, showed no membrane insertion even in monolayers containing cholesterol, suggesting the formation of a CLIC1-cholesterol pre-complex. Our results therefore suggest that CLIC1 membrane interaction involves CLIC1 binding to cholesterol located in the membrane for its initial docking followed by insertion. Subsequent structural rearrangements of the protein would likely also be required along with oligomerisation to form functional ion channels. PMID:26875987

  9. Cholesterol Promotes Interaction of the Protein CLIC1 with Phospholipid Monolayers at the Air–Water Interface

    Directory of Open Access Journals (Sweden)

    Khondker R. Hossain

    2016-02-01

    Full Text Available CLIC1 is a Chloride Intracellular Ion Channel protein that exists either in a soluble state in the cytoplasm or as a membrane bound protein. Members of the CLIC family are largely soluble proteins that possess the intriguing property of spontaneous insertion into phospholipid bilayers to form integral membrane ion channels. The regulatory role of cholesterol in the ion-channel activity of CLIC1 in tethered lipid bilayers was previously assessed using impedance spectroscopy. Here we extend this investigation by evaluating the influence of cholesterol on the spontaneous membrane insertion of CLIC1 into Langmuir film monolayers prepared using 1-palmitoyl-2-oleoylphosphatidylcholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-ethanolamine and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine alone or in combination with cholesterol. The spontaneous membrane insertion of CLIC1 was shown to be dependent on the presence of cholesterol in the membrane. Furthermore, pre-incubation of CLIC1 with cholesterol prior to its addition to the Langmuir film, showed no membrane insertion even in monolayers containing cholesterol, suggesting the formation of a CLIC1-cholesterol pre-complex. Our results therefore suggest that CLIC1 membrane interaction involves CLIC1 binding to cholesterol located in the membrane for its initial docking followed by insertion. Subsequent structural rearrangements of the protein would likely also be required along with oligomerisation to form functional ion channels.

  10. CLIC OVERVIEW

    CERN Document Server

    Tomas, R

    2009-01-01

    The CLIC study is exploring the scheme for an electronpositron collider with a centre-of-mass energy of 3 TeV in order to make the multi-TeV range accessible for lepton physics. The current goal of the project is to demonstrate the feasibility of the technology by the year 2010. Recently, important progress has been made concerning the high-gradient accelerating structure tests and the experiments with beam in the CLIC test facility, CTF3. On the organizational side, the CLIC international collaborations have significantly gained momentum considerably boosting the CLIC study.

  11. CLIC Overview

    CERN Document Server

    Tomás, R

    2010-01-01

    The CLIC study is exploring the scheme for an electronpositron collider with a centre-of-mass energy of 3 TeV in order to make the multi-TeV range accessible for lepton physics. The current goal of the project is to demonstrate the feasibility of the technology by the year 2010. Recently, important progress has been made concerning the high-gradient accelerating structure tests and the experiments with beam in the CLIC test facility, CTF3. On the organizational side, the CLIC international collaborations have significantly gained momentum considerably boosting the CLIC study.

  12. The CLIC Post-Collision Line

    CERN Document Server

    Gschwendtner, E; Elsener, K; Sailer, A; Uythoven, J; Appleby, R B; Salt, M; Ferrari, A; Ziemann, V

    2010-01-01

    The 1.5 TeV CLIC beams, with a total power of 14 MW per beam, are disrupted at the interaction point due to the very strong beam-beam effect. As a result, some 3.5 MW reach the main dump in form of beamstrahlung photons. About 0.5 MW of e+e- pairs with a very broad energy spectrum need to be disposed of along the post-collision line. The conceptual design of this beam line will be presented. Emphasis will be on the optimization studies of the CLIC post-collision line design with respect to the energy deposition in windows, dumps and absorbers, on the design of the luminosity monitoring for a fast feedback to the beam steering and on the background conditions for the luminosity monitoring equipment.

  13. CLIC Brochure

    CERN Multimedia

    De Melis, Cinzia

    2015-01-01

    After the discovery of the Higgs boson and with upgrades to higher energy and luminosity, the LHC is mapping the route of particle physics into the future. The next step in this journey of discovery could be a linear electron-positron collider, which would complement the LHC and allow high precision measurements of the Higgs boson, the top quark and electroweak processes in addition to possible new physics beyond the Standard Model. The Compact Linear Collider is under development by two worldwide collaborations, pushing the limits of particle acceleration and detection. Technological R&D, physics simulations and engineering studies must all come together to make CLIC a reality.

  14. Silicon pixel R&D for CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)754303

    2016-01-01

    Challenging detector requirements are imposed by the physics goals at the future multi-TeV e+e- Compact Linear Collider (CLIC). A single point resolution of 3μm for the vertex detector and 7μm for the tracker is required. Moreover, the CLIC vertex detector and tracker need to be extremely light weighted with a material budget of 0.2 % X0 per layer in the ver- tex detector and 1-2%X0 in the tracker. A fast time slicing of 10ns is further required to suppress background from beam-beam interactions. A wide range of sensor and readout ASIC technologies are investigated within the CLIC silicon pixel R&D effort. Various hybrid planar sensor assemblies with a pixel size of 25x25μm2 and 55x55μm2 have been produced and characterised by laboratory measurements and during test-beam campaigns. Experimental and simulation results for thin (50μm-500μm) slim edge and active-edge planar, and High-Voltage CMOS sensors hybridised to various readout ASICs (Timepix, Timepix3, CLICpix) are presented.

  15. CLIC accelerator modules under construction at CERN

    CERN Multimedia

    Anna Pantelia

    2012-01-01

    The Compact LInear Collider (CLIC) study is dedicated to the design of an electron-positron (e- e+) linear accelerator, colliding particle beams at the energy of 3 TeV. The CLIC required luminosity can be reached with powerful particle beams (14 MW each) colliding with extremely small dimensions and high beam stability at the interaction point. The accelerated particle beams must have dimensions of 45 nm in the horizontal plane and 1 nm in the vertical plane. CLIC relies upon a novel two-beam acceleration concept in which the Radio Frequency (RF) power is extracted from a low energy but high-intensity particle beam, called Drive Beam (DB), and transferred to a parallel high energy accelerating particle beam, called Main Beam (MB). The extraction and transfer of the RF power is achieved by the Power Extraction and Transfer Structures (PETS) and the particle beam acceleration is achieved with high precision RF-Accelerating Structures (AS), operating at 11.9942 GHz with an accelerating gradient of 100 MV/m, whi...

  16. Beam Position Monitoring at CLIC

    CERN Document Server

    Prochnow, J

    2003-01-01

    At the European Organisation for Nuclear Research CERN in Geneva, Switzerland the design of the Compact LInear Collider (CLIC) for high energy physics is studied. To achieve the envisaged high luminosity the quadrupole magnets and radio-frequency accelerating structures have to be actively aligned with micron precision and submicron resolution. This will be done using beam-based algorithms which rely on beam position information inside of quadrupoles and accelerating structures. After a general introduction to the CLIC study and the alignment algorithms, the concept of the interaction between beams and radio-frequency structures is given. In the next chapter beam measurements and simulations are described which were done to study the performance of cavity beam position monitors (BPM). A BPM design is presented which is compatible with the multi-bunch operation at CLIC and could be used to align the quadrupoles. The beam position inside the accelerating structures will be measured by using the structures thems...

  17. Benchmarking of the Placet and Dimad tracking codes using the CLIC Post-Collision line

    CERN Document Server

    Ahmed, I; Ferrari, A; Latina, A

    2009-01-01

    In this benchmarking study, two contemporary codes, DIMAD and PLACET, are compared. We consider the 20 mrad post-collision line of the Compact Linear Collider (CLIC) and perform tracking studies of heavily disrupted post-collision electron beams. We successfully find that the two codes provide an equivalent description of the beam transport from the interaction point to the final dump.

  18. CLIC Detector Power Requirements

    CERN Document Server

    Gaddi, A

    2013-01-01

    An estimate for the CLIC detector power requirements is outlined starting from the available data on power consumptions of the four LHC experiments and considering the differences between a typical LHC Detector (CMS) and the CLIC baseline detector concept. In particular the impact of the power pulsing scheme for the CLIC Detector electronics on the overall detector consumption is considered. The document will be updated with the requirements of the sub-detector electronics once they are more defined.

  19. CLIC PHYSICS OVERVIEW

    CERN Document Server

    Bozovic-Jelisavcic, Ivanka

    2016-01-01

    In this paper, based on the invited talk at the 17th Lomonosov Conference of Elementary Particle Physics, the physics program at the future Compact Linear Collider (CLIC) will be reviewed, with particular emphasis on the Higgs physics studies. It will be demonstrated, on the basis of detailed physics and detector studies carried out at CLIC, that the CLIC is indeed a precision tool for studies both in the Higgs sector and beyond the Standard Model.

  20. CLIC MDI Overview

    OpenAIRE

    Gatignon, Lau

    2012-01-01

    This paper gives an introduction to the layout of the CLIC Machine Detector Interface as it has been defined for the CLIC Conceptual Design Report. We concentrate on the specific case of the CLIC_SiD detector, although the push-pull concept for two detectors has been included in the design. Some recent work and developments are described as well. However, for the details we refer to the detailed technical talks at this conference.

  1. CLIC: Status and Plan

    CERN Document Server

    Sailer, Andre

    2014-01-01

    The Compact Linear Collider (CLIC) is a high energy electron–positron col- lider with a maximal centre-of-mass energy of 3 TeV. In order to achieve high luminosity small bunches with high intensity are necessary. These lead to strong beam-beam forces, which create a challenging background environment. The accelerator concept and the detectors designed for CLIC are presented. Results from detector benchmark studies presented in the CLIC conceptual design report are summarised.

  2. Preparing for CLIC tests

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    The Canon 5 undergoes first brazing for preparation in the CLIC study at the CLIC Test Facility 2 (CTF2). This will test injection for a proposed linear collider that will further explore discoveries made at the LHC. Electric fields in the canon will boost electrons into the acceleration fields of the collider.

  3. Simulation of Beam-Beam Background at CLIC

    CERN Document Server

    Sailer, A

    2010-01-01

    The dense beams used at CLIC to achieve a high luminosity will cause a large amount of background particles through beam-beam interactions. Generator level studies with GUINEAPIG and full detector simulation studies with an ILD based CLIC detector have been performed to evaluate the amount of beam-beam back- ground hitting the vertex detector.

  4. CLIC Drive Beam Phase Stabilisation

    CERN Document Server

    Gerbershagen, Alexander; Schulte, Daniel

    The thesis presents phase stability studies for the Compact Linear Collider (CLIC) and focuses in particular on CLIC Drive Beam longitudinal phase stabilisation. This topic constitutes one of the main feasibility challenges for CLIC construction and is an essential component of the current CLIC stabilisation campaign. The studies are divided into two large interrelated sections: the simulation studies for the CLIC Drive Beam stability, and measurements, data analysis and simulations of the CLIC Test Facility (CTF3) Drive Beam phase errors. A dedicated software tool has been developed for a step-by-step analysis of the error propagation through the CLIC Drive Beam. It uses realistic RF potential and beam loading amplitude functions for the Drive and Main Beam accelerating structures, complete models of the recombination scheme and compressor chicane as well as of further CLIC Drive Beam modules. The tool has been tested extensively and its functionality has been verified. The phase error propagation at CLIC h...

  5. Design of the Injection and extraction system and related machine protection for the Clic Damping Rings

    CERN Document Server

    Apsimon, Robert; Barnes, Mike; Borburgh, Jan; Goddard, Brennan; Papaphilippou, Yannis; Uythoven, Jan

    2014-01-01

    Linear machines such as CLIC have relatively low rates of collision between bunches compared to their circular counterparts. In order to achieve the required luminosity, a very small spot size is envisaged at the interaction point, thus a low emittance beam is needed. Damping rings are essential for producing the low emittances needed for the CLIC main beam. It is crucial that the beams are injected and extracted from the damping rings in a stable and repeatable fashion to minimise emittance blow-up and beam jitter at the interaction point; both of these effects will deteriorate the luminosity at the interaction point. In this paper, the parameters and constraints of the injection and extraction systems are considered and the design of these systems is optimised within this parameter space. Related machine protection is considered in order to prevent damage from potential failure modes of the injection and extraction systems.

  6. CLIC brochure (English version)

    CERN Multimedia

    Lefevre, Christiane

    2012-01-01

    The world's biggest and most powerful accelerator, the LHC, is mapping the route of particle physics for the future. The next step, to complement the LHC in exploring this new region, is most likely to be a linear electron-positron collider. The Compact Linear Collider (CLIC) is a novel approach to such a collider. It is currently under development by the CLIC collaboration, which is hosted at CERN.

  7. Luminosity performance studies of the compact linear collider with intra-train feedback system at the interaction point

    Energy Technology Data Exchange (ETDEWEB)

    Resta-Lopez, J; Burrows, P N; Christian, G, E-mail: j.restalopez@physics.ox.ac.u [John Adams Institute for Accelerator Science, Oxford University, Oxford, OX1 3RH (United Kingdom)

    2010-09-15

    To achieve the design luminosity at future linear colliders, control of beam stability at the sub-nanometre level at the interaction point will be necessary. Any source of beam motion which results in relative vertical offsets of the two beams at the interaction point may significantly reduce the luminosity from the nominal value. Beam-based intra-train feedback systems located in the interaction region are foreseen to correct the relative beam-beam offset and thus to steer the two beams into collision. These feedback systems must be capable of acting within the bunch train. In addition, these feedback systems might considerably help to relax the tight stability tolerances required for the final doublet magnets. For the Compact Linear Collider (CLIC), the extremely short nominal bunch spacing (0.5 ns) and very short nominal pulse duration (156 ns) make the intra-train feedback implementation technically very challenging. In this paper the conceptual design of an intra-train feedback system for the CLIC interaction point is described. Results of luminosity performance simulations are presented and discussed for different scenarios of ground motion. We also show how the intra-train feedback system can help to relax the very tight tolerances of the vertical vibration on the CLIC final doublet quadrupoles.

  8. The CLIC Detector Concept

    CERN Document Server

    Pitters, Florian Michael

    2016-01-01

    CLIC is a concept for a future linear collider that would provide e+e- collisions at up to 3 TeV. The physics aims require a detector system with excellent jet energy and track momentum resolution, highly efficient flavour-tagging and lepton identification capabilities, full geometrical coverage extending to low polar angles and timing information in the order of nanoseconds to reject beam-induced background. To deal with those requirements, an extensive R&D programme is in place to overcome current technological limits. The CLIC detector concept includes a low-mass all-silicon vertex and tracking detector system and fine-grained calorimeters designed for particle flow analysis techniques, surrounded by a 4 T solenoid magnet. An overview of the requirements and design optimisations for the CLIC detector concept is presented.

  9. M10.3.4: CLIC crab cavity specifications completed

    CERN Document Server

    Dexter, A; Ambattu, P; Shinton, I; Jones, R

    2010-01-01

    The starting point of Sub-task 2 is to document the currently anticipated requirements for the CLIC crab cavity system. This milestone concerns completion of the basic specifications for the CLIC crab cavity system. This comprises kick, power requirement, phase and amplitude stability, technology choice, and RF layout. The wakefield calculations of a baseline CLIC cavity will be used to estimate the required damping of the higher order modes as well as other special modes in crab cavities (the lower and same order modes).

  10. CLIC CRAB CAVITY SPECIFICATIONS MILESTONE: M10.3.4

    CERN Document Server

    Ambattu, P; Dexter, A; Jones, R; McIntosh, P; Shinton, I

    2010-01-01

    The starting point of Sub-task 2 is to document the currently anticipated requirements for the CLIC crab cavity system. This milestone concerns completion of the basic specifications for the CLIC crab cavity system. This comprises kick, power requirement, phase and amplitude stability, technology choice, and RF layout. The wakefield calculations of a baseline CLIC cavity will be used to estimate the required damping of the higher order modes as well as other special modes in crab cavities (the lower and same order modes).

  11. CLIC Muon Sweeper Design

    CERN Document Server

    Aloev, A; Gatignon, L; Modena, M; Pilicer, B; Tapan, I

    2016-01-01

    There are several background sources which may affect the analysis of data and detector performans at the CLIC project. One of the important background source is halo muons, which are generated along the beam delivery system (BDS), for the detector performance. In order to reduce muon background, magnetized muon sweepers have been used as a shielding material that is already described in a previous study for CLIC [1]. The realistic muon sweeper has been designed with OPERA. The design parameters of muon sweeper have also been used to estimate muon background reduction with BDSIM Monte Carlo simulation code [2, 3].

  12. CLIC Test Facility 3

    CERN Multimedia

    Kossyvakis, I; Faus-golfe, A

    2007-01-01

    The design of CLIC is based on a two-beam scheme, where short pulses of high power 30 GHz RF are extracted from a drive beam running parallel to the main beam. The 3rd generation CLIC Test Facility (CTF3) will demonstrate the generation of the drive beam with the appropriate time structure, the extraction of 30 GHz RF power from this beam, as well as acceleration of a probe beam with 30 GHz RF cavities. The project makes maximum use of existing equipment and infrastructure of the LPI complex, which became available after the closure of LEP.

  13. Study of a 5-Tesla large aperture coil for the CLIC detector

    CERN Document Server

    Cure, B

    2011-01-01

    The present design of a CLIC detector foresees a large solenoid magnet with a 6 m aperture and a magnetic induction of 5 T at the interaction point. This can be achieved by a thin superconducting coil. This report gives the typical main parameters of such a coil and presents the feasibility based on and compared with the CMS and Atlas solenoid coil designs, indicating the limits on the conductor and the identified R&D prospects.

  14. The CLIC Vertex Detector

    CERN Document Server

    Dannheim, D

    2015-01-01

    The precision physics needs at TeV-scale linear electron-positron colliders (ILC and CLIC) require a vertex-detector system with excellent flavour-tagging capabilities through a meas- urement of displaced vertices. This is essential, for example, for an explicit measurement of the Higgs decays to pairs of b-quarks, c-quarks and gluons. Efficient identification of top quarks in the decay t → W b will give access to the ttH-coupling measurement. In addition to those requirements driven by physics arguments, the CLIC bunch structure calls for hit tim- ing at the few-ns level. As a result, the CLIC vertex-detector system needs to have excellent spatial resolution, full geometrical coverage extending to low polar angles, extremely low material budget, low occupancy facilitated by time-tagging, and sufficient heat removal from sensors and readout. These considerations challenge current technological limits. A detector concept based on hybrid pixel-detector technology is under development for the CLIC ver- tex det...

  15. The CLIC Vertex Detector

    Science.gov (United States)

    Dannheim, D.

    2015-03-01

    The precision physics needs at TeV-scale linear electron-positron colliders (ILC and CLIC) require a vertex-detector system with excellent flavour-tagging capabilities through a measurement of displaced vertices. This is essential, for example, for an explicit measurement of the Higgs decays to pairs of b-quarks, c-quarks and gluons. Efficient identification of top quarks in the decay t → Wb will give access to the ttH-coupling measurement. In addition to those requirements driven by physics arguments, the CLIC bunch structure calls for hit timing at the few-ns level. As a result, the CLIC vertex-detector system needs to have excellent spatial resolution, full geometrical coverage extending to low polar angles, extremely low material budget, low occupancy facilitated by time-tagging, and sufficient heat removal from sensors and readout. These considerations challenge current technological limits. A detector concept based on hybrid pixel-detector technology is under development for the CLIC vertex detector. It comprises fast, low-power and small-pitch readout ASICs implemented in 65 nm CMOS technology (CLICpix) coupled to ultra-thin planar or active HV-CMOS sensors via low-mass interconnects. The power dissipation of the readout chips is reduced by means of power pulsing, allowing for a cooling system based on forced gas flow. This contribution reviews the requirements and design optimisation for the CLIC vertex detector and gives an overview of recent R&D achievements in the domains of sensors, readout and detector integration.

  16. $2\\times250$ GeV CLIC $\\gamma\\gamma$ Collider Based on its Drive Beam FEL

    CERN Document Server

    Aksakal, Husnu

    2007-01-01

    CLIC is a linear $e^+e^-$ ($\\gamma\\gamma$) collider project which uses a drive beam to accelerate the main beam. The drive beam provides RF power for each corresponding unit of the main linac through energy extracting RF structures. CLIC has a wide range of center-of-mass energy options from 150 GeV to 3 TeV. The present paper contains optimization of Free Electron Laser (FEL) using one bunch of CLIC drive beam in order to provide polarized light amplification using appropriate wiggler and luminosity spectrum of $\\gamma\\gamma$ collider for $E_{cm}$=0.5 TeV. Then amplified laser can be converted to a polarized high-energy $\\gamma$ beam at the Conversion point (CP-prior to electron positron interaction point) in the process of Compton backscattering. At the CP a powerful laser pulse (FEL) focused to main linac electrons (positrons). Here this scheme described and it is show that CLIC drive beam parameters satisfy the requirement of FEL additionally essential undulator parameters has been defined. Achievable $\\g...

  17. Technological challenges of CLIC

    CERN Document Server

    CERN. Geneva; Döbert, Steffen; Arnau-Izquierdo, G; Redaelli, Stefano; Mainaud, Helène; Lefèvre, Thibaut

    2006-01-01

    Future e+e- Linear Colliders offer the potential to explore new physics at the TeV scale and beyond to very high precision. While the International Linear Collider (ILC) scheme of a collider in the 0.5 - 1 TeV range enters the engineering design phase, the Compact Linear Collider (CLIC) study explores the technical feasibility of a collider capable of reaching into the multi-TeV energy domain. Key ingredients of the CLIC scheme are acceleration at high-frequency (30 GHz) and high-gradient (150 MV/m) in normal conducting structures and the use of the so-called Two Beam Acceleration concept, where a high-charge electron beam (drive beam) running parallel to the main beam is decelerated to provide the RF power to accelerate the main beam itself. A vigorous R&D effort is presently developed by the CLIC international collaboration to demonstrate its feasibility by 2010, when the first physics results from LHC should be available to guide the choice of the centre-of-mass energy better suited to explore the futu...

  18. BSM physics at CLIC

    CERN Document Server

    Simoniello, Rosa

    2016-01-01

    The Compact Linear Collider (CLIC) is an option for a future electron-positron collider operating at centre-of-mass energies from a few hundred GeV up to 3 TeV. The search for phenomena beyond the Standard Model through direct observation of new particles and precision measurements is one of the main motivations for the high-energy stages of CLIC. An overview of physics benchmark studies assuming different new physics scenarios is given in this contribution. These studies are based on full detector simulations. New particles can be discovered in most of the considered scenarios almost up to the kinematic limit ($\\sqrt{s}$/2 for pair production). The low background conditions at CLIC provide extended discovery potential compared to hadron colliders, for example in the case of non-coloured TeV-scale SUSY particles. In addition to direct particle searches, BSM models can be probed up to scales of tens of TeV through precision measurements. Examples, including recent results on the reaction $e^+e^- \\to \\gamma\\gam...

  19. Higgs physics at CLIC

    CERN Document Server

    Lukic, Strahinja

    2016-01-01

    The Compact Linear Collider CLIC is an option for a future multi-TeV electron-positron collider, offering the potential for a rich precision physics programme, combined with sensitivity to a wide range of new phenomena. The CLIC physics potential for measurements of the 125 GeV Higgs boson has been studied using full detector simulations for several centre-of-mass energies. The presented results provide crucial input to the energy staging strategy for the CLIC accelerator. The complete physics program for measurements of accessible Higgs boson couplings is presented in this talk. All measurements available at a given centre-of-mass energy were included in combined fits. Operation at a few hundred GeV allows the couplings and width of the Higgs boson to be determined in a model-independent manner through the study of the Higgsstrahlung and WW-fusion processes. At a lepton collider, the measurement of the Higgsstrahlung cross section using the recoil mass technique sets the absolute scale for all Higgs coupling...

  20. Higgs physics at CLIC

    CERN Document Server

    Lukić, Strahinja

    2016-01-01

    The Compact Linear Collider CLIC is an option for a future multi-TeV electron-positron collider, offering the potential for a rich precision physics programme, combined with sensitivity to a wide range of new phenomena. The CLIC physics potential for measurements of the 125 GeV Higgs boson has been studied using full detector simulations for several centre-of-mass energies. The presented results provide crucial input to the energy staging strategy for the CLIC accelerator. The complete physics program for measurements of accessible Higgs boson couplings is presented in this contribution. The ultimate measurement precision is reached when all measurements available at a given centre-of-mass energy are included in combined fits. Operation at a few hundred GeV allows the couplings and width of the Higgs boson to be determined in a model-independent manner through the study of the Higgsstrahlung and WW-fusion processes. At a lepton collider, the measurement of the Higgsstrahlung cross section using the recoil mas...

  1. Background and Energy Deposition Studies for the CLIC Post-Collision Line

    CERN Document Server

    Appleby, R B; Deacon, L C; Gschwendtner, E

    2011-01-01

    After the interaction point, the 1.5 TeV, 14MW CLIC electron/positron beams must be transported safely to the main beam dump. In designing the CLIC post-collision line detailed simulations must be carried out in order to ensure that losses are kept within reasonable limits. Results for back-scattered photon flux arriving at the detector are recalculated after updates and enhancements to the geometry description used in the study presented in [1]. Initial results of neutron fluxes are presented. Additionally, energy deposition calculations are carried out, showing that, when the full electromagnetic showers are included, in the current design the standard magnet coils would have a short lifetime due to radiation damage to conventional insulation material. Changing the magnet mask material from graphite to iron and lengthening the intermediate dump by 2m of iron are shown to substantially lessen the energy deposition in the magnet coils and thereby extend magnet lifetimes.

  2. Accelerator and Technical Sector Seminar: Mechanical stabilization and positioning of CLIC quadrupoles with sub-nanometre resolution

    CERN Multimedia

    2011-01-01

    Thursday 24 November 2010 Accelerator and Technical Sector Seminar at 14:15  -  BE Auditorium, bldg. 6 (Meyrin) – please note unusual place Mechanical stabilization and positioning of CLIC quadrupoles with sub-nanometre resolution Stef Janssens /EN-MME Abstract: To reach the required luminosity at the CLIC interaction point, about 4000 quadrupoles are needed to obtain a vertical beam size of 1 nm at the interaction point. The mechanical jitter of the quadrupole magnets will result in an emittance growth. An active vibration isolation system is required to reduce vibrations from the ground and from external forces to about 1.5 nm integrated root mean square (r.m.s.) vertical displacement at 1 Hz. A short overview of vibration damping and isolation strategies will be presented as well as a comparison of existing systems. The unprecedented resolution requirements and the instruments enabling these measurements will be discussed. The vibration sources from which the magnets need to...

  3. CLIC quadrupole stabilization and nano-positioning

    CERN Document Server

    Collette, C; Artoos, K; Fernandez Carmona, P; Guinchard, M; Hauviller, C

    2010-01-01

    In the Compact LInear Collider (CLIC) currently under study, electrons and positrons will be accelerated in two linear accelerators to collide at the interaction point with an energy of 0.5- 3 TeV. This machine is constituted of a succession of accelerating structures, used to accelerate the beams of particles, and electromagnets (quadrupoles) used to focus the beams. In order to ensure good performances, the quadrupoles have to be extremely stable. Additionally, they should also have the capability to move by steps of some tens of nanometers every 20 ms with a precision of +/- 1nm. This paper proposes a holistic approach to fulfill alternatively both requirements using the same device. The concept is based on piezoelectric hard mounts to isolate the quadrupoles from the ground vibrations in the sensitive range between 1 and 20 Hz, and to provide nano-positioning capabilities. It is also shown that this strategy ensures robustness to external forces (acoustic noise, water flow for the cooling, air flow for th...

  4. CLIC Physics Overview

    CERN Document Server

    AUTHOR|(SzGeCERN)471575

    2016-01-01

    This paper, based on the invited talk given at the 17th Lomonosov Conference of Elementary Particle Physics, summarizes the physics program at CLIC, with particular emphasis on the Higgs physics studies. The physics reach of CLIC operating in three energy stages, at 350 GeV, 1.4 TeV and 3 TeV center-of-mass energies is reviewed. The energy-staged approach is motivated by the high-precision physics measurements in the Higgs and top sector as well as by direct and indirect searches for beyond the Standard Model physics. The first stage, at or above 350 GeV, gives access to precision Higgs physics through the Higgsstrahlung and WW-fusion production processes, providing absolute values of the Higgs couplings to fermions and bosons. This stage also addresses precision top physics around the top-pair-production threshold. The second stage, at 1.4 TeV, opens the energy frontier, allowing for the discovery of new physics phenomena. This stage also gives access to additional Higgs properties, such as the top-Yukawa co...

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

    Energy Technology Data Exchange (ETDEWEB)

    Berger, E.; Demarteau, M.; Repond, J.; Xia, L.; Weerts, H. (High Energy Physics); (Many)

    2012-02-10

    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 maximize 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

  6. The Physics Prospects for CLIC

    CERN Document Server

    ELLIS, J.

    2008-01-01

    Following a brief outline of the CLIC project, this talk summarizes some of the principal motivations for an e+e− collider with ECM = 3 TeV. It is shown by several examples that CLIC would represent a significant step beyond the LHC and ILC in its capabilities for precision measurements at high energies. It would make possible a complete study of a light Higgs boson, including rare decay modes, and would provide a unique tool to study a heavy Higgs boson. CLIC could also complete the studies of supersymmetric spectra, if sparticles are relatively light, and discover any heavier sparticles. It would also enable deeper probes of extra dimensions, new gauge bosons and excited quarks or leptons. CLIC has unique value to add to experimental particle physics, whatever the LHC discovers.

  7. CLIC Crab Cavity Design Optimisation for Maximum Luminosity

    Energy Technology Data Exchange (ETDEWEB)

    Dexter, A.C.; /Lancaster U. /Cockcroft Inst. Accel. Sci. Tech.; Burt, G.; /Lancaster U. /Cockcroft Inst. Accel. Sci. Tech.; Ambattu, P.K.; /Lancaster U. /Cockcroft Inst. Accel. Sci. Tech.; Dolgashev, V.; /SLAC; Jones, R.; /Manchester U.

    2012-04-25

    The bunch size and crossing angle planned for CERN's compact linear collider CLIC dictate that crab cavities on opposing linacs will be needed to rotate bunches of particles into alignment at the interaction point if the desired luminosity is to be achieved. Wakefield effects, RF phase errors between crab cavities on opposing linacs and unpredictable beam loading can each act to reduce luminosity below that anticipated for bunches colliding in perfect alignment. Unlike acceleration cavities, which are normally optimised for gradient, crab cavities must be optimised primarily for luminosity. Accepting the crab cavity technology choice of a 12 GHz, normal conducting, travelling wave structure as explained in the text, this paper develops an analytical approach to optimise cell number and iris diameter.

  8. CLIC crab cavity design optimisation for maximum luminosity

    Energy Technology Data Exchange (ETDEWEB)

    Dexter, A.C., E-mail: a.dexter@lancaster.ac.uk [Lancaster University, Lancaster, LA1 4YR (United Kingdom); Cockcroft Institute, Daresbury, Warrington, WA4 4AD (United Kingdom); Burt, G.; Ambattu, P.K. [Lancaster University, Lancaster, LA1 4YR (United Kingdom); Cockcroft Institute, Daresbury, Warrington, WA4 4AD (United Kingdom); Dolgashev, V. [SLAC, Menlo Park, CA 94025 (United States); Jones, R. [University of Manchester, Manchester, M13 9PL (United Kingdom)

    2011-11-21

    The bunch size and crossing angle planned for CERN's compact linear collider CLIC dictate that crab cavities on opposing linacs will be needed to rotate bunches of particles into alignment at the interaction point if the desired luminosity is to be achieved. Wakefield effects, RF phase errors between crab cavities on opposing linacs and unpredictable beam loading can each act to reduce luminosity below that anticipated for bunches colliding in perfect alignment. Unlike acceleration cavities, which are normally optimised for gradient, crab cavities must be optimised primarily for luminosity. Accepting the crab cavity technology choice of a 12 GHz, normal conducting, travelling wave structure as explained in the text, this paper develops an analytical approach to optimise cell number and iris diameter.

  9. Clic ring to main Linac

    CERN Document Server

    Stulle, F; Snuverink, J; Latina, A; Molloy, S

    2010-01-01

    The low emittance transport had been identified as one of the feasibility issues for CLIC. We discuss beam dynamics challenges occurring in the beam lines connecting the damping rings and the main linac. And we outline how these motivate design choices for the general RTML layout as well as its integration into the overall CLIC layout. Constraints originating from longitudinal dynamics and stabilization requirements of beam energy and phase at the main linac entrance are emphasized.

  10. The CLIC Physics Potential

    CERN Document Server

    AUTHOR|(SzGeCERN)554857

    2016-01-01

    The physics and detector studies for the Compact Linear Collider (CLIC) are introduced. A staged programme of $e^{+}e^{−}$ collisions covering $\\sqrt{s}$ = 380 GeV, 1.5 TeV, and 3 TeV would allow precise measurements of Higgs boson couplings, in many cases to the percent level. This corresponds to precision higher than that expected for the high-luminosity Large Hadron Collider. Such precise Higgs coupling measurements would allow sensitivity to a variety of new physics models and the ability to distinguish between them. In addition, new particles directly produced in pairs could be measured with great precision, and measurements in the top-quark sector would provide sensitivity to new physics effects at the scales of tens of TeV.

  11. CLIC Status and Outlook

    CERN Document Server

    Stapnes, Stapnes

    2012-01-01

    The Compact Linear Collider study (CLIC) is in the process of completing a Conceptual Design Report (CDR) for a multi-TeV linear electron-positron collider. The CLICconcept is based on high gradient normal-conducting accelerating structures. The RF power for the acceleration of the colliding beams is produced by a novel two beam acceleration scheme, where power is extracted from a high current drive beam that runs parallel with the main linac. In order to establish the feasibility of this concept a number of key issues have been addressed. A short summary of the progress and status of the corresponding studies will be given, as well as an outline of the preparation and work towards an implementation plan by 2016.

  12. Tunable Achromats and CLIC Applications

    CERN Document Server

    D'Amico, T E

    2000-01-01

    It is imperative for linear colliders that the bunch length be adjustable. In most cases bunch compression is required, but recently, in the design of the Compact LInear Collider (CLIC) RF Power Source, it was shown that bunch stretching may also be necessary. In some situations, both modes may be needed, which implies the need for tunable magnetic insertions. This is even more essential in a test facility, to span a wide experimental range. In addition, flexible tuning provides a better control of the stability of an isochronous insertion. To start a numerical search for a tunable insertion from scratch is very uncertain because the related phase space is very uneven. However, a starting point obtained with an analytical approximation is often sufficient to ensure convergence. Another advantage of the analytical treatment described in this paper is that it sheds light on the shape of the entire phase space. To achieve this the isochronous achromat developed previously has been given tuning capabilities by ex...

  13. Impact of the New CLIC Beam Parameters on the Design of the Post-Collision Line and its Exit Window

    CERN Document Server

    Ferrari, A

    2008-01-01

    Following the recent modification of the CLIC beam parameters, we present an updated design of the post-collision line. As a result of the increase of the beamstrahlung photon cone size, the separation of the outgoing beams by the vertical magnetic chicane is more difficult, but still possible. The main changes in the post-collision line design include the implementation of a common dump for the wrong-sign charged particles of the coherent pairs and for the low-energy tails of the disrupted beam, as well as a significant reduction of the overall lattice length (allowing removal of the large refocusing quadrupoles). The thermal and mechanical stresses in the new exit window, 150 m downstream of the interaction point, were computed. We conclude that, despite the recent changes of the CLIC beam parameters and the necessary modifications of the post-collision line and its exit window, their performance is not significantly affected.

  14. CLIC expands to include the Southern Hemisphere

    CERN Multimedia

    Roberto Cantoni

    2010-01-01

    Australia has recently joined the CLIC collaboration: the enlargement will bring new expertise and resources to the project, and is especially welcome in the wake of CERN budget redistributions following the recent adoption of the Medium Term Plan.   The countries involved in CLIC collaboration With the signing of a Memorandum of Understanding on 26 August 2010, the ACAS network (Australian Collaboration for Accelerator Science) became the 40th member of in the multilateral CLIC collaboration making Australia the 22nd country to join the collaboration. “The new MoU was signed by the ACAS network, which includes the Australian Synchrotron and the University of Melbourne”, explains Jean-Pierre Delahaye, CLIC Study Leader. “Thanks to their expertise, the Australian institutes will contribute greatly to the CLIC damping rings and the two-beam test modules." Institutes from any country wishing to join the CLIC collaboration are invited to assume responsibility o...

  15. CLIC vertex detector R&D

    Science.gov (United States)

    Alipour Tehrani, Niloufar

    2016-07-01

    A vertex detector concept is under development for the proposed multi-TeV linear e+e- Compact Linear Collider (CLIC). To perform precision physics measurements in a challenging environment, the CLIC vertex detector pushes the technological requirements to the limits. This paper reviews the requirements for the CLIC vertex detector and gives an overview of recent R&D achievements in the domains of sensor, readout, powering and cooling.

  16. Relativistic point interactions: Approximation by smooth potentials

    Science.gov (United States)

    Hughes, Rhonda J.

    1997-06-01

    We show that the four-parameter family of one-dimensional relativistic point interactions studied by Benvegnu and Dąbrowski may be approximated in the strong resolvent sense by smooth, local, short-range perturbations of the Dirac Hamiltonian. In addition, we prove that the nonrelativistic limits correspond to the Schrödinger point interactions studied extensively by the author and Paul Chernoff.

  17. Tissue and subcellular distribution of CLIC1

    Directory of Open Access Journals (Sweden)

    Edwards John C

    2007-02-01

    Full Text Available Abstract Background CLIC1 is a chloride channel whose cellular role remains uncertain. The distribution of CLIC1 in normal tissues is largely unknown and conflicting data have been reported regarding the cellular membrane fraction in which CLIC1 resides. Results New antisera to CLIC1 were generated and were found to be sensitive and specific for detecting this protein. These antisera were used to investigate the distribution of CLIC1 in mouse tissue sections and three cultured cell lines. We find CLIC1 is expressed in the apical domains of several simple columnar epithelia including glandular stomach, small intestine, colon, bile ducts, pancreatic ducts, airway, and the tail of the epididymis, in addition to the previously reported renal proximal tubule. CLIC1 is expressed in a non-polarized distribution in the basal epithelial cell layer of the stratified squamous epithelium of the upper gastrointesitinal tract and the basal cells of the epididymis, and is present diffusely in skeletal muscle. Distribution of CLIC1 was examined in Panc1 cells, a relatively undifferentiated, non-polarized human cell line derived from pancreatic cancer, and T84 cells, a human colon cancer cell line which can form a polarized epithelium that is capable of regulated chloride transport. Digitonin extraction was used to distinguish membrane-inserted CLIC1 from the soluble cytoplasmic form of the protein. We find that digitonin-resistant CLIC1 is primarily present in the plasma membrane of Panc1 cells. In T84 cells, we find digitonin-resistant CLIC1 is present in an intracellular compartment which is concentrated immediately below the apical plasma membrane and the extent of apical polarization is enhanced with forskolin, which activates transepithelial chloride transport and apical membrane traffic in these cells. The sub-apical CLIC1 compartment was further characterized in a well-differentiated mouse renal proximal tubule cell line. The distribution of CLIC1 was

  18. Overview of the CLIC beam instrumentation

    CERN Document Server

    Lefèvre, T

    2011-01-01

    The performances of the Compact Linear Collider (CLIC) would rely on extremely tight tolerances on most beam parameters. The requirements for the CLIC beam instrumentation have been reviewed and studied in detail for the whole accelerator complex. In the context of the completion of the CLIC Conceptual Design Report, a first attempt was made to propose a technical solution for every CLIC instruments. Even if these choices were based on most recent technological achievements, whenever possible, alternatives solutions focusing on potential improvements on performance, reliability or cost minimization are proposed and will be studied in the future. This paper presents an overview of the CLIC beam instruments, gives a status of their already achieved performances and presents the future work activities.

  19. Common ground in ILC and CLIC detector concepts

    CERN Multimedia

    Daisy Yuhas

    2013-01-01

    The Compact Linear Collider and the International Linear Collider will accelerate particles and create collisions in different ways. Nonetheless, the detector concepts under development share many commonalities.   Timepix chips under scrutiny in the DESY test beam with the help of the beam telescope. CERN physicist Dominik Dannheim explains that the CLIC detector plans are adaptations of the ILC detector designs with a few select modifications. “When we started several years ago, we did not want to reinvent the wheel,” says Dannheim. “The approved ILC detector concepts served as an excellent starting point for our designs.” Essential differences Both CLIC and ILC scientists foresee general-purpose detectors that make measurements with exquisite precision. These colliders, however, have very different operating parameters, which will have important consequences for the various detector components. The ILC’s collision energy is set at 500 GeV ...

  20. CLIC inner detectors cooling simulations

    CERN Document Server

    Duarte Ramos, F.; Villarejo Bermudez, M.

    2014-01-01

    The strict requirements in terms of material budget for the inner region of the CLIC detector concepts require the use of a dry gas for the cooling of the respective sen- sors. This, in conjunction with the compactness of the inner volumes, poses several challenges for the design of a cooling system that is able to fulfil the required detec- tor specifications. This note introduces a detector cooling strategy using dry air as a coolant and shows the results of computational fluid dynamics simulations used to validate the proposed strategy.

  1. Precision Higgs boson measurement at CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)718111

    2016-01-01

    The design of the next generation collider in high energy physics will primarily focus on the possibility to achieve high precision of the measurements of interest. The necessary precision limits are set, in the first place, by the measurement of the Higgs boson but also by measurements that are sensitive to signs of New Physics. The Compact Linear Collider (CLIC) is an attractive option for a future multi-TeV linear electron-positron collider, with the potential to cover a rich physics program with high precision. In this lecture the CLIC accelerator, detector and backgrounds will be presented with emphesis on the capabilities of CLIC for precision Higgs physics.

  2. First phase of CLIC R&D complete

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    Let’s turn back the clocks to 2002: the LHC is still under construction, the wrap-up of the LEP physics programme is still in recent memory and the future of electron-positron accelerators at CERN is ambiguous. It was then that CLIC set out to prove the feasibility of their novel accelerator design in the CTF3 test facility. Though once a tall order for the collaboration, the recently released CLIC Conceptual Design Report has proven many of the major design elements… bringing to an end the first phase of CLIC R&D and pointing toward detailed performance optimisation studies in the next phase.   Streak camera images of the final beam, illustrating the combination of beams in the Combiner Ring. Over a decade ago, the CTF3 team set up shop in the vacated LIL injector site, once home to the weathered machine that delivered electrons and positrons to LEP. Rebuilding and upgrading the machine piece by piece, the CTF3 team converted this mA linac into a high-current drive b...

  3. CLIC's three-step plan

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    In early October, the Compact Linear Collider (CLIC) collaboration published its final Conceptual Design Report. Accompanying it was a strategic summary document that describes a whole new approach to the project: developing the linear e+e− collider in three energy stages. Though CLIC’s future still depends on signs from the LHC, its new staged approach to high-energy electron-positron physics for the post-LHC era is nothing short of convincing.   Instead of asking for a 48-kilometre-long commitment right off the bat, the CLIC collaboration is now presenting an accelerator that can be constructed in stages. For example, it could begin as an 11-kilometre 500 GeV accelerator that could later be extended to a 27-kilometre 1.5 TeV machine. Finally, after a decade or so of data taking, it could be taken up to the full 48-kilometre 3 TeV facility (see image 2). “Not only is the approach technically and financially practical, it also offers a very convincing physics prog...

  4. The 30 GHz transfer structure for the CLIC study

    CERN Document Server

    Carron, G; Thorndahl, L

    1998-01-01

    In the so-called "Two-Beam Acceleration Scheme" the energy of a drive beam is converted to rf power by means of a "Transfer Structure", which plays the role of power source. In the Transfer Structure the bunched drive beam is decelerated by the electromagnetic field which it induces and builds up by the coherent interaction of successive bunches with the chosen longitudinal mode. The CLIC Transfer Structure is original in that it operates at 30 GHz and uses teeth-like corrugations to slow down the hybrid TM mode to make it synchronous with the drive beam. The beam energy is transformed into rf power, which travels along the structure and is collected by the output couplers. The 30 GHz rf power is then transported by means of two waveguides to two main linac disk-loaded accelerating structures. This report describes the CLIC Transfer Structure design, 3-D computer simulations, model construction and measure-ments as well as the prototype construction and testing with the low energy beam in the CLIC Test Facili...

  5. Acquisition system for the CLIC Module

    CERN Document Server

    Vilalte, Sebastien

    2011-01-01

    The status of R&D activities for CLIC module acquisition are discussed [1]. LAPP is involved in the design of the local CLIC module acquisition crate, described in the document Study of the CLIC Module Front-End Acquisition and Evaluation Electronics [2]. This acquisition system is a project based on a local crate, assigned to the CLIC module, including several mother boards. These motherboards are foreseen to hold mezzanines dedicated to the different subsystems. This system has to work in radiation environment. LAPP is involved in the development of Drive Beam stripline position monitors read-out, described in the document Drive Beam Stripline BPM Electronics and Acquisition [3]. LAPP also develops a generic acquisition mezzanine that allows to perform all-around acquisition and components tests for drive beam stripline BPM read-out.

  6. LHC and CLIC LLRF final reports

    CERN Document Server

    Dexter, A; Woolley, B; Ambattu, P; Tahir, I; Syratchev, Igor; Wuensch, Walter

    2013-01-01

    Crab cavities rotate bunches from opposing beams to achieve effective head-on collision in CLIC or collisions at an adjustable angle in LHC. Without crab cavities 90% of achievable luminosity at CLIC would be lost. In the LHC, the crab cavities allow the same or larger integrated luminosity while reducing significantly the requested dynamic range of physics detectors. The focus for CLIC is accurate phase synchronisation of the cavities, adequate damping of wakefields and modest amplitude stability. For the LHC, the main LLRF issues are related to imperfections: beam offsets in cavities, RF noise, measurement noise in feedback loops, failure modes and mitigations. This report develops issues associated with synchronising the CLIC cavities. It defines an RF system and experiments to validate the approach. It reports on the development of hardware for measuring the phase performance of the RF distributions system and cavities. For the LHC, the hardware being very close to the existing LLRF, the report focuses on...

  7. Detector Optimization of the CLIC Tracker

    CERN Document Server

    Saxe, Gandalf

    2015-01-01

    CLIC (Compact Linear Collider) is a proposed high-energy electron-positron collider at CERN [1] that, if approved, will be built at the feet of the Jura Mountains in Switzerland, passing through CERN. As opposed to hadrons, electrons (e-) and positrons (e+) are elementary particles. Therefore, e-e+ collisions give a well defined initial state which allows high precision studies. A circular collider is not a viable option when going to high energies (several TeV) for a e-e+ collider due to synchrotron radiation. Therefore CLIC is designed as a linear collider. CLIC is proposed to be build in three center-of-mass energy stages: 380 GeV, 1.4 TeV and 3.0 TeV. The CLIC physics program includes the high precision measurements of the Higgs and top properties, the observation of rare processes, and the possible discovery of new particles [3].

  8. Successful start for new CLIC test facility

    CERN Multimedia

    2004-01-01

    A new test facility is being built to study key feasibility issues for a possible future linear collider called CLIC. Commissioning of the first part of the facility began in June 2003 and nominal beam parameters have been achieved already.

  9. CLIC CTF3 for open days

    CERN Multimedia

    CLIC

    2013-01-01

    CLIC – the Compact Linear Collider – is a study for a future accelerator that reaches unprecedented energies for electrons and their antimatter twins, positrons. It uses a novel two-beam acceleration scheme in which the electrons and positrons are propelled to high energy by an additional high current electron beam, the so-called Drive Beam. In order to generate this high current Drive Beam, a long train of electron bunches is accelerated, parts of the train delayed in a Delay Loop and Combiner Rings, and interleaved by transversely deflecting radio-frequency cavities. The CLIC Test Facility CTF3, which is shown in the movie, examines the new technologies envisioned by the CLIC design, in particular the Drive Beam generation and the two-beam acceleration. It is a scaled-down version of the CLIC facility, and it has demonstrated the feasibility of the novel scheme.

  10. CLIC CTF3 for open days

    CERN Multimedia

    2013-01-01

    (subt french) CLIC – the Compact Linear Collider – is a study for a future accelerator that reaches unprecedented energies for electrons and their antimatter twins, positrons. It uses a novel two-beam acceleration scheme in which the electrons and positrons are propelled to high energy by an additional high current electron beam, the so-called Drive Beam. In order to generate this high current Drive Beam, a long train of electron bunches is accelerated, parts of the train delayed in a Delay Loop and Combiner Rings, and interleaved by transversely deflecting radio-frequency cavities. The CLIC Test Facility CTF3, which is shown in the movie, examines the new technologies envisioned by the CLIC design, in particular the Drive Beam generation and the two-beam acceleration. It is a scaled-down version of the CLIC facility, and it has demonstrated the feasibility of the novel scheme.

  11. CLIC Accelerated R&D

    CERN Document Server

    Wilson, Ian H

    2005-01-01

    An accelerated R&D programme to demonstrate the key feasibility issues of the CLIC scheme before 2010 was approved by the CERN Council in March 2004. This report describes the activities, extra resources and time schedule to complete this programme. The activities are presented in the form of work-packages. Laboratories, Universities and Funding Agencies around the world have been invited by the CERN DG to participate in the programme by taking full technical responsibility for part, complete or several work packages and/or providing voluntary contributions "a la carte", in cash, in kind and/or in man-power. The intention is to set-up a multi-lateral collaboration between all laboratories interested in such a development.

  12. A Luminosity Calorimeter for CLIC

    CERN Document Server

    Abramowicz, H; Kananov, S; Levy, A; Sadeh, I

    2009-01-01

    For the relative precision of the luminosity measurement at CLIC, a preliminary target value of 1% is being assumed. This may be accomplished by constructing a finely granulated calorimeter, which will measure Bhabha scattering at small angles. In order to achieve the design goal, the geometrical parameters of the calorimeter need to be defined. Several factors influence the design of the calorimeter; chief among these is the need to minimize the error on the luminosity measurement while avoiding the intense beam background at small angles. In this study the geometrical parameters are optimized for the best performance of the calorimeter. In addition, the suppression of physics background to Bhabha scattering is investigated and a set of selection cuts is introduced.

  13. Multibunch Emittance Preservation in CLIC

    CERN Document Server

    Guignard, Gilbert

    1996-01-01

    In high-frequency linacs, where the wakefields are strong, the stability of a train of bunches is critical. The beam break-up due to long range wakefields induces a decoherence of the bunch oscillations and a consequent blow-up of the effective betatron emittances of the whole train. Since the Compact Linear Collider (CLIC) study now includes several bunches per pulse, it is important to analyse numerically and theoretically this emittance blow-up. possibilities of controlling the beam break-up without upsetting the single bunch stability have been considered: first a multibunch generalization of the BNS damping principle, secondly an attenuation of the long-range fields, and thirdly an increase of the focusing in order to overconstrain the beam. Simulation codes have been written for both checking the theoretical predictions and investigating the requirements associated with a possible application to the main linac. Animated graphics make it possible to get a didactic display of the multibunch instability.

  14. Physics at the CLIC e$^{+}$e$^{-}$ Linear Collider -- Input to the Snowmass process 2013

    OpenAIRE

    Abramowicz, Halina; Abusleme, Angel; Battaglia, Marco; Świentek, Krzysztof; Szalay, Marco; Tanabe, Tomohiko; Tesař, Michal; Thamm, Andrea; Thomson, Mark; Garcia, Juan Trenado; Uggerhøj, Ulrik I.; van der Kraaij, Erik; Vila, Iván; Benoit, Mathieu; Vilella, Eva

    2013-01-01

    This paper summarizes the physics potential of the CLIC high-energy e+e- linear collider. It provides input to the Snowmass 2013 process for the energy-frontier working groups on The Higgs Boson (HE1), Precision Study of Electroweak Interactions (HE2), Fully Understanding the Top Quark (HE3), as well as The Path Beyond the Standard Model -- New Particles, Forces, and Dimensions (HE4). It is accompanied by a paper describing the CLIC accelerator study, submitted to the Frontier Capabilities gr...

  15. Physics at the CLIC $e^{+}e^{-}$ Linear Collider - Input to the Snowmass process 2013

    CERN Document Server

    Abramowicz, Halina; Afanaciev, K.; Alexander, G.; Alipour Tehrani, N.; Alonso, O.; Andersen, K.K.; Arfaoui, S.; Balazs, C.; Barklow, T.; Battaglia, M.; Benoit, M.; Bilki, B.; Blaising, J.J.; Boland, M.; Boronat, M.; Bozovic Jelisavcic, I.; Burrows, P.; Chefdeville, M.; Contino, R.; Dannheim, D.; Demarteau, M.; Diaz Gutierrez, M.A.; Dieguez, A.; Duarte Campderros, J.; Eigen, G.; Elsener, K.; Feldman, D.; Felzmann, U.; Firlej, M.; Firu, E.; Fiutowski, T.; Francis, K.; Gaede, F.; Garcia Garcia, I.; Ghenescu, V.; Giudice, G.; Graf, N.; Grefe, C.; Grojean, C.; Gupta, R.S.; Hauschild, M.; Holmestad, H.; Idzik, M.; Joram, C.; Kananov, S.; Karyotakis, Y.; Killenberg, M.; Klempt, W.; Kraml, S.; Krupa, B.; Kulis, S.; Lastovicka, T.; LeBlanc, G.; Levy, A.; Levy, I.; Linssen, L.; Lucaci Timoce, A.; Lukic, S.; Makarenko, V.; Marshall, J.; Martin, V.; Mikkelsen, R.E.; Milutinovic-Dumbelovic, G.; Miyamoto, A.; Monig, K.; Moortgat-Pick, G.; Moron, J.; Munnich, A.; Neagu, A.; Pandurovic, M.; Pappadopulo, D.; Pawlik, B.; Porod, W.; Poss, S.; Preda, T.; Rassool, R.; Rattazzi, R.; Redford, S.; Reichold, A.; Repond, J.; Riemann, S.; Robson, A.; Roloff, P.; Ros, E.; Rosten, J.; Ruiz-Jimeno, A.; Rzehak, H.; Sailer, A.; Schlatter, D.; Schulte, D.; Sefkow, F.; Seidel, K.; Shumeiko, N.; Sicking, E.; Simon, F.; Smith, J.; Soldner, C.; Stapnes, S.; Strube, J.; Suehara, T.; Swientek, K.; Szalay, M.; Tanabe, T.; Tesar, M.; Thamm, A.; Thomson, M.; Trenado Garcia, J.; Uggerhoj, U.I.; van der Kraaij, E.; Vila, I.; Vilella, E.; Villarejo, M.A.; Vogel Gonzalez, M.A.; Vos, M.; Watson, N.; Weerts, H.; Wells, J.D.; Weuste, L.; Wistisen, T.N.; Wootton, K.; Xia, L.; Zawiejski, L.; Zgura, I.S.

    2013-01-01

    This paper summarizes the physics potential of the CLIC high-energy e+e- linear collider. It provides input to the Snowmass 2013 process for the energy-frontier working groups on The Higgs Boson (HE1), Precision Study of Electroweak Interactions (HE2), Fully Understanding the Top Quark (HE3), as well as The Path Beyond the Standard Model -- New Particles, Forces, and Dimensions (HE4). It is accompanied by a paper describing the CLIC accelerator study, submitted to the Frontier Capabilities group of the Snowmass process

  16. CLICdp Overview. Overview of physics potential at CLIC

    Directory of Open Access Journals (Sweden)

    Levy Aharon

    2015-01-01

    Full Text Available CLICdp, the CLIC detector and physics study, is an international collaboration presently composed of 23 institutions. The collaboration is addressing detector and physics issues for the future Compact Linear Collider (CLIC, a high-energy electron-positron accelerator which is one of the options for the next collider to be built at CERN. Precision physics under challenging beam and background conditions is the key theme for the CLIC detector studies. This leads to a number of cutting-edge R&D activities within CLICdp. The talk includes a brief introduction to CLIC, accelerator and detectors, hardware R&D as well as physics studies at CLIC.

  17. Light-flavor squark reconstruction at CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)548062; Weuste, Lars

    2015-01-01

    We present a simulation study of the prospects for the mass measurement of TeV-scale light- flavored right-handed squark at a 3 TeV e+e collider based on CLIC technology. The analysis is based on full GEANT4 simulations of the CLIC_ILD detector concept, including Standard Model physics backgrounds and beam-induced hadronic backgrounds from two- photon processes. The analysis serves as a generic benchmark for the reconstruction of highly energetic jets in events with substantial missing energy. Several jet finding algorithms were evaluated, with the longitudinally invariant kt algorithm showing a high degree of robustness towards beam-induced background while preserving the features typically found in algorithms developed for e+e- collisions. The presented study of the reconstruction of light-flavored squarks shows that for TeV-scale squark masses, sub-percent accuracy on the mass measurement can be achieved at CLIC.

  18. Wakefield Damping for the CLIC Crab Cavity

    Energy Technology Data Exchange (ETDEWEB)

    Ambattu, P.K.; Burt, G.; Dexter, A.C.; Carter, R.G.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Khan, V.; Jones, R.M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.; Dolgashev, V.; /SLAC

    2011-12-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  19. Wakefield damping for the CLIC crab cavity

    CERN Document Server

    Ambattu, P K; Dexter, A C; Carter, R G; Khan, V; Jones, R M; Dolgashev, V

    2009-01-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  20. WAKEFIELD DAMPING FOR THE CLIC CRAB CAVITY

    CERN Document Server

    Ambattu, P; Dexter, A; Carter, R; Khan, V; Jones, R; Dolgashev, V

    2009-01-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  1. Physics highlights at ILC and CLIC

    CERN Document Server

    Lukić, Strahinja

    2015-01-01

    In this lecture, the physics potential for the e+e- linear collider experiments ILC and CLIC is reviewed. The experimental conditions are compared to those at hadron colliders and their intrinsic value for precision experiments, complementary to the hadron colliders, is discussed. The detector concepts for ILC and CLIC are outlined in their most important aspects related to the precision physics. Highlights from the physics program and from the benchmark studies are given. It is shown that linear colliders are a promising tool, complementing the LHC in essential ways to test the Standard Model and to search for new physics.

  2. New clic-g structure design

    CERN Document Server

    AUTHOR|(CDS)2082335

    2016-01-01

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

  3. CLIC preparations go up a notch

    CERN Multimedia

    2007-01-01

    The Compact Linear Collider gears up for post-LHC physics with an international workshop. A schematic diagram of CLIC.In June CERN gained a new building: number 2010. And as chance would have it, this is more than just a number to its new residents. By the year 2010, teams working at the new CLIC Experimental Area, along with the already established CLIC Test Facility Three (CTF3), hope to have demonstrated the feasibility of the Compact Linear Collider and, depending on results from the LHC, embark on its final design and proposal. A workshop on 16t-18 October brought people from all around the world to CERN to exchange ideas and hear how the ambitious project is progressing. CLIC is a project that aims to extend lepton collider technology to multi-TeV energy physics, colliding leptons with a centre-of-mass-energy up to 3TeV, more than ten times the energy of the LEP. This is only possible in a linear collider, where no energy is lo...

  4. The CLIC positron source based on compton schemes

    CERN Document Server

    Rinolfi, L; Braun, H; Papaphilippou, Y; Schulte, D; Vivoli, A; Zimmermann, F; Dadoun, O; Lepercq, P; Roux, R; Variola, A; Zomer, F; Pogorelski, I; Yakimenko, V; Gai, W; Liu, W; Kamitani, T; Omori, T; Urakawa, J; Kuriki, M; Takahasi, TM; Bulyak, E; Gladkikh, P; Chehab, R; Clarke, J

    2010-01-01

    The CLIC polarized positron source is based on a positron production scheme in which polarized photons are produced by a Compton process. In one option, Compton backscattering takes place in a so-called “Compton ring”, where an electron beam of 1 GeV interacts with circularly-polarized photons in an optical resonator. The resulting circularly-polarized gamma photons are sent on to an amorphous target, producing pairs of longitudinally polarized electrons and positrons. The nominal CLIC bunch population is 4.2x109 particles per bunch at the exit of the Pre-Damping Ring (PDR). Since the photon flux coming out from a "Compton ring" is not sufficient to obtain the requested charge, a stacking process is required in the PDR. Another option is to use a Compton Energy Recovery Linac (ERL) where a quasicontinual stacking in the PDR could be achieved. A third option is to use a "Compton Linac" which would not require stacking. We describe the overall scheme as well as advantages and constraints of the three option...

  5. R&D Challenges of a CLIC Vertex Detector

    CERN Document Server

    van der Kraaij, E

    2010-01-01

    The Compact Linear Collider (CLIC) is a concept for an electron-positron collider with a center- of-mass energy of up to 3 TeV. Given the unprecedented experimental conditions at CLIC none of the technologies available today can fulfill all requirements set for the vertex detector. At the conference these conditions and the challenges they pose for the R&D of a CLIC vertex detector were presented.

  6. A new framework for interactive segmentation of point clouds

    OpenAIRE

    Liu, K.; J. Boehm

    2014-01-01

    Point cloud segmentation is a fundamental problem in point processing. Segmenting a point cloud fully automatically is very challenging due to the property of point cloud as well as different requirements of distinct users. In this paper, an interactive segmentation method for point clouds is proposed. Only two strokes need to be drawn intuitively to indicate the target object and the background respectively. The draw strokes are sparse and don't necessarily cover the whole object. Given the ...

  7. The CLIC feasibility demonstration in CTF3

    CERN Document Server

    Skowroński, P K; Bettoni, S; Constance, B; Corsini, R; Divall Csatari, M; Dabrowski, A E; Doebert, S; Dubrovskiy, A; Kononenko, O; Olvegaard, M; Persson, T; Rabiller, A; Tecker, F; Farabolini, W; Lillestol, R L; Adli, E; Palaia, A; Ruber, R

    2011-01-01

    The objective of the CLIC Test Facility CTF3 is to demonstrate the feasibility issues of the CLIC two-beam technology: the efficient generation of a very high current drive beam, used as the power source to accelerate the main beam to multi-TeV energies with gradients of over 100 MeV/m, and stable drive beam deceleration. Results of successful beam acceleration with over 100 MeV/m energy gain are shown. Measurements of drive beam deceleration over a chain of Power Extraction Structures (PETS) are presented. The achieved RF power levels, the stability of the power production and of the deceleration are discussed. Finally, we give an overview of the remaining issues to be addressed by the end of 2011.

  8. Academic Training - Technological challenges of CLIC

    CERN Multimedia

    Françoise Benz

    2006-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 12, 13, 14, 15 and 16 June 11:00-12:00 - Auditorium, bldg 500 Technological challenges of CLIC R. Corsini, S. Doebert, S. Redaelli, T.Lefevre, CERN-AB and G. Arnau Izquierdo, H. Mainaud, CERN-TS Future e+e- Linear Colliders offer the potential to explore new physics at the TeV scale and beyond to very high precision. While the International Linear Collider (ILC) scheme of a collider in the 0.5 - 1 TeV range enters the engineering design phase, the Compact Linear Collider (CLIC) study explores the technical feasibility of a collider capable of reaching into the multi-TeV energy domain. Key ingredients of the CLIC scheme are acceleration at high-frequency (30 GHz) and high-gradient (150 MV/m) in normal conducting structures and the use of the so-called Two Beam Acceleration concept, where a high-charge electron beam (drive beam) running parallel to the main beam is decelerated to provide the RF power to accelerate the main beam itself. A vigorous R&...

  9. Light-flavor squark reconstruction at CLIC

    Science.gov (United States)

    Simon, Frank; Weuste, Lars

    2015-08-01

    We present a simulation study of the prospects for the mass measurement of TeV-scale light-flavored right-handed squarks at a 3 TeV collider based on CLIC technology. In the considered model, these particles decay into their standard-model counterparts and the lightest neutralino, resulting in a signature of two jets plus missing energy. The analysis is based on full GEANT4 simulations of the CLIC_ILD detector concept, including Standard Model physics backgrounds and beam-induced hadronic backgrounds from two-photon processes. The analysis serves as a generic benchmark for the reconstruction of highly energetic jets in events with substantial missing energy. Several jet finding algorithms were evaluated, with the longitudinally invariant algorithm showing a high degree of robustness towards beam-induced background while preserving the features typically found in algorithms developed for collisions. The presented study of the reconstruction of light-flavored squarks shows that for TeV-scale squark masses, sub-percent accuracy on the mass measurement can be achieved at CLIC.

  10. Higgs and BSM physics at CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)669060

    2015-01-01

    The Compact Linear Collider (CLIC) is a possible future multi-TeV linear electron-positron collider, offering the potential for a rich Standard Model physics programme and sensitivity to a wide range of phenomena beyond the Standard Model. The physics reach of CLIC has been studied for several centre-of-mass energies, motivating a staged construction and providing the opportunity for precise studies of the properties of the 125 GeV Higgs boson. Operation at a few hundred GeV allows the couplings and width of the Higgs to be determined in a model independent manner through the study of the Higgsstrahlung and WW-fusion processes. Operation at higher centre-of-mass energies, up to 3 TeV, provides higher statistics and the potential to study rare Higgs decays, the top Yukawa coupling and the Higgs self-coupling. The results at all energy stages are combined in a model independent global Higgs fit. The higher energy stages of CLIC are targeted to searches for physics beyond the Standard Model. Within the kinematic...

  11. Submicron multi-bunch BPM for CLIC

    Energy Technology Data Exchange (ETDEWEB)

    Schmickler, H.; Soby, L.; /CERN; Lunin, A.; Solyak, N.; Wendt, M.; /Fermilab

    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 to 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.

  12. Impact of Dynamic Magnetic fields on the CLIC Main Beam

    CERN Document Server

    Snuverink, J; Jach, C; Jeanneret, JB; Schulte, D; Stulle, F

    2010-01-01

    The Compact Linear Collider (CLIC) accelerator has strong precision requirements on the position of the beam. The beam position will be sensitive to external dynamic magnetic fields (stray fields) in the nanotesla regime. The impact of these fields on the CLIC main beam has been studied by performing simulations on the lattices and tolerances have been determined. Several mitigation techniques will be discussed.

  13. Critical points for finite Fibonacci chains of point delta-interactions and orthogonal polynomials

    Energy Technology Data Exchange (ETDEWEB)

    De Prunele, E, E-mail: eprunele@univ-fcomte.fr [Institut UTINAM, UMR CNRS 6213, Universite de Franche-Comte, 16 route de Gray, 25030 Besancon Cedex (France)

    2011-10-21

    For a one-dimensional Schroedinger operator with a finite number n of point delta-interactions with a common intensity, the parameters are the intensity, the n - 1 intercenter distances and the mass. Critical points are points in the parameters space of the Hamiltonian where one bound state appears or disappears. The study of critical points for Hamiltonians with point delta-interactions arranged along a Fibonacci chain is shown to be closely related to the study of the so-called Fibonacci operator, a discrete one-dimensional Schroedinger-type operator, which occurs in the context of tight binding Hamiltonians. These critical points are the zeros of orthogonal polynomials previously studied in the context of special diatomic linear chains with elastic nearest-neighbor interaction. Properties of the zeros (location, asymptotic behavior, gaps, ...) are investigated. The perturbation series from the solvable periodic case is determined. The measure which yields orthogonality is investigated numerically from the zeros. It is shown that the transmission coefficient at zero energy can be expressed in terms of the orthogonal polynomials and their associated polynomials. In particular, it is shown that when the number of point delta-interactions is equal to a Fibonacci number minus 1, i.e. when the intervals between point delta-interactions form a palindrome, all the Fibonacci chains at critical points are completely transparent at zero energy. (paper)

  14. From glutathione transferase to pore in a CLIC

    CERN Document Server

    Cromer, B A; Morton, C J; Parker, M W; 10.1007/s00249-002-0219-1

    2002-01-01

    Many plasma membrane chloride channels have been cloned and characterized in great detail. In contrast, very little is known about intracellular chloride channels. Members of a novel class of such channels, called the CLICs (chloride intracellular channels), have been identified over the last few years. A striking feature of the CLIC family of ion channels is that they can exist in a water- soluble state as well as a membrane-bound state. A major step forward in understanding the functioning of these channels has been the recent crystal structure determination of one family member, CLIC1. The structure confirms that CLICs are members of the glutathione S- transferase superfamily and provides clues as to how CLICs can insert into membranes to form chloride channels. (69 refs).

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

    CERN Document Server

    Burrows, P; Draper, M; Garvey, T; Lebrun, P; Peach, K; Phinney, N; Schmickler, H; Schulte, D; Toge, N

    2012-01-01

    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 studies 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 ...

  16. Status of vertex and tracking detector R&D at CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)754272

    2015-01-01

    The physics aims at the future CLIC high-energy linear e+e- collider set very high precision requirements on the performance of the vertex and tracking detectors. Moreover, these detectors have to be well adapted to the experimental conditions, such as the bunch train structure of the beam and the presence of beam-induced backgrounds. The principal challenges are: a point resolution of a few micron, ultra-low mass (~0.2% X0 per layer for the inner vertex region), very low power dissipation (compatible with air-flow cooling in the inner vertex region) and pulsed power operation, complemented with ~10 ns time stamping capabilities. An overview of the R&D program for pixel and tracking detectors at CLIC will be presented, including recent results on an innovative hybridisation concept based on capacitive coupling between active sensors (HV-CMOS) and readout ASICs (CLICpix).

  17. The physics benchmark processes for the detector performance studies used in CLIC CDR Volume 3

    CERN Document Server

    Allanach, B.J.; Desch, K.; Ellis, J.; Giudice, G.; Grefe, C.; Kraml, S.; Lastovicka, T.; Linssen, L.; Marschall, J.; Martin, S.P.; Muennich, A.; Poss, S.; Roloff, P.; Simon, F.; Strube, J.; Thomson, M.; Wells, J.D.

    2012-01-01

    This note describes the detector benchmark processes used in volume 3 of the CLIC conceptual design report (CDR), which explores a staged construction and operation of the CLIC accelerator. The goal of the detector benchmark studies is to assess the performance of the CLIC ILD and CLIC SiD detector concepts for different physics processes and at a few CLIC centre-of-mass energies.

  18. Multiple tipping points and optimal repairing in interacting networks

    Science.gov (United States)

    Majdandzic, Antonio; Braunstein, Lidia A.; Curme, Chester; Vodenska, Irena; Levy-Carciente, Sary; Eugene Stanley, H.; Havlin, Shlomo

    2016-03-01

    Systems composed of many interacting dynamical networks--such as the human body with its biological networks or the global economic network consisting of regional clusters--often exhibit complicated collective dynamics. Three fundamental processes that are typically present are failure, damage spread and recovery. Here we develop a model for such systems and find a very rich phase diagram that becomes increasingly more complex as the number of interacting networks increases. In the simplest example of two interacting networks we find two critical points, four triple points, ten allowed transitions and two `forbidden' transitions, as well as complex hysteresis loops. Remarkably, we find that triple points play the dominant role in constructing the optimal repairing strategy in damaged interacting systems. To test our model, we analyse an example of real interacting financial networks and find evidence of rapid dynamical transitions between well-defined states, in agreement with the predictions of our model.

  19. Alignement général du CLIC: stratégie et progrès

    CERN Document Server

    Mainaud-Durand, H

    2008-01-01

    La faisabilité concernant le pré-alignement actif du CLIC sera démontrée si l?on peut prouver qu?il existe une référence et ses capteurs associés permettant l?alignement des composants à mieux que 3 microns (1?). Pour répondre à ce challenge, une méthode de mesure d?écarts à un fil tendu est proposée, basée sur 40 ans de pratique de cette technique au CERN. Quelques problèmes demeurent concernant cette méthode : la connaissance de la forme du fil tendu utilisé comme référence droite, la détermination du géoïde à la précision souhaitée et le développement de capteurs bas coût permettant des mesures sub-micrométriques. Des études ont été entreprises afin de lever les derniers points en suspens, pendant que cette solution est intégrée dans une proposition concernant l?alignement général du CLIC. Cela implique un grand nombre d?interactions au niveau du projet, dans des domaines aussi différents que le génie civil, l?intégration, la physique du faisceau, la métrologie des �...

  20. CARE-JRA2* Activities on Photo-Injectors and CLIC Test Facility (CTF3)

    CERN Document Server

    Rinolfi, Louis

    2005-01-01

    In the frame of the CARE project, there is a Joint Research Activity (JRA2) called PHIN (PHoto-INjectors). The main objective of this JRA is to perform Research and Development on charge-production by interaction of a laser pulse with material within RF fields and improve or extend existing infrastructures. Another activity of PHIN is the coordination of the activities of various Institutes concerning photo-injectors. A brief review of the work of the eight European laboratories involved in PHIN is presented. One of these R&D topics is the construction of a photo-injector for the CLIC Test Facility (CTF3). In this context the status of CTF3 and its main goals - the demonstration of the feasibility of the key issues of the CLIC two-beam acceleration scheme - is also presented.

  1. Spectrometers for RF breakdown studies for CLIC

    Science.gov (United States)

    Jacewicz, M.; Ziemann, V.; Ekelöf, T.; Dubrovskiy, A.; Ruber, R.

    2016-08-01

    An e+e- collider of several TeV energy will be needed for the precision studies of any new physics discovered at the LHC collider at CERN. One promising candidate is CLIC, a linear collider which is based on a two-beam acceleration scheme that efficiently solves the problem of power distribution to the acceleration structures. The phenomenon that currently prevents achieving high accelerating gradients in high energy accelerators such as the CLIC is the electrical breakdown at very high electrical field. The ongoing experimental work within the CLIC collaboration is trying to benchmark the theoretical models focusing on the physics of vacuum breakdown which is responsible for the discharges. In order to validate the feasibility of accelerating structures and observe the characteristics of the vacuum discharges and their eroding effects on the structure two dedicated spectrometers are now commissioned at the high-power test-stands at CERN. First, the so called Flashbox has opened up a possibility for non-invasive studies of the emitted breakdown currents during two-beam acceleration experiments. It gives a unique possibility to measure the energy of electrons and ions in combination with the arrival time spectra and to put that in context with accelerated beam, which is not possible at any of the other existing test-stands. The second instrument, a spectrometer for detection of the dark and breakdown currents, is operated at one of the 12 GHz stand-alone test-stands at CERN. Built for high repetition rate operation it can measure the spatial and energy distributions of the electrons emitted from the acceleration structure during a single RF pulse. Two new analysis tools: discharge impedance tracking and tomographic image reconstruction, applied to the data from the spectrometer make possible for the first time to obtain the location of the breakdown inside the structure both in the transversal and longitudinal direction thus giving a more complete picture of the

  2. Conceptual Design for CLIC Gun Pulser

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Tao [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2016-01-08

    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.

  3. Electro-Weak Fits at CLIC

    CERN Document Server

    De Curtis, S

    2002-01-01

    The aim of the future linear colliders is to extend the sensitivity to new physics beyond the reach of the LHC. Several models predict the existence of new vector resonances in the multi-TeV region. We review the existing limits on the masses of these new resonances from LEP/SLC and TEVATRON data and from the atomic parity violation measurements, in some specific models. We study the potential of a multi-TeV e+e- collider, such as CLIC, for the determination of their properties and nature.

  4. Combined Fits of CLIC Higgs Results for the Snowmass Process

    CERN Document Server

    Simon, F; Roloff, P

    2013-01-01

    This note presents three combined fits of CLIC Higgs physics results, a model- independent fit based on minimal assumptions and two model-dependent fits assuming that the total width is described by the sum of nine (seven) different visible final states with coupling parameters given by the deviation of the re- spective partial widths from their SM values. The input values are a snapshot of the CLIC Higgs analyses as of September 2013. The results demonstrate the capabilities of the full three-stage CLIC physics program for a precise ex- ploration of the Higgs sector.

  5. Collaborative interaction points in post-discharge stroke care

    Directory of Open Access Journals (Sweden)

    Nadia Davoody

    2014-11-01

    Full Text Available Introduction: Lack of appropriate electronic tools for supporting patient involvement and collaboration with care professionals is a problem in health care. Methods: Care and rehabilitation processes of post-discharge stroke patients were analysed using the concept of interaction points where patients, next-of-kin and care professionals interact and exchange information. Thirteen interviews with care professionals and five non-participatory observations were performed. Data were analysed using content analysis and modelling of interaction points in the patient journey. Results: Patient participation and interaction patterns vary; patients requiring home care have a passive role and next-of-kin or nurses become advocates by coordinating care on behalf of the patient, whereas patients who are able to visit primary care coordinate their own care by initiating interactions. Important categories of participation include the following: participation in care planning, in monitoring risk factors and in rehabilitation planning. Conclusions: Designing a supportive electronic tool requires understanding the interactions and patients’ activity levels at each interaction point. A tool for patients with higher activity level should support them to coordinate their own care, whereas for a less-active patient group, the tool could focus on supporting next-of-kin and care professionals in motivating, guiding and including passive patients in their care and rehabilitation processes.

  6. Phase diagram and critical end point for strongly interacting quarks.

    Science.gov (United States)

    Qin, Si-xue; Chang, Lei; Chen, Huan; Liu, Yu-xin; Roberts, Craig D

    2011-04-29

    We introduce a method based on chiral susceptibility, which enables one to draw a phase diagram in the chemical-potential-temperature plane for strongly interacting quarks whose interactions are described by any reasonable gap equation, even if the diagrammatic content of the quark-gluon vertex is unknown. We locate a critical end point at (μ(E),T(E))∼(1.0,0.9)T(c), where T(c) is the critical temperature for chiral-symmetry restoration at μ=0, and find that a domain of phase coexistence opens at the critical end point whose area increases as a confinement length scale grows.

  7. Multiple Tipping Points and Optimal Repairing in Interacting Networks

    CERN Document Server

    Majdandzic, Antonio; Curme, Chester; Vodenska, Irena; Levy-Carciente, Sary; Stanley, H Eugene; Havlin, Shlomo

    2015-01-01

    Systems that comprise many interacting dynamical networks, such as the human body with its biological networks or the global economic network consisting of regional clusters, often exhibit complicated collective dynamics. To understand the collective behavior of these systems, we investigate a model of interacting networks exhibiting the fundamental processes of failure, damage spread, and recovery. We find a very rich phase diagram that becomes exponentially more complex as the number of networks is increased. In the simplest example of $n=2$ interacting networks we find two critical points, 4 triple points, 10 allowed transitions, and two "forbidden" transitions, as well as a manifold of metastable regions represented by complex hysteresis. Knowing and understanding the phase diagram have an immediate practical implication; it enables us to find the optimal strategy for repairing partially or fully damaged interconnected networks. To support our model, we analyze an example of real interacting financial net...

  8. Summary of the BDS and MDI CLIC08 Working Group

    CERN Document Server

    Tomás, R; Ahmed, I; Ambatu, PK; Angal-Kalinin, D; Barlow, R; Baud, J P; Bolzon, B; Braun, H; Burkhardt, H; Burt, GC; Corsini, R; Dalena, B; Dexter, AC; Dolgashev, V; Elsener, K; Fernandez Hernando, JL; Gaillard, G; Geffroy, N; Jackson, F; Jeremie, A; Jones, RM; McIntosh, P; Moffeit, K; Peltier, F; Resta-López, J; Rumolo, G; Schulte, D; Seryi, A; Toader, A; Zimmermann, F

    2008-01-01

    This note summarizes the presentations held within the Beam Delivery System and Machine Detector Interface working group of the CLIC08 workshop. The written contributions have been provided by the presenters on a voluntary basis.

  9. Luminosity Upgrade of CLIC LHC ep/gp Collider

    CERN Document Server

    Aksakal, H; Nergiz, Z; Schulte, D; Zimmermann, F

    2007-01-01

    An energy frontier or QCD Explorer ep and collider can be realized by colliding high-energy photons generated by Compton backscattered off a CLIC electron beam, at either 75 GeV or 1.5 TeV, with protons or ions stored in the LHC. In this study we discuss a performance optimization of this type of collider by tailoring the parameters of both CLIC and LHC. An estimate of the ultimately achievable luminosity is given.

  10. A high resolution cavity BPM for the CLIC Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Chritin, N.; Schmickler, H.; Soby, L.; /CERN; Lunin, A.; Solyak, N.; Wendt, M.; Yakovlev, V.; /Fermilab

    2010-08-01

    In frame of the development of a high resolution BPM system for the CLIC Main Linac we present the design of a cavity BPM prototype. It consists of a waveguide loaded dipole mode resonator and a monopole mode reference cavity, both operating at 15 GHz, to be compatible with the bunch frequencies at the CLIC Test Facility. Requirements, design concept, numerical analysis, and practical considerations are discussed.

  11. Requirements of CLIC Beam Loss Monitoring System

    CERN Document Server

    Sapinski, M; Holzer, EB; Jonker, M; Mallows, S; Otto, T; Welsch, C

    2010-01-01

    The Compact Linear Collider (CLIC) [1] is a proposed multi-TeV linear electron-positron collider being designed by a world-wide collaboration. It is based on a novel twobeam acceleration scheme in which two beams (drive and main beam) are placed in parallel to each other and energy is transferred from the drive beam to the main one. Beam losses on either of them can have catastrophic consequences for the machine, because of high intensity (drive beam) or high energy and small emittance (main beam). In the framework of machine protection, a Beam Loss Monitoring (BLM) system has to be put in place. This paper discusses the requirements for the beam loss system in terms of detector sensitivity, resolution, dynamic range and ability to distinguish losses originating from various sources. The two-beam module where the protection from beam losses is particularly challenging and important, is studied.

  12. Mustafa environment description and users' guide with applications to CLIC

    CERN Document Server

    Guignard, Gilbert

    1998-01-01

    In the main linacs of future linear colliders, the control of the emittances and the stability of a train of bunches are critical. It was therefore important for the Compact Linear Collider study (CLIC) to have a tool allowing numerical investigations of these questions. An interactive environment called MUSTAFA (MUltibunch Simulation and Tracking Algorithm for Future Accelerators) has been created and different tools have been developed over the time according to the needs. Progressively, these code and interactive facilities evolved into two main features, their portability on PCs independent from the main frame computers and their analysis capability using animated graphics. All the codes have been written under the MS-DOS operating system. The main application MBTR has been written in FORTRAN, the animated graphics facility MOVIE and the so-called MBUNCH utility program in QUICKBASIC (MS V4.5). The MBUNCH code was created in order to manage in a user friendly set-up the other two mentioned as well as the ...

  13. Critical Points in Nuclei and Interacting Boson Model Intrinsic States

    CERN Document Server

    Ginocchio, J N; Ginocchio, Joseph N.

    2003-01-01

    We consider properties of critical points in the interacting boson model, corresponding to flat-bottomed potentials as encountered in a second-order phase transition between spherical and deformed $\\gamma$-unstable nuclei. We show that intrinsic states with an effective $\\beta$-deformation reproduce the dynamics of the underlying non-rigid shapes. The effective deformation can be determined from the the global minimum of the energy surface after projection onto the appropriate symmetry. States of fixed $N$ and good O(5) symmetry projected from these intrinsic states provide good analytic estimates to the exact eigenstates, energies and quadrupole transition rates at the critical point.

  14. The synchro laser system for the CLIC Test Facility

    International Nuclear Information System (INIS)

    The CLIC Test Facility at CERN uses a laser driven 3 GHz electron gun. Considerable effort has been spent to develop a laser system, which meets the requirements of the Test Facility. The laser is based on a diode-pumped ND:YLF mode-locked oscillator. It delivers a 250 MHz train of laser pulses at 1047 nm with a length of 6.6 ps. A phase-locked timing stabilizer is used to synchronize the laser with the rf-gun. One or two pulses are amplified to 10 mJ. The amplifier system is based on a regenerative amplifier and two single pass power amplifiers. A set of harmonic generators deliver laser pulses at 523 nm, 262 nm and optional at 209nm. The measured pulse length after amplification and harmonic generations is 8 ± 2 ps (FWHM). A good pointing stability and a reasonable uniform transverse profile is obtained by relay imaging and spatial filtering. For some experiments, a train of electron bunches is used. A new pulse train generator working at 262 nm was developed to split the laser beam into 12 pulses. The simultaneous amplification of two seed laser pulses gives the possibility to double the number of pulses in the train without the need to add further splitting stages

  15. Les mesures de métrologie pour le CLIC

    CERN Document Server

    Cherif, A

    2008-01-01

    Le projet CLIC est en tout point un défi technique majeur ; c?est le cas également pour la mesure dimensionnelle. Quels sont les équipements et les méthodes qui permettent de caractériser les pièces avec une incertitude de mesure aussi réduite que possible, vu les tolérances micrométriques imposées ? Afin de répondre à cette question, une veille technologique a été maintenue sur une longue période. Les acteurs relevants ont été contactés pour bénéficier d?une ouverture sur les dernières avancées dans le domaine. Différentes techniques ont été étudiées et comparées telles que la digitalisation, la tomographie X, la mesure tridimensionnelle. L'assemblage de haute précision des composants est aussi primordial. Sa mise en ?uvre sous un microscope optique ou à l'aide d'une machine tridimensionnelle est en cours d?étude. L'exposé traitera aussi de la mesure de rugosité, un domaine où nous disposons de moyens adaptés aux exigences spécifiques du projet.

  16. Silicon pixel-detector R&D for CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)718101

    2016-01-01

    The physics aims at the future CLIC high-energy linear e+e- collider set very high precision requirements on the performance of the vertex and tracking detectors. Moreover, these detectors have to be well adapted to the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The principal challenges are: a point resolution of a few μm, ultra-low mass (∼ 0.2% X${}_0$ per layer for the vertex region and ∼ 1 % X${}_0$ per layer for the outer tracker), very low power dissipation (compatible with air-flow cooling in the inner vertex region) and pulsed power operation, complemented with ∼ 10 ns time stamping capabilities. A highly granular all-silicon vertex and tracking detector system is under development, following an integrated approach addressing simultaneously the physics requirements and engineering constraints. For the vertex-detector region, hybrid pixel detectors with small pitch (25 μm) and analog readout are explored. For the outer trac...

  17. Evaluation of 65nm technology for CLIC pixel front-end

    CERN Document Server

    Valerio, P; Ballabriga, R; Campbell, M; Llopart, X

    2011-01-01

    The CLIC vertex detector design requires a high single point resolution (~ 3 μm) and a precise time stamp (≤ 10 ns). In order to achieve this spatial resolution, small pixels (in the order of 20 μm pitch) must be used, together with the measurement of the charge deposition of neighbouring channels. Designing such small pixels requires the use of a deep downscaled CMOS technology. This note describes the design and characterisation of suitable building blocks implemented in a commercial 65 nm process. The characterisation included an evaluation of the radiation hardness of the blocks.

  18. Radiation and Background Levels in a CLIC Detector due to Beam-Beam Effects Optimisation of Detector Geometries and Technologies

    CERN Document Server

    Sailer, André; Lohse, Thomas

    2013-01-10

    The high charge density---due to small beam sizes---and the high energy of the proposed CLIC concept for a linear electron--positron collider with a centre-of-mass energy of up to 3~TeV lead to the production of a large number of particles through beam-beam interactions at the interaction point during every bunch crossing (BX). A large fraction of these particles safely leaves the detector. A still significant amount of energy will be deposited in the forward region nonetheless, which will produce secondary particles able to cause background in the detector. Furthermore, some particles will be created with large polar angles and directly cause background in the tracking detectors and calorimeters. The main sources of background in the detector, either directly or indirectly, are the incoherent $mathrm{e}^{+}mathrm{e}^{-}$ pairs and the particles from $gammagamma ightarrow$ hadron events. The background and radiation levels in the detector have to be estimated, to study if a detector is feasible, that can han...

  19. Physics performance for measurements of chargino and neutralino pair production at a 1.4 TeV CLIC collider

    CERN Document Server

    Roloff, Philipp

    2013-01-01

    A study of chargino and neutralino pair production at a CLIC collider operating at √s = 1.4 TeV is presented. Fully hadronic final states with four jets and missing transverse energy were considered. The analysis was performed using full detector simulation and including pileup from gg → hadrons interactions. Results for the masses and production cross sections of the chargino and the next-to-lightest neutralino are discussed.

  20. Elastic interaction of point defects in cubic and hexagonal crystals

    Science.gov (United States)

    Kukushkin, S. A.; Osipov, A. V.; Telyatnik, R. S.

    2016-05-01

    The elastic interaction of two point defects in cubic and hexagonal structures has been considered. On the basis of the exact expression for the tensor Green's function of the elastic field obtained by the Lifschitz-Rozentsveig for a hexagonal medium, an exact formula for the interaction energy of two point defects has been obtained. The solution is represented as a function of the angle of their relative position on the example of semiconductors such as III-nitrides and α-SiC. For the cubic medium, the solution is found on the basis of the Lifschitz-Rozentsveig Green's tensors corrected by Ostapchuk, in the weak-anisotropy approximation. It is proven that the calculation of the interaction energy by the original Lifschitz-Rozentsveig Green's tensor leads to the opposite sign of the energy. On the example of the silicon crystal, the approximate solution is compared with the numerical solution, which is represented as an approximation by a series of spherical harmonics. The range of applicability of the continual approach is estimated by the quantum mechanical calculation of the lattice Green's function.

  1. CLIC TWO-BEAM MODULE FOR THE CLIC CONCEPTUAL DESIGN AND RELATED EXPERIMENTAL PROGRAM*

    CERN Document Server

    Samoshkin, A; Solodko, A; Riddone, G

    2011-01-01

    The CLIC (Compact LInear Collider) study is a site independent study exploring technological developments to extend linear colliders into the Multi-TeV colliding beam energy range. The two-beam linear accelerator being studied at CERN involves the design and integration of many different technical systems, tightly bound and influencing each other. For the construction of two linacs it has been decided to proceed with a modular design, and repetitive two-beam modules of a few types were defined. The modules consist of micron-level precision components operating under ultra-high vacuum as required by the beam physics. For the CLIC Conceptual Design Report, the development and system integration is mainly focused on the most complex module type containing the highest number of components and technical systems. For proving the proper functioning of the needed technical systems and confirming their feasibility it has been decided to build four prototype modules and test them without beam. In addition, three module...

  2. CLIC Two-Beam Module for the CLIC Conceptual Design and related experimental program

    CERN Document Server

    Samoshkin, A; Solodko, A; Riddone, G

    2011-01-01

    The CLIC (Compact LInear Collider) study is a site independent study exploring technological developments to extend linear colliders into the Multi-TeV colliding beam energy range. The two-beam linear accelerator being studied at CERN involves the design and integration of many different technical systems, tightly bound and influencing each other. For the construction of two linacs it has been decided to proceed with a modular design, and repetitive two-beam modules of a few types were defined. The modules consist of micron-level precision components operating under ultra-high vacuum as required by the beam physics. For the CLIC Conceptual Design Report, the development and system integration is mainly focused on the most complex module type containing the highest number of components and technical systems. For proving the proper functioning of the needed technical systems and confirming their feasibility it has been decided to build four prototype modules and test them without beam. In addition, three module...

  3. The CLIC electron and positron polarized sources

    CERN Document Server

    Rinolfi, Louis; Bulyak, Eugene; Chehab, Robert; Dadoun, Olivier; Gai, Wei; Gladkikh, Peter; Kamitani, Takuya; Kuriki, Masao; Liu, Wanming; Maryuama, Takashi; Omori, Tsunehiko; Poelker, Matt; Sheppard, John; Urakawa, Junji; Variola, Alessandro; Vivoli, Alessandro; Yakimenko, Vitaly; Zhou, Feng; Zimmermann, Frank

    2010-01-01

    The CLIC polarized electron source is based on a DC gun where the photocathode is illuminated by a laser beam. Each micro-bunch has a charge of 6x109 e−, a width of 100 ps and a repetition rate of 2 GHz. A peak current of 10 A in the micro-bunch is a challenge for the surface charge limit of the photo-cathode. Two options are feasible to generate the 2 GHz e− bunch train: 100 ps micro-bunches can be extracted from the photo-cathode either by a 2 GHz laser system or by generating a macro-bunch using a ~200 ns laser pulse and a subsequent RF bunching system to produce the appropriate micro-bunch structure. Recent results obtained by SLAC, for the latter case, are presented. The polarized positron source is based on a positron production scheme in which polarized photons are produced by a laser Compton scattering process. The resulting circularly-polarized gamma photons are sent onto a target, producing pairs of longitudinally polarized electrons and positrons. The Compton backscattering process occurs eithe...

  4. Minimizing Emittance for the CLIC Damping Ring

    CERN Document Server

    Braun, H; Levitchev, E; Piminov, P; Schulte, Daniel; Siniatkin, S; Vobly, P P; Zimmermann, Frank; Zolotarev, Konstantin V; CERN. Geneva

    2006-01-01

    The CLIC damping rings aim at unprecedented small normalized equilibrium emittances of 3.3 nm vertical and 550 nm horizontal, for a bunch charge of 2.6·109 particles and an energy of 2.4 GeV. In this parameter regime the dominant emittance growth mechanism is intra-beam scattering. Intense synchrotron radiation damping from wigglers is required to counteract its effect. Here the overall optimization of the wiggler parameters is described, taking into account state-of-the-art wiggler technologies, wiggler effects on dynamic aperture, and problems of wiggler radiation absorption. Two technical solutions, one based on superconducting magnet technology the other on permanent magnets are presented. Although dynamic aperture and tolerances of this ring design remain challenging, benefits are obtained from the strong damping. For optimized wigglers, only bunches for a single machine pulse may need to be stored, making injection/extraction particularly simple and limiting the synchrotron-radiation power. With a 36...

  5. Status of Wakefield Monitor Experiments at the CLIC Test Facility

    CERN Document Server

    Lillestøl, Reidar; Aftab, Namra; Corsini, Roberto; Döbert, Steffen; Farabolini, Wilfrid; Grudiev, Alexej; Javeed, Sumera; Pfingstner, Juergen; Wuensch, Walter

    2016-01-01

    For the very low emittance beams in CLIC, it is vital to mitigate emittance growth which leads to reduced luminosity in the detectors. One factor that leads to emittance growth is transverse wakefields in the accelerating structures. In order to combat this the structures must be aligned with a precision of a few um. For achieving this tolerance, accelerating structures are equipped with wakefield monitors that measure higher-order dipole modes excited by the beam when offset from the structure axis. We report on such measurements, performed using prototype CLIC accelerating structures which are part of the module installed in the CLIC Test Facility 3 (CTF3) at CERN. Measurements with and without the drive beam that feeds rf power to the structures are compared. Improvements to the experimental setup are discussed, and finally remaining measurements that should be performed before the completion of the program are summarized.

  6. CLIC/ILC Researchers Explore New Avenues for Collaboration

    CERN Multimedia

    Katarina Anthony

    2010-01-01

    Researchers from CLIC and ILC met for their first common International Workshop on Linear Colliders, which was held in Geneva from 18 to 22 October. Although the talks were mostly scientific and technical, the political message behind them was a breakthrough, as the workshop showed the progress made in unifying the two communities.   The International Workshop on Linear Colliders (IWLC), which was organised by the European Committee for Future Accelerators, hosted by CERN, and held at CERN and the International Conference Centre in Geneva, attracted a large audience of about 500 experts. Although there have been other joint conferences between the CLIC and ILC communities before, they have all been focused on specific technical and/or managerial issues. The IWLC was part of an ongoing effort by CLIC and ILC to provide an environment in which researchers can exchange ideas, inform their peers about their most recent achievements and work together on common issues. Given the possible technical ov...

  7. Haptic tumor augmentation: exploring multi-point interaction.

    Science.gov (United States)

    Jeon, Seokhee; Harders, Matthias

    2014-01-01

    We currently explore the application of haptic augmentation in the context of palpation training systems. The key idea is to modify real touch sensations with computed haptic feedback. In earlier work, we have introduced an algorithmic framework for determining appropriate augmentation forces during interaction at one contact point. In this paper, we present an extension of the approach to deal with manipulations at more than one contact location. At the heart of our method is the data-driven estimation of Hunt-Crossley model parameters in a pre-computation step. Feeding the parameters into a contact dynamics model allows us to approximate the feedback behavior of various physical tissue mock-ups. Further, we combine the parameter estimation with the tracking of the position of a stiffer inclusion in the mock-up. These data are employed to create a model of movement due to external forces. The combination of these models then allows us to represent and render the mutual effects at multiple contact points. Several experiments have been carried out on a setup with two haptic devices. Comparisons of recorded with simulated interaction data demonstrate the performance and potential of our method.

  8. Beam Loading Compensation in the Main Linac of CLIC

    OpenAIRE

    Schulte, D.; Syratchev, I.

    2000-01-01

    Compensation of multi-bunch beam loading is of great importance in the main linac of the Compact Linear Collider (CLIC). The bunch-to-bunch energy variation has to stay below 1 part in 1000. In CLIC, the RF power is obtained by decelerating a drive beam which is formed by merging a number of short bunch trains. A promising scheme for tackling beam loading in the main linac is based on varying the lengths of the bunch trains in the drive beam. The scheme and its expected performance are presen...

  9. Higgs Physics at the CLIC Electron-Positron Linear Collider

    CERN Document Server

    Roloff, Philipp Gerhard

    2016-01-01

    The Compact Linear Collider (CLIC) is an option for a future $e^+e^-$ collider operating at centre-of-mass energies up to 3 TeV, providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper presents the Higgs physics reach of CLIC operating in three energy stages, $\\sqrt{s} =$ 350 GeV, 1.4 TeV and 3 TeV. The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung ($e^+e^-\\to ZH$) and $WW$-fusion ($e^+e^-\\to H\

  10. Single Z' production at CLIC based on e^- gamma collisions

    OpenAIRE

    Soa, D. V.; H.N. Long(Institute of Physics, VAST, 10 Dao Tan, Ba Dinh, Hanoi, Vietnam); Binh, D. T.; Khoi, D. P.

    2003-01-01

    We analyze the potential of CLIC based on e- gamma collisions to search for new $Z'$ gauge boson. Single Z' production at e-gamma colliders in two SU(3)_C X SU(3)_L X U(1)_N models: the minimal model and the model with right-handed (RH) neutrinos is studied in detail. Results show that new Z' gauge bosons can be observed at the CLIC, and the cross sections in the model with RH neutrinos are bigger than those in the minimal one.

  11. Vertex-Detector R&D for CLIC

    CERN Document Server

    Dannheim, D

    2014-01-01

    A detector concept based on hybrid planar pixel-detector technology is under development for the CLIC vertex detector. It comprises fast, low-power and small-pitch readout ASICs implemented in 65 nm CMOS technology (CLICpix) coupled to ultra-thin sensors via low-mass interconnects. The power dissipation of the readout chips is reduced by means of power pulsing, allowing for a cooling system based on forced gas flow. In this paper the CLIC vertex-detector requirements are reviewed and the current status of R&D on sensors, readout and detector integration is presented.

  12. Polarized positron source with a Compton multiple interaction point line

    CERN Document Server

    Chaikovska, I; Dadoun, O; Lepercq, P; Variola, A

    2014-01-01

    Positron sources are critical components of the future linear collider projects. This is essentially due to the high luminosity required, orders of magnitude higher than existing ones. In addition, polarization of the positron beam rather expands the physics research potential of the machine. In this framework, the Compton sources for polarized positron production are taken into account where the high energy gamma rays are produced by the Compton scattering and subsequently converted into the polarized electron-positron pairs in a target-converter. The Compton multiple Interaction Point (IP) line is proposed as one of the solutions to increase the number of the positrons produced. The gamma ray production with the Compton multiple IP line is simulated and used for polarized positron generation. Later, a capture section based on an adiabatic matching device (AMD) followed by a pre-injector linac is simulated to capture and accelerate the positron beam.

  13. Computation of multi-material interactions using point method

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Duan Z [Los Alamos National Laboratory; Ma, Xia [Los Alamos National Laboratory; Giguere, Paul T [Los Alamos National Laboratory

    2009-01-01

    Calculations of fluid flows are often based on Eulerian description, while calculations of solid deformations are often based on Lagrangian description of the material. When the Eulerian descriptions are used to problems of solid deformations, the state variables, such as stress and damage, need to be advected, causing significant numerical diffusion error. When Lagrangian methods are used to problems involving large solid deformat ions or fluid flows, mesh distortion and entanglement are significant sources of error, and often lead to failure of the calculation. There are significant difficulties for either method when applied to problems involving large deformation of solids. To address these difficulties, particle-in-cell (PIC) method is introduced in the 1960s. In the method Eulerian meshes stay fixed and the Lagrangian particles move through the Eulerian meshes during the material deformation. Since its introduction, many improvements to the method have been made. The work of Sulsky et al. (1995, Comput. Phys. Commun. v. 87, pp. 236) provides a mathematical foundation for an improved version, material point method (MPM) of the PIC method. The unique advantages of the MPM method have led to many attempts of applying the method to problems involving interaction of different materials, such as fluid-structure interactions. These problems are multiphase flow or multimaterial deformation problems. In these problems pressures, material densities and volume fractions are determined by satisfying the continuity constraint. However, due to the difference in the approximations between the material point method and the Eulerian method, erroneous results for pressure will be obtained if the same scheme used in Eulerian methods for multiphase flows is used to calculate the pressure. To resolve this issue, we introduce a numerical scheme that satisfies the continuity requirement to higher order of accuracy in the sense of weak solutions for the continuity equations

  14. Occupancy in the CLIC_ILD Time Projection Chamber

    CERN Document Server

    KILLENBERG, M.

    2011-01-01

    We report on the occupancy in the CLIC ILD TPC caused by the beam induced background from gg !hadrons, e+e- pairs and beam halo muons. In addition the particle composition of the backgrounds and the origin of back-scattering particles have been studied.

  15. Photon-Nucleon Collider based on LHC and CLIC

    CERN Document Server

    Aksakal, Husnu; Schulte, Daniel; Zimmermann, Frank

    2005-01-01

    We describe the scheme of a photon-nucleon collider where high energy photons generated by Compton backscattering off a CLIC electron beam, at either 75 GeV or 1.5 TeV are collided with protons or ions stored in LHC. Different design constraints for such a collider are discussed and achievable luminosity performance is estimated.

  16. A Versatile Beam Loss Monitoring System for CLIC

    CERN Document Server

    Kastriotou, Maria; Farabolini, Wilfrid; Holzer, Eva Barbara; Nebot Del Busto, Eduardo; Tecker, Frank; Welsch, Carsten

    2016-01-01

    The design of a potential CLIC beam loss monitoring (BLM) system presents multiple challenges. To successfully cover the 48 km of beamline, ionisation chambers and optical fibre BLMs are under investigation. The former fulfils all CLIC requirements but would need more than 40000 monitors to protect the whole facility. For the latter, the capability of reconstructing the original loss position with a multi-bunch beam pulse and multiple loss locations still needs to be quantified. Two main sources of background for beam loss measurements are identified for CLIC. The two-beam accelerator scheme introduces so-called crosstalk, i.e. detection of losses originating in one beam line by the monitors protecting the other. Moreover, electrons emitted from the inner surface of RF cavities and boosted by the high RF gradients may produce signals in neighbouring BLMs, limiting their ability to detect real beam losses. This contribution presents the results of dedicated experiments performed in the CLIC Test Facility to qu...

  17. Grid Interface Design for the Compact Linear Collider (CLIC)

    CERN Document Server

    Jankovic, Maria; Clare, Jon; Wheeler, Pat; Aguglia, Davide

    2015-01-01

    This paper discusses the grid interface challenges for CERN’s proposed Compact Linear Colliders’ (CLIC) klystron modulators, including a 280 MW power system optimisation. The modular multilevel converter is evaluated as a candidate topology for a Medium Voltage grid interface along with a control method for reducing the impact of klystron modulators on the electrical network.

  18. Pulse Power Modulator development for the CLIC Damping Ring Kickers

    CERN Document Server

    Holma, Janne

    2012-01-01

    The Compact Linear Collider (CLIC) study is exploring the scheme for an electron-positron collider with high luminosity (10-34 – 10-35 cm-2s-1) and a nominal centre-of-mass energy of 3 TeV: CLIC would complement LHC physics in the multi-TeV range. The CLIC design relies on Pre-Damping Rings (PDR) and Damping Rings (DR) to achieve the very low emittance, through synchrotron radiation, needed for the luminosity requirements of CLIC. To limit the beam emittance blow-up due to oscillations, the pulse power modulators for the DR kickers must provide extremely flat, high-voltage pulses: the 2 GHz specification called for a 160 ns duration flat-top of 12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 %. In order to meet these demanding specifications, a combination of broadband impedance matching, optimized electrical circuit layout and advanced control techniques is required. A solid-state modulator, the inductive adder, is the most promising approach to meeting the demanding specifications...

  19. Update on beam loss monitoring at CTF3 for CLIC

    CERN Document Server

    Devlin, L J; Effinger, E; Holzer, E B; del Busto, E N; Mallows, S; Branger, E

    2013-01-01

    The primary role of the beam loss monitoring (BLM) system for the compact linear collider (CLIC) study is to work within the machine protection system. Due to the size of the CLIC facility, a BLM that covers large distances along the beam line is highly desirable, in particular for the CLIC drive beam decelerators, which would alternatively require some ~40,000 localised monitors. Therefore, an optical fibre BLM system is currently under investigation which can cover large sections of beam line at a time. A multimode fibre has been installed along the Test Beam Line at the CLIC test facility (CTF3) where the detection principle is based on the production of Cherenkov photons within the fibre resulting from beam loss and their subsequent transport along the fibre where they are then detected at the fibre ends using silicon photomultipliers. Several additional monitors including ACEMs, PEP-II and diamond detectors have also been installed. In this contribution the first results from the BLMs are presented, comp...

  20. A 12 GHZ RF Power source for the CLIC study

    CERN Document Server

    Peauger, F; Curt, S; Doebert, S; McMonagle, G; Rossat, G; Schirm, KM; Syratchev, I; Timeo, L; Kuzikhov, S; Vikharev, AA; Haase, A; Sprehn, D; Jensen, A; Jongewaard, EN; Nantista, CD; Vlieks, A

    2010-01-01

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  1. Fixed point sensitivity analysis of interacting structured populations.

    Science.gov (United States)

    Barabás, György; Meszéna, Géza; Ostling, Annette

    2014-03-01

    Sensitivity analysis of structured populations is a useful tool in population ecology. Historically, methodological development of sensitivity analysis has focused on the sensitivity of eigenvalues in linear matrix models, and on single populations. More recently there have been extensions to the sensitivity of nonlinear models, and to communities of interacting populations. Here we derive a fully general mathematical expression for the sensitivity of equilibrium abundances in communities of interacting structured populations. Our method yields the response of an arbitrary function of the stage class abundances to perturbations of any model parameters. As a demonstration, we apply this sensitivity analysis to a two-species model of ontogenetic niche shift where each species has two stage classes, juveniles and adults. In the context of this model, we demonstrate that our theory is quite robust to violating two of its technical assumptions: the assumption that the community is at a point equilibrium and the assumption of infinitesimally small parameter perturbations. Our results on the sensitivity of a community are also interpreted in a niche theoretical context: we determine how the niche of a structured population is composed of the niches of the individual states, and how the sensitivity of the community depends on niche segregation. PMID:24368160

  2. Structural/control interaction (payload pointing and micro-g)

    Science.gov (United States)

    Larson, C. R.

    1987-01-01

    A 203rd order simulation model was developed to evaluate the space station customer accommodation payload pointing and micro-g requirements. The simulation shows the pointing errors on the telescope are significantly smaller than at the base of the telescope. The pointing results could change when the parametric studies are performed. The results show the micro-g requirement is met with an active isolation system.

  3. Intra-Beam scattering in the CLIC Damping Rings

    CERN Document Server

    Vivoli, A

    2010-01-01

    The CLIC 3 TeV nominal design requires very low emittance of the electron and positron beams to be reached in the damping rings. Due to low energy and to relatively high bunch charge and ultra-low emittance, Intra-Beam Scattering (IBS) effect is very strong and an accurate calculation is needed to check if the required emittance is effectively reached. For this reason it is being developed at CERN a new software for IBS and Radiation Effects (SIRE), which simulates the evolution of the beam particle distribution in the damping rings, taking into account radiation damping, IBS and quantum excitation. In this paper we present the results of our simulations performed with SIRE on a lattice of the CLIC damping rings.

  4. Measurement of stau_1 pair production at CLIC

    CERN Document Server

    Muennich, A.

    2012-01-01

    We present a study performed for the CLIC Conceptual Design Report Volume 3 on the measurement of stau_1 pair production at sqrt(s) = 1.4 TeV. Only the hadronic decay of taus are considered. Results obtained using full detector simulation and including beam-induced backgrounds for the mass and for the production cross section of the stau_1 are discussed.

  5. Golden Jubilee Photos: A CLIC for the future

    CERN Multimedia

    2004-01-01

    http://www.cern.ch/cern50/ Prototype copper accelerating structures for CLIC. New accelerator projects take many years to make and mature. When the LHC project was still only a twinkle in CERN's eye, research was already starting on a new machine. A small team at CERN was setting about the task of studying a high-energy, compact, lepton linear collider, known as CLIC. This is possibly set to become the collider of the future. A machine of this kind has all the advantages of a collider (the total collision energy is equal to the sum of the energies of the two colliding beams) without the drawback of synchrotron radiation, which is produced when particles are accelerated around a ring and thus puts a limit on the energy of such colliders. But in a project as technically challenging as CLIC, considerable technological hurdles must be overcome. To limit the linear collider's length to some tens of kilometres, the beams must acquire a considerable quantity of energy per metre travelled. The collision rate (lumi...

  6. Recent results with HV-CMOS and planar sensors for the CLIC vertex detector

    CERN Document Server

    AUTHOR|(SzGeCERN)734627

    2016-01-01

    The physics aims for the future multi-TeV e+e- Compact Linear Collider (CLIC) impose high precision requirements on the vertex detector which has to match the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The principal challenges are: a point resolution of 3μm, 10 ns time stamping capabilities, low mass (⇠0.2% X0 per layer), low power dissipation and pulsed power operation. Recent results of test beam measurements and GEANT4 simulations for assemblies with Timepix3 ASICs and thin active-edge sensors are presented. The 65 nm CLICpix readout ASIC with 25μm pitch was bump bonded to planar silicon sensors and also capacitively coupled through a thin layer of glue to active HV-CMOS sensors. Test beam results for these two hybridisation concepts are presented.

  7. A closer look at the beam-beam processes at ILC and CLIC

    CERN Document Server

    Hartin, Anthony

    2012-01-01

    The strength of the electromagnetic fields in the bunch collision at a linear collider will have a significant effect, yielding large numbers of beamstrahlung photons and associated coherent pair production. These effects are limited in the proposed ILC beam parameters which limit the strength of the bunch field to $\\Upsilon_{\\text{ave}}=0.27$. The CLIC 3 Tev design by comparison has a $\\Upsilon_{\\text{ave}}=3.34$ yielding huge number of coherent pairs. In terms of the precision physics programs of these proposed colliders there is an imperative to investigate the effect of the strong bunch fields on higher order processes. From the exact wavefunctions used in the calculation of transition rates within the Furry interaction picture, and using appropriate simplifications, a multiplicative factor to the coupling constants was obtained. This indicates a significant variation to the transition rate near threshold energies. Further studies are in progress to calculate the exact effect on expected observables.

  8. CLIC Detector Concepts as described in the CDR: Differences between the GEANT4 and Engineering Models

    CERN Document Server

    Elsener, K; Schlatter, D; Siegrist, N

    2011-01-01

    The CLIC_ILD and CLIC_SiD detector concepts as used for the CDR Vol. 2 in 2011 exist both in GEANT4 simulation models and in engineering layout drawings. At this early stage of a conceptual design, there are inevitably differences between these models, which are described in this note.

  9. Occupancy in the CLIC ILD Time Projection Chamber using Pixelised Readout

    CERN Document Server

    Killenberg, Martin

    2013-01-01

    The occupancy in the CLIC ILD TPC caused by the beam induced background from gamma gamma -> hadrons, e+e- pairs and beam halo muons is very high for conventional pad readout. We show that the occupancy for a pixelised TPC readout is moderate and might be a viable solution to operate a TPC at CLIC.

  10. Scalar leptoquark production at TESLA and CLIC based eγ colliders

    International Nuclear Information System (INIS)

    We study scalar leptoquark production at TESLA and CLIC based eγ colliders. Both direct and resolved contributions to the cross section are examined. We find that the masses of scalar leptoquarks can be probed up to about 0.9 TeV at TESLA and 2.6 TeV at CLIC. (orig.)

  11. Scalar leptoquark production at TESLA and CLIC based e-gamma colliders

    OpenAIRE

    Cakir, O.; Ateser, E.; Koru, H.

    2002-01-01

    We study scalar leptoquark production at TESLA and CLIC based e-gamma colliders. Both direct and resolved contributions to the cross section are examined. We find that the masses of scalar leptoquarks can be probed up to about 0.9 TeV at TESLA and 2.6 TeV at CLIC.

  12. Interaction of Point Defects with Twin Boundaries in Copper

    Institute of Scientific and Technical Information of China (English)

    S. A. Ahmad; Razia Ramzan

    2007-01-01

    The interaction between small vacancy clusters and twin boundaries in copper is studied by using many-body potential developed by Ackland et al. for fcc metals. The interaction energies of single-, dj- and tri-vacancy clusters with (111) and (112) twin boundaries are computed using well established simulation techniques. For (111) twins the vacancy clusters are highly repelled when they are on the adjacent planes, and are attracted when they are away from the boundary. In the case of (112) twins, vacancy clusters are more attracted to the boundary when they are near the boundary as compared to away from it. Vacancy clusters on both the sides of the boundary are also investigated, and it is observed that the clusters energetically prefer to lie on the off-mirror sites as compared to the mirror position across the twin.

  13. Resonant Transmission in One-Dimensional Quantum Systems with Two Parity-Invariant Point Interactions

    CERN Document Server

    Konno, Kohkichi; Takahashi, Rohta

    2016-01-01

    We discuss one-dimensional quantum systems with two parity-invariant point interactions within the framework of quantum mechanics. By investigating the conditions under which resonant transmission occurs, we show that an infinite number of resonant peaks appear only when (anti-)symmetric relations between the parameters which characterize the point interactions hold.

  14. Design of a highly segmented Endcap at a CLIC detector

    CERN Document Server

    Gerwig, H; Siegrist, N

    2010-01-01

    This technical note describes a possible design for a highly segmented end-cap at a CLIC detector with a strong magnetic field up to 5 Tesla. Reinforcement is horizontal in order to allow an insertion of the muon chambers from the side. Construction issues, assembly questions as well as muon chamber access and support questions have been studied. A FEA analysis to optimize dead space for physics and checking the weakening effect of alignment channels through the end-cap have been performed.

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

    CERN Document Server

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

    2006-01-01

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

  16. Achievements and Future Plans of CLIC Test Facilities

    CERN Document Server

    Braun, Hans Heinrich

    2001-01-01

    CTF2 was originally designed to demonstrate the feasibility of two-beam acceleration with high current drive beams and a string of 30 GHz CLIC accelerating structure prototypes (CAS). This goal was achieved in 1999 and the facility has since been modified to focus on high gradient testing of CAS's and 30 GHz single cell cavities (SCC). With these modifications, it is now possible to provide 30 GHz RF pulses of more than 150 MW and an adjustable pulselength from 3 to 15 ns. While the SCC results are promising, the testing of CAS's revealed problems of RF breakdown and related surface damage. As a consequence, a new R&D program has been launched to advance the understanding of RF breakdown processes, to improve surface properties, investigate new materials and to optimise the structure geometries of the CAS's. In parallel the construction of a new facility named CTF3 has started. CTF3 will mainly serve two purposes. The first is the demonstration of the CLIC drive beam generation scheme. CTF3 will acceler-a...

  17. R&D for the Vertexing at CLIC

    CERN Document Server

    Redford, S

    2015-01-01

    The Compact Linear Collider is a candidate to be the next high-energy particle physics collider. Using a novel acceleration technique, electrons and positrons would be brought into collision with a centre-of-mass energy of up to 3 TeV. Despite challenging levels of beam-induced background, this would provide a relatively clean environment in which to perform precision physics measurements. The vertex detector would be crucial in achieving this, and would need to provide accurate particle tracking information to facilitate secondary vertex reconstruction and jet flavour-tagging. With this goal in mind, current technological limits are being stretched to design a low occupancy, low mass and low-power dissipation vertex detector for CLIC. A concept comprising thin hybrid pixel detectors coupled to high- performance readout ASICs, power-pulsing and air-flow cooling is under development. In this paper, the CLIC vertex detector requirements are reviewed and the current status of R&D on sensors, readout, powerin...

  18. Brilliant positron sources for CLIC and other collider projects

    CERN Document Server

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

    2013-01-01

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

  19. Off-Axis Undulator Radiation for CLIC Drive Beam Diagnostics

    CERN Document Server

    Jeff, A; Welsch, CP

    2013-01-01

    The Compact LInear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 1015 electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. In this paper we propose the use of relatively inexpensive permanent-magnet undulators to generate off-axis visible Synchrotron Radiation from the CLIC Drive Beam. The field strength and period length of the undulator should be designed such that the on-axis undulator wavelength is in the ultra-violet. A smaller but still useable amount of visible light is then generated in a hollow cone. This light can be reflected out of the beam pipe by a ring-shaped mirror placed downstream and imaged on a camera. In this contribution, results of SRW and ZEMA...

  20. Feasibility study of multipoint based laser alignment system for CLIC

    CERN Document Server

    Stern, G; Mainaud-Durand, H; Piedigrossi, D; Geiger, A

    2012-01-01

    CLIC (Compact LInear Collider) is a study for a future electron-positron collider that would allow physicists to explore a new energy region beyond the capabilities oftoday’s particle accelerators. Alignment is one of the major challenges within the CLIC study in order to achieve the high requirement of a multi-TeV center of mass colliding beam energy range (nominal 3 TeV). To reach this energy in a realistic and cost efficient scenario all accelerator components have to be aligned with an accuracy of 10 μm over a sliding window of 200 m. The demand for a straight line reference is so far based on stretched wires coupled with Wire Positioning Sensors (WPS). These solutions are currently further developed inorder to reduce the drawbacks which are mainly given by their costs and difficult implementation. However, it should be validated through inter-comparison with a solution ideally based on a different physical principle. Therefore, a new metrological approach is proposed using a laser beam as straight lin...

  1. Higgs Physics at the CLIC Electron-Positron Linear Collider

    CERN Document Server

    Abramowicz, H; Afanaciev, K; Tehrani, N Alipour; Balázs, C; Benhammou, Y; Benoit, M; Bilki, B; Blaising, J -J; Boland, M J; Boronat, M; Borysov, O; Božović-Jelisavčić, I; Buckland, M; Bugiel, S; Burrows, P N; Charles, T K; Daniluk, W; Dannheim, D; Dasgupta, R; Demarteau, M; Gutierrez, M A Díaz; Eigen, G; Elsener, K; Felzmann, U; Firlej, M; Firu, E; Fiutowski, T; Fuster, J; Gabriel, M; Gaede, F; García, I; Ghenescu, V; Goldstein, J; Green, S; Grefe, C; Hauschild, M; Hawkes, C; Hynds, D; Idzik, M; Kačarević, G; Kalinowski, J; Kananov, S; Klempt, W; Kopec, M; Krawczyk, M; Krupa, B; Kucharczyk, M; Kulis, S; Laštovička, T; Lesiak, T; Levy, A; Levy, I; Linssen, L; Lukić, S; Maier, A A; Makarenko, V; Marshall, J S; Mei, K; Milutinović-Dumbelović, G; Moroń, J; Moszczyński, A; Moya, D; Münker, R M; Münnich, A; Neagu, A T; Nikiforou, N; Nikolopoulos, K; Nürnberg, A; Pandurović, M; Pawlik, B; Codina, E Perez; Peric, I; Petric, M; Pitters, F; Poss, S G; Preda, T; Protopopescu, D; Rassool, R; Redford, S; Repond, J; Robson, A; Roloff, P; Ros, E; Rosenblat, O; Ruiz-Jimeno, A; Sailer, A; Schlatter, D; Schulte, D; Shumeiko, N; Sicking, E; Simon, F; Simoniello, R; Sopicki, P; Stapnes, S; Ström, R; Strube, J; Świentek, K P; Szalay, M; Tesař, M; Thomson, M A; Trenado, J; Uggerhøj, U I; van der Kolk, N; van der Kraaij, E; Pinto, M Vicente Barreto; Vila, I; Gonzalez, M Vogel; Vos, M; Vossebeld, J; Watson, M; Watson, N; Weber, M A; Weerts, H; Wells, J D; Weuste, L; Winter, A; Wojtoń, T; Xia, L; Xu, B; Żarnecki, A F; Zawiejski, L; Zgura, I -S

    2016-01-01

    The Compact Linear Collider (CLIC) is an option for a future e+e- collider operating at centre-of-mass energies up to 3 TeV, providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper presents the Higgs physics reach of CLIC operating in three energy stages, sqrt(s) = 350 GeV, 1.4 TeV and 3 TeV. The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung (e+e- -> ZH) and WW-fusion (e+e- -> Hnunu), resulting in precise measurements of the production cross sections, the Higgs total decay width Gamma_H, and model-independent determinations of the Higgs couplings. Operation at sqrt(s) > 1 TeV provides high-statistics samples of Higgs bosons produced through WW-fusion, enabling tight constraints on the Higgs boson couplings. Studies of the rarer processes e+e- -> ttH and e+e- -> HHnunu would allow measurements of the top Yukawa coupling and the Higgs boson self-coupling. This paper presents detailed studies of...

  2. Experimental Program for the CLIC test facility 3 test beam line

    CERN Document Server

    Adli, E; Dobert, S; Olvegaard, M; Schulte, D; Syratchev, I; Lillestol, Reidar

    2010-01-01

    The CLIC Test Facility 3 Test Beam Line is the first prototype for the CLIC drive beam decelerator. Stable transport of the drive beam under deceleration is a mandatory component in the CLIC two-beam scheme. In the Test Beam Line more than 50% of the total energy will be extracted from a 150 MeV, 28 A electron drive beam, by the use of 16 power extraction and transfer structures. A number of experiments are foreseen to investigate the drive beam characteristics under deceleration in the Test Beam Line, including beam stability, beam blow up and the efficiency of the power extraction. General benchmarking of decelerator simulation and theory studies will also be performed. Specially designed instrumentation including precision BPMs, loss monitors and a time-resolved spectrometer dump will be used for the experiments. This paper describes the experimental program foreseen for the Test Beam Line, including the relevance of the results for the CLIC decelerator studies.

  3. Studies on the thermo-mechanical behavior of the CLIC two-beam module

    CERN Document Server

    Nousiainen, R; Österberg, K

    2010-01-01

    To fulfil the mechanical requirements set by the luminosity goals of the CLIC collider, currently under study, the 2-m two-beam modules, the shortest repetitive elements in the main linac, have to be controlled at micrometer level. At the same time these modules are exposed to variable high power dissipation while the accelerator is ramped up to nominal power as well as when the mode of CLIC operation is varied. This will result into inevitable temperature excursions driving mechanical distortions in and between different module components. A FEM model is essential to estimate and simulate the fundamental thermo-mechanical behaviour of the CLIC two-beam module to facilitate its design and development. In this paper, the fundamental thermal environments for the RF-components of the module are described. Also the thermal and structural results for the studied module configuration are presented showing the fundamental thermo-mechanical behaviour under the main CLIC collider operation conditions.

  4. Investigation and evaluation of pointing modalities for interactive stereoscopic 3D TV

    OpenAIRE

    Haiyue Yuan,; Calic, J.; Fernando, A.; Kondoz, A

    2013-01-01

    The recent proliferation of stereoscopic three dimensional (3D) video technology has fostered a large body of research into 3D video capture, production, compression and delivery. However, little research has been dedicated to the design practices of stereoscopic 3D video interaction. Interaction tasks such as pointing and selection are critical to the consumer's experience of the 3D video technology. This paper presents investigation of pointing modalities in the context of stereoscopic 3D t...

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

    CERN Document Server

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

    2012-01-01

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

  6. Is Infant Initiation of Joint Attention by Pointing Affected by Type of Interaction?

    Science.gov (United States)

    Franco, Fabia; Perucchini, Paola; March, Barbara

    2009-01-01

    This article reports the results of two experiments studying the effects of type of interaction on infant production of declarative pointing. In Experiment 1, intensity of social presence was manipulated in adult-infant interaction with 12-19-month-olds (no social presence; adult responding only; adult also initiating joint attentional bids).…

  7. Analysis of SUSY Heavy Higgs events at CLIC

    CERN Document Server

    Quevillon, J

    2009-01-01

    This paper reports the results of a study of the supersymmetric neutral heavy Higgs boson production channel e+e− → H◦A◦ → bb ̄bb ̄ at √s = 3 TeV. Reconstruction of data simulated at generator level shows a significant degradation of SUSY Heavy Higgs signal caused by γγ to hadrons background at s = 3 TeV. The importance of analysis procedures such as event cuts and transversal momentum cuts during jet-clustering to reduce the impact of the hadron background is underlined. Reconstruction at both the generator level and at the level of a full detector simulation forces us to introduce cuts to improve the quality of the results. This note describes a preliminary study of SUSY Heavy Higgs at CLIC - a more detailed paper on an extended study is in preparation.

  8. Physics requirements for Scalar Muons searches at CLIC

    CERN Document Server

    Battaglia, M

    2010-01-01

    The determination of smuon and neutralino masses in smuon pair production is an important part of the program of spectroscopic studies of Supersymmetry at a high energy linear collider. In this note we report the first results of a study of e+e− → μ ̃R+μ ̃R− in a high-mass, cosmology-motivated Supersymmetric scenario at 3 TeV at CLIC. This process is a good example to study requirements on the beam energy spectrum and polarisation and the track momentum resolution in a simple final state. We discuss the expected accuracy on the mass measurements as a function of the momentum resolution, luminosity spectrum, beam polarisation and time stamping capability. Results obtained at generator level are validated by comparison to full simulation and reconstruction. Preliminary requirements for the detector performances and beam polarisation are presented.

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

    CERN Document Server

    AUTHOR|(CDS)2091976; Koivunen, Visa

    2016-04-04

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

  10. 8th CLIC/CTF3 Collaboration Meeting

    CERN Document Server

    2003-01-01

    The eighth CTF3 collaboration meeting was held at CERN on 30th September and 1st October 2003. All collaborating institutes participated: LNF (Frascati), LAL (Orsay), RAL (Oxford), SLAC (Stanford) and Uppsala University. This year a new collaboration partner (North Western University Illinois) participated for the first time. In addition many CERN groups made important contributions. Important results from operation of the Preliminary phase - the bunch combination by a factor of 4 and 5 - were reported, an important proof of principle for the CLIC Drive Beam scheme. A highlight of the commissioning of the Initial phase was the successful operation of the accelerating structures with 100 % beam loading with nominal beam parameters. Impressive progress was reported on all activities. The design and layout studies are far advanced and very active hardware design and prototyping is going on. Series production of many components has already started. The major milestones for 2004 are the installation and commission...

  11. Dynamics on the positron capture and accelerating sections of CLIC

    CERN Document Server

    Poirier, Freddy; Vivoli, Alessandro; Dadoun, Olivier; Lepercq, Pierre; Variola, Alessandro

    2011-01-01

    The CLIC Pre-Injector Linac for the e+ beam is composed of an Adiabatic Matching Device (AMD) followed by 4 (or 5) accelerating RF structures embedded in a solenoidal magnetic field. The accelerating sections are based on 2 GHz long travelling wave structures. In this note, the positrons capture strategy downstream the AMD is reviewed. The first RF structure can be phased either for full acceleration or for deceleration. In the latter case, the simulations results show that the number of e+ capture at the end of the 200 MeV Pre-Injector Linac is increased. Then the impact of the space charge is presented. Additional techniques are also studied to explore the potentiality of increasing the number of e+ namely an extra RF field at the beginning of the capture section and a higher solenoidal field.

  12. PACMAN – an Innovative Doctoral Programme for CLIC

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    The final network project funded under the European Commission’s Seventh Framework Programme (FP7), Marie Curie Actions, held its kick-off meeting at CERN on 20 November 2013.   PACMAN – a study on Particle Accelerator Components Metrology and Alignment to the Nanometre scale – is in the final stage of recruiting 10 PhD students to do research on beam instrumentation, metrology, micrometric alignment, magnetic measurements, nano-positioning and high-precision engineering. The students will acquire multi-disciplinary expertise in advanced engineering combined with a broad span of transferable skills. “PACMAN gives us the opportunity to attract students to CERN at a key moment in the CLIC study,” said Frédérick Bordry, Head of CERN’s Technology Department. “This is also an ideal opportunity to further develop CERN’s networks with industry and universities.” “The project is...

  13. Capacitively coupled hybrid pixel assemblies for the CLIC vertex detector

    CERN Document Server

    Alipour Tehrani, Niloufar; Benoit, Mathieu; Dannheim, Dominik; Dette, Karola; Hynds, Daniel; Kulis, Szymon; Peric, Ivan; Petric, Marko; Redford, Sophie; Sicking, Eva; Valerio, Pierpaolo

    2015-01-01

    The vertex detector at the proposed CLIC multi-TeV linear e+e- collider must have minimal material content and high spatial resolution, combined with accurate time-stamping to cope with the expected high rate of beam-induced backgrounds. One of the options being considered is the use of active sensors implemented in a commercial high-voltage CMOS process, capacitively coupled to hybrid pixel ASICs. A prototype of such an assembly, using two custom designed chips (CCPDv3 as active sensor glued to a CLICpix readout chip), has been characterised both in the lab and in beam tests at the CERN SPS using 120 GeV/c positively charged hadrons. Results of these characterisation studies are presented both for single and dual amplification stages in the active sensor. Pixel cross-coupling results are also presented, showing the sensitivity to placement precision and planarity of the glue layer.

  14. Two Models Relevant to the Interaction of a Point Charge and a Magnetic Moment

    CERN Document Server

    Boyer, Timothy H

    2012-01-01

    An understanding of the interaction of a point charge and a magnetic moment is crucial for understanding the experiments involving electromagnetic momentum carried by permeable materials as well as the experimentally-observed Aharonov-Bohm and Aharonov-Casher phase shifts. Here we present two simple models for a magnetic moment which have vastly different interactions with a distant point charge. It is suggested that a satisfactory theoretical understanding of the interaction is still lacking and that the "hidden momentum" interpretation has been introduced into the textbook literature prematurely.

  15. A point-based rendering approach for real-time interaction on mobile devices

    Institute of Scientific and Technical Information of China (English)

    LIANG XiaoHui; ZHAO QinPing; HE ZhiYing; XIE Ke; LIU YuBo

    2009-01-01

    Mobile device is an Important interactive platform. Due to the limitation of computation, memory, display area and energy, how to realize the efficient and real-time interaction of 3D models based on mobile devices is an important research topic. Considering features of mobile devices, this paper adopts remote rendering mode and point models, and then, proposes a transmission and rendering approach that could interact in real time. First, improved simplification algorithm based on MLS and display resolution of mobile devices is proposed. Then, a hierarchy selection of point models and a QoS transmission control strategy are given based on interest area of operator, interest degree of object in the virtual environment and rendering error. They can save the energy consumption. Finally, the rendering and interaction of point models are completed on mobile devices. The experiments show that our method is efficient.

  16. Inverted point-contact spectrum of electron-phonon interactions in arsenic homocontacts

    Science.gov (United States)

    Khotkevich, A. V.; Krasnyi, A. S.

    2016-04-01

    The point-contact (microcontact) spectra (second derivatives of the current-voltage characteristics) of As/As point homocontacts are measured at liquid helium temperatures. Inversion of the sign of the point-contact spectrum is observed as a result of the destruction of electron localization in the arsenic contacts owing to electron-phonon interactions. The point-contact spectrum contains two major peaks at energies of 10 and 25 meV. The boundary of the single-phonon part of the spectrum corresponds to 34 meV. This agrees with available data on the density of phonon states. Assuming that the inverted point-contact spectrum reflects features of the electro-phonon interaction spectral function, the mean-square frequency of the phonons is calculated and the Debye temperature is estimated.

  17. Planned Contributions of The Wcrp Climate and Cryosphere (clic) Project To Mountain Hydrological Studies

    Science.gov (United States)

    Barry, R. G.

    interactions of snow cover and seasonally frozen ground and their influence on the hydrologic cycle. Another element of CliC addresses the monitoring of cryospheric indicators of climate change. The impacts of global change on elements of the cryosphere may have significant social and economic ramifications. Concerns in mountain regions in- clude: reductions in glacier area and snow cover impacting water resources, winter recreation, and transportation; the melt of alpine frozen ground leading to slope insta- bilities and damage to structures; changes in snow pack and lake and river ice regimes 1 affecting biogeochemistry, wildlife and aquatic species. 2

  18. The occupancy in the Hadronic Calorimeter endcap of the CLIC detector

    CERN Document Server

    van Dam, S.B.

    2014-01-01

    To achieve the optimal physics performance of a detector for a linear electron–positron col- lider it is essential to minimize the effect of the beam-induced background. Incoherent electron–positron pairs shower in the very forward region of the CLIC detector and cause a too high occupancy of approximately 80% in the inner radius of the HCal endcap. The occupancy is studied by performing full detector simulations and reduced by changing the material and thickness of the support tube that serves as shielding. The effect of the tile size in the HCal endcap is also studied. A minimal occupancy of ⇠ 4% in the HCal inner radius can be reached with a thick tungsten support tube. When taking a more realistic engineering point of view into account and including polyethylene, an occupancy of ⇠ 8% is achieved. These results show that it is possible to reduce the occupancy due to incoherent pairs in the HCal endcap to a similar level as that due to gg ! hadrons events.

  19. Theoretical and practical feasibility demonstration of a micrometric remotely controlled pre-alignment system for the CLIC linear collider

    CERN Document Server

    Mainaud Durand, H; Chritin, N; Griffet, S; Kemppinen, J; Sosin, M; Touze, T

    2011-01-01

    The active pre-alignment of the Compact Linear Collider (CLIC) is one of the key points of the project: the components must be pre-aligned w.r.t. a straight line within a few microns over a sliding window of 200 m, along the two linacs of 20 km each. The proposed solution consists of stretched wires of more than 200 m, overlapping over half of their length, which will be the reference of alignment. Wire Positioning Sensors (WPS), coupled to the supports to be pre-aligned, will perform precise and accurate measurements within a few microns w.r.t. these wires. A micrometric fiducialisation of the components and a micrometric alignment of the components on common supports will make the strategy of pre-alignment complete. In this paper, the global strategy of active pre-alignment is detailed and illustrated by the latest results demonstrating the feasibility of the proposed solution.

  20. Interaction of a point charge with the surface of a uniaxial dielectric

    CERN Document Server

    Ribič, Primož Rebernik

    2013-01-01

    We analyze the force on a point charge moving at relativistic speeds parallel to the surface of a uniaxial dielectric. Two cases are examined: a lossless dielectric with no dispersion and a dielectric with a plasma type response. The treatment focuses on the peculiarities of the strength and direction of the interaction force as compared to the isotropic case. We show that a plasma type dielectric can, under specific conditions, repel the point charge.

  1. Contact Point Generation for Convex Polytopes in Interactive Rigid Body Dynamics

    DEFF Research Database (Denmark)

    Silcowitz-Hansen, Morten; Niebe, Sarah Maria; Erleben, Kenny

    When computing contact forces in rigid body dynamics systems, most state-of-the-art solutions use iterative methods such as the projected Gauss–Seidel (PGS) method. Methods such as the PGS method are preferred for their robustness. However, the time-critical nature of interactive applications...... for convex polytopes. A novel contact point generation method is presented, which is based on growth distances and Gauss maps. We demonstrate improvements when using our method in the context of interactive rigid body simulation...

  2. Digraph Matrix Analysis for systems interactions at Indian Point Unit 3. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Alesso, H.P.; Altenbach, T.J.; Prassinos, P.G.; Lappa, D.A.; Kimura, C.Y.; Patenaude, C.J.; Sacks, I.J.; Ashmore, B.C.; Fromme, D.C.; Hershberger, M.V.

    1986-01-01

    This report documents the analysis of the Indian Point Plant, Unit 3 (IP-3) for adverse systems interactions using DMA. The primary objective of the study was to compare the effectiveness of DMA in finding systems interactions. To this end a parallel study was funded at Brookhaven National Laboratory (BNL). The results of this study and the BNL study will then be compared by NRC to the results of a similar study performed by the Power Authority of the State of New York. A secondary objective of this study was to determine systems interactions in selected combinations of safety systems at IP-3. 24 refs., 22 figs., 29 tabs.

  3. Wrapping interactions and the genus expansion of the 2-point function of composite operators

    OpenAIRE

    Torrielli, Alessandro; Sieg, Christoph

    2005-01-01

    We perform a systematic analysis of wrapping interactions for a general class of theories with color degrees of freedom, including N=4 SYM. Wrapping interactions arise in the genus expansion of the 2-point function of composite operators as finite size effects that start to appear at a certain order in the coupling constant at which the range of the interaction is equal to the length of the operators. We analyze in detail the relevant genus expansions, and introduce a strategy to single out t...

  4. Hubbard model for ultracold bosonic atoms interacting via zero-point-energy-induced three-body interactions

    Science.gov (United States)

    Paul, Saurabh; Johnson, P. R.; Tiesinga, Eite

    2016-04-01

    We show that, for ultracold neutral bosonic atoms held in a three-dimensional periodic potential or optical lattice, a Hubbard model with dominant, attractive three-body interactions can be generated. In fact, we derive that the effect of pairwise interactions can be made small or zero starting from the realization that collisions occur at the zero-point energy of an optical lattice site and the strength of the interactions is energy dependent from effective-range contributions. We determine the strength of the two- and three-body interactions for scattering from van der Waals potentials and near Fano-Feshbach resonances. For van der Waals potentials, which for example describe scattering of alkaline-earth atoms, we find that the pairwise interaction can only be turned off for species with a small negative scattering length, leaving the 88Sr isotope a possible candidate. Interestingly, for collisional magnetic Feshbach resonances this restriction does not apply and there often exist magnetic fields where the two-body interaction is small. We illustrate this result for several known narrow resonances between alkali-metal atoms as well as chromium atoms. Finally, we compare the size of the three-body interaction with hopping rates and describe limits due to three-body recombination.

  5. An application of interacting shear flows theory: exact solution for unsteady oblique stagnation point flow

    Institute of Scientific and Technical Information of China (English)

    Guibo Li; Minguo Dai; Zhi Gao

    2006-01-01

    An analytical solution of the governing equations of the interacting shear flows for unsteady oblique stagnation point flow is obtained. It has the same form as that of the exact solution obtained from the complete NS equations and physical analysis and relevant discussions are then presented.

  6. A New Technique For Information Processing of CLIC Technical Documentation

    CERN Document Server

    Tzermpinos, Konstantinos

    2013-01-01

    The scientific work presented in this paper could be described as a novel, systemic approach to the process of organization of CLIC documentation. The latter refers to the processing of various sets of archived data found on various CERN archiving services in a more friendly and organized way. From physics aspect, this is equal to having an initial system characterized by high entropy, which after some transformation of energy and matter will produce a final system of reduced entropy. However, this reduction in entropy can be considered valid for open systems only, which are sub-systems of grander isolated systems, to which the total entropy will always increase. Thus, using as basis elements from information theory, systems theory and thermodynamics, the unorganized form of data pending to be organized to a higher form, is modeled as an initial open sub-system with increased entropy, which, after the processing of information, will produce a final system with decreased entropy. This systemic approach to the ...

  7. Top quark mass measurements at and above threshold at CLIC

    CERN Document Server

    Seidel, Katja; Tesar, Michal; Poss, Stephane

    2013-01-01

    We present a study of the expected precision of the top quark mass determination, measured at a linear $e^+e^-$ collider based on CLIC technology. GEANT4-based detector simulation and full event reconstruction including realistic physics and beam-induced background levels are used. Two different techniques to measure the top mass are studied: The direct reconstruction of the invariant mass of the top quark decay products and the measurement of the mass together with the strong coupling constant in a threshold scan, in both cases including first studies of expected systematic uncertainties. For the direct reconstruction, experimental uncertainties around 100 MeV are achieved, which are at present not matched by a theoretical understanding on a similar level. With a threshold scan, total uncertainties of around 100 MeV are achieved, including theoretical uncertainties in a well-defined top mass scheme. For the threshold scan, the precision at ILC is also studied to provide a comparison of the two linear collide...

  8. Capacitively coupled hybrid pixel assemblies for the CLIC vertex detector

    Science.gov (United States)

    Tehrani, N. Alipour; Arfaoui, S.; Benoit, M.; Dannheim, D.; Dette, K.; Hynds, D.; Kulis, S.; Perić, I.; Petrič, M.; Redford, S.; Sicking, E.; Valerio, P.

    2016-07-01

    The vertex detector at the proposed CLIC multi-TeV linear e+e- collider must have minimal material content and high spatial resolution, combined with accurate time-stamping to cope with the expected high rate of beam-induced backgrounds. One of the options being considered is the use of active sensors implemented in a commercial high-voltage CMOS process, capacitively coupled to hybrid pixel ASICs. A prototype of such an assembly, using two custom designed chips (CCPDv3 as active sensor glued to a CLICpix readout chip), has been characterised both in the lab and in beam tests at the CERN SPS using 120 GeV/c positively charged hadrons. Results of these characterisation studies are presented both for single and dual amplification stages in the active sensor, where efficiencies of greater than 99% have been achieved at -60 V substrate bias, with a single hit resolution of 6.1 μm . Pixel cross-coupling results are also presented, showing the sensitivity to placement precision and planarity of the glue layer.

  9. Progress on modelling of the thermo-mechanical behavior of the CLIC two-beam module

    CERN Document Server

    Raatikainen, R; Niinikoski, T; Riddone, G

    2011-01-01

    under study, imposes micrometer mechanical stability of the 2-m long two-beam modules, the shortest repetitive elements of the main linacs. These modules will be exposed to variable high power dissipation during operation resulting in mechanical distortions in and between module components. The stability of the CLIC module will be tested in laboratory conditions at CERN in a full-scale prototype module. In this paper, the FEA model developed for CLIC prototype module is described. The thermal and structural results for the new module configuration are presented considering the thermo-mechanical behavior of the CLIC collider in its primary operation modes. These results will be compared to the laboratory measurements to be done during 2011 and 2012 with the full-scale prototype module. The experimental results will allow for better understanding of the module behaviour and they will be propagated back to the present thermo-mechanical model.

  10. 3D FEA Computation of the CLIC Machine Detector Interface Magnets

    CERN Document Server

    Bartalesi, A

    2012-01-01

    A critical aspect of the Compact Linear Collider (CLIC) design is represented by the Accelerator/Experiment interface (called Machine Detector Interface or MDI). In the 3 TeV CLIC layout, the final focus QD0 quadrupole will be located inside the end-cap of the detector itself. This complex MDI scenario required to be simulated with a full 3D-FE analysis. This study was critical to check and control the magnetic cross-talk between the detector solenoid and the final focus magnet and therefore to optimize the design of an “antisolenoids” system needed to shield the QD0 and the e-/e+ beams from the detector magnetic field. In this paper the development and evolution of the computational FE model is presented together with the results obtained and their implication on the CLIC MDI design.

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

    CERN Document Server

    Shipman, Nicholas; Jones, Roger

    2016-01-01

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

  12. RF Design of the TW Buncher for the CLIC Drive Beam Injector (2nd report)

    CERN Document Server

    Shaker, Hamed

    2016-01-01

    CLIC is based on the two beams concept that one beam (drive beam) produces the required RF power to accelerate another beam (main beam). The drive beam is produced and accelerated up to 50MeV inside the CLIC drive beam injector. The drive beam injector main components are a thermionic electron gun, three sub-harmonic bunchers, a pre-buncher, a TW buncher, 13 accelerating structures and one magnetic chicane. This document is the second report of the RF structure design of the TW buncher. This design is based on the beam dynamic design done by Shahin Sanaye Hajari due to requirements mentioned in CLIC CDR. A disk-loaded tapered structure is chosen for the TW buncher. The axial electric field increases strongly based on the beam dynamic requirements. This second report includes the study of HOM effects, retuning the cells, study of dimensional tolerances and the heat dissipation on the surface.

  13. Detector optimization studies and light Higgs decay into muons at CLIC

    Energy Technology Data Exchange (ETDEWEB)

    Grefe, Christian

    2013-09-15

    The Compact Linear Collider (CLIC) is a concept for a future e{sup +}e{sup -} linear collider with a center-of-mass energy of up to 3 TeV. The design of a CLIC experiment is driven by the requirements related to the physics goals, as well as by the experimental conditions. For example, the short time between two bunch crossings of 0.5 ns and the backgrounds due to beamstrahlung have direct impact on the design of a CLIC experiment. The Silicon Detector (SiD) is one of the concepts currently being discussed as a possible detector for the International Linear Collider (ILC). In this thesis we develop a modified version of the SiD simulation model for CLIC, taking into account the specific experimental conditions. In addition, we developed a software tool to investigate the impact of beam-related backgrounds on the detector by overlaying events from different simulated event samples. Moreover, we present full simulation studies, determining the performance of the calorimeter and tracking systems. We show that the track reconstruction in the all-silicon tracker of SiD is robust in the presence of the backgrounds at CLIC. Furthermore, we investigate tungsten as a dense absorber material for the hadronic calorimeter, which allows for the construction of a compact hadronic calorimeter that fulfills the requirements on the energy resolution and shower containment without a significant increase of the coil radius. Finally, the measurement of the decays of light Higgs bosons into two muons is studied in full simulation. We find that with an integrated luminosity of 2 ab{sup -1}, corresponding to 4 years of data taking at CLIC, the respective Higgs branching ratio can be determined with a statistical uncertainty of approximately 15%.

  14. Detector optimization studies and light Higgs decay into muons at CLIC

    International Nuclear Information System (INIS)

    The Compact Linear Collider (CLIC) is a concept for a future e+e- linear collider with a center-of-mass energy of up to 3 TeV. The design of a CLIC experiment is driven by the requirements related to the physics goals, as well as by the experimental conditions. For example, the short time between two bunch crossings of 0.5 ns and the backgrounds due to beamstrahlung have direct impact on the design of a CLIC experiment. The Silicon Detector (SiD) is one of the concepts currently being discussed as a possible detector for the International Linear Collider (ILC). In this thesis we develop a modified version of the SiD simulation model for CLIC, taking into account the specific experimental conditions. In addition, we developed a software tool to investigate the impact of beam-related backgrounds on the detector by overlaying events from different simulated event samples. Moreover, we present full simulation studies, determining the performance of the calorimeter and tracking systems. We show that the track reconstruction in the all-silicon tracker of SiD is robust in the presence of the backgrounds at CLIC. Furthermore, we investigate tungsten as a dense absorber material for the hadronic calorimeter, which allows for the construction of a compact hadronic calorimeter that fulfills the requirements on the energy resolution and shower containment without a significant increase of the coil radius. Finally, the measurement of the decays of light Higgs bosons into two muons is studied in full simulation. We find that with an integrated luminosity of 2 ab-1, corresponding to 4 years of data taking at CLIC, the respective Higgs branching ratio can be determined with a statistical uncertainty of approximately 15%.

  15. The Nature of Child-Adult Interaction. From Turn-Taking to Understanding Pointing and Use of Pointing Gestures

    Directory of Open Access Journals (Sweden)

    Białek Arkadiusz

    2014-08-01

    Full Text Available Analyses of interactions between an adult and a one-year-old child are often connected with studying early communicative competences, e.g. the child’s participation in turn-taking sequences, in joint attention, and use of pointing gestures. Infants’ communicative behaviors were studied using a structured observational measure - the Early Social Communication Scales (Mundy et al., 2003 in a study of 358 12-month-old children. An exploratory factor analysis revealed: (i a distinction between the categories of initiation and response among the behaviors displayed, (ii simple and complex behavior categories occurring; (iii the presence within one factor of behaviors fulfilling various functions (e.g. requesting and sharing interest. An analysis of the results showed that communicative competences can be classified according to their level and ignoring their function, and made it possible to suggest modifications to the way in which behaviors are coded on the ESCS and to complement the procedure of studying early communicative competences.

  16. Risk of multiple interacting tipping points should encourage rapid CO2 emission reduction

    Science.gov (United States)

    Cai, Yongyang; Lenton, Timothy M.; Lontzek, Thomas S.

    2016-05-01

    Evidence suggests that several elements of the climate system could be tipped into a different state by global warming, causing irreversible economic damages. To address their policy implications, we incorporated five interacting climate tipping points into a stochastic-dynamic integrated assessment model, calibrating their likelihoods and interactions on results from an existing expert elicitation. Here we show that combining realistic assumptions about policymakers’ preferences under uncertainty, with the prospect of multiple future interacting climate tipping points, increases the present social cost of carbon in the model nearly eightfold from US$15 per tCO2 to US$116 per tCO2. Furthermore, passing some tipping points increases the likelihood of other tipping points occurring to such an extent that it abruptly increases the social cost of carbon. The corresponding optimal policy involves an immediate, massive effort to control CO2 emissions, which are stopped by mid-century, leading to climate stabilization at <1.5 °C above pre-industrial levels.

  17. Experimental tests on the air cooling of the CLIC vertex detector

    CERN Document Server

    Duarte Ramos, Fernando; Nuiry, Francois-Xavier

    2016-01-01

    The strict requirements in terms of material budget for the inner region of the CLIC detector concept require the use of a dry gas for the cooling of the respective sensors. This, in conjunction with the compactness of the inner volumes, poses several challenges for the design of a cooling system that is able to fulfil the required detector specifications. This note summarizes the results obtained from experimental tests on the air cooling of the CLIC vertex detector as well as their comparison with the corresponding computational fluid dynamics simulations.

  18. Energy and Beam-Offset dependence of the Luminosity weighted depolarization for CLIC

    CERN Document Server

    Esberg, Jakob; Uggerhoj, Ulrik; Dalena, Barbara

    2011-01-01

    We report on simulations of e+e- depolarization due to beam-beam effects. These effects are studied for CLIC at 3 TeV, using GUINEA PIG++. We find a strong energy dependence of the luminosity weighted depolarization. In the luminosity peak at CLIC the total luminosity weighted depolarization remains below the one per-mil level. The effect of a vertical offset on the energy dependent depolarization is investigated. The depolarization in the luminosity peak remains below per-cent level even for 5sy offsets.

  19. Status of the Stripline Beam Position Monitor developement for the CLIC Drive Beam

    CERN Document Server

    Benot-Morell, A; Wendt, M; Faus-Golfe, A; Nappa, J M; Vilalte, S; Smith, S

    2013-01-01

    In collaboration with SLAC, LAPP and IFIC, a first prototype of a stripline Beam Position Monitor (BPM) for the CLIC Drive Beam and its associated readout electronics has been successfully tested in the CLIC Test Facility linac (CTF3) at CERN. In addition, a modified prototype with downstream terminated striplines is under development to improve the suppression of unwanted RF signal interference. This paper presents the results of the beam tests, and the most relevant aspects for the modified stripline BPM design and its expected improvements.

  20. Collective effects and experimental verification of the CLIC drive beam and decelerator

    OpenAIRE

    2014-01-01

    The Compact Linear Collider (CLIC) is a potential next-generation particle collider, in which electrons and positrons collide at a center-of-mass energy of up to 3 TeV. In order to reach a high accelerating gradient and reduce the length of the machine, CLIC uses a novel two-beam scheme. Here, the acceleration energy for the main beam is provided by energy extraction from a secondary electron drive beam, by the use of Power Extraction and Transfer Structures (PETS). This Ph.D. thesis descr...

  1. Highlights from CERN: The CLIC Project for a Future e$^{+}$e$^{−}$ Linear Collider

    CERN Document Server

    Tecker, Frank

    2007-01-01

    A high luminosity ( 10$^{34}$-10$^{35}$ cm$^{2}$/s) linear electron-positron Collider (CLIC) with a nominal centre-of-mass energy of 3 TeV is under study in the framework of an international collaboration of laboratories and institutes, with the aim to provide the HEP community with a new facility for the post LHC era. After a brief introduction of the physics motivation, the CLIC scheme to extend Linear Colliders into the Multi-TeV colliding beam energy range will be described. In the following, the main challenges and the very promising achievements already obtained will be presented.

  2. Mechanical integration studies for the CLIC vertex and inner tracking detectors

    CERN Document Server

    Villarejo Bermudez, M.A.; Gerwig, H.

    2015-01-01

    Since the publication of the CLIC Conceptual Design Report, work has proceeded in order to establish a preliminary mechanical design for the innermost CLIC detector region. This note proposes a design for the main Carbon-Fibre Reinforced Polymer (CFRP) structural elements of the inner detectors, for the beam pipe and their supports. It also describes an assembly sequence for the integration of the sensors and the mechanical components. Mechanical simulations of different structural elements and a material budget estimation are appended. Details of a proposed cabling layout for all the subdetectors are included.

  3. Two-point correlation function in systems with van der Waals type interaction

    OpenAIRE

    Dantchev, Daniel M.

    2001-01-01

    The behavior of the bulk two-point correlation function $G({\\bf r};T|d)$ in $d$-dimensional system with van der Waals type interactions is investigated and its consequences on the finite-size scaling properties of the susceptibility in such finite systems with periodic boundary conditions is discussed within mean-spherical model which is an example of Ornstein and Zernike type theory. The interaction is supposed to decay at large distances $r$ as $r^{-(d+\\sigma)}$, with $2

  4. A Unique Computational Algorithm to Simulate Probabilistic Multi-Factor Interaction Model Complex Material Point Behavior

    Science.gov (United States)

    Chamis, Christos C.; Abumeri, Galib H.

    2010-01-01

    The Multi-Factor Interaction Model (MFIM) is used to evaluate the divot weight (foam weight ejected) from the launch external tanks. The multi-factor has sufficient degrees of freedom to evaluate a large number of factors that may contribute to the divot ejection. It also accommodates all interactions by its product form. Each factor has an exponent that satisfies only two points--the initial and final points. The exponent describes a monotonic path from the initial condition to the final. The exponent values are selected so that the described path makes sense in the absence of experimental data. In the present investigation, the data used was obtained by testing simulated specimens in launching conditions. Results show that the MFIM is an effective method of describing the divot weight ejected under the conditions investigated.

  5. Generalized One-Dimensional Point Interaction in Relativistic and Non-relativistic Quantum Mechanics

    OpenAIRE

    Shigehara, T.; Mizoguchi, H.; T. Mishima; Cheon, Taksu

    1999-01-01

    We first give the solution for the local approximation of a four parameter family of generalized one-dimensional point interactions within the framework of non-relativistic model with three neighboring $\\delta$ functions. We also discuss the problem within relativistic (Dirac) framework and give the solution for a three parameter family. It gives a physical interpretation for so-called $\\epsilon$ potential. It will be also shown that the scattering properties at high energy substantially diff...

  6. Preliminary investigation of interconnected systems interactions for the safety injection system of Indian Point-3

    Energy Technology Data Exchange (ETDEWEB)

    Alesso, H.P.; Lappa, D.A.; Smith, C.F.; Sacks, I.J.

    1983-03-04

    The rich diversity of ideas and techniques for analyzing interconnected systems interaction has presented the NRC with the problem of identifying methods appropriate for their own review and audit. This report presents the findings of a preliminary study using the Digraph Matrix Analysis method to evaluate interconnected systems interactions for the safety injection system of Indian Point-3. The analysis effort in this study was subjected to NRC constraints regarding the use of Boolean logic, the construction of simplified plant representations or maps, and the development of heuristic measures as specified by the NRC. The map and heuristic measures were found to be an unsuccessful approach. However, from the effort to model and analyze the Indian Point-3 safety injection system, including Boolean logic in the model, singleton and doubleton cut-sets were identified. It is recommended that efforts excluding Boolean logic and utilizing the NRC heuristic measures not be pursed further and that the Digraph Matrix approach (or other comparable risk assessment technique) with Boolean logic included to conduct the audit of the Indian Point-3 systems interaction study.

  7. Interactions of point defects with stacking faults in oxygen-free phosphorus-containing copper

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yunguo, E-mail: yunguo@kth.se [Division of Materials Technology, Department of Materials Science and Engineering, Royal Institute of Technology (KTH), S-100 44 Stockholm (Sweden); Korzhavyi, Pavel A., E-mail: pavelk@kth.se [Division of Materials Technology, Department of Materials Science and Engineering, Royal Institute of Technology (KTH), S-100 44 Stockholm (Sweden); Institute of Metal Physics, Ural Division of the Russian Academy of Sciences, 620219 Ekaterinburg (Russian Federation)

    2015-07-15

    The interactions of stacking faults and point defects in oxygen-free phosphorus-containing copper are investigated using ab initio methods. Although monovacancies can act as traps for H impurities or OH groups, the calculations show that two vacancies only weakly bind with each other and this interaction terminates at the third nearest-neighbor distance. An interstitial P tends to form a Cu–P dumbbell-like cluster around the lattice site and can readily combine with a vacancy to become a substitutional impurity. It is also found that the intrinsic stacking-fault energy of copper strongly depends on the temperature as well as on the presences of point defects. The intrinsic stacking-fault energy varies between 20 and 77 mJ/m{sup 2} depending on the presence of point defects in the faulted region. These point defects are also found to affect the unstable stacking-fault energy, but they always increase the twinning tendency of copper. Among them, the substitutional P is found to have the strongest effects, decreasing the intrinsic stacking-fault energy and increasing the twinnability.

  8. Proposal for an alignment method of the CLIC linear accelerator - From geodesic networks to the active pre-alignment

    International Nuclear Information System (INIS)

    The compact linear collider (CLIC) is the particle accelerator project proposed by the european organization for nuclear research (CERN) for high energy physics after the large hadron collider (LHC). Because of the nano-metric scale of the CLIC leptons beams, the emittance growth budget is very tight. It induces alignment tolerances on the positions of the CLIC components that have never been achieved before. The last step of the CLIC alignment will be done according to the beam itself. It falls within the competence of the physicists. However, in order to implement the beam-based feedback, a challenging pre-alignment is required: 10 μm at 3σ along a 200 m sliding window. For such a precision, the proposed solution must be compatible with a feedback between the measurement and repositioning systems. The CLIC pre-alignment will have to be active. This thesis does not demonstrate the feasibility of the CLIC active pre-alignment but shows the way to the last developments that have to be done for that purpose. A method is proposed. Based on the management of the Helmert transformations between Euclidean coordinate systems, from the geodetic networks to the metrological measurements, this method is likely to solve the CLIC pre-alignment problem. Large scale facilities have been built and Monte-Carlo simulations have been made in order to validate the mathematical modeling of the measurement systems and of the alignment references. When this is done, it will be possible to extrapolate the modeling to the entire CLIC length. It will be the last step towards the demonstration of the CLIC pre-alignment feasibility. (author)

  9. Wrapping interactions and the genus expansion of the 2-point function of composite operators

    CERN Document Server

    Sieg, C; Sieg, Christoph; Torrielli, Alessandro

    2005-01-01

    We perform a systematic analysis of wrapping interactions for a general class of theories with color degrees of freedom, including N=4 SYM. Wrapping interactions arise in the genus expansion of the 2-point function of composite operators as finite size effects that start to appear at a certain order in the coupling constant at which the range of the interaction is equal to the length of the operators. We analyze in detail the relevant genus expansions, and introduce a strategy to single out the wrapping contributions, based on adding spectator fields. We use a toy model to demonstrate our procedure, performing all computations explicitly. Although completely general, our treatment should be particularly useful for applications to the recent problem of wrapping contributions in some checks of the AdS/CFT correspondence.

  10. Development and testing of a double length pets for the CLIC experimental area

    CERN Document Server

    Sánchez, L; Gavela, D; Lara, A; Rodríguez, E; Gutiérrez, J L; Calero, J; Toral, F; Samoshkin, A; Gudkov, D; Riddone, G

    2014-01-01

    CLIC (compact linear collider) is a future e þ e collider based on normal-conducting technology, currently under study at CERN. Its design is based on a novel two-beam acceleration scheme. The main beam gets RF power extracted from a drive beam through power extraction and transfer structures (PETS). The technical feasibility of CLIC is currently being proved by its Third Test Facility (CTF3) which includes the CLIC experimental area (CLEX). Two Double Length CLIC PETS will be installed in CLEX to validate their performance with beam. This paper is focused on the engineering design, fabrication and validation of this PETS fi rst prototype. The design consists of eight identical bars, separated by radial slots in which damping material is located to absorb transverse wake fi elds, and two compact couplers placed at both ends of the bars to extract the generated power. The PETS bars are housed inside a vacuum tank designed to make the PETS as compact as possible. Several joint techniques such as vacuum brazing...

  11. Software and Parameters for Detailed TPC Studies in the CLIC CDR

    CERN Document Server

    Killenberg, M.

    2011-01-01

    For the TPC occupancy and time stamping studies in the CLIC CDR the MarlinTPC software package has been used in combination with Mokka for the full detector simulation. This document describes the working principle of the Marlin processors used for digitisation and reconstruction, and lists the parameters for reference.

  12. Cherenkov Fibers for Beam Loss Monitoring at the CLIC Two Beam Module

    CERN Document Server

    van Hoorne, Jacobus Willem; Holzer, E B

    The Compact Linear Collider (CLIC) study is a feasibility study aiming at a nominal center of mass energy of 3TeV and is based on normal conducting travelling-wave accelerating structures, operating at very high field gradients of 100 MV/m. Such high fields require high peak power and hence a novel power source, the CLIC two beam system, has been developed, in which a high intensity, low energy drive beam (DB) supplies energy to a high energy, low intensity main beam (MB). At the Two Beam Modules (TBM), which compose the 2x21km long CLIC main linac, a protection against beam losses resulting from badly controlled beams is necessary and particularly challenging, since the beam power of both main beam (14 MW) and drive beam (70 MW) is impressive. To avoid operational downtimes and severe damages to machine components, a general Machine Protection System (MPS) scheme has been developed. The Beam Loss Monitoring (BLM) system is a key element of the CLIC machine protection system. Its main role will be to detect p...

  13. Bounds on the electromagnetic dipole moments through the single top production at the CLIC

    CERN Document Server

    Koksal, M; Gutierrez-Rodriguez, A

    2016-01-01

    We obtain bounds on the anomalous magnetic and electric dipole moments of the $t$-quark from a future high-energy and high-luminosity linear electron positron collider, such as the CLIC, with unpolarized and polarized electron beams which are a powerful tool to determine new physics. We consider the processes $\\gamma e^- \\to \\bar t b\

  14. Development and testing of a double length pets for the CLIC experimental area

    Science.gov (United States)

    Sánchez, L.; Carrillo, D.; Gavela, D.; Lara, A.; Rodríguez, E.; Gutiérrez, J. L.; Calero, J.; Toral, F.; Samoshkin, A.; Gudkov, D.; Riddone, G.

    2014-05-01

    CLIC (compact linear collider) is a future e+e- collider based on normal-conducting technology, currently under study at CERN. Its design is based on a novel two-beam acceleration scheme. The main beam gets RF power extracted from a drive beam through power extraction and transfer structures (PETS). The technical feasibility of CLIC is currently being proved by its Third Test Facility (CTF3) which includes the CLIC experimental area (CLEX). Two Double Length CLIC PETS will be installed in CLEX to validate their performance with beam. This paper is focused on the engineering design, fabrication and validation of this PETS first prototype. The design consists of eight identical bars, separated by radial slots in which damping material is located to absorb transverse wakefields, and two compact couplers placed at both ends of the bars to extract the generated power. The PETS bars are housed inside a vacuum tank designed to make the PETS as compact as possible. Several joint techniques such as vacuum brazing, electron beam and arc welding were used to complete the assembly. Finally, several tests such as dimensional control and leak testing were carried out to validate design and fabrication methods. In addition, RF measurements at low power were made to study frequency tuning.

  15. HIGGS PHYSICS WITH A GAMMA GAMMA COLLIDER BASED ON CLIC 1*.

    Energy Technology Data Exchange (ETDEWEB)

    ASNER,D.; BURKHARDT,H.; DE ROECK,A.; ELLIS,J.; GRONBERG,J.; HEINEMEYER,S.; SCHMITT,M.; SCHULTE,D.; VELASCO,M.; ZIMMERMAN,F.

    2001-11-01

    We present the machine parameters and physics capabilities of the CLIC Higgs Experiment (CLICHE), a low-energy {gamma}{gamma} collider based on CLIC 1, the demonstration project for the higher-energy two-beam accelerator CLIC. CLICHE is conceived as a factory capable of producing around 20,000 light Higgs bosons per year. We discuss the requirements for the CLIC 1 beams and a laser backscattering system capable of producing a {gamma}{gamma} total (peak) luminosity of 2.0 (0.36) x 10{sup 34} cm{sup -2} s{sup -1} with E{sub CM}({gamma}{gamma}) 115 GeV. We show how CLICHE could be used to measure accurately the mass, {bar b}b, WW and {gamma}{gamma} decays of a light Higgs boson. We illustrate how these measurements may distinguish between the Standard Model Higgs boson and those in supersymmetric and more general two-Higgs-doublet models, complementing the measurements to be made with other accelerators. We also comment on other prospects in {gamma}{gamma} and e{sup -}{gamma} physics with CLICHE.

  16. Halo and tail simulations with applications to the CLIC drive beam

    CERN Document Server

    Fitterer, M; Adli, E; Burkhardt, H; Dalena, B; Rumolo, G; Schulte, D; Latina, A; Ahmed, I

    2010-01-01

    We report about generic halo and tail simulations and estimates. Previous studies weremainly focused on very high energies as relevant for the beam delivery systems of linear colliders. We have now studied, applied and extended these simulations to lower energies as relevant for the CLIC drive beam.

  17. Development of an X-Band Dielectric-Based Wakefield Power Extractor for Potential CLIC Applications

    CERN Document Server

    Jing, C -J; Kanareykin, A; Schoessow, P; Conde, M E; Gai, W; Power, J G; Syratchev, I

    2011-01-01

    In the past decade, tremendous efforts have been put into the development of the CLIC Power Extraction and Transfer Structure (PETS), and significant progress has been made. However, one concern remains the manufacturing cost of the PETS, particularly considering the quantities needed for a TeV machine. A dielectric-based wakefield power extractor in principle is much cheaper to build. A low surface electric field to gradient ratio is another big advantage of the dielectric-loaded accelerating/decelerating structure. We are currently investigating the possibility of using a cost-effective dielectric-based wakefield power extractor as an alternative to the CLIC PETS. We designed a 12 GHz dielectric-based power extractor which has a similar performance to CLIC PETS with parameters 23 mm beam channel, 240 ns pulse duration, 135 MW output per structure using the CLIC drive beam. In order to study potential rf breakdown issues, as a first step we are building a 11.424 GHz dielectric-based power extractor scaled fr...

  18. Intent Inference for Hand Pointing Gesture-Based Interactions in Vehicles.

    Science.gov (United States)

    Ahmad, Bashar I; Murphy, James K; Langdon, Patrick M; Godsill, Simon J; Hardy, Robert; Skrypchuk, Lee

    2016-04-01

    Using interactive displays, such as a touchscreen, in vehicles typically requires dedicating a considerable amount of visual as well as cognitive capacity and undertaking a hand pointing gesture to select the intended item on the interface. This can act as a distractor from the primary task of driving and consequently can have serious safety implications. Due to road and driving conditions, the user input can also be highly perturbed resulting in erroneous selections compromising the system usability. In this paper, we propose intent-aware displays that utilize a pointing gesture tracker in conjunction with suitable Bayesian destination inference algorithms to determine the item the user intends to select, which can be achieved with high confidence remarkably early in the pointing gesture. This can drastically reduce the time and effort required to successfully complete an in-vehicle selection task. In the proposed probabilistic inference framework, the likelihood of all the nominal destinations is sequentially calculated by modeling the hand pointing gesture movements as a destination-reverting process. This leads to a Kalman filter-type implementation of the prediction routine that requires minimal parameter training and has low computational burden; it is also amenable to parallelization. The substantial gains obtained using an intent-aware display are demonstrated using data collected in an instrumented vehicle driven under various road conditions. PMID:25935053

  19. Weak interaction rates for Kr and Sr waiting-point nuclei under rp-process conditions

    Energy Technology Data Exchange (ETDEWEB)

    Sarriguren, P., E-mail: sarriguren@iem.cfmac.csic.e [Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid (Spain)

    2009-10-12

    Weak interaction rates are studied in neutron deficient Kr and Sr waiting-point isotopes in ranges of densities and temperatures relevant for the rp process. The nuclear structure is described within a microscopic model (deformed QRPA) that reproduces not only the half-lives but also the Gamow-Teller strength distributions recently measured. The various sensitivities of the decay rates to both density and temperature are discussed. Continuum electron capture is shown to contribute significantly to the weak rates at rp-process conditions.

  20. Point Defects in Double Helix Induced by Interaction of Silver Nanoparticles with DNA

    CERN Document Server

    Bregadze, Vasil G; Giorgadze, Tamar G; Monaselidze, Jamlet R; Jaliashvili, Zaza V; Khuskivadze, Temur B

    2012-01-01

    Interaction of DNA-silver nanoparticles (AgNPs) complexes with H3O+, Cu2+ and Cl- has been studied by spectro-photometric, spectro-fluorimetric and differential scanning micro calorimetric methods. It is shown that DNA is a catalyst in redox reactions taking place in AgNPs adsorbed on its surface. We also demonstrate that Ag+ ions that are freed after corrosion of nanoparticles show absorption into the inner part of DNA double helix, i.e. they make the so-called cross-links between complementary base pairs of DNA. The cross-links present point defects of DNA which leads in-vivo to cell death.

  1. Regulation of the membrane insertion and conductance activity of the metamorphic chloride intracellular channel protein CLIC1 by cholesterol.

    Directory of Open Access Journals (Sweden)

    Stella M Valenzuela

    Full Text Available The Chloride Intracellular ion channel protein CLIC1 has the ability to spontaneously insert into lipid membranes from a soluble, globular state. The precise mechanism of how this occurs and what regulates this insertion is still largely unknown, although factors such as pH and redox environment are known contributors. In the current study, we demonstrate that the presence and concentration of cholesterol in the membrane regulates the spontaneous insertion of CLIC1 into the membrane as well as its ion channel activity. The study employed pressure versus area change measurements of Langmuir lipid monolayer films; and impedance spectroscopy measurements using tethered bilayer membranes to monitor membrane conductance during and following the addition of CLIC1 protein. The observed cholesterol dependent behaviour of CLIC1 is highly reminiscent of the cholesterol-dependent-cytolysin family of bacterial pore-forming proteins, suggesting common regulatory mechanisms for spontaneous protein insertion into the membrane bilayer.

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

    CERN Document Server

    Nurminen, Janne

    2012-01-01

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

  3. Synergetic effects of Mn and Si in the interaction with point defects in bcc Fe

    Energy Technology Data Exchange (ETDEWEB)

    Bakaev, A., E-mail: abakaev@sckcen.be [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, Mol B2400 (Belgium); Center for Molecular Modeling, Department of Physics and Astronomy, Ghent University, Technologiepark 903, 9052 Zwijnaarde (Belgium); Department of Experimental Nuclear Physics, Institute of Physics, Nanotechnologies and Telecommunications, St. Petersburg State Polytechnical University, 29 Polytekhnicheskaya Str., 195251 St. Petersburg (Russian Federation); Terentyev, D. [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, Mol B2400 (Belgium); He, X. [China Institute of Atomic Energy, PO Box 275-51, 102413 Beijing (China); Van Neck, D. [Center for Molecular Modeling, Department of Physics and Astronomy, Ghent University, Technologiepark 903, 9052 Zwijnaarde (Belgium)

    2014-12-15

    The interaction of Mn, Si and Cr with a vacancy and self-interstitial defects in BCC Fe has been analyzed using ab initio calculations. While the interaction of the considered solute clusters with a single vacancy is linearly additive, there is a considerable synergetic effect in the case of self-interstitial atoms, found to bind strongly with Mn–Si pairs. The latter therefore act as deep trapping configurations for self-interstitials. At the same time, the presence of the point defects nearby weakly attractive Mn–Si pairs significantly enhances the solute–solute binding. The revealed effects are rationalized on the basis of charge density and local magnetic moment distributions.

  4. Interaction Energy Calculations of Edge Dislocation with Point Defects in FCC Cu

    International Nuclear Information System (INIS)

    Swelling has always been a limitation for long term operating reactors. The simple Bias model has done a good job in describing swelling in electron irradiation. In order to apply it to neutron irradiation, there's the key parameter named Bias Factor (Bd), which plays an important role in the model, has to be figured out. However, the Bds fitted from experiments are not consistent with those derived from elasticity theory. The major problem lies on the fact that analytical interactions based on elasticity theory are not valid around the dislocation core region. Hence a careful work about the interaction energy map is required in order to have numerical solution of Bd. In the present work, we apply large scale of atomistic calculations with EAM potential to get the interaction energy map between Point Defects (Vacancy and dumbbell SIAs along <100> directions) and dislocation in FCC Cu, as a demonstration of general FCC based material. General properties are checked in atomistic calculation results; Comparison has been made between the elasticity results and the atomistic results. The atomistic calculation of interaction maps show reasonable profiles. And they give better description around the dislocation core region. (author)

  5. Elucidation of multiple-point interactions of pyranine fluoroprobe during the gelation.

    Science.gov (United States)

    Yilmaz, Yasar; Uysal, Nihan; Gelir, Ali; Guney, Orhan; Aktas, Demet K; Gogebakan, Savas; Oner, Aylin

    2009-03-01

    We have studied the multiple-point interactions of the pyranine (8-hydroxypyrene-1,3,6-trisulfonic acid, trisodium salt; 3sPyOH) fluoroprobe with polymer chains during the free-radical polymerization of acrylamide (AAm) by using the steady state fluorescence measurements. We observed a considerable blue shift from 515nm to 406nm in the emission spectra due to a C-O ether bond formation between the hydroxylic oxygen of 3sPyOH and a terminal C-atom of the growing AAm chain. Furthermore ionic (electrostatic) interactions occur between the three ionized sulfonic acid groups (SO(3)(-)) of 3sPyOH and protonated amide groups on the AAm chains. These electrostatic interactions also cause a gradual red shift in the maximum of the short-wavelength-peak, from 406nm to 430nm. The results showed that the pyranine can be used as a probe for real time monitoring of the polymerization process of AAm system since it monitors both the progression of the polymerization via chemical binding over OH group and the change in the local density of the polymerizing sample by means of the gradual red shift in the short-wavelength-peak via ionic interactions over SO(3)(-) groups.

  6. Ab initio study of Cr interactions with point defects in bcc Fe

    International Nuclear Information System (INIS)

    Full text of publication follows. Ferritic martensitic steels are candidate structural materials for fast neutron reactors, and in particular high-Cr reduced-activation steels. In Fe-Cr alloys, Cr plays a major role in the radiation-induced evolution of the mechanical properties. Using ab initio calculations based on density functional theory, the properties of Cr in α-Fe have been investigated. The intrinsic point defect formation energies were found to be larger in model bcc Cr as compared to those in ferromagnetic bcc Fe. The interactions of Cr with point defects (vacancy and self interstitials) have been characterised. Single Cr atoms interact weakly with vacancies but significantly with self-interstitial atoms. Mixed interstitials of any interstitial symmetry are bound. Configurations where two Cr atoms are in nearest neighbour position are generally unfavourable in bcc Fe except when they are a part of a interstitial complex. Mixed interstitials do not have as strong directional stability as pure Fe interstitials have. The effects on the results using the atom description scheme of either the ultrasoft pseudo-potential (USPP) or the projector augmented wave (PAW) formalisms are connected to the differences in local magnetic moments that the two methods predict. As expected for the Fe-Cr system, the results obtained using the PAW method are more reliable than the ones obtained with USPP. (authors)

  7. Strong field effects on physics processes at the Interaction Point of future linear colliders

    CERN Document Server

    Hartin, A; Porto, S

    2013-01-01

    Future lepton colliders will be precision machines whose physics program includes close study of the Higgs sector and searches for new physics via polarised beams. The luminosity requirements of such machines entail very intense lepton bunches at the interaction point with associated strong electromagnetic fields. These strong fields not only lead to obvious phenomena such as beamstrahlung, but also potentially affect every particle physics process via virtual exchange with the bunch fields. For precision studies, strong field effects have to be understood to the sub-percent level. Strong external field effects can be taken into account exactly via the Furry Picture or, in certain limits, via the Quasi-classical Operator method . Significant theoretical development is in progress and here we outline the current state of play.

  8. The V0 detector is two disks of counters in both sides of the interaction point.

    CERN Multimedia

    Grossiord, Jean-Yves

    2006-01-01

    The V0 detector is two disks of counters in both sides of the interaction point. Here is the V0C disk to be fixed on the front face of the muon spectrometer absorber. It is made of 48 scintillating elements coupled to two wavelength fibre layers which emit and guide the light up to connrctors arounda case made of Carbon fibre plates. The light going out of connectors is collected by an optical fibre bundle and transmitted at 3 metres to photo-multipliers which convert light to electrical signal. The elements are set in the case following 2 small rings of 8 counters and 2 large rings of 16 counters grouped two by two. 32 channels of detection distributed around the LHC beam pipe constitute thus the detector

  9. Correction of beam-beam effects in luminosity measurement in the forward region at CLIC

    CERN Document Server

    Lukic, Strahinja

    2013-01-01

    Procedures for correcting the beam-beam effects in luminosity measurement at CLIC at 3 TeV CM energy are described and tested using Monte Carlo simulations: - Correction of the angular counting loss due to the combined Beamstrahlung and initial-state radiation (ISR) effects, based on the reconstructed velocity of the collision frame of the Bhabha scattering. - Deconvolution of the luminosity spectrum distortion due to the ISR emission. - Correction of the counting bias due to the finite calorimeter energy resolution. All procedures were tested by simulation. Bhabha events were generated using BHLUMI, and used in Guinea-PIG to simulate the outgoing momenta of Bhabha particles in the bunch collisions at CLIC. Residual uncertainties after correction are listed in a table in the conclusions. The beam-beam related systematic counting uncertainty in the luminosity peak can be reduced to the order of permille.

  10. Correction of beam-beam effects in luminosity measurement in the forward region at CLIC

    CERN Document Server

    Lukic, Strahinja

    2013-01-01

    Procedures for correcting the beam-beam effects in luminosity measurement at CLIC at 3 TeV CM energy are described and tested using Monte Carlo simulations: -> Correction of the angular counting loss due to the combined Beamstrahlung and initial-state radiation (ISR) effects, based on the reconstructed velocity of the collision frame of the Bhabha scattering. -> Deconvolution of the luminosity spectrum distortion due to the ISR emission. -> Correction of the counting bias due to the finite calorimeter energy resolution. All procedures were tested by simulation. Bhabha events were generated using BHLUMI, and used in Guinea-PIG to simulate the outgoing momenta of Bhabha particles in the bunch collisions at CLIC. Residual uncertainties after correction are listed in a table in the conclusions. The beam-beam related systematic counting uncertainty in the luminosity peak can be reduced to the order of permille.

  11. Status of a study of stabilization and fine positioning of CLIC quadrupoles to the nanometre level

    CERN Document Server

    Artoos, K; Esposito, M; Fernandez Carmona, P; Guinchard, M; Hauviller, C; Janssens, S; Kuzmin, A; Leuxe, R; Moron Ballester, R

    2011-01-01

    Mechanical stability to the nanometre and below is required for the Compact Linear Collider (CLIC) quadrupoles to frequencies as low as 1 Hz. An active stabilization and positioning system based on very stiff piezo electric actuators and inertial reference masses is under study for the Main Beam Quadrupoles (MBQ). The stiff support was selected for robustness against direct forces and for the option of incrementally repositioning the magnet with nanometre resolution. The technical feasibility was demonstrated by a representative test mass being stabilized and repositioned to the required level in the vertical and lateral direction. Technical issues were identified and the development programme of the support, sensors, and controller was continued to increase the performance, integrate the system in the overall controller, adapt to the accelerator environment, and reduce costs. The improvements are implemented in models, test benches, and design of the first stabilized prototype CLIC magnet. The characterizati...

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

    CERN Document Server

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

    2011-01-01

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

  13. Power pulsing scheme for analog and digital electronics of the vertex detectors at CLIC

    CERN Document Server

    Blanchot, Georges

    2015-01-01

    The precision requirements of the vertex detector at CLIC impose strong limitations on the mass of such a detector (< 0.2% of a radiation length, Xo, per layer). To achieve such a low material budget, ultra-thin hybrid pixel detectors are foreseen, while the mass for cooling and services will be reduced by implementing a power pulsing scheme that takes advantage of the low duty cycle of the accelerator. The principal aim is to achieve significant power reduction without compromising the power integrity supplied to the front-end electronics. This report summarises the study of a power pulsing scheme to power the vertex barrel electronics of the future CLIC experiment. Its main goal is to describe in more detail what has been already presented in TWEPP conferences and other presentations. The report can therefore serve as an operator manual for future use and development of the system

  14. Optimal Power System and Grid Interface Design Considerations for the CLICs Klystron Modulators

    CERN Document Server

    Marija, Jankovic; Jon, Clare; Pat, Wheeler; Davide, Aguglia

    2015-01-01

    The Compact Linear Collider (CLIC) is an electron-positron collider under study at CERN with the aim to explore the next generation of high precision/high energy particles physics. The CLIC’s drive beams will be accelerated by approximately 1300 klystrons, requiring highly efficient and controllable solid state capacitor discharge modulators. Capacitor charger specifications include the requirement to mask the pulsed effect of the load from the utility grid, ensure maximum power quality, control the derived DC voltage precisely (to maximize accuracy for the modulators being implemented), and achieve high efficiency and operability of the overall power system. This paper presents the work carried out on the power system interface for the CLIC facility. In particular it discusses the challenges on the utility interface and analysis of the grid interface converters with regards to required functionality, efficiency, and control methodologies.

  15. TCAD simulations of High-Voltage-CMOS Pixel structures for the CLIC vertex detector

    CERN Document Server

    Buckland, Matthew Daniel

    2016-01-01

    The requirements for precision physics and the experimental conditions at CLIC result in stringent constraints for the vertex detector. Capacitively coupled active pixel sensors with 25 μm pitch implemented in a commercial 180 nm High-Voltage CMOS (HV-CMOS) process are currently under study as a candidate technology for the CLIC vertex detector. Laboratory calibration measurements and beam tests with prototypes are complemented by detailed TCAD and electronic circuit simulations, aiming for a comprehensive understanding of the signal formation in the HV-CMOS sensors and subsequent readout stages. In this note 2D and 3D TCAD simulation results of the prototype sensor, the Capacitively Coupled Pixel Detector version three (CCPDv3), will be presented. These include the electric field distribution, leakage current, well capacitance, transient response to minimum ionising particles and charge-collection.

  16. Beam dynamics and wakefield suppression in interleaved damped and detuned structures for CLIC

    CERN Document Server

    D'Elia, A; Khan, V F; Jones, R M; Latina, A; Nesmiyan, I; Riddone, G

    2013-01-01

    Acceleration of multiple bunches of charged particles in the main linacs of the Compact Linear Collider (CLIC) with high accelerating fields provides two major challenges: firstly, to ensure the surface electromagnetic fields do not cause electrical breakdown and subsequent surface damage, and secondly, to ensure the beam-excited wakefields are sufficiently suppressed to avoid appreciable emittance dilution. In the baseline design for CLIC, heavy wakefield suppression is used (Q ~ 10) [1] and this ensures the beam quality is well-preserved [2]. Here we discuss an alternative means to suppress the wakefield which relies on strong detuning of the cell dipole frequencies, together with moderate damping, effected by manifolds which are slot-coupled to each accelerating cell. This damped and detuned wakefield suppression scheme is based on the methodology developed for the Japanese Linear Collider/Next Linear Collider (JLC/NLC) [3]. Here we track the multi-bunch beam down the complete collider, u...

  17. Stabilization of the Beam Intensity in the Linac at the CTF3 CLIC Test Facility

    CERN Document Server

    Dubrovskiy, A; Bathe, BN; Srivastava, S

    2013-01-01

    A new electron beam stabilization system has been introduced in CTF3 in order to open new possibilities for CLIC beam studies in ultra-stable conditions and to provide a sustainable tool to keep the beam intensity and energy at its reference values for long term operations. The stabilization system is based on a pulse-to-pulse feedback control of the electron gun to compensate intensity deviations measured at the end of the injector and at the beginning of the linac. Thereby it introduces negligible beam distortions at the end of the linac and it significantly reduces energy deviations. A self-calibration mechanism has been developed to automatically configure the feedback controller for the optimum performance. The residual intensity jitter of 0.045% of the stabilized beam was measured whereas the CLIC requirement is 0.075%.

  18. Technologies and R&D for a High Resolution Cavity BPM for the CLIC Main Beam

    CERN Document Server

    Towler, J R; Soby, L; Wendt, M; Boogert, S T; Cullinan, F J; Lyapin, A

    2013-01-01

    The Main Beam (MB) linac of the Compact Linear Collider (CLIC) requires a beam orbit measurement system with high spatial (50 nm) and high temporal resolution (50 ns) to resolve the beam position within the 156 ns long bunch train, traveling on an energy-chirped, minimum dispersive trajectory. A 15 GHz prototype cavity BPM has been commissioned in the probe beam-line of the CTF3 CLIC Test Facility. We discuss performance and technical details of this prototype installation, including the 15 GHz analogue downconverter, the data acquisition and the control electronics and software. An R&D outlook is given for the next steps, which requires a system of 3 cavity BPMs to investigate the full resolution potential.

  19. Production of excited electrons at TESLA and CLIC based egamma colliders

    CERN Document Server

    Kirca, Z; Cakir, O

    2003-01-01

    We analyze the potential of TESLA and CLIC based electron-photon colliders to search for excited spin-1/2 electrons. The production of excited electrons in the resonance channel through the electron- photon collision and their subsequent decays to leptons and electroweak gauge bosons are investigated. We study in detail the three signal channels of excited electrons and the corresponding backgrounds through the reactions egamma yields egamma, egamma yields eZ and egamma yields vW. Excited electrons with masses up to about 90% of the available collider energy can be probed down to the coupling f = f prime = 0.05(0.1) at TESLA(CLIC) based egamma colliders. 22 Refs.

  20. Study of the Thermo-Mechanical Behavior of the CLIC Two-Beam Modules

    CERN Document Server

    Rossi, F; Riddone, G; Österberg, K; Kossyvakis, I; Gudkov, D; Samochkine, A

    2013-01-01

    The final luminosity target of the Compact LInear Collider (CLIC) imposes a micron-level stability requirement on the two-meter repetitive two-beam modules constituting the main linacs. Two-beam prototype modules are being assembled to extensively study their thermo-mechanical behaviour under different operation modes. The power dissipation occurring in the modules will be reproduced and the efficiency of the corresponding cooling systems validated. At the same time, the real environmental conditions present in the CLIC tunnel will be studied. Air conditioning and ventilation systems have been installed in the dedicated laboratory. The air temperature will be changed from 20 to 40°C, while the air flow rate will be varied up to 0.8 m/s. During all experimental tests, the alignment of the RF structures will be monitored to investigate the influence of power dissipation and air temperature on the overall thermo-mechanical behaviour. \

  1. Thermo-Mechanical tests for the CLIC two-beam module study

    CERN Document Server

    Xydou, A; Riddone, G; Daskalaki, E

    2014-01-01

    The luminosity goal of CLIC requires micron level precision with respect to the alignment of the components on its two-meter long modules, composing the two main linacs. The power dissipated inside the module components introduces mechanical deformations affecting their alignment and therefore the resulting machine performance. Several two-beam prototype modules must be assembled to extensively measure their thermo-mechanical behavior under different operation modes. In parallel, the real environmental conditions present in the CLIC tunnel should be studied. The air conditioning and ventilation system providing specified air temperature and flow has been installed in the dedicated laboratory. The power dissipation occurring in the modules is being reproduced by the electrical heaters inserted inside the RF structure mock-ups and the quadrupoles. The efficiency of the cooling systems is being verified and the alignment of module components is monitored. The measurement results will be compared to finite elemen...

  2. Interactive effect of cerium and aluminum on the ignition point and the oxidation resistance of magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Lin Pengyu [Key Laboratory of Automobile Materials of Ministry of Education, School of Materials Science and Engineering, Nanling Campus of Jilin University, Changchun Jilin 130025 (China)], E-mail: linpengyu2000@yahoo.com.cn; Zhou Hong; Li Wei; Li Wenping; Sun Na [Key Laboratory of Automobile Materials of Ministry of Education, School of Materials Science and Engineering, Nanling Campus of Jilin University, Changchun Jilin 130025 (China); Yang Rong [Public Mathematics Teaching and Research Center, College of Mathematics, Qianwei Campus of Jilin University, Changchun Jilin 130012 (China)

    2008-09-15

    This paper focused on the interactive effect of cerium (Ce) addition and aluminum (Al) content in magnesium alloy on ignition point and oxidation resistance. Ce content played an important role in improving the oxidation resistance of Mg alloy. Ignition point ascended with increasing Ce content. 0.25 wt% Ce content in Mg alloys could greatly improve tightness of the oxide film of Mg alloys. However, when Ce content in the alloy exceeded its solid solubility, ignition point descended. Furthermore, Al content in the alloy also influenced the ignition point. The higher the Al content was, the lower the ignition point.

  3. Touch and gravitropic set-point angle interact to modulate gravitropic growth in roots

    Science.gov (United States)

    Massa, G. D.; Gilroy, S.

    2003-01-01

    Plant roots must sense and respond to a variety of environmental stimuli as they grow through the soil. Touch and gravity represent two of the mechanical signals that roots must integrate to elicit the appropriate root growth patterns and root system architecture. Obstacles such as rocks will impede the general downwardly directed gravitropic growth of the root system and so these soil features must be sensed and this information processed for an appropriate alteration in gravitropic growth to allow the root to avoid the obstruction. We show that primary and lateral roots of Arabidopsis do appear to sense and respond to mechanical barriers placed in their path of growth in a qualitatively similar fashion. Both types of roots exhibited a differential growth response upon contacting the obstacle that directed the main axis of elongation parallel to the barrier. This growth habit was maintained until the obstacle was circumvented, at which point normal gravitropic growth was resumed. Thus, the gravitational set-point angle of the primary and lateral roots prior to encountering the barrier were 95 degrees and 136 degrees respectively and after growing off the end of the obstacle identical set-point angles were reinstated. However, whilst tracking across the barrier, quantitative differences in response were observed between these two classes of roots. The root tip of the primary root maintained an angle of 136 degrees to the horizontal as it traversed the barrier whereas the lateral roots adopted an angle of 154 degrees. Thus, this root tip angle appeared dependent on the gravitropic set-point angle of the root type with the difference in tracking angle quantitatively reflecting differences in initial set-point angle. Concave and convex barriers were also used to analyze the response of the root to tracking along a continuously varying surface. The roots maintained the a fairly fixed angle to gravity on the curved surface implying a constant resetting of this tip angle

  4. Estimation of the temperature dependent interaction between uncharged point defects in Si

    Energy Technology Data Exchange (ETDEWEB)

    Kamiyama, Eiji [Department of Communication Engineering, Okayama Prefectural University, 111 Kuboki, Soja-shi, Okayama-ken 719-1197 (Japan); GlobalWafers Japan Co., Ltd., 30 Soya, Hadano, Kanagawa, 257-8566 (Japan); Vanhellemont, Jan [Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, Ghent B-9000 (Belgium); Sueoka, Koji [Department of Communication Engineering, Okayama Prefectural University, 111 Kuboki, Soja-shi, Okayama-ken 719-1197 (Japan)

    2015-01-15

    A method is described to estimate the temperature dependent interaction between two uncharged point defects in Si based on DFT calculations. As an illustration, the formation of the uncharged di-vacancy V{sub 2} is discussed, based on the temperature dependent attractive field between both vacancies. For that purpose, all irreducible configurations of two uncharged vacancies are determined, each with their weight given by the number of equivalent configurations. Using a standard 216-atoms supercell, nineteen irreducible configurations of two vacancies are obtained. The binding energies of all these configurations are calculated. Each vacancy is surrounded by several attractive sites for another vacancy. The obtained temperature dependent of total volume of these attractive sites has a radius that is closely related with the capture radius for the formation of a di-vacancy that is used in continuum theory. The presented methodology can in principle also be applied to estimate the capture radius for pair formation of any type of point defects.

  5. Estimation of the temperature dependent interaction between uncharged point defects in Si

    Directory of Open Access Journals (Sweden)

    Eiji Kamiyama

    2015-01-01

    Full Text Available A method is described to estimate the temperature dependent interaction between two uncharged point defects in Si based on DFT calculations. As an illustration, the formation of the uncharged di-vacancy V2 is discussed, based on the temperature dependent attractive field between both vacancies. For that purpose, all irreducible configurations of two uncharged vacancies are determined, each with their weight given by the number of equivalent configurations. Using a standard 216-atoms supercell, nineteen irreducible configurations of two vacancies are obtained. The binding energies of all these configurations are calculated. Each vacancy is surrounded by several attractive sites for another vacancy. The obtained temperature dependent of total volume of these attractive sites has a radius that is closely related with the capture radius for the formation of a di-vacancy that is used in continuum theory. The presented methodology can in principle also be applied to estimate the capture radius for pair formation of any type of point defects.

  6. The Event Display for CLIC: DD4hep Compatibility and Improvements

    CERN Document Server

    Quast, Thorben

    2015-01-01

    This document is a short summary of my contributions to the Event Display for the CLICdp Software group in the context of CERN’s Summer Student Programme 2015. After a brief outline of CLIC and the relevant software package, the project is motivated. The individual achievements and their technical realizations are explained rather qualitatively, as details are well documented directly in the source code.

  7. Implications of a Curved Tunnel for the Main Linac of CLIC

    CERN Document Server

    Latina, Andrea; Schulte, Daniel

    2006-01-01

    Preliminary studies of a linac that follows the earth curvature are presented for the CLIC main linac. The curvature of the tunnel is modeled in a realistic way by use of geometry changing elements. The emittance preservation is studied for a perfect machine as well as taking into account imperfections. Results for a curved linac are compared with those for a laser-straight machine.

  8. Nonlinear Optimization of CLIC DRS New Design with Variable Bends and High Field Wigglers

    CERN Document Server

    Ghasem, H.; Alabau-Gonzalvo, J.; Papadopoulou, S.; Papaphilippou, Y.

    2016-01-01

    The new design of CLIC damping rings is based on longitudinal variable bends and high field superconducting wiggler magnets. It provides an ultra-low horizontal normalised emittance of 412 nm-rad at 2.86 GeV. In this paper, nonlinear beam dynamics of the new design of the damping ring (DR) with trapezium field profile bending magnets have been investigated in detail. Effects of the misalignment errors have been studied in the closed orbit and dynamic aperture.

  9. Parameter scan for the CLIC Damping rings under the infleunce of intrabeam scattering

    CERN Document Server

    Antoniou, F; Papaphilippou, Y; Vivoli, A

    2010-01-01

    Due to the high bunch density, the output emittances of the CLIC Damping Rings (DR) are strongly dominated by the effect of Intrabeam Scattering (IBS). In an attempt to optimize the ring design, the bench-marking of the multiparticle tracking code SIRE with the classical IBS formalisms and approximations is first considered. The scaling of the steady state emittances and IBS growth rates is also studied, with respect to several ring parameters including energy, bunch charge and wiggler characteristics.

  10. Pre-Alignment of CLIC using the Double-Wire Method

    CERN Document Server

    Coosemans, Williame

    1998-01-01

    The pre-alignment and active control method for the Compact Linear Collider (CLIC) is described. Two new types of instruments are used in this system - a biaxial Wire Positioning System (WPS) which uses a stretched wire as the spatial reference, and a capacitive three axes Tilt Meter System (TMS). The instruments, and the way they are used with the well-known Hydrostatic Levelling System (HLS) are described.

  11. Interaction of a Magnet and a Point Charge: Unrecognized Internal Electromagnetic Momentum

    CERN Document Server

    Boyer, Timothy H

    2014-01-01

    Whereas nonrelativistic mechanics always connects the total momentum of a system to the motion of the center of mass, relativistic systems, such as interacting electromagnetic charges, can have internal linear momentum in the absence of motion of the center of energy of the system. This internal linear momentum of the system is related to the controversial concept of "hidden momentum." We suggest that the term "hidden momentum" be abandoned. Here we use the relativistic conservation law for the center of energy to give an unambiguous definition of the "internal momentum of a system," and then we exhibit this internal momentum for the system of a magnet (modeled as a circular ring of moving charges) and a distant static point charge. The calculations provide clear illustrations of this system for three cases: a) the moving charges of the magnet are assumed to continue in their unperturbed motion, b) the moving charges of the magnet are free to accelerate but have no mutual interactions, and c) the moving charg...

  12. Power production experiments at the Test Beam Line in the CLIC Test Facility 3

    CERN Document Server

    Lillestøl, Reidar Lunde; Adli, Erik; Lundheim, Lars Magne

    2010-01-01

    CLIC is an international study of a future multi-TeV electron-positron linear collider, where the energy of a high-intensity drive beam is extracted and transferred to the main beam via Power Extraction and Transfer Structures (PETS) in the form of rf power. The study of power production is therefore essential for the feasibility of CLIC. Power production in PETS has been studied, and ex- periments have been performed in the decelerator Test Beam Line in the CLIC Test Facility 3. In particular, the correlation of the power production and the beam position inside the structure has been studied. It is shown that the total produced power is constant when the beam has a position offset through the PETS. In addition, the difference between the measured phases from each side is independent of the beam position, which allows for efficient combination of the fields. However, the ratio of the power on each side of the PETS unexpectedly shows a linear dependence on the horizontal offset, with a correlation value of 0.8...

  13. Mass and Cross Section Measurements of light-flavored Squarks at CLIC

    CERN Document Server

    WEUSTE, L.

    2011-01-01

    We present a study of the prospects for the measurement of TeV-scale light-flavored right-squark masses and and the production cross sections at a 3 TeV e+e- collider based on CLIC technology. The analysis, performed in the framework of the CLIC Conceptual Design Report, is based on full Geant4 simulations of the CLIC ILD detector concept, including standard model physics background and machine related hadronic background from two-photon processes. The events were reconstructed using particle flow event reconstruction, and the mass and cross sections were obtained from a template fit built from generator-level simulations with smearing to parametrize the detector response. For an integrated luminosity of 2 ab^-1, a statistical precision of 5.9 GeV, corresponding to 0.52%, was obtained for unseparated first and second generation right squarks. For the combined cross section, a precision of 0.07 fb, corresponding to 5%, was obtained.

  14. Klystron Modulators for the 3 TeV CLIC Scheme An Overview

    CERN Document Server

    Pearce, P

    2001-01-01

    The CLIC (Compact Linear Collider) design is based on the Two-Beam technology being developed at CERN. The Drive Beam accelerator will have about 200 multi-beam klystron-modulator (MBK-M) RF power sources for each drive beam linac. These multi-beam klystrons (MBKs) should provide up to 50 MW peak power at 937 MHz, with a 100 ms pulse width and operating at 100 Hz repetition frequency. The CLIC drive beam injector will also use a number of these same MBK-Ms operating at slightly lower power levels. A 0.5 MW peak power, 468 MHz klystron with a bandwidth of around 150 MHz will be required for the sub-harmonic buncher in each drive beam injector chain as well. The Main Beams injector complex is required to deliver e+ and e- beams at 9 GeV via the transfer lines to the CLIC Main Beam accelerator. The present injector complex design uses a series of linacs to accelerate the electron and positron beams coming from RF guns working at 1.5 GHz up to an energy of 1.98 GeV before they are put into damping rings. Each of ...

  15. En route vers la nano stabilisation de CLIC faisceau principale et focalisation finale

    CERN Document Server

    Artoos, K; Guinchard, M; Hauviller, Claude; Lackner, F; CERN. Geneva. TS Department

    2008-01-01

    Pour atteindre la luminosité voulue de CLIC, la taille transversale du faisceau doit être de l?ordre du nanomètre. Ceci nécessite une stabilité vibratoire des quadripôles du faisceau principal de 1 nm et même 0.1 nm pour les doublets de la focalisation finale. La nano technologie et la nano stabilisation sont des activités qui évoluent rapidement dans l?industrie et centres de recherche pour des applications très variées comme l?électronique, l?optique, la chimie voire la médecine. Cette présentation décrit les avancées techniques nécessaires pour atteindre l?objectif de CLIC et les projets et collaborations R&D prévus pour démontrer la faisabilité de la nano stabilisation de CLIC en 2010.

  16. ACE3P Computations of Wakefield Coupling in the CLIC Two-Beam Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Candel, Arno; Li, Z.; Ng, C.; Rawat, V.; Schussman, G.; Ko, K.; /SLAC; Syratchev, I.; Grudiev, A.; Wuensch, W.; /CERN

    2010-10-27

    The Compact Linear Collider (CLIC) provides a path to a multi-TeV accelerator to explore the energy frontier of High Energy Physics. Its novel two-beam accelerator concept envisions rf power transfer to the accelerating structures from a separate high-current decelerator beam line consisting of power extraction and transfer structures (PETS). It is critical to numerically verify the fundamental and higher-order mode properties in and between the two beam lines with high accuracy and confidence. To solve these large-scale problems, SLAC's parallel finite element electromagnetic code suite ACE3P is employed. Using curvilinear conformal meshes and higher-order finite element vector basis functions, unprecedented accuracy and computational efficiency are achieved, enabling high-fidelity modeling of complex detuned structures such as the CLIC TD24 accelerating structure. In this paper, time-domain simulations of wakefield coupling effects in the combined system of PETS and the TD24 structures are presented. The results will help to identify potential issues and provide new insights on the design, leading to further improvements on the novel CLIC two-beam accelerator scheme.

  17. X-band crab cavities for the CLIC beam delivery system

    CERN Document Server

    Burt, G; Dexter, A C; Abram, T; Dolgashev, V; Tantawi, S; Jones, R M

    2009-01-01

    The CLIC machine incorporates a 20 mrad crossing angle at the IP to aid the extraction of spent beams. In order to recover the luminosity lost through the crossing angle a crab cavity is proposed to rotate the bunches prior to collision. The crab cavity is chosen to have the same frequency as the main linac (11.9942 GHz) as a compromise between size, phase stability requirements and beam loading. It is proposed to use a HE11 mode travelling wave structure as the CLIC crab cavity in order to minimise beam loading and mode separation. The position of the crab cavity close to the final focus enhances the effect of transverse wake-fields so effective wake-field damping is required. A damped detuned structure is proposed to suppress and de-cohere the wake-field hence reducing their effect. Design considerations for the CLIC crab cavity will be discussed as well as the proposed high power testing of these structures at SLAC.

  18. Measurement of the H$\\rightarrow$WW$^*$ Branching Ratio at 1.4TeV using the semileptonic final state at CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)762723; Watson, Nigel

    2016-01-01

    This note summarises a study to evaluate the potential to measure the H$\\rightarrow$WW$^*$ branching fraction at CLIC, 1.4TeV centre-of-mass energy, with the CLIC_ILD detector, using the WW$\\rightarrow$qql$\

  19. rp-Process weak-interaction mediated rates of waiting-point nuclei

    CERN Document Server

    Nabi, Jameel-Un

    2012-01-01

    Electron capture and positron decay rates are calculated for neutron-deficient Kr and Sr waiting point nuclei in stellar matter. The calculation is performed within the framework of pn-QRPA model for rp-process conditions. Fine tuning of particle-particle, particle-hole interaction parameters and a proper choice of the deformation parameter resulted in an accurate reproduction of the measured half-lives. The same model parameters were used to calculate stellar rates. Inclusion of measured Gamow-Teller strength distributions finally led to a reliable calculation of weak rates that reproduced the measured half-lives well under limiting conditions. For the rp-process conditions, electron capture and positron decay rates on $^{72}$Kr and $^{76}$Sr are of comparable magnitude whereas electron capture rates on $^{78}$Sr and $^{74}$Kr are 1--2 orders of magnitude bigger than the corresponding positron decay rates. The pn-QRPA calculated electron capture rates on $^{74}$Kr are bigger than previously calculated. The p...

  20. Transition metal solute interactions with point defects in fcc iron from first principles

    Science.gov (United States)

    Hepburn, D. J.; MacLeod, E.; Ackland, G. J.

    2015-07-01

    We present a comprehensive set of first-principles electronic structure calculations of the properties of substitutional transition metal solutes and point defects in austenite (face-centered cubic, paramagnetic Fe). Clear trends were observed in these quantities across the transition metal series, with solute-defect interactions strongly related to atomic size, and only weakly related to more subtle details of magnetic or electronic structure. Oversized solutes act as strong traps for both vacancy and self-interstitial defects and as nucleation sites for the development of protovoids and small self-interstitial loops. The consequent reduction in defect mobility and net defect concentrations in the matrix explains the observation of reduced swelling and radiation-induced segregation. Our analysis of vacancy-mediated solute diffusion demonstrates that below about 400 K Ni and Co will be dragged by vacancies and their concentrations should be enhanced at defect sinks. Cr and Cu show opposite behavior and are depleted at defect sinks. The stable configuration of some oversized solutes is neither interstitial nor substitutional; rather they occupy two adjacent lattice sites. The diffusion of these solutes proceeds by a novel mechanism, which has important implications for the nucleation and growth of complex oxide nanoparticles contained in oxide dispersion strengthened steels. Interstitial-mediated solute diffusion is negligible for all except the magnetic solutes (Cr, Mn, Co, and Ni). Our results are consistent across several antiferromagnetic states and surprising qualitative similarities with ferromagnetic (body-centered cubic) Fe were observed; this implies that our conclusions will be valid for paramagnetic iron.

  1. An interactive mapping tool for visualizing lacunarity of laser scanned point clouds

    Science.gov (United States)

    Kania, Adam; Székely, Balázs

    2016-04-01

    Lacunarity, a measure of the spatial distribution of the empty space in a certain model or real space over large spatial scales, is found to be a useful descriptive quantity in many fields using imagery, including, among others, geology, dentistry, neurology. Its application in ecology was suggested more than 20 years ago. The main problem of its application was the lack of appropriate high resolution data. Nowadays, full-waveform laser scanning, also known as FWF LiDAR, provides the tool for mapping the vegetation in unprecedented details and accuracy. Consequently, the lacunarity concept can be revitalized, in order to study the structure of the vegetation in this sense as well. Calculation of lacunarity, even if it is done in two dimensions (2D), is still has its problems: on one hand it is a number-crunching procedure, on the other hand, it produces 4D results: at each 3D point it returns a set of data that are function of scale. These data sets are difficult to visualize, to evaluate, and to compare. In order to solve this problem, an interactive mapping tool has been conceptualized that is designed to manipulate and visualize the data, lets the user set parameters for best visualization or comparison results. The system is able to load large amounts of data, visualize them as lacunarity curves, or map view as horizontal slices or in 3D point clouds coloured according to the user's choice. Lacunarity maps are presented as a series of (usually) horizontal profiles, e.g. rasters, which cells contain color-mapped values of selected lacunarity of the point cloud. As lacunarity is usually analysed in a series of successive windows sizes, the tool can show a series of rasters with sequentially animated lacunarity maps calculated for various window sizes. A very fast switching of colour schemes is possible to facilitate rapid visual feedback to better understand underlying data patterns exposed by lacunarity functions. In the comparison mode, two sites (or two areas

  2. Mechanical design of a pre-isolator for the CLIC final focusing magnets

    CERN Document Server

    Gaddi, A; Ramos, F; Siegrist, N

    2012-01-01

    Due to the very small vertical beam sizes, the final focusing elements at the future CLIC linear collider need to be stable against vibrations to below 0.15 nanometres at frequencies above about 4 Hz. One of the key elements in the strategy to achieve such a stable environment is a passive, heavy pre-isolator. In this report, the results from the dynamic finite element analyses of the proposed design for such a passive preisolator are summarized. Furthermore, the results from a low frequency, heavy mass passive vibration isolation test set-up used to validate the calculations are shown.

  3. Measurement of the Higgs decay to electroweak bosons at low and intermediate CLIC energies

    CERN Document Server

    AUTHOR|(SzGeCERN)471575; Milutinovic-Dumbelovic, Gordana; Pandurovic, Mila; Lukic, Strahinja

    2016-01-01

    In this paper a simulation of measurements of the Higgs boson decay to electroweak bosons in $e^+e^-$ collisions at CLIC is presented. Higgs boson production and subsequent $H\\rightarrow ZZ^\\ast$ and $H\\rightarrow WW^\\ast$ decay processes were simulated alongside the relevant background processes at 350 GeV and 1.4 TeV center-of-mass energy. Full detector simulation and event reconstruction were used under realistic beam conditions. The achievable statistical precision of the measured product of the Higgs production cross section and the branching ratio for the analysed decays has been determined.

  4. X-Band Crab Cavities for the CLIC Beam Delivery System

    Energy Technology Data Exchange (ETDEWEB)

    Burt, G.; Ambattu, P.K.; Dexter, A.C.; Abram, T.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Dolgashev, V.; Tantawi, S.; /SLAC; Jones, R.M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.

    2011-11-22

    The CLIC machine incorporates a 20 mrad crossing angle at the IP to aid the extraction of spent beams. In order to recover the luminosity lost through the crossing angle a crab cavity is proposed to rotate the bunches prior to collision. The crab cavity is chosen to have the same frequency as the main linac (11.9942 GHz) as a compromise between size, phase stability requirements and beam loading. It is proposed to use a HE11 mode travelling wave structure as the CLIC crab cavity in order to minimise beam loading and mode separation. The position of the crab cavity close to the final focus enhances the effect of transverse wake-fields so effective wake-field damping is required. A damped detuned structure is proposed to suppress and de-cohere the wake-field hence reducing their effect. Design considerations for the CLIC crab cavity will be discussed as well as the proposed high power testing of these structures at SLAC. Design of a crab cavity for CLIC is underway at the Cockcroft Institute in collaboration with SLAC. This effort draws on a large degree of synergy with the ILC crab cavity developed at the Cockcroft Institute and other deflecting structure development at SLAC. A study of phase and amplitude variations in the cavity suggests that the tolerances are very tight and require a 'beyond state of the art' LLRF control system. A study of cavity geometry and its effect on the cavity fields has been performed using Microwave studio. This study has suggested that for our cavity an iris radius between 4-5 mm is optimum with an iris thickness of 2-3 mm based on group velocity and peak fields. A study of the cavity wakefields show that the single bunch wakes are unlikely to be a problem but the short bunch spacing may cause the multi-bunch wakefields to be an issue. This will require some of the modes to be damped strongly so that the wake is damped significantly before any following bunch arrives. Various methods of damping have been investigated and

  5. El mundo en un clic: usabilidad y accesibilidad en la Web

    OpenAIRE

    Domènech, Luisa

    2004-01-01

    La filosofía de Internet es el acceso libre a la información, pero esta información se encuentra limitada espacialmente por dos vertientes, el navegador y el tamaño del monitor donde se visualiza la información. A la hora de construir las páginas Web para su visualización en Internet, los arquitectos de la información deberían cumplir una serie de requerimientos para que el visitante obtenga la información deseada en poco tiempo y con pocos clic de ratón.

  6. Production of excited electrons at TESLA and CLIC based $e\\gamma$ colliders

    CERN Document Server

    Aydin, Z Z; Kirca, Z

    2003-01-01

    We analyze the potential of TESLA and CLIC based electron-photon colliders to search for excited spin-1/2 electrons. The production of excited electrons in the resonance channel through the electron-photon collision and their subsequent decays to leptons and electroweak gauge bosons are investigated. We study in detail the three signal channels of excited electrons and the corresponding backgrounds through the reactions e gamma --> e gamma, e gamma --> eZ and e gamma --> nu W. Excited electrons can be discovered with the masses up to about 90% of the available collider energy.

  7. Z′ Resonance and Associated Zh Production at Future Higgs Boson Factory: ILC and CLIC

    OpenAIRE

    A. Gutiérrez-Rodríguez; Hernández-Ruíz, M. A.

    2015-01-01

    We study the prospects of the B-L model with an additional $Z'$ boson to be a Higgs boson factory at high-energy and high-luminosity linear electron positron colliders, such as the ILC and CLIC, through the Higgs-strahlung process $e^{+}e^{-}\\rightarrow (Z, Z') \\to Zh$, including both the resonant and non-resonant effects. We evaluate the total cross section of $Zh$ and we calculate the total number of events for integrated luminosities of 500-2000\\hspace{0.8mm}$fb^{-1}$ and center of mass en...

  8. Feed Forward Orbit Correction in the CLIC Ring to Main LINAC Transfer lines

    CERN Document Server

    Apsimon, R; Schulte, D; Uythoven, J

    2014-01-01

    The emittance growth in the betatron collimation system of the 27 km long transfer lines between the CLIC damping rings and the main LINAC depends strongly on the transverse orbit jitter. The resulting stability requirements of the damping ring extraction elements seem extremely difficult to achieve. Position and angle feed forward systems in these long transfer lines bring the specified parameters of the extraction elements within reach. The designs of the optics and feed forward hardware are presented together with tracking simulations of the systems.

  9. Fluka and thermo-mechanical studies for the CLIC main dump

    CERN Document Server

    Mereghetti, Alessio; Vlachoudis, Vasilis

    2011-01-01

    In order to best cope with the challenge of absorbing the multi-MW beam, a water beam dump at the end of the CLIC post-collision line has been proposed. The design of the dump for the Conceptual Design Report (CDR) was checked against with a set of FLUKA Monte Carlo simulations, for the estimation of the peak and total power absorbed by the water and the vessel. Fluence spectra of escaping particles and activation rates of radio-nuclides were computed as well. Finally, the thermal transient behavior of the water bath and a thermo-mechanical analysis of the preliminary design of the window were done.

  10. Interaction-Point Phase-Space Characterization using Single-Beam and Luminous-Region Measurements at PEP-II

    Energy Technology Data Exchange (ETDEWEB)

    Kozanecki, W; /Saclay; Bevan, A.J.; /Queen Mary, U. of London; Viaud, B.F.; /Montreal U.; Cai, Y.; Fisher, A.S.; O' Grady, C.; Lindquist, B.; Roodman, A.; J.M.Thompson, M.Weaver; /SLAC

    2008-09-09

    We present an extensive experimental characterization of the e{sup {+-}} phase space at the interaction point of the SLAC PEP-II B-Factory, that combines a detailed mapping of luminous-region observables using the BABAR detector, with stored-beam measurements by accelerator techniques.

  11. Study of point defects at low concentrations by internal friction measurement of their interaction with dislocations

    International Nuclear Information System (INIS)

    Different internal friction theories based on the presence of point defects at dislocations are compared with experimental results in irradiated metals and their conditions of validity are discussed. Then the experimental results obtained in irradiated copper on the creation of point defects at dislocations and subsequent annealing behaviour are compared with several theoretical models

  12. Investigating the Impact of Asp181 Point Mutations on Interactions between PTP1B and Phosphotyrosine Substrate

    Science.gov (United States)

    Liu, Mengyuan; Wang, Lushan; Sun, Xun; Zhao, Xian

    2014-05-01

    Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of insulin and leptin signaling, which suggests that it is an attractive therapeutic target in type II diabetes and obesity. The aim of this research is to explore residues which interact with phosphotyrosine substrate can be affected by D181 point mutations and lead to increased substrate binding. To achieve this goal, molecular dynamics simulations were performed on wild type (WT) and two mutated PTP1B/substrate complexes. The cross-correlation and principal component analyses show that point mutations can affect the motions of some residues in the active site of PTP1B. Moreover, the hydrogen bond and energy decomposition analyses indicate that apart from residue 181, point mutations have influence on the interactions of substrate with several residues in the active site of PTP1B.

  13. Development of modifications to the material point method for the simulation of thin membranes, compressible fluids, and their interactions

    Energy Technology Data Exchange (ETDEWEB)

    York, A.R. II [Sandia National Labs., Albuquerque, NM (United States). Engineering and Process Dept.

    1997-07-01

    The material point method (MPM) is an evolution of the particle in cell method where Lagrangian particles or material points are used to discretize the volume of a material. The particles carry properties such as mass, velocity, stress, and strain and move through a Eulerian or spatial mesh. The momentum equation is solved on the Eulerian mesh. Modifications to the material point method are developed that allow the simulation of thin membranes, compressible fluids, and their dynamic interactions. A single layer of material points through the thickness is used to represent a membrane. The constitutive equation for the membrane is applied in the local coordinate system of each material point. Validation problems are presented and numerical convergence is demonstrated. Fluid simulation is achieved by implementing a constitutive equation for a compressible, viscous, Newtonian fluid and by solution of the energy equation. The fluid formulation is validated by simulating a traveling shock wave in a compressible fluid. Interactions of the fluid and membrane are handled naturally with the method. The fluid and membrane communicate through the Eulerian grid on which forces are calculated due to the fluid and membrane stress states. Validation problems include simulating a projectile impacting an inflated airbag. In some impact simulations with the MPM, bodies may tend to stick together when separating. Several algorithms are proposed and tested that allow bodies to separate from each other after impact. In addition, several methods are investigated to determine the local coordinate system of a membrane material point without relying upon connectivity data.

  14. Using the Userʼs Point of View for Interaction on Mobile Devices

    OpenAIRE

    Francone, Jérémie; Nigay, Laurence

    2011-01-01

    We study interaction modalities for mobile devices (smartphones and tablets) that rely on a camera-based head tracking. This technique defines new possibilities for input and output interaction. For output, by computing the position of the device according to the user's head, it is for example possible to realistically control the viewpoint on a 3D scene (Head-Coupled Perspective, HCP). This technique improves the output interaction bandwidth by enhancing the depth perception and by allowing ...

  15. A CLIC Damping Wiggler Prototype at ANKA: Commissioning and Preparations for a Beam Dynamics Experimental Program

    CERN Document Server

    Bernhard, Axel; Casalbuoni, Sara; Ferracin, Paolo; Garcia Fajardo, Laura; Gerstl, Stefan; Gethmann, Julian; Grau, Andreas; Huttel, Erhard; Khrushchev, Sergey; Mezentsev, Nikolai; Müller, Anke-Susanne; Papaphilippou, Yannis; Saez de Jauregui, David; Schmickler, Hermann; Schoerling, Daniel; Shkaruba, Vitaliy; Smale, Nigel; Tsukanov, Valery; Zisopoulos, Panagiotis; Zolotarev, Konstantin

    2016-01-01

    In a collaboration between CERN, BINP and KIT a prototype of a superconducting damping wiggler for the CLIC damping rings has been installed at the ANKA synchrotron light source. On the one hand, the foreseen experimental program aims at validating the technical design of the wiggler, particularly the conduction cooling concept applied in its cryostat design, in a long-term study. On the other hand, the wiggler's influence on the beam dynamics particularly in the presence of collective effects is planned to be investigated. ANKA's low-alpha short-bunch operation mode will serve as a model system for these studies on collective effects. To simulate these effects and to make verifiable predictions an accurate model of the ANKA storage ring in low-alpha mode, including the insertion devices is under parallel development. This contribution reports on the first operational experience with the CLIC damping wiggler prototype in the ANKA storage ring and steps towards the planned advanced experimental program with th...

  16. CLIC Main Linac Beam-Loading Compensation by Drive Beam Phase Modulation

    CERN Document Server

    Corsini, R; Syratchev, I V

    1999-01-01

    The CLIC final focus momentum acceptance of ± 0.5 % limits the bunch-to-bunch energy variation in the main beam to less than ± 0.1 %, since the estimated single-bunch contribution is ± 0.4 %. On the other hand, a relatively high beam-loading of the main accelerating structures (about 16 %) is unavoidable in order to optimize the RF-to-beam efficiency. Therefore, a compensation method is needed to reduce the resulting bunch-to-bunch energy spread of the main beam. Up to now, it has been planned to obtain the RF pulse shape needed for compensation by means of a charge ramp in the drive beam pulse. On the other hand, the use of constant-current drive beam pulses would make the design and operation of the drive beam injector considerably simpler. In this paper we present a possible solution adapted to the CLIC two-beam scheme with constant-current pulses, based on phase modulation of the drive beam bunches.

  17. First Magnetic Tests of a Superconducting Damping Wiggler for the CLIC Damping Rings

    CERN Document Server

    Schoerling, D; Bernhard, A; Karppinen, M; Maccaferri, R; Peiffer, P; Rossmanith, R

    2010-01-01

    Each of the proposed CLIC electron and positron damping rings will be equipped with 76 wigglers. The length of each wiggler is 2 m, the period length lambda 40 to 50 mm, and the beam-stay-clear gap 13 mm. The minimum required mid-plane field B0 is 2.5 T, that can only be obtained with superconducting technologies. In order to demonstrate the feasibility of such a wiggler, a short model with a period length of 40mm was built and successfully tested at CERN. The measured mid-plane field was 2 T at 4.2K and 2.5 T at 1.9 K in the center of a 16mm gap. The currents were 730 and 910 A, respectively. To fulfill the field specification for the CLIC damping rings at 4.2 K it is planned to replace the Nb-Ti wire with a Nb3Sn wire.

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

    CERN Document Server

    Huopana, J

    2010-01-01

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

  19. Studies on high-precision machining and assembly of CLIC RF structures

    CERN Document Server

    Huopana, J; Riddone, G; Österberg, K

    2010-01-01

    The Compact Linear Collider (CLIC) is currently under development at CERN as a potential multi-TeV e+e– collider. The manufacturing and assembly tolerances for the required RF components are essential for the final efficiency and for the operation of CLIC. The proper function of an accelerating structure is sensitive to mechanical errors in the shape and the alignment of the accelerating cavity. The current tolerances are in the micron range. This raises challenges in the field of mechanical design and demands special manufacturing technologies and processes. Currently the mechanical design of the accelerating structures is based on a disk design. Alternatively, it is possible to create the accelerating assembly from quadrants, which has the potential to be favoured for the mass production due to simplicity and cost. In this case, the functional shape inside of the accelerating structure remains the same and a single assembly uses less parts. This paper focuses on the development work done in design and sim...

  20. Initial measurements on a prototype inductive adder for the CLIC kicker systems

    CERN Document Server

    Holma, Janne

    2013-01-01

    The CLIC study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings will produce, through synchrotron radiation, ultra-low emittance beam with high bunch charge. To avoid beam emittance increase, the damping ring kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the extraction kickers of the DRs are particularly demanding: the flattops of the pulses must be ±12.5 kV with a combined ripple and droop of not more than ±0.02 % (±2.5 V). An inductive adder is a very promising approach to meeting the specifications. To achieve ultra-flat pulses with a fast rise time the output impedance of the inductive adder needs to be well matched to the system impedance. The parasitic circuit elements of the inductive adder have a significant effect upon the output impedance and these values are very difficult to calculate accurately analytically. To predict these paramet...

  1. Fast Beam-ion Instabilities in CLIC Main Linac Vacuum Specifications

    CERN Document Server

    Oeftiger, Adrian

    2011-01-01

    Specifications for the vacuum pressure in the CLIC electron Main Linac are determined by the onset of the fast beam-ion instability (FBII). When the electron beam is accelerated in the Main Linac, it ionizes the residual gas in the chamber through scattering ionization. If the density of ions around the beam exceeds a certain threshold, a resonant motion between the electron beam and the ions can be excited. A two-stream instability appears and as a result the beam acquires a coherent motion, which can quickly lead to beam quality degradation or even complete loss. Thus, the vacuum pressure must be kept below this threshold to prevent the excitation of FBII. The CLIC Main Linac poses an additional challenge with respect to previous FBII situations, because the gas ionization does not solely occur via scattering. The submicrometric beam sizes lead to extremely high electric fields around the beam and therefore result in field ionization beyond a certain threshold. The residual gas in the corresponding volume a...

  2. Integration of the PHIN RF Gun into the CLIC Test Facility

    CERN Document Server

    Döbert, Steffen

    2006-01-01

    CERN is a collaborator within the European PHIN project, a joint research activity for Photo injectors within the CARE program. A deliverable of this project is an rf Gun equipped with high quantum efficiency Cs2Te cathodes and a laser to produce the nominal beam for the CLIC Test Facility (CTF3). The nominal beam for CTF3 has an average current of 3.5 A, 1.5 GHz bunch repetition frequency and a pulse length of 1.5 ìs (2332 bunches) with quite tight stability requirements. In addition a phase shift of 180 deg is needed after each train of 140 ns for the special CLIC combination scheme. This rf Gun will be tested at CERN in fall 2006 and shall be integrated as a new injector into the CTF3 linac, replacing the existing injector consisting of a thermionic gun and a subharmonic bunching system. The paper studies the optimal integration into the machine trying to optimize transverse and longitudinal phase space of the beam while respecting the numerous constraints of the existing accelerator. The presented scheme...

  3. A high phase advance damped and detuned structure for the main linacs of CLIC

    CERN Document Server

    Khan, Vasim; Jones, Roger M; Wuensch, Walter; Grudiev, A

    2010-01-01

    The main accelerating structures for the CLIC are designed to operate at an average accelerating gradient of 100 MV/m. The accelerating frequency has been optimised to 11.994 GHz with a phase advance of 2π/3 [1] of the main accelerating mode. The moderately damped and detuned structure (DDS) design [2-3] is being studied as an alternative to the strongly damped WDS design [1]. Both these designs are based on the nominal accelerating phase advance. Here we explore high phase advance (HPA) structures in which the group velocity of the rf fields is reduced compared to that of standard (2π/3) structures. The electrical breakdown strongly depends on the fundamental mode group velocity. Hence it is expected that electrical breakdown is less likely to occur in the HPA structures. We report on a study of both the fundamental and dipole modes in a CLIC_DDS_ HPA structure, designed to operate at 5π/6 phase advance per cell. Higher order dipole modes in both the standard and HPA structures are also studied.

  4. Measurements on Prototype Inductive Adders with Ultra-Flat-Top Output Pulses for CLIC DR Kickers

    CERN Document Server

    Holma, J; Belver-Aguilar, C

    2014-01-01

    The CLIC study is investigating the technical feasibility of an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. To avoid beam emittance increase, the DR kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the DR extraction kickers call for a 160 ns duration flat-top pulses of ±12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 % (±2.5 V). An inductive adder is a very promising approach to meeting the specifications because this topology allows the use of both passive and analogue modulation methods to adjust the output waveform. Recently, two five-layer, 3.5 kV, prototype inductive adders have been built at CERN. The first of these has been used to test the passive and active analogue modulation methods to compensate voltage droop and ripple of the output pulses. Pulse waveforms have been reco...

  5. Stabilization and Fine Positioning to the Nanometre Level of the CLIC Main Beam Quadrupoles

    CERN Document Server

    Artoos, K; Fernandez Carmona, P; Guinchard, M; Hauviller, C; Janssens, S; Kuzmin, A; Lackner, F; Leuxe, R; Slaathaug, A

    2010-01-01

    The CLIC main beam quadrupoles need to be stabilized to 1.5 nm integrated R.M.S. displacement at 1 Hz. The choice was made to apply active stabilization with piezoelectric actuators in a rigid support with flexural guides. The advantages of this choice are the robustness against external forces and the possibility to make fast incremental nanometre positioning of the magnet with the same actuators. The study and feasibility demonstration is made in several steps from a single degree of freedom system (s.d.o.f.) with a small mass, a s.d.o.f. with a large mass, leading to the demonstration including the smallest (type 1) and largest (type 4) CLIC main beam quadrupoles. The paper discusses the choices of the position and orientation of the actuators and the tailored rigidities of the flexural hinges in the multi degree of freedom system, and the corresponding MIMO control system. The compatibility with the magnet support and micrometre alignment system is essential. The status of the study and performed tests wi...

  6. CLIC main beam quadrupole active pre-alignment based on cam movers

    CERN Document Server

    Kemppinen, J; Leuxe, R; Mainaud Durand, H; Sandomierski, J; Sosin, M

    2012-01-01

    Compact Linear Collider (CLIC) is a study for a future 48 km long linear electron-positron collider in the multi TeV range. Its target luminosity can only be reached if the main beam quadrupoles (MB quads) are actively pre-aligned within 17 µm in sliding windows of 200 m with respect to a straight reference line. In addition to the positioning requirement, the pre-alignment system has to provide a rigid support for the nano-stabilization system to ensure that the first eigenfrequency is above 100 Hz. Re-adjustment based on cam movers was chosen for detailed studies to meet the stringent pre-alignment requirements. There are four different types of MB quads in CLIC. Their lengths and masses vary so that at least two types of cam movers have to be developed. The validation of the cams with less stringent space restrictions has proceeded to a test setup in 5 degrees of freedom (DOF). Prototypes of the more demanding, smaller cams have been manufactured and they are under tests in 1 DOF. This paper describes the...

  7. Measurement of sigma(ee->Hnunu)xBR(H->tautau) at CLIC @ 1.4 TeV

    CERN Document Server

    Münnich, A.

    2013-01-01

    This detector benchmark study evaluates the statistical precision with which the H -> tautau branching ratio times cross section can be measured at CLIC running at rout(s)= 1.4 TeV. Only the hadronic decays of taus are considered.

  8. Interactions between hairy rod anionic conjugated polyelectrolytes and nonionic alkyloxyethylene surfactants in aqueous solution: Observations from cloud point behaviour

    OpenAIRE

    Fonseca, Sofia M.; Eusébio, M. Ermelinda; Castro, Ricardo; Burrows, Hugh D.; Tapia, Maria José; Olsson, Ulf

    2007-01-01

    The effect of three anionic, hairy-rod fluorene based conjugated polyelectrolytes on the cloud points of the alkyloxyethylene surfactants C10E3, C12E4, C12E5, and C12E6 has been studied in aqueous solution. Although the association behaviour of these rigid polymers with surfactants is different from that of more flexible polyelectrolytes, both types of polymers are seen to increase the cloud points, probably as a consequence of associative interactions. The possible importance of Coulombic in...

  9. No Regularity Singularities Exist at Points of General Relativistic Shock Wave Interaction between Shocks from Different Characteristic Families

    CERN Document Server

    Reintjes, Moritz

    2015-01-01

    We give a constructive proof that coordinate transformations exist which raise the regularity of the gravitational metric tensor from $C^{0,1}$ to $C^{1,1}$ in a neighborhood of points of shock wave collision in General Relativity. The proof applies to collisions between shock waves coming from different characteristic families, in spherically symmetric spacetimes. Our result here implies that spacetime is locally inertial and corrects an error in our earlier RSPA-publication, which led us to the false conclusion that such coordinate transformations, which smooth the metric to $C^{1,1}$, cannot exist. Thus, our result implies that regularity singularities, (a type of mild singularity introduced in our RSPA-paper), do not exist at points of interacting shock waves from different families in spherically symmetric spacetimes. Our result generalizes Israel's celebrated 1966 paper to the case of such shock wave interactions but our proof strategy differs fundamentally from that used by Israel and is an extension o...

  10. Nonlinear fast magnetoacoustic wave interaction with 2D magnetic X-points in the ion cyclotron range of frequencies

    CERN Document Server

    Threlfall, J W; De Moortel, I; McClements, K G; Arber, T D

    2012-01-01

    Context. This paper investigates the role of the Hall term in the propagation and dissipation of waves which interact with 2D magnetic X-points and considers the effect of the Hall term on the nature of the resulting reconnection. Aims. The goal is to determine how the evolution of a nonlinear fast magnetoacoustic wave pulse, and the behaviour of the oscillatory reconnection which results from the interaction of the pulse with a line-tied 2D magnetic X-point, is affected by the Hall term in the generalised Ohm's law. Methods. A Lagrangian remap shock-capturing code (Lare2d) is used to study the evolution of an initial fast magnetoacoustic wave annulus for a range of values of the ion skin depth (di) in resistive Hall MHD. A magnetic null-point finding algorithm is also used to locate and track the evolution of the multiple null-points that are formed in the system. Results. In general, the fast wave is coupled to a shear wave and, for finite di, to whistler and ion cyclotron waves. Dispersive whistler effects...

  11. Quantum fluctuation theorem in an interacting setup: point contacts in fractional quantum Hall edge state devices

    OpenAIRE

    Komnik, A.; Saleur, H.

    2011-01-01

    We verify the validity of the Cohen-Gallavotti fluctuation theorem for the strongly correlated problem of charge transfer through an impurity in a chiral Luttinger liquid, which is realizable experimentally as a quantum point contact in a fractional quantum Hall edge state device. This is accomplished via the development of an analytical method to calculate the full counting statistics (FCS) of the problem in all the parameter regimes involving the temperature, the Hall voltage, and the gate ...

  12. Interaction between Speech and Gesture: Strategies for Pointing to Distant Objects

    OpenAIRE

    Pfeiffer, Thies; Efthimiou, Eleni; Kouroupetroglou, Georgios; Fotinea, Stavroula-Evita

    2012-01-01

    Referring to objects using multimodal deictic expressions is an important form of communication. This work addresses the question on how pragmatic factors affect content distribution between the modalities speech and gesture. This is done by analyzing a study on deictic pointing gestures to objects under two conditions: with and without speech. The relevant pragmatic factor was the distance to the referent object. As one main result two strategies were identified which were used by participan...

  13. SUSY Fits and their Implications for ILC and CLIC

    CERN Document Server

    Heinemeyer, S

    2016-01-01

    We review results from our frequentist analysis of the parameter space of the pMSSM10, in which the following 10 soft SUSY-breaking parameters are specified independently at the mean scalar top mass scale Msusy = \\sqrt{M_stop1 M_stop2}: the gaugino masses M_{1,2,3}, the 1st-and 2nd-generation squark masses M_squ1 = M_squ2, the third-generation squark mass M_squ3, a common slepton mass M_slep and a common trilinear mixing parameter A, the Higgs mixing parameter mu, the pseudoscalar Higgs mass M_A and tan beta, the ratio of the two Higgs vacuum expectation values. We implemented the LHC searches for strongly- and electroweakly-interacting sparticles and light stops, so as to confront the pMSSM10 parameter space with all relevant SUSY searches. In addition, our analysis includes Higgs mass and rate measurements, SUSY Higgs exclusion bounds, the measurements of \\bmm, other B-physics observables, electroweak precision observables, the cold dark matter density and the searches for spin-independent dark matter scatt...

  14. Influence of the vector interaction and an external magnetic field on the isentropes near the chiral critical end point

    CERN Document Server

    Costa, Pedro

    2016-01-01

    The location of the critical end point (CEP) and the isentropic trajectories in the QCD phase diagram are investigated. We use the (2+1) Nambu$-$Jona-Lasinio model with the Polyakov loop coupling for different scenarios, namely by imposing zero strange quark density, which is the case in the ultra relativistic heavy-ion collisions, and $\\beta$-equilibrium. The influence of strong magnetic fields and of the vector interaction on the isentropic trajectories around the CEP is discussed. It is shown that the vector interaction and the magnetic field, having opposite effects on the first-order transition, affect the isentropic trajectories differently: as the vector interaction increases, the first-order transition becomes weaker and the isentropes become smoother; when a strong magnetic field is considered, the first-order transition is strengthened and the isentropes are pushed to higher temperatures. No focusing of isentropes in region towards the CEP is seen.

  15. Low-energy hypernuclear spectra with microscopic particle-rotor model with relativistic point coupling hyperon-nucleon interaction

    CERN Document Server

    Mei, H; Yao, J M; Motoba, T

    2016-01-01

    We extend the microscopic particle-rotor model for hypernuclear low-lying states by including the derivative and tensor coupling terms in the point-coupling nucleon-$\\Lambda$ particle ($N\\Lambda$) interaction. Taking $^{13}_{~\\Lambda}$C as an example, we show that a good overall description for excitation spectra is achieved with four sets of effective $N\\Lambda$ interaction. We find that the $\\Lambda$ hyperon binding energy decreases monotonically with increasing the strengths of the high-order interaction terms. In particular, the tensor coupling term decreases the energy splitting between the first $1/2^-$ and $3/2^-$ states and increases the energy splitting between the first $3/2^+$ and $5/2^+$ states in $^{13}_{~\\Lambda}$C.

  16. Influence of the vector interaction and an external magnetic field on the isentropes near the chiral critical end point

    Science.gov (United States)

    Costa, Pedro

    2016-06-01

    The location of the critical end point (CEP) and the isentropic trajectories in the QCD phase diagram are investigated. We use the (2 +1 ) Nambu-Jona-Lasinio model with the Polyakov loop coupling for different scenarios, namely by imposing zero strange quark density, which is the case in the ultrarelativistic heavy ion collisions, and β equilibrium. The influence of strong magnetic fields and of the vector interaction on the isentropic trajectories around the CEP is discussed. It is shown that the vector interaction and the magnetic field, having opposite effects on the first-order transition, affect the isentropic trajectories differently: as the vector interaction increases, the first-order transition becomes weaker and the isentropes become smoother; when a strong magnetic field is considered, the first-order transition is strengthened and the isentropes are pushed to higher temperatures. No focusing of isentropes in region towards the CEP is seen.

  17. Beam Tests of a Prototype Stripline Beam Position Monitoring System for the Drive Beam of the CLIC Two-beam Module at CTF3

    CERN Document Server

    Benot-Morell, Alfonso; Nappa, Jean-Marc; Vilalte, Sebastien; Wendt, Manfred

    2016-01-01

    In collaboration with LAPP and IFIC, two units of a prototype stripline Beam Position Monitor (BPM) for the CLIC Drive Beam (DB), and its associated readout electronics have been successfully installed and tested in the Two-Beam-Module (TBM) at the CLIC Test Facility 3 (CTF3) at CERN. This paper gives a short overview of the BPM system and presents the performance measured under different Drive Beam configurations.

  18. Furry picture transition rates in the intense fields at a lepton collider interaction point

    CERN Document Server

    Hartin, Anthony

    2015-01-01

    The effect on particle physics processes by intense electromagnetic fields in the charge bunch collisions at future lepton colliders is considered. Since the charge bunch fields are tied to massive sources (the $e^{+}e^{-}$ charges), a reference frame is chosen in which the fields appear to be co-propagating. Solutions of the Dirac equation minimally coupled to the electromagnetic fields reasonably associated with two intense overlapping charge bunches are obtained and found to be a Volkov solution with respect to a null 4-vector whose 3-vector part lies in the common propagation direction. These solutions are used within the Furry interaction picture to calculate the beamstrahlung transition rate for electron radiation due to interaction with the electromagnetic fields of two colliding charge bunches. New analytic expressions are obtained and compared numerically with the beamstrahlung in the electromagnetic field of one charge bunch. The techniques developed will be applied to other collider physics process...

  19. Furry picture transition rates in the intense fields at a lepton collider interaction point

    Directory of Open Access Journals (Sweden)

    A. Hartin

    2015-04-01

    Full Text Available The effect on particle physics processes by intense electromagnetic fields in the charge bunch collisions at future lepton colliders is considered. Since the charge bunch fields are tied to massive sources (the e+e− charges, a reference frame is chosen in which the fields appear to be co-propagating. Solutions of the Dirac equation minimally coupled to the electromagnetic fields reasonably associated with two intense overlapping charge bunches are obtained and found to be a Volkov solution with respect to a null 4-vector whose 3-vector part lies in the common propagation direction. These solutions are used within the Furry interaction picture to calculate the beamstrahlung transition rate for electron radiation due to interaction with the electromagnetic fields of two colliding charge bunches. New analytic expressions are obtained and compared numerically with the beamstrahlung in the electromagnetic field of one charge bunch. The techniques developed will be applied to other collider physics processes in due course.

  20. An assessment of the moving point method for numerical calculation of fluid-structure interaction in water hammer

    International Nuclear Information System (INIS)

    The problem of providing an accurate numerical method for modelling fluid-structure interaction in practical water hammer calculations for power station pipe networks is addressed. The application of the moving point method to a problem representative of practical water hammer is presented. A suitable model including both liquid pressure waves and pipe wall tension waves if formulated as a set of partial differential equations with algebraic equations and boundary and initial conditions. The problem is non-dimensionalized, to identify key parameters, and a suitable linearized problem is constructed by omitting small terms. The problem is transformed to characteristic variables which are shown to be simply transported along the pipe without change of value. This motivates the choice of the moving point method. In the course of the work a program WHOMP (Water Hammer On Moving Points) was developed which exploits the moving point method. It is specific to the problem of a single pipe with thin elastic walls but the boundary and initial conditions permitted are sufficiently general that any reasonable physical problem for a single pipe can be addressed. Results of WHOMP for the model problem are compared with experimental and other numerical results including superficially those from a commercially available code FLUSTRIN. Some consideration of extending the moving point method to practical pipe networks is given. This includes the incorporation of bending and torsion waves in the pipe wall and incorporation of additional physics leading to significant non-linearity. (author)

  1. Interaction of High Flash Point Electrolytes and PE-Based Separators for Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Andreas Hofmann

    2015-08-01

    Full Text Available In this study, promising electrolytes for use in Li-ion batteries are studied in terms of interacting and wetting polyethylene (PE and particle-coated PE separators. The electrolytes are characterized according to their physicochemical properties, where the flow characteristics and the surface tension are of particular interest for electrolyte–separator interactions. The viscosity of the electrolytes is determined to be in a range of η = 4–400 mPa∙s and surface tension is finely graduated in a range of γL = 23.3–38.1 mN∙m−1. It is verified that the technique of drop shape analysis can only be used in a limited matter to prove the interaction, uptake and penetration of electrolytes by separators. Cell testing of Li|NMC half cells reveals that those cell results cannot be inevitably deduced from physicochemical electrolyte properties as well as contact angle analysis. On the other hand, techniques are more suitable which detect liquid penetration into the interior of the separator. It is expected that the results can help fundamental researchers as well as users of novel electrolytes in current-day Li-ion battery technologies for developing and using novel material combinations.

  2. Improving the Performance of Interactive TCP Applications using End-point Based and Network Level Techniques

    Directory of Open Access Journals (Sweden)

    Varun G Menon

    2012-04-01

    Full Text Available Recent measurement based studies reveal that most of the Internet connections are short in terms of the amount of traffic they carry, while a small fraction of the connections are carrying a largeportion of the traffic.. Most of these short flows are from interactive applications like telnet, gaming that use TCP protocol for connection establishment and data transfer. These short TCP flows suffer from severe response-time performance degradations when multiplexed with long-lived flows during times of network congestion. The reasons for this problem is that, in the absence of large number of packets the short flows are unable to get a detailed knowledge about the level of underlying network congestion and even a single packet loss forces long retransmission timeouts. Also as the numbers of packets are less they are not able to develop large congestion windows and thus unable to jumpstart the next data burst. Due to this, clients of interactive applications suffer from increased response time for data packets sent and they try to upgrade their short flows to long flows by sending dummy packets into the network even when they do not have any data to send. This behavior can lead to severe congestion in the network and causes harm to statistical multiplexing in the Internet. This paper aims at providing easy to implement techniques that can be used by the clients of interactive applications to get much better performance without causing any serious congestion in the network.

  3. Long-range interactions in the ozone molecule: spectroscopic and dynamical points of view

    CERN Document Server

    Lepers, Maxence; Dulieu, Olivier

    2012-01-01

    Using the multipolar expansion of the electrostatic energy, we have characterized the asymptotic interactions between an oxygen atom O$(^3P)$ and an oxygen molecule O$_2(^3\\Sigma_g^-)$, both in their electronic ground state. We have calculated the interaction energy induced by the permanent electric quadrupoles of O and O$_2$ and the van der Waals energy. On one hand we determined the 27 electronic potential energy surfaces including spin-orbit connected to the O$(^3P)$ + O$_2(^3\\Sigma_g^-)$ dissociation limit of the O--O$_2$ complex. On the other hand we computed the potential energy curves characterizing the interaction between O$(^3P)$ and a O$_2(^3\\Sigma_g^-)$ molecule in its lowest vibrational level and in a low rotational level. Such curves are found adiabatic to a good approximation, namely they are only weakly coupled to each other. These results represent a first step for modeling the spectroscopy of ozone bound levels close to the dissociation limit, as well as the low energy collisions between O an...

  4. Relativistic point dynamics general equations, constant proper masses, interactions between electric charges, variable proper masses, collisions

    CERN Document Server

    Arzeliès, Henri

    1972-01-01

    Relativistic Point Dynamics focuses on the principles of relativistic dynamics. The book first discusses fundamental equations. The impulse postulate and its consequences and the kinetic energy theorem are then explained. The text also touches on the transformation of main quantities and relativistic decomposition of force, and then discusses fields of force derivable from scalar potentials; fields of force derivable from a scalar potential and a vector potential; and equations of motion. Other concerns include equations for fields; transfer of the equations obtained by variational methods int

  5. Induced dipole-dipole interactions in light diffusion from point dipoles

    Science.gov (United States)

    Cherroret, Nicolas; Delande, Dominique; van Tiggelen, Bart A.

    2016-07-01

    We develop a perturbative treatment of induced dipole-dipole interactions in the diffusive transport of electromagnetic waves through disordered atomic clouds. The approach is exact at order 2 in the atomic density and accounts for the vector character of light. It is applied to the calculations of the electromagnetic energy stored in the atomic cloud, which modifies the energy transport velocity, and of the light scattering and transport mean free paths. Results are compared to those obtained from a purely scalar model for light.

  6. Multi-step lining-up correction of the CLIC trajectory

    CERN Document Server

    D'Amico, T E

    1999-01-01

    In the CLIC main linac it is very important to minimise the trajectory excursion and consequently the emittance dilution in order to obtain the required luminosity. Several algorithms have been proposed and lately the ballistic method has proved to be very effective. The trajectory correction method described hereafter retains the main advantages of the latter while adding some interesting features. It is based on the separation of the unknown variables like the quadrupole misalignments, the offset and slope of the injection straight line and the misalignments of the beam position monitors (BPM). This is achieved by referring the trajectory relatively to the injection line and not to the average pre-alignment line and by using two trajectories each corresponding to slightly different quadrupole strengths. A reference straight line is then derived onto which the beam is bent by a kick obtained by moving the first quadrupole. The other quadrupoles are then aligned on that line. The quality of the correction dep...

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

    CERN Document Server

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

    2011-01-01

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

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

    CERN Document Server

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

    2014-01-01

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

  9. High power operation with beam of a CLIC pets equipped with on/off mechanism

    CERN Document Server

    Syratchev, I; Dubrovskiy, A; Skowronski, P; Ruber, R

    2012-01-01

    One of the feasibility issues of the CLIC two-beam scheme, is the possibility of rapidly switching off the rf power production in an individual Power Extraction and Transfer Structures (PETS) in case of breakdowns, either in the PETS or one of the main beam accelerating structures. The proposed solution is to use a variable external reflector connected to the PETS. When activated, this scheme allows us to gradually manipulate the rf power transfer to the accelerating structure and to reduce the rf power production in the PETS itself by a factor of 4. Recently the first operation of the Two Beam Test Stand (TBTS) PETS equipped with an ON/OFF mechanism was performed in CTF3. In this paper we will present the results of the PETS operation when powered by the drive beam up to high peak power levels (>100 MW) and compare them to expectations.

  10. Experience on Fabrication and Assembly of the First CLIC Two-Beam Module Prototype

    CERN Document Server

    Gudkov, D; Riddone, G; Rossi, F; Lebet, S

    2013-01-01

    The CLIC two-beam module prototypes are intended to prove the design of all technical systems under the different operation modes. Two validation programs are currently under way and they foresee the construction of four prototype modules for mechanical tests without beam and three prototype modules for tests with RF and beam. The program without beam will show the capability of the technical solutions proposed to fulfil the stringent requirements on radio-frequency, supporting, pre-alignment, stabilization, vacuum and cooling systems. The engineering design was performed with the use of CAD/CAE software. Dedicated mock-ups of RF structures, with all mechanical interfaces and chosen technical solutions, are used for the tests and therefore reliable results are expected. The components were fabricated by applying different technologies and methods for manufacturing and joining. The first full-size prototype module was assembled in 2012. This paper is focused on the production process including the comparison o...

  11. Low-level feedback control for the phase regulation of CLIC Drive Beam Klystrons

    CERN Document Server

    AUTHOR|(SzGeCERN)752526

    2015-01-01

    The requirement of luminosity loss below 1% raises tight tolerances for the phase and power stability of the CLIC drive beam (DB) klystrons and consequently for the high voltage pulse ripple of the modulators. A low-level RF (LLRF) feedback system needs to be developed and combined with the modulator in order to guarantee the phase and amplitude tolerances. To this aim, three feedback control strategies were investigated, i) Proportional Integral (PI) controller, ii) Linear Quadratic Integral Regulator (LQI) and iii) Model Predictive Controller (MPC). The klystron, as well as the incident phase noise were modelled and used for the design and evaluation of the controllers. First simulation results are presented along with future steps and directions.

  12. Numerical Verification of the Power Transfer and Wakefield Coupling in the Clic Two-Beam Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Candel, Arno; Li, Z.; Ng, C.; Rawat, V.; Schussman, G.; Ko, K.; /SLAC; Syratchev, I.; Grudiev, A.; Wuensch, W.; /CERN

    2011-08-19

    The Compact Linear Collider (CLIC) provides a path to a multi-TeV accelerator to explore the energy frontier of High Energy Physics. Its two-beam accelerator (TBA) concept envisions complex 3D structures, which must be modeled to high accuracy so that simulation results can be directly used to prepare CAD drawings for machining. The required simulations include not only the fundamental mode properties of the accelerating structures but also the Power Extraction and Transfer Structure (PETS), as well as the coupling between the two systems. Time-domain simulations will be performed to understand pulse formation, wakefield damping, fundamental power transfer and wakefield coupling in these structures. Applying SLAC's parallel finite element code suite, these large-scale problems will be solved on some of the largest supercomputers available. The results will help to identify potential issues and provide new insights on the design, leading to further improvements on the novel two-beam accelerator scheme.

  13. Z′ Resonance and Associated Zh Production at Future Higgs Boson Factory: ILC and CLIC

    International Nuclear Information System (INIS)

    We study the prospects of the B-L model with an additional Z′ boson to be a Higgs boson factory at high-energy and high-luminosity linear electron positron colliders, such as the ILC and CLIC, through the Higgs-strahlung process e+e-→(Z,Z′)→Zh, including both the resonant and the nonresonant effects. We evaluate the total cross section of Zh and we calculate the total number of events for integrated luminosities of 500–2000 fb−1 and center of mass energies between 500 and 3000 GeV. We find that the total number of expected Zh events can reach 106, which is a very optimistic scenario and it would be possible to perform precision measurements for both Z′ and Higgs boson in future high-energy e+e- colliders experiments

  14. Z′ Resonance and Associated Zh Production at Future Higgs Boson Factory: ILC and CLIC

    Directory of Open Access Journals (Sweden)

    A. Gutiérrez-Rodríguez

    2015-01-01

    Full Text Available We study the prospects of the B-L model with an additional Z′ boson to be a Higgs boson factory at high-energy and high-luminosity linear electron positron colliders, such as the ILC and CLIC, through the Higgs-strahlung process e+e-→(Z,Z′→Zh, including both the resonant and the nonresonant effects. We evaluate the total cross section of Zh and we calculate the total number of events for integrated luminosities of 500–2000 fb−1 and center of mass energies between 500 and 3000 GeV. We find that the total number of expected Zh events can reach 106, which is a very optimistic scenario and it would be possible to perform precision measurements for both Z′ and Higgs boson in future high-energy e+e- colliders experiments.

  15. Initial study on the shape optimisation of the CLIC crab cavity

    CERN Document Server

    Ambattu, P K; Carter, R G; Dexter, A C; Jones, R M; McIntosh, P

    2008-01-01

    The compact linear collider (CLIC) requires a crab cavity to align bunches prior to collision. The bunch structure demands tight amplitude and phase tolerances of the RF fields inside the cavity, for the minimal luminosity loss. Beam loading effects require special attention as it is one potential sources of field errors in the cavity. In order to assist the amplitude and phase control, we propose a travelling wave (TW) structure with a high group velocity allowing rapid propagation of errors out of the system. Such a design makes the cavity structure significantly different from previous ones. This paper will look at the implications of this on other cavity parameters and the optimisation of the cavity geometry.

  16. High Power RF Induced Thermal Fatigue in the High Gradient CLIC Accelerating Structures

    CERN Document Server

    Arnau-Izquierdo, G; Heikkinen, S; Neupert, N; Wuensch, W

    2007-01-01

    The need for high accelerating gradients for the CLIC (Compact Linear Collider) imposes considerable constraints on the materials of the accelerating structures. The surfaces exposed to high pulsed RF (Radio Frequency) currents are subjected to cyclic thermal stresses possibly resulting in surface break up by fatigue. Various high strength alloys from the group of high conductivity copper alloys have been selected and have been tested in different states, with different surface treatments and in different stress ratios. Low to medium cycle fatigue data (up to 108 cycles) of fully compressive surface thermal stresses has been collected by means of a pulsed laser surface heating apparatus. The surface damage has been characterized by SEM observations and roughness measurements. High cycle fatigue data, up to 7x1010 cycles, of varying stress ratio has been collected in high frequency bulk fatigue tests using an ultrasonic apparatus. Up-to-date results from these experiments are presented.

  17. [Three patterns of interaction between soil and non-point source P-pollutants in agricultural watershed].

    Science.gov (United States)

    Wang, Xia-hui; Yin, Cheng-qing; Yan, Xiao; Shan, Bao-qing; Wang, Wei-dong

    2004-07-01

    Typical agricultural watershed was selected to study the interactions between soil matrix and non-point source P-pollutants in surface runoff under simulative conditions. The soil samples were taken in different spatial locations in this watershed and were under different degree of human disturbance. The results showed that the interactions between different soil matrix and phosphorus could be divided into three patterns:retention, release and combination of retention and release. Soil of retention pattern has strong adsorption capacity of phosphate and will retain phosphorus from polluted runoff. Soil of release pattern has significant desorption capacity of phosphate and will release phosphorus to the runoff. Soil of retention and release combination pattern will retain or release phosphorus according to the phosphate concentration in the polluted runoff. These results showed that soil matrix in different spatial locations in the agricultural watershed have different ecological functions and environmental values under the processing of natural conditions and human disturbance. From the view of occurrence of non-point source pollution, these soils could become the sink of pollutants as well as the source of pollutants. Under some conditions, there has a conversion between sink and source of them. These results are valuable for control of non-point source pollution on watershed level, identification of key source area of pollutants and improvement of efficiency of control measures.

  18. Physics potential of the BR(H →WW∗) measurement at a √s=350 GeV and √s=1.4 TeV CLIC collider

    CERN Document Server

    Pandurovic, Mila

    2016-01-01

    Precision measurements of the number of properties of the Higgs boson, like invariant mass and couplings to the Standard Model particles, represent one of the key measurements of the CLIC physic program. The CLIC energy staging scenario allows to perform these meas- urements using different Higgs production channels. The Higgs decay to a WW pair, which is analysed at two CLIC energy stages, plays an important role in this program, as it gives access to the relative Higgs couplings to the vector bosons and to the total Higgs decay width. The studies presented here are part of an ongoing effort to investigate the full physics potential of the CLIC collider.

  19. Complaints as starting point for vicious cycles in customer-employee-interactions

    Directory of Open Access Journals (Sweden)

    Eva eTraut-Mattausch

    2015-10-01

    Full Text Available A ring-model of vicious cycles in customer-employee-interaction is proposed: Service employees perceive complaints as a threat to their self-esteem resulting in defense responses such as an increased need for cognitive closure, a devaluation of the customer and their information and degrading service behavior. Confronted with such degrading service behavior, customers react defensively as well, by devaluing the employee for example with regard to his/her competence and by reducing repurchase and positive word-of-mouth. Three studies investigated each link in this ring-model. In study 1, participants were confronted with an aggressive or neutral customer complaint. Results show that motivated closed-mindedness (one aspect of the need for cognitive closure increases after an aggressive complaint leading to a devaluation of the customer and their information, and in turn to a degrading service reaction. In study 2, participants were confronted with a degrading or favorable service reaction. Results show that they devaluate the employees’ competence after receiving a degrading service reaction and thus reduce their intention to repurchase. In study 3, we finally examined our predictions investigating real customer-employee-interactions: We analyzed data from an evaluation study in which mystery callers tested the service hotline of an airline. Results show that the employees’ competence is devaluated after degrading behavior and thus reduces positive word-of-mouth.

  20. Interaction of Magnetic Field and Nonlinear Convection in the Stagnation Point Flow over a Shrinking Sheet

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar

    2016-01-01

    Full Text Available The steady two-dimensional boundary layer stagnation point flow due to a shrinking sheet is analyzed. The combined effects of magnetic field and nonlinear convection are taken into account. The governing equations for the flow are modeled and then simplified using the similarity transformation and boundary layer approach. The numerical solution of the reduced equations is obtained by the second-order finite difference scheme also known as Keller box method. The influence of the pertinent parameters of the problem on velocity and temperature profiles, skin friction, and sheet temperature gradient are presented through the graphs and tables and discussed. The magnetic field and nonlinear convection parameters significantly enhance the solution range.

  1. Atlas of point contact spectra of electron-phonon interactions in metals

    CERN Document Server

    Khotkevich, A V

    1995-01-01

    The characteristics of electrical contacts have long attracted the attention of researchers since these contacts are used in every electrical and electronic device. Earlier studies generally considered electrical contacts of large dimensions, having regions of current concentration with diameters substantially larger than the characteristic dimensions of the material: the interatomic distance, the mean free path for electrons, the coherence length in the superconducting state, etc. [110]. The development of microelectronics presented to scientists and engineers the task of studying the characteristics of electrical contacts with ultra-small dimensions. Characteristics of point contacts such as mechanical stability under continuous current loads, the magnitudes of electrical fluctuations, inherent sensitivity in radio devices and nonlinear characteristics in connection with electromagnetic radiation can not be understood and altered in the required way without knowledge of the physical processes occurring in c...

  2. Peridotite-melt interaction: A key point for the destruction of cratonic lithospheric mantle

    Institute of Scientific and Technical Information of China (English)

    ZHANG HongFu

    2009-01-01

    This paper presents an overview of recent studies dealing with different ages of mantle peridotitic xenoliths and xenocrysts from the North China Craton, with aim to provide new ideas for further study on the destruction of the North China Craton. Re-Os isotopic studies suggest that the lithospheric mantle of the North China Craton is of Archean age prior to its thinning. The key reason why such a low density and highly refractory Archean lithospheric mantle would be thinned is changes in composition, thermal regime, and physical properties of the lithospheric mantle due to interaction of peridotites with melts of different origins. Inward subducUon of circum craton plates and collision with the North China Craton provided not only the driving force for the destruction of the craton, but also continuous melts derived from partial melting of subducted continental or oceanic crustal materials that resulted in the compositional change of the lithospheric mantle. Regional thermal anomaly at ca. 120 Ma led to the melting of highly modified iithospheric mantle. At the same time or subsequently lithospheric extension and asthenospheric upwelling further reinforced the melting and thinning of the lithospheric mantle. Therefore, the destruction and thinning of the North China Craton is a combined result of peridotite-melt interaction (addition of volatile), enhanced regional thermal anomaly (temperature increase) and lithospheric extension (decompression). Such a complex geological process finally produced a "mixed" lithospheric mantle of highly chemical heterogeneity during the Mesozoic and Cenozoic. It also resulted in significant difference in the composition of mantle peridotitic xenoliths between different regions and times.

  3. Stellar weak interaction rates and shape coexistence for {sup 68}Se and {sup 72}Kr waiting points

    Energy Technology Data Exchange (ETDEWEB)

    Petrovici, A.; Andrei, O. [National Institute for Physics and Nuclear Engineering, Bucharest (Romania)

    2015-10-15

    Beyond-mean-field results on stellar beta-decay and continuum electron capture rates for the rp-process waiting point nuclei {sup 68}Se and {sup 72}Kr at densities ρY{sub e} = 10{sup 4}-10{sup 7} mol/cm{sup 3} and temperatures T = 10{sup 8}-10{sup 10} K are presented. The structure of the even-even parent and odd-odd daughter nuclei dominated by shape coexistence and mixing is self-consistently described within the complex Excited Vampir model using realistic effective interactions in rather large model spaces. The influence of the shape mixing in the structure of the low-lying parent states as well as in the independently calculated daughter states on the stellar weak interaction rates is discussed. (orig.)

  4. Interaction of a Magnet and a Point Charge: Unrecognized Internal Electromagnetic Momentum Eliminates the Myth of Hidden Mechanical Momentum

    CERN Document Server

    Boyer, Timothy H

    2014-01-01

    A model calculation using the Darwin Lagrangian is carried out for a magnet consisting of two current-carrying charges constrained by centripetal forces to move in a circular path in the presence of the electric field from a distant external point charge. In the limit that the magnet's two charges are non-interacting, the calculation recovers the only valid calculation for hidden mechanical momentum. However, if the magnet's charges are mutually interacting, then there is internal electromagnetic linear momentum associated with the perturbed magnet's electrostatic charge distribution and the motion of the magnet's charges. This internal electromagnetic momentum does not seem to be recognized as distinct from the familiar external electromagnetic momentum associated with the electric field of the external charge and the magnetic field of the unperturbed magnet. In the multiparticle limit, the hidden mechanical momentum becomes negligible while the internal electromagnetic momentum provides the compensating lin...

  5. Design of the 15 GHz BPM test bench for the CLIC test facility to perform precise stretchedwire RF measurements

    CERN Document Server

    Silvia Zorzetti, Silvia; Galindo Muño, Natalia; Wendt, Manfred

    2015-01-01

    The Compact Linear Collider (CLIC) requires a low emittance beam transport and preservation, thus a precise control of the beam orbit along up to 50 km of the accelerator components in the sub-m regime is required. Within the PACMAN3 (Particle Accelerator Components Metrology and Alignment to the Nanometer Scale) PhD training action a study with the objective of pre-aligning the electrical centre of a 15 GHz cavity beam position monitor (BPM) to the magnetic centre of the main beam quadrupole is initiated. Of particular importance is the design of a specific test bench to study the stretched-wire setup for the CLIC Test Facility (CTF3) BPM, focusing on the aspects of microwave signal excitation, transmission and impedance-matching, as well as the mechanical setup and reproducibility of the measurement method.

  6. Conséquences des perturbations de la gravité sur l'alignement du CLIC

    CERN Document Server

    Becker, F

    1999-01-01

    For the CLIC alignment, the accuracy required for the definition of the geometrical references entails the evaluation of the effects of the Earth's gravity field's disturbances. The distortions of the WPS wires, of the water in the hydrostatic levelling network and of the ground resulting from the Moon and the Sun's attractions and from the neighbouring masses are therefore estimated. Solutions are suggested for the distortions important enough to have to be taken into account.

  7. Sources, potentials and fields in Lorenz and Coulomb gauge: Cancellation of instantaneous interactions for moving point charges

    International Nuclear Information System (INIS)

    We investigate the coupling of the electromagnetic sources (charge and current densities) to the scalar and vector potentials in classical electrodynamics, using Green function techniques. As is well known, the scalar potential shows an action-at-a-distance behavior in Coulomb gauge. The conundrum generated by the instantaneous interaction has intrigued physicists for a long time. Starting from the differential equations that couple the sources to the potentials, we here show in a concise derivation, using the retarded Green function, how the instantaneous interaction cancels in the calculation of the electric field. The time derivative of a specific additional term in the vector potential, present only in Coulomb gauge, yields a supplementary contribution to the electric field which cancels the gradient of the instantaneous Coulomb gauge scalar potential, as required by gauge invariance. This completely eliminates the contribution of the instantaneous interaction from the electric field. It turns out that a careful formulation of the retarded Green function, inspired by field theory, is required in order to correctly treat boundary terms in partial integrations. Finally, compact integral representations are derived for the Liénard–Wiechert potentials (scalar and vector) in Coulomb gauge which manifestly contain two compensating action-at-a-distance terms. - Highlights: ► We investigate action-at-a-distance effects in electrodynamics in detail. ► We calculate the instantaneous interactions for scalar and vector potentials. ► The cancellation mechanism involves the retarded Green function. ► The mechanism is confirmed on the example of moving point charges. ► The Green function has to be treated with care for nontrivial boundary terms.

  8. Influence of the inverse magnetic catalysis and the vector interaction in the location of the critical end point

    CERN Document Server

    Costa, Pedro; Menezes, Débora P; Moreira, João; Providência, Constança

    2015-01-01

    The effect of a strong magnetic field on the location of the critical end point (CEP) in the QCD phase diagram is discussed under different scenarios. In particular, we consider the contribution of the vector interaction and take into account the inverse magnetic catalysis obtained in lattice QCD calculations at zero chemical potential. The discussion is realized within the (2+1) Polyakov--Nambu--Jona-Lasinio model. It is shown that the vector interaction and the magnetic field have opposite competing effects, and that the winning effect depends strongly on the intensity of the magnetic field. The inverse magnetic catalysis at zero chemical potential has two distinct effects for magnetic fields above $\\gtrsim 0.3$ GeV$^2$: it shifts the CEP to lower chemical potentials, hinders the increase of the CEP temperature and prevents a too large increase of the baryonic density at the CEP. For fields $eB<0.1$ GeV$^2$ the competing effects between the vector contribution and the magnetic field can move the CEP to r...

  9. Energy Deposition and DPA in the Superconducting Links for the HILUMI LHC Project at the LHC Interaction Points

    CERN Document Server

    AUTHOR|(CDS)2092158; Broggi, Francesco; Santini, C; Ballarino, Amalia; Cerutti, Francesco; Esposito, Luigi Salvatore

    2015-01-01

    In the framework of the upgrade of the LHC machine, the powering of the LHC magnets foresees the removal of the power converters and distribution feedboxes from the tunnel and its location at the surface[1]. The Magnesium Diboride (MgB2) connecting lines in the tunnel will be exposed to the debris from 7+7 TeV p-p interaction. The Superconducting (SC) Links will arrive from the surface to the tunnel near the separation dipole, at about 80 m from the Interaction Point at IP1 and IP5. The Connection Box (where the cables of the SC Links are connected to the NbTi bus bar) will be close to the beam pipe. The debris and its effect on the MgB2 SC links in the connection box (energy deposition and displacement per atom) are presented. The effect of thermal neutrons on the Boron consumption and the contribution of the lithium nucleus and the alpha particle on the DPA are evaluated. The results are normalized to an integrated luminosity of 3000 fb-1, value that represents the LHC High Luminosity lifetime. The dose de...

  10. Development and Validation of a Multipoint Based Laser Alignment System for CLIC

    CERN Document Server

    Stern, G; Lackner, F; Mainaud-Durand, H; Piedigrossi, D; Sandomierski, J; Sosin, M; Geiger, A; Guillaume, S

    2013-01-01

    Alignment is one of the major challenges within CLIC study, since all accelerator components have to be aligned with accuracy up to 10 μm over sliding windows of 200 m. So far, the straight line reference concept has been based on stretched wires coupled with Wire Positioning Sensors. This concept should be validated through inter-comparison with an alternative solution. This paper proposes an alternative concept where laser beam acts as straight line reference and optical shutters coupled with cameras visualise the beam. The principle was first validated by a series of tests using low-cost components. Yet, in order to further decrease measurement uncertainty in this validation step, a high-precision automatised micrometric table and reference targets have been added to the setup. The paper presents the results obtained with this new equipment, in terms of measurement precision. In addition, the paper gives an overview of first tests done at long distance (up to 53 m), having emphasis on beam divergence

  11. High Frequency Effects of Impedances and Coatings in the CLIC Damping Rings

    CERN Document Server

    Koukovini Platia, Eirini; Rumolo, G

    The Compact Linear Collider (CLIC) is a 3 TeV eÅe¡ machine, currently under design at CERN, that targets to explore the terascale particle physics regime. The experiment requires a high luminosity of 2£1034 cm2 s¡1, which can be achieved with ultra low emittances delivered from the Damping Rings (DRs) complex. The high bunch brightness of the DRs gives rise to several collective effects that can limit the machine performance. Impedance studies during the design stage of the DR are of great importance to ensure safe operation under nominal parameters. As a first step, the transverse impedance model of the DRis built, accounting for the wholemachine. Beam dynamics simulations are performedwith HEADTAIL to investigate the effect on beam dynamics. For the correct impedancemodeling of the machine elements, knowledge of the material properties is essential up to hundreds of GHz, where the bunch spectrum extends. Specifically, Non Evaporable Getter (NEG) is a commonly used coating for good vacuumbut its properti...

  12. A Trajectory Correction based on Multi-Step Lining-up for the CLIC Main Linac

    CERN Document Server

    D'Amico, T E

    1999-01-01

    In the CLIC main linac it is very important to minimise the trajectory excursion and consequently the emittance dilution in order to obtain the required luminosity. Several algorithms have been proposed and lately the ballistic method has proved to be very effective. The trajectory method described in this Note retains the main advantages of the latter while adding some interesting features. It is based on the separation of the unknown variables like the quadrupole misalignments, the offset and slope of the injection straight line and the misalignments of the beam position monitors (BPM). This is achieved by referring the trajectory relatively to the injection line and not to the average pre-alignment line and by using two trajectories each corresponding to slightly different quadrupole strengths. A reference straight line is then derived onto which the beam is bent by a kick obtained by moving the first quadrupole. The other quadrupoles are then aligned on that line. The quality of the correction depends mai...

  13. A Gas-Jet Profile Monitor for the CLIC Drive Beam

    CERN Document Server

    Jeff, A; Lefevre, T; Tzoganis, V; Welsch, C P

    2013-01-01

    The Compact Linear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 1015 electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. Profile monitors using gas ionisation or fluorescence have been used at a number of accelerators. Typically, extra gas must be injected at the monitor and the rise in pressure spreads for some distance down the beam pipe. In contrast, a gas jet can be fired across the beam into a receiving chamber, with little gas escaping into the rest of the beam pipe. In addition, a gas jet shaped into a thin plane can be used like a screen on which the beam crosssectionis imaged. In this paper we present some arrangements for the generation of such a jet. In ...

  14. Instrumentation for Longitudinal Beam Gymnastics in FEL's and at the CLIC Test Facility 3

    CERN Document Server

    Lefèvre, T; Bravin, E; Burger, S; Corsini, R; Döbert, S; Soby, L; Tecker, F A; Urschutz, P; Welsch, C P; Alesini, D; Biscari, C; Buonomo, B; Coiro, O; Ghigo, A; Marcellini, F; Preger, B; Dabrowski, A; Velasco, M; Craievich, P; Ferianis, M; Veronese, M; Ferrari, A

    2008-01-01

    Built at CERN by an international collaboration, the CLIC Test Facility 3 (CTF3) aims at demonstrating the feasibility of a high luminosity 3 TeV e+-e- collider by the year 2010. One of the main issues to be demonstrated is the generation of a high average current (30 A) high frequency (12 GHz) bunched beam by means of RF manipulation. At the same time, Free Electron Lasers (FEL) are developed in several places all over the world with the aim of providing high brilliance photon sources. These machines rely on the production of high peak current electron bunches. The required performances put high demands on the diagnostic equipment and innovative longitudinal monitors have been developed during the past years. This paper gives an overview of the longitudinal instrumentation developed at ELETTRA and CTF3, where a special effort was made in order to implement at the same time non-intercepting devices for online monitoring, and destructive diagnostics which have the advantage of providing more detailed informati...

  15. Design of a new UHV all-metal joint for CLIC

    CERN Document Server

    Lutkiewicz, P; Rathjen, Ch

    2009-01-01

    All-metal joints are widely used in the vacuum systems of particle accelerators. The most common ConFlat® design consists of a flat soft copper gasket captured between two stainless steel flanges with sharp edges (knives). The gasket is plastically deformed and a high contact pressure develops around knives to obtain leak tightness. For large accelerators, a high reliability and a cost-optimized design are required. A smooth internal transition between flanges is needed for the RF waveguides of the compact linear collider (CLIC), with limited deformation of the inner part of the gasket. We present the study of a flange meeting these requirements. First the finite element analysis (FEA) of the Stanford linear accelerator center (SLAC) X-band all-metal joint, which has a similar specification, is shown. Some drawbacks, such as non-homogeneous sealing properties, are highlighted. Then, a new joint design is described. FEA results are presented and are compared with experimental measurements carried out on proto...

  16. Optimum frequency and gradient for the CLIC main linac accelerating structure

    CERN Document Server

    Grudiev, A; Wuensch, Walter

    2006-01-01

    A novel procedure for the optimization of CLIC main linac parameters including operating frequency and the accelerating gradient is presented. The optimization procedure takes into account both beam dynamics and high power rf constraints. Beam dynamics constraints are given by emittance growth due to short- and long-range transverse wakefields. RF constraints are given by rf breakdown and pulsed surface heating limitations of the accelerating structure. Interpolation of beam and structure parameters in a wide range allows hundreds of millions of accelerating structures to be analyzed to find the structure with the highest ratio of luminosity to main linac input power, which is used as the figure of merit. The frequency and gradient have been varied in the ranges 12-30 GHz and 90-150 MV/m respectively. It is shown that the optimum frequency lies in the range from 16 to 20 GHz depending on the accelerating gradient and that the optimum gradient is below 100 MV/m. Based on our current understanding of the constr...

  17. Studies of Cs3Sb cathodes for the CLIC drive beam photo injector option

    CERN Document Server

    Martini, Irene; Doebert, Steffen; Fedosseev, Valentine; Hessler, Christoph; Martyanov, Mikhail

    2013-01-01

    Within the CLIC (Compact Linear Collider) project, feasibility studies of a photo injector option for the drive beam as an alternative to its baseline design using a thermionic electron gun are on-going. This R&D program covers both the laser and the photocathode side. Whereas the available laser pulse energy in ultra-violet (UV) is currently limited by the optical defects in the 4thharmonics frequency conversion crystal induced by the0.14 ms long pulse trains, recent measurements of Cs3Sbphotocathodes sensitive to green light showed their potential to overcome this limitation. Moreover, using visible laser beams leads to better stability of produced electron bunches and one can take advantages of the availability of higher quality optics. The studied Cs3Sbphotocathodes have been produced in the CERN photo emission laboratory using the co-deposition technique and tested in a DC gun set-up. The analysis of data acquired during the cathode production process will be presented in this paper, as well as the r...

  18. Physics performances for Z' searches at 3 TeV and 1.5 TeV CLIC

    CERN Document Server

    Blaising, Jean-Jacques

    2012-01-01

    Extra neutral gauge bosons (Z') are predicted in many extensions of the Standard Model (SM). In the minimal anomaly-free Z' model (AFZ'), the phenomenology is controlled by only three parameters beyond the SM ones, the Z' mass and two effective coupling constants g'_Y and g'_{BL}. We study the Z' 5-sigma discovery potential in e+e- collisions at 1.4 and 3 TeV CLIC. Assuming LHC discovers a Z' of 5 TeV mass, the expected accuracies on the Z'mu+mu- couplings are presented. We discuss also the requirements on detector performance and beam polarization.

  19. Analysis of the behaviour of the CLIC_SiD iron return yoke during a seismic event

    CERN Document Server

    Duarte Ramos, F.

    2012-01-01

    The iron return yoke of the CLIC SiD detector concept is composed of three barrel rings and two endcap discs which, during a seismic event, are subjected to horizontal and vertical accelerations that can result in both a mechanical failure of internal structural elements and high deformations which can lead to unwanted collisions with other internal or external detector elements, as well as the walls of the experimental cavern. This report presents the results from the analysis of the return yoke barrel rings and endcaps under a seismic event load case.

  20. Study of the hybrid controller electronics for the nano-stabilization of mechanical vibrations of CLIC quadrupoles

    CERN Document Server

    Fernandez Carmona, P; Collette, C; Esposito, M; Guinchard, M; Janssens, S; Kuzmin, A; Moron Ballester, R

    2011-01-01

    In order to achieve the required levels of luminosity in the CLIC linear collider, mechanical stabilization of quadrupoles to the nanometre level is required. The paper describes a design of hybrid electronics combining an analogue controller and digital communication with the main machine controller. The choice of local analogue control ensures the required low latency while still keeping sufficiently low noise level. Furthermore, it reduces the power consumption, rack space and cost. Sensitivity to radiation single events upsets is reduced compared to a digital controller. The digital part is required for fine tuning and real time monitoring via digitization of critical parameters.

  1. Sensitivity on the Dipole Moments of the τ-Neutrino at e+e- Colliders: ILC and CLIC

    Directory of Open Access Journals (Sweden)

    A. Gutiérrez-Rodríguez

    2014-01-01

    Full Text Available We study the sensitivity on the anomalous magnetic and electric dipole moments of the τ-neutrino at a high-energy and high-luminosity linear electron positron collider, such as the ILC or CLIC, through the reaction e+e-→νν̅γ. We obtain limits on the dipole moments at the future linear colliders energies. For integrated luminosities of 500 fb−1 and center of mass energies between 0.5 and 3 TeV, the future e+e- colliders may improve the existing limits by two or three orders of magnitude.

  2. The power of the three-point correlation function: disentangling interacting dark energy cosmologies and estimating the halo bias

    CERN Document Server

    Moresco, Michele; Baldi, Marco; Moscardini, Lauro; Cimatti, Andrea

    2013-01-01

    We investigate the possibility of constraining coupled dark energy (cDE) cosmologies using the three-point correlation function (3PCF). Making use of the CoDECS N-body simulations, we study the statistical properties of cold dark matter (CDM) haloes for a variety of models, including a fiducial $\\Lambda$CDM scenario and five models in which dark energy (DE) and CDM mutually interact. We measure both the halo 3PCF, $\\zeta(\\theta)$, and the reduced 3PCF, $Q(\\theta)$, at different scales ($2

  3. Onset of deconfinement and search for the critical point of strongly interacting matter at CERN SPS energies

    CERN Document Server

    Rybczyński, Maciej

    2014-01-01

    The exploration of the QCD phase diagram particularly the search for a phase transition from hadronic to partonic degrees of freedom and possibly a critical endpoint, is one of the most challenging tasks in present heavy-ion physics. As observed by the NA49 experiment, several hadronic observables in central Pb+Pb collisions at the CERN SPS show qualitative changes in their energy dependence. These features are not observed in elementary interactions and indi- cate the onset of a phase transition in the SPS energy range. The existence of a critical point is expected to result in the increase of event-by-event fluctuations of various hadronic observables provided that the freeze-out of the measured hadrons occurs close to its location in the phase di- agram and the evolution of the final hadron phase does not erase the fluctuations signals. Further information about the existence and nature of a phase transition in the SPS energy range can be gained from the studies of event-by-event fluctuations of final stat...

  4. PACMAN study of FSI and micro-triangulation for the pre-alignment of CLIC

    CERN Document Server

    Kamugasa, William Solomon

    2015-01-01

    The alignment precision of linear colliders is extremely demanding owing to the very narrow beam size at the interaction point. Unlike circular colliders, particles in linear colliders have only one chance to collide and are hence tightly focused to maximise the number of interactions per collision. The PACMAN* project is dedicated to study the integration of both fiducialization and alignment of the components on a common support. FSI (Frequency Scanning Interferometry) and Micro-triangulation will contribute to this goal. FSI realized by Etalon AG’s Absolute Multiline system and Micro-triangulation implemented by QDaedalus system developed at ETH Zurich offer precision of 0.5 μm/m and 2.4 μm/m respectively. However, these systems need to be improved in order to provide the necessary geometric information via distance measurements (multilateration) and angle measurements (triangulation), respectively. The paper describes the current status and the future developments of Absolute Multiline and QDaedalus, ...

  5. Analysis of test-beam data with hybrid pixel detector prototypes for the Compact LInear Collider (CLIC) vertex detectors

    CERN Document Server

    Pequegnot, Anne-Laure

    2013-01-01

    The LHC is currently the most powerful accelerator in the world. This proton-proton collider is now stoppped to increase significantly its luminosity and energy, which would provide a larger discovery potential in 2014 and beyond. A high-energy $e^{+}e^{-}$ collider, such as CLIC, is an option to complement and to extend the LHC physics programme. Indeed, a lepton collider gives access to additional physics processes, beyond those observable at the LHC, and therefore provides new discovery potential. It can also provide complementary and/or more precise information about new physics uncovered at the LHC. Many essential features of a detector are required to deliver the full physics potential of this CLIC machine. In this present report, I present my work on the vertex detector R\\&D for this future linear collider, which aims at developping highly granular and ultra-thin position sensitive detection devices with very low power consumption and fast time-stamping capability. We tested here thin silicon pixel...

  6. Development of Stripline Kickers for Low Emittance Rings: Application to the Beam Extraction Kicker for CLIC Damping Rings

    CERN Document Server

    AUTHOR|(SzGeCERN)728476; Toral Fernandez, Fernando

    In the framework of the design study of Future Linear Colliders, the Compact Linear Collider (CLIC) aims for electron-positron collisions with high luminosity at a nominal centre-of-mass energy of 3 TeV. To achieve the luminosity requirements, Pre-Damping Rings (PDRs) and Damping Rings (DRs) are required: they reduce the beam emittance before the beam is accelerated in the main linac. Several injection and extraction systems are needed to inject and extract the beam from the PDRs and DRs. The work of this Thesis consists of the design, fabrication and laboratory tests of the first stripline kicker prototype for beam extraction from the CLIC DRs, although the methodology proposed can be extended to stripline kickers for any low emittance ring. The excellent field homogeneity required, as well as a good transmission of the high voltage pulse through the electrodes, has been achieved by choosing a novel electrode shape. With this new geometry, it has been possible to benefit from all the advantages that the most...

  7. Real-time non-invasive eyetracking and gaze-point determination for human-computer interaction and biomedicine

    Science.gov (United States)

    Talukder, Ashit; Morookian, John-Michael; Monacos, S.; Lam, R.; Lebaw, C.; Bond, A.

    2004-01-01

    Eyetracking is one of the latest technologies that has shown potential in several areas including human-computer interaction for people with and without disabilities, and for noninvasive monitoring, detection, and even diagnosis of physiological and neurological problems in individuals.

  8. Design and Manufacturing Description of the Prototype Striplines for the Extraction Kicker of the CLIC Damping Rings

    CERN Document Server

    Belver-Aguilar, C; Faus-Golfe, A; Gómez, J; Gutiérrez, D; Toral, F

    2013-01-01

    The Pre-Damping Rings (PDRs) and Damping Rings (DRs) of CLIC are needed to reduce the beam emittances to the small values required for the main linacs. The injection and extraction, from the PDRs and DRs, are carried out by kicker systems. In order to achieve both low beam coupling impedance and reasonable broadband impedance matching to the electrical circuit, striplines have been chosen for the kicker elements. The design of the stripline kicker was previously carried out by modelling the striplines with simulation codes such as HFSS, Quickfield and CST Particle Studio. In order to have a complete analysis of the striplines, the effect of electrode supports and coaxial feedthroughs have been studied in detail. In this paper, electromagnetic analyses of the complete striplines, including fabrication tolerances, are reported. Furthermore, a new idea for impedance matching is presented.

  9. Analytical considerations for linear and nonlinear optimization of the TME cells. Application to the CLIC pre-damping rings

    CERN Document Server

    Fanouria, Antoniou

    2014-01-01

    The theoretical minimum emittance cells are the optimal configurations for achieving the absolute minimum emittance, if specific optics constraints are satisfied at the middle of the cell's dipole. Linear lattice design options based on an analytical approach for the theoretical minimum emittance cells are presented in this paper. In particular the parametrization of the quadrupole strengths and optics functions with respect to the emittance and drift lengths is derived. A multi-parametric space can be then created with all the cell parameters, from which one can chose any of them to be optimized. An application of this approach are finally presented for the linear and non-linear optimization of the CLIC Pre-damping rings.

  10. 散乱点云特征边缘交互提取%Interactive extraction of boundary of specified target feature on scat-tered point cloud

    Institute of Scientific and Technical Information of China (English)

    刘增艺; 江开勇; 林俊义

    2016-01-01

    A method of interactive extraction of boundary of specified target feature is proposed to extract the boundary of specified target feature from the scattered point cloud with multiple feature boundary. Firstly, the point cloud of specified feature and its surrounding is picked up. The topological relations of scattered point cloud are established with KD tree, then the k-nearest points of each point would be searched. Whether the point is the boundary point is judged by the maximum value of angle difference which is calculated by projection points on the least square plane with the k-nearest points. Lastly, one point on the boundary of the specified feature is picked up as the seed point, then according to a fixed direction to search for boundary points, until the entire closed boundary is extracted. Experiments show that, this method can accurately obtain any specified target feature boundary on the scattered point cloud.%为了在具有多个特征边界的散乱点云上提取指定目标特征边界,提出了一种基于目标特征边界交互提取的算法。拾取目标特征及其周围的点云。利用 KD树建立散乱点云的空间拓扑关系,计算出每个数据点的k 邻域。通过数据点k邻域构成的最小二乘平面的投影点角度差,根据角度差的最大值来判断该点是否为边界点。拾取目标特征边界上的某个点作为种子点,按照某一个固定方向搜索边界点,直到搜索整条封闭边界为止。实验表明,该方法能够准确获取散乱点云上任意指定目标特征的边界。

  11. 基于OpenInventor的海量点云交互式管理%Interactive Arrangement of Massive Point Cloud Based on Open Inventor

    Institute of Scientific and Technical Information of China (English)

    张培培; 程效军

    2012-01-01

    针对三维激光扫描点云数据量庞大、管理复杂等不足,结合海量点云数据的特点,采用面向对象和交互式的三维图形库OpenInventor作为开发工具,实现对海量点云的三维动态展示以及法向量和空间坐标的交互式提取等功能。%Considering the characteristic of point cloud data, 3D dynamic visualization expression and interactive extraction of corresponding coordinates and normal of massive point cloud data are achieved based on open inventor as an object-oriented and interactive 3D graphic library. Experi- mental results show that the programming based on open inventor is efficient to provide a support for the interactive organization and preprocessing of massive point cloud data.

  12. One-dimensional scattering problem, self-adjoint extensions, renormalizations and point $\\delta$-interactions for Coulomb potential

    CERN Document Server

    Mineev, V S

    2003-01-01

    In the paper the one-dimensional one-center scattering problem with the initial potential $\\alpha |x|^{-1}$ on the whole axis is treated and reduced to the search for allowable self-adjoint extensions. Using the laws of conservation as necessary conditions in the singular point alongside with account of the analytical structure of fundamental solutions, it allows us to receive exact expressions for the wave functions (i.e. for the boundary conditions), scattering coefficients and the singular corrections to the potential, as well as the corresponding bound state spectrum. It turns out that the point $\\delta$-shaped correction to the potential should be present without fail at any choice of the allowable self-adjoint extension, moreover a form of these corrections corresponds to the form of renormalization terms obtained in quantum electrodynamics. Thus, the proposed method shows the unequivocal connection among the boundary conditions, scattering coefficients and $\\delta$-shaped additions to the potential. Ta...

  13. Issues and Feasibility Demonstration of Positioning Closed Loop Control for the CLIC Supporting System Using a Test Mock-up with Five Degrees of Freedom

    CERN Document Server

    Sosin, M; Chritin, N; Griffet, S; Kemppinen, J; Mainaud Durand, H; Rude, V; Sterbini, G

    2012-01-01

    Since several years, CERN is studying the feasibility of building a high energy e+ e- linear collider: the CLIC (Compact LInear Collider). One of the challenges of such a collider is the pre-alignment precision and accuracy requirement on the transverse positions of the linac components, which is typically 14 μm over a window of 200 m. To ensure the possibility of positioning within such tight constraints, CERN Beams Department’s Survey team has worked intensively at developing the methods and technology needed to achieve that objective. This paper describes activities which were performed on a test bench (mock-up) with five degrees of freedom (DOF) for the qualification of control algorithms for the CLIC supporting system active-pre-alignment. Present understanding, lessons learned (“know how”), issues of sensors noise and mechanical components nonlinearities are presented.

  14. Design of the 15 GHz BPM test bench for the CLIC test facility to perform precise stretched-wire RF measurements

    Science.gov (United States)

    Zorzetti, Silvia; Fanucci, Luca; Galindo Muñoz, Natalia; Wendt, Manfred

    2015-09-01

    The Compact Linear Collider (CLIC) requires a low emittance beam transport and preservation, thus a precise control of the beam orbit along up to 50 km of the accelerator components in the sub-μm regime is required. Within the PACMAN3 (Particle Accelerator Components Metrology and Alignment to the Nanometer Scale) PhD training action a study with the objective of pre-aligning the electrical centre of a 15 GHz cavity beam position monitor (BPM) to the magnetic centre of the main beam quadrupole is initiated. Of particular importance is the design of a specific test bench to study the stretched-wire setup for the CLIC Test Facility (CTF3) BPM, focusing on the aspects of microwave signal excitation, transmission and impedance-matching, as well as the mechanical setup and reproducibility of the measurement method.

  15. Design of the 15 GHz BPM test bench for the CLIC test facility to perform precise stretched-wire RF measurements

    International Nuclear Information System (INIS)

    The Compact Linear Collider (CLIC) requires a low emittance beam transport and preservation, thus a precise control of the beam orbit along up to 50 km of the accelerator components in the sub-μm regime is required. Within the PACMAN3 (Particle Accelerator Components Metrology and Alignment to the Nanometer Scale) PhD training action a study with the objective of pre-aligning the electrical centre of a 15 GHz cavity beam position monitor (BPM) to the magnetic centre of the main beam quadrupole is initiated. Of particular importance is the design of a specific test bench to study the stretched-wire setup for the CLIC Test Facility (CTF3) BPM, focusing on the aspects of microwave signal excitation, transmission and impedance-matching, as well as the mechanical setup and reproducibility of the measurement method. (paper)

  16. Alignment Methods Developed for the Validation of the Thermal and Mechanical Behaviour of the Two Beam Test Modules for the CLIC Project

    CERN Document Server

    Mainaud Durand, Helene; Sosin, Mateusz; Rude, Vivien

    2014-01-01

    CLIC project will consist of more than 20 000 two meters long modules. A test setup made of three modules is being built at CERN to validate the assembly and integration of all components and technical systems and to validate the short range strategy of pre-alignment. The test setup has been installed in a room equipped with a sophisticated system of ventilation able to reproduce the environmental conditions of the CLIC tunnel. Some of the components have been equipped with electrical heaters to simulate the power dissipation, combined with a water cooling system integrated in the RF components. Using these installations, to have a better understanding of the thermal and mechanical behaviour of a module under different operation modes, machine cycles have been simulated; the misalignment of the components and their supports has been observed. This paper describes the measurements methods developed for such a project and the results obtained.

  17. Modified interactions among globular proteins below isoelectric point in the presence of mono-, di- and tri-valent ions: A small angle neutron scattering study

    Science.gov (United States)

    Das, Kaushik; Kundu, Sarathi; Mehan, Sumit; Aswal, V. K.

    2016-02-01

    Both short range attraction and long range electrostatic repulsion exist among globular protein Bovine Serum Albumin in solution below its isoelectric point (pI ≈ 4.8). At pD ≈ 4.0, below pI, protein has a net positive surface charge although local charge inhomogeneity presents. Small angle neutron scattering study reveals that in the presence of both mono-(Na+) and di-(Ni2+) valent ions attractive interaction increases and repulsive interaction decreases with the increase of salt concentration. However, for tri-valent (Fe3+) ions, both attractive and repulsive interaction increases with increasing salt concentration but the relative strength of repulsion is more than the attraction.

  18. Model-based testing for space-time interaction using point processes: An application to psychiatric hospital admissions in an urban area

    CERN Document Server

    Meyer, Sebastian; Rössler, Wulf; Held, Leonhard

    2015-01-01

    Spatio-temporal interaction is inherent to cases of infectious diseases and occurrences of earthquakes, whereas the spread of other events, such as cancer or crime, is less evident. Statistical significance tests of space-time clustering usually assess the correlation between the spatial and temporal (transformed) distances of the events. Although appealing through simplicity, these classical tests do not adjust for the underlying population nor can they account for a distance decay of interaction. We propose to use the framework of an endemic-epidemic point process model to jointly estimate a background event rate explained by seasonal and areal characteristics, as well as a superposed epidemic component representing the hypothesis of interest. We illustrate this new model-based test for space-time interaction by analysing psychiatric inpatient admissions in Zurich, Switzerland (2007-2012). Several socio-economic factors were found to be associated with the admission rate, but there was no evidence of genera...

  19. Getting the point across: exploring the effects of dynamic virtual humans in an interactive museum exhibit on user perceptions.

    Science.gov (United States)

    Rivera-Gutierrez, Diego; Ferdig, Rick; Li, Jian; Lok, Benjamin

    2014-04-01

    We have created “You, M.D.”, an interactive museum exhibit in which users learn about topics in public health literacy while interacting with virtual humans. You, M.D. is equipped with a weight sensor, a height sensor and a Microsoft Kinect that gather basic user information. Conceptually, You, M.D. could use this user information to dynamically select the appearance of the virtual humans in the interaction attempting to improve learning outcomes and user perception for each particular user. For this concept to be possible, a better understanding of how different elements of the visual appearance of a virtual human affects user perceptions is required. In this paper, we present the results of an initial user study with a large sample size (n =333) ran using You, M.D. The study measured users’ reactions based on the user’s gender and body-mass index (BMI) when facing virtual humans with BMI either concordant or discordant from the user’s BMI. The results of the study indicate that concordance between the users’ BMI and the virtual human’s BMI affects male and female users differently. The results also show that female users rate virtual humans as more knowledgeable than male users rate the same virtual humans.

  20. Interactive Learning Media for Lenses and Their Applications Using Macro Visual Basic in Microsoft PowerPoint

    Science.gov (United States)

    Sami Novita, Sari; Nurul Khotimah, Siti; Hidayat, Wahyu

    2016-08-01

    There are two types of lenses are used, namely a convex lens and a concave lens. Microscope is a tool that uses two convex lenses as the eyepiece and objective lens because it can form a magnified image. Instead concave lens is usually used as a spectacle lens for nearsightedness patients because the distance of image formed is closer than the distance of the object. Just like a mirror, the image formation by lenses also can be conveniently determined with ray diagrams. Therefore, this research aims to create a simulation of ray diagrams in the process of image formation by lenses and their applications using Macro Visual Basic in Microsoft PowerPoint. Lenses applications made are the microscope simulation and the combined lenses which consist of a concave-convex lens combined and a convex-concave lens combined. This research begins with the preparation of material on the image formation by lenses and their application. Second, made an appearance on the program which consists of a PowerPoint slide, CommandButton, Textbox, OptionButton, Shape and others then wrote programs in Macro Visual Basic procedure to active the command to do. Input of this simulation can be given in the form of object distance, focal point distance of lens and height of objects. The data will be processed according to commands contained in macros procedure to result image distance, image height, image magnification and the properties of image. In addition to result the data, media can also provide output in the form of ray diagrams simulation on the image formation that can be used to assist students understanding the image formation by lenses.

  1. 超大幅面显示系统触点融合交互%Touch-Point Fusion Interaction for Large Display HCI System

    Institute of Scientific and Technical Information of China (English)

    朱立新; 王虎

    2012-01-01

    针对超高分辨率大幅面显示系统目前因缺少高效的人机交互设备导致应用受限问题,提出了一种基于多相机激光触点跟踪的交互方法。该方法通过在单个显示单元融合多个触点跟踪设备的交互信息,提高了交互精度;通过跨显示单元的触点空间变换实现了对大幅面显示系统的支持,提高了系统的扩展性。试验表明,该方法可应用于大幅面显示系统的人机交互设备。%Aimed at the problem of lacking an efficient human computer interaction (HCI) system for super high resolution large display, an interaction method based on multi-camera touch-point tracking is proposed. In this method, the touch-point tracking fusion method is applied to in- creasing the precision of interaction and the translational transform of touch-points is applied to providing the Iarge display interaction ability. The design is extensible for the modularized de- sign. Experimental results show that the method can be used in the HCI system for the large dis- play.

  2. Theoretical Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Critical Point Properties, Local Energy Densities, and Bonded Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Gibbs, Gerald V.; Cox, David F.; Rosso, Kevin M.; Ross, Nancy L.; Downs, R. T.; Spackman, M. A.

    2007-03-01

    Bond critical point and local energy density properties together with net atomic charges were calculated for theoretical electron density distributions, F(r), generated for a variety of Fe and Cu metal-sulfide materials with high- and low-spin Fe atoms in octahedral coordination and high-spin Fe atoms in tetrahedral coordination. The electron density, F(rc), the Laplacian, 32F(rc), the local kinetic energy, G(rc), and the oxidation state of Fe increase as the local potential energy density, V(rc), the Fe-S bond lengths, and the coordination numbers of the Fe atoms decrease. The properties of the bonded interactions for the octahedrally coordinated low-spin Fe atoms for pyrite and marcasite are distinct from those for high-spin Fe atoms for troilite, smythite, and greigite. The Fe-S bond lengths are shorter and the values of F(rc) and 32F(rc) are larger for pyrite and marcasite, indicating that the accumulation and local concentration of F(r) in the internuclear region are greater than those involving the longer, high-spin Fe-S bonded interactions. The net atomic charges and the bonded radii calculated for the Fe and S atoms in pyrite and marcasite are also smaller than those for sulfides with high-spin octahedrally coordinated Fe atoms. Collectively, the Fe-S interactions are indicated to be intermediate in character with the low-spin Fe-S interactions having greater shared character than the highspin interactions. The bond lengths observed for chalcopyrite together with the calculated bond critical point properties are consistent with the formula Cu+Fe3+S2. The bond length is shorter and the F(rc) value is larger for the FeS4 tetrahedron displayed by metastable greigite than those displayed by chalcopyrite and cubanite, consistent with a proposal that the Fe atom in greigite is tetravalent. S-S bond paths exist between each of the surface S atoms of adjacent slabs of FeS6 octahedra comprising the layer sulfide smythite, suggesting that the neutral Fe3S4 slabs are

  3. Theoretical electron density distributions for Fe- and Cu-sulfide earth materials: a connection between bond length, bond critical point properties, local energy densities, and bonded interactions.

    Science.gov (United States)

    Gibbs, G V; Cox, D F; Rosso, K M; Ross, N L; Downs, R T; Spackman, M A

    2007-03-01

    Bond critical point and local energy density properties together with net atomic charges were calculated for theoretical electron density distributions, rho(r), generated for a variety of Fe and Cu metal-sulfide materials with high- and low-spin Fe atoms in octahedral coordination and high-spin Fe atoms in tetrahedral coordination. The electron density, rho(rc), the Laplacian, triangle down2rho(rc), the local kinetic energy, G(rc), and the oxidation state of Fe increase as the local potential energy density, V(rc), the Fe-S bond lengths, and the coordination numbers of the Fe atoms decrease. The properties of the bonded interactions for the octahedrally coordinated low-spin Fe atoms for pyrite and marcasite are distinct from those for high-spin Fe atoms for troilite, smythite, and greigite. The Fe-S bond lengths are shorter and the values of rho(rc) and triangle down2rho(rc) are larger for pyrite and marcasite, indicating that the accumulation and local concentration of rho(r) in the internuclear region are greater than those involving the longer, high-spin Fe-S bonded interactions. The net atomic charges and the bonded radii calculated for the Fe and S atoms in pyrite and marcasite are also smaller than those for sulfides with high-spin octahedrally coordinated Fe atoms. Collectively, the Fe-S interactions are indicated to be intermediate in character with the low-spin Fe-S interactions having greater shared character than the high-spin interactions. The bond lengths observed for chalcopyrite together with the calculated bond critical point properties are consistent with the formula Cu+Fe3+S2. The bond length is shorter and the rho(rc) value is larger for the FeS4 tetrahedron displayed by metastable greigite than those displayed by chalcopyrite and cubanite, consistent with a proposal that the Fe atom in greigite is tetravalent. S-S bond paths exist between each of the surface S atoms of adjacent slabs of FeS6 octahedra comprising the layer sulfide smythite

  4. Observations of internal solitary wave reflection at a step-like submarine bank and strong oblique interaction at Race Point Channel, (Cape Cod).

    Science.gov (United States)

    da Silva, Jose C. B.; Grimshaw, Roger H. J.; Magalhaes, Jorge M.

    2010-05-01

    A recent study revealed that Race Point Channel (in Cape Cod, Massachusetts) is a hotspot of internal solitary wave generation. SAR images suggest that the waves are generated within the channel (which has a flat bottom) during the ebb phase of the tide (flowing offshore) and propagate upstream during the initial stages of their formation. Some of these waves propagate into Massachusetts Bay (further North) and interact with the well known Stellwagen Bank internal waves that are generated on the lee-side of the Bank. The southern flank of Stellwagen Bank has very sharp bathymetric gradients and can be considered as a vertical step. Here we discuss the results of analysis of 25 TerraSAR-X radar images (in very high spatial resolution, 3 meters) and a collection of ENVISAT/ERS tandem mission acquisitions (separated in time by approximately 30 minutes) that reveal details about internal wave reflection at the southern flank of Stellwagen Bank. The SAR data also show transmission of internal waves over the Bank and subsequent interaction with lee-waves generated at the eastern side of Stellwagen Bank. The radar backscatter profiles are compared with theory of the transformation of a weakly nonlinear interfacial solitary wave in a two-layer model over a step. The coefficients of wave reflection and transmission are calculated based on typical stratification of the region and assuming linear theory of long interfacial waves. In addition, collision of reflected waves from the Bank with internal waves generated at the Race Point channel (one tidal cycle after) has been occasionally observed. The radar backscatter profiles suggest that the total wave amplitude during the interaction is greater than that obtained by simply adding the individual solitary wave amplitudes, which is in agreement with the theory of obliquely interacting solitary waves at a near critical angle (150°). This may imply localized turbulent mixing as a result of internal solitary wave interaction at

  5. X-ray and optical study on point defect formation and interaction under irradiation adn doping of KCl

    International Nuclear Information System (INIS)

    Optical and X-ray diffuse scattering methods have been applied to investigate structural changes, taking place in KCl crystals during irradiation with γ-quanta and doping with barium. It is shown that γ-irradiation of ''pure'' and doped KCl crystals mainly leads to formation of F-centers and spherical vacancy complexes. F-center concentration in irradiated addition crystals (3x10-6) has turned out to be 25% lower, than in irradiated pure ones (4x10-6), which is connected with interaction of radiation and addition defects. The type of defects, causing assymetry in the distribution of diffuse scattering has been determined. Appearance of scattering ability modulation over direction during irradiation of KCl pure crystals has been found. Critical radius of spherical complexes formed during irradiation has been estimated, it appeared to be 2.5 a, where a is a lattice period

  6. Carbon, oxygen and their interaction with intrinsic point defects in solar silicon ribbon material: A speculative approach

    Science.gov (United States)

    Goesele, U.; Ast, D. G.

    1983-01-01

    Some background information on intrinsic point defects is provided and on carbon and oxygen in silicon in so far as it may be relevant for the efficiency of solar cells fabricated from EFG ribbon material. The co-precipitation of carbon and oxygen and especially of carbon and silicon self interstitials are discussed. A simple model for the electrical activity of carbon-self-interstitial agglomerates is presented. The self-interstitial content of these agglomerates is assumed to determine their electrical activity and that both compressive stresses (high self-interstitial content) and tensile stresses (low self-interstitial content) give rise to electrical activity of the agglomerates. The self-interstitial content of these carbon-related agglomerates may be reduced by an appropriate high temperature treatment and enhanced by a supersaturation of self-interstitials generated during formation of the p-n junction of solar cells. Oxygen present in supersaturation in carbon-rich silicon may be induced to form SiO, precipitates by self-interstitials generated during phosphorus diffusion. It is proposed that the SiO2-Si interface of the precipates gives rise to a continuum of donor stables and that these interface states are responsible for at least part of the light inhancement effects observed in oxygen containing EFG silicon after phosphorus diffusion.

  7. Benchmark calculations of the complete configuration-interaction limit of Born–Oppenheimer diagonal corrections to the saddle points of isotopomers of the H + H2 reaction

    Energy Technology Data Exchange (ETDEWEB)

    Mielke, Steven L.; Schwenke, David; Peterson, Kirk A.

    2005-06-08

    We present a detailed ab initio study of the effect that the Born–Oppenheimer diagonal correction (BODC) has on the saddle point properties of the H3 system and its isotopomers. Benchmark values are presented that are estimated to be within 0.1 cm–1 of the complete configuration interaction limit. We consider the basis set and correlation treatment requirements for accurate BODC calculations, and both are observed to be more favorable than for the Born–Oppenheimer energies. The BODC raises the H + H2 barrier height by 0.1532 kcal/mol and slightly narrows the barrier—with the imaginary frequency increasing by ~2%.

  8. Deciphering the Dynamics of Non-Covalent Interactions Affecting Thermal Stability of a Protein: Molecular Dynamics Study on Point Mutant of Thermus thermophilus Isopropylmalate Dehydrogenase.

    Science.gov (United States)

    Sharma, Reetu; Sastry, G Narahari

    2015-01-01

    Thermus thermophilius isopropylmalate dehydrogenase catalyzes oxidative decarboxylation and dehydrogenation of isopropylmalate. Substitution of leucine to alanine at position 172 enhances the thermal stability among the known point mutants. Exploring the dynamic properties of non-covalent interactions such as saltbridges, hydrogen bonds and hydrophobic interactions to explain thermal stability of a protein is interesting in its own right. In this study dynamic changes in the non-covalent interactions are studied to decipher the deterministic features of thermal stability of a protein considering a case study of a point mutant in Thermus thermophilus isopropylmalate dehydrogenase. A total of four molecular dynamic simulations of 0.2 μs were carried out on wild type and mutant's functional dimers at 300 K and 337 K. Higher thermal stability of the mutant as compared to wild type is revealed by root mean square deviation, root mean square fluctuations and Cα-Cα distance with an increase in temperature from 300 K to 337 K. Most of the regions of wild type fluctuate higher than the corresponding regions of mutant with an increase in temperature. Cα-Cα distance analysis suggests that long distance networks are significantly affected in wild type as compared to the mutant. Short lived contacts are higher in wild type, while long lived contacts are lost at 337 K. The mutant forms less hydrogen bonds with water as compared to wild type at 337 K. In contrast to wild type, the mutant shows significant increase in unique saltbridges, hydrogen bonds and hydrophobic contacts at 337 K. The current study indicates that there is a strong inter-dependence of thermal stability on the way in which non-covalent interactions reorganize, and it is rewarding to explore this connection in single mutant studies.

  9. Deciphering the Dynamics of Non-Covalent Interactions Affecting Thermal Stability of a Protein: Molecular Dynamics Study on Point Mutant of Thermus thermophilus Isopropylmalate Dehydrogenase.

    Directory of Open Access Journals (Sweden)

    Reetu Sharma

    Full Text Available Thermus thermophilius isopropylmalate dehydrogenase catalyzes oxidative decarboxylation and dehydrogenation of isopropylmalate. Substitution of leucine to alanine at position 172 enhances the thermal stability among the known point mutants. Exploring the dynamic properties of non-covalent interactions such as saltbridges, hydrogen bonds and hydrophobic interactions to explain thermal stability of a protein is interesting in its own right. In this study dynamic changes in the non-covalent interactions are studied to decipher the deterministic features of thermal stability of a protein considering a case study of a point mutant in Thermus thermophilus isopropylmalate dehydrogenase. A total of four molecular dynamic simulations of 0.2 μs were carried out on wild type and mutant's functional dimers at 300 K and 337 K. Higher thermal stability of the mutant as compared to wild type is revealed by root mean square deviation, root mean square fluctuations and Cα-Cα distance with an increase in temperature from 300 K to 337 K. Most of the regions of wild type fluctuate higher than the corresponding regions of mutant with an increase in temperature. Cα-Cα distance analysis suggests that long distance networks are significantly affected in wild type as compared to the mutant. Short lived contacts are higher in wild type, while long lived contacts are lost at 337 K. The mutant forms less hydrogen bonds with water as compared to wild type at 337 K. In contrast to wild type, the mutant shows significant increase in unique saltbridges, hydrogen bonds and hydrophobic contacts at 337 K. The current study indicates that there is a strong inter-dependence of thermal stability on the way in which non-covalent interactions reorganize, and it is rewarding to explore this connection in single mutant studies.

  10. Spectroscopic studies of surface-gas interactions and catalyst restructuring at ambient pressure: mind the gap{exclamation_point}

    Energy Technology Data Exchange (ETDEWEB)

    Rupprechter, Guenther; Weilach, Christian [Institute of Materials Chemistry, Vienna University of Technology, Veterinaerplatz 1, A-1210 Vienna (Austria)], E-mail: grupp@imc.tuwien.ac.at

    2008-05-07

    Recent progress in the application of surface vibrational spectroscopy at ambient pressure allows us to monitor surface-gas interactions and heterogeneous catalytic reactions under conditions approaching those of technical catalysis. The surface specificity of photon-based methods such as polarization modulation infrared reflection absorption spectroscopy (PM-IRAS) and sum frequency generation (SFG) spectroscopy is utilized to monitor catalytically active surfaces while they function at high pressure and high temperature. Together with complementary information from high-pressure x-ray photoelectron spectroscopy (HP-XPS) and high-resolution transmission electron microscopy (HRTEM), reaction mechanisms can be deduced on a molecular level. Well defined model catalysts, prepared under ultrahigh vacuum (UHV), are typically employed in such studies, including smooth and stepped single crystals, thin oxide films, and oxide-supported nanoparticles. A number of studies on unsupported and supported noble metal (Pd, Rh) catalysts are presented, focusing on the transformation of the catalysts from the 'as-prepared' to the 'active state'. This often involves pronounced alterations in catalyst structure and composition, for example the creation of surface carbon phases, surface oxides or surface alloys, as well as nanoparticle restructuring. The reactivity studies include CH{sub 3}OH, CH{sub 4} and CO oxidation with gas phase analysis by gas chromatography and mass spectrometry. Differing results between studies under ultrahigh vacuum and ambient pressure, and between studies on single crystals and supported nanoparticles, demonstrate the importance of 'minding the gap' between idealized and realistic conditions.

  11. An Analysis of the Interactive Development between Lhasa and Shigatse from the Perspective of the Intensity of their Economic Contact and Regional Breaking Point

    Institute of Scientific and Technical Information of China (English)

    QIU Lilan

    2014-01-01

    In the Tibet Autonomous Region , Lhasa and Shigatse are the two core cities in the region’ s development , and they play a leading role for the development of other counties and cit-ies.From the perspective of research on urban ag-glomeration and urban geography , the two cities have a relationship of interactive contact and com-mon development .Within the context of rapid ur-banization in China , the interactive development between Lhasa and Shigatse has become an inevita-ble research focus for the socio-economic construc-tion of Tibet . The intensity of economic contact is used tomeasure the degree of regional economic ties.Onthe one hand, it can reflect the city’ s economiccenter ability to radiate out to the surrounding areas.On the other hand, it can also reflect the levelof acceptance of the surrounding areas to the city’s economic center ability to radiate out tothem.According to the results of economic calculation,the intensity of economic contact betweenLhasa and Shigatse from 2007 to 2011 steadily increasedwith an annual rate of about 20%.Thecontinuous increase of the intensity of economiccontact also meant that the influence of Lhasa andShigatse on the surrounding cities is expanding .Moreover, comparative data show that due to restrictionson the population and level of economicdevelopment, there is still a big gap in Lhasa andShigatse if compared with other urbanized areas inChina.However, regarding the increasing speedof the intensity of contact with other core cities,Lhasa and Shigatse have achieved remarkable a -chievements. During the 1930’ s, William J.Reilly proposedthe Law of Retail Gravitation which was usedby P.D.Converse in the field of urban managementto differentiate the scope of influence ofneighboring cities.In 1949, he put forward theconcept of “Breaking Point” together with a relevantcomputational formula.The Breaking Point isnormally determined by the scale of two cities andthe distance between them.According to the

  12. High-voltage pixel detectors in commercial CMOS technologies for ATLAS, CLIC and Mu3e experiments

    CERN Document Server

    Peric,I et al.

    2013-01-01

    High-voltage particle detectors in commercial CMOS technologies are a detector family that allows implementation of low-cost, thin and radiation-tolerant detectors with a high time resolution. In the R/D phase of the development, a radiation tolerance of 1015 neq=cm2 , nearly 100% detection efficiency and a spatial resolution of about 3 μm were demonstrated. Since 2011 the HV detectors have first applications: the technology is presently the main option for the pixel detector of the planned Mu3e experiment at PSI (Switzerland). Several prototype sensors have been designed in a standard 180 nm HV CMOS process and successfully tested. Thanks to its high radiation tolerance, the HV detectors are also seen at CERN as a promising alternative to the standard options for ATLAS upgrade and CLIC. In order to test the concept, within ATLAS upgrade R/D, we are currently exploring an active pixel detector demonstrator HV2FEI4; also implemented in the 180 nm HV process.

  13. A Study of e+e− → H0A0 → bbbb at 3 TeV at CLIC

    CERN Document Server

    Battaglia, M

    2010-01-01

    The precise determination of the masses of the CP-odd and -even heavy Higgs bosons is an important part of the study of Supersymmetry and its relation with cosmology through dark matter. This note presents a determination of the A0 mass with the e+e− → H0A0 → bb ̄bb ̄ process for a dark matter motivated cMSSM scenario with MA = 1141 GeV at CLIC. The analysis is performed with full simulation and reconstruction at √s=3 TeV accounting for beamstrahlung effects. SM and SUSY backgrounds are considered and the effect of the overlay of γγ → hadrons events on the signal is studied for various assumptions for the detector time-stamping capabilities. The di-jet mass resolution is improved by applying a kinematic fit. The A0 mass can be determined with a statistical accuracy of ≃ 3-5 GeV for 3 ab−1 of integrated luminosity and 0 to 20 bunch crossings of γγ background integrated in one event, respectively.

  14. High-voltage pixel detectors in commercial CMOS technologies for ATLAS, CLIC and Mu3e experiments

    CERN Document Server

    Peric, Ivan; Backhaus, Malte; Barbero, Marlon; Benoit, Mathieu; Berger, Niklaus; Bompard, Frederic; Breugnon, Patrick; Clemens, Jean-Claude; Dannheim, Dominik; Dierlamm, Alexander; Feigl, Simon; Fischer, Peter; Fougeron, Denis; Garcia-Sciveres, Maurice; Heim, Timon; Hügging, Fabian; Kiehn, Moritz; Kreidl, Christian; Krüger, Hans; La Rosa, Alessandro; Liu, Jian; Lütticke, Florian; Mariñas, Carlos; Meng, Lingxin; Miucci, Antonio; Münstermann, Daniel; Nguyen, Hong Hanh; Obermann, Theresa; Pangaud, Patrick; Perrevoort, Ann-Kathrin; Rozanov, Alexandre; Schöning, André; Schwenker, Benjamin; Wiedner, Dirk

    2013-01-01

    High-voltage particle detectors in commercial CMOS technologies are a detector family that allows implementation of low-cost, thin and radiation-tolerant detectors with a high time resolution. In the R/D phase of the development, a radiation tolerance of 10 15 n eq = cm 2 , nearly 100% detection ef fi ciency and a spatial resolution of about 3 μ m were demonstrated. Since 2011 the HV detectors have fi rst applications: the technology is presently the main option for the pixel detector of the planned Mu3e experiment at PSI (Switzerland). Several prototype sensors have been designed in a standard 180 nm HV CMOS process and successfully tested. Thanks to its high radiation tolerance, the HV detectors are also seen at CERN as a promising alternative to the standard options for ATLAS upgrade and CLIC. In order to test the concept, within ATLAS upgrade R/D, we are currently exploring an active pixel detector demonstrator HV2FEI4; also implemented in the 180 nm HV process

  15. Neutral Higgs Boson Pair-Production and Trilinear Self-Couplings in the MSSM at ILC and CLIC Energies

    CERN Document Server

    Gutiérrez-Rodríguez, A; Sampayo, O A

    2009-01-01

    We study pair-production as well as the triple self-couplings of the neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) at the Future International Linear $e^{+}e^{-}$ Collider (ILC) and Compact Linear Collider (CLIC). The analysis is based on the reactions $e^{+}e^{-}\\to b \\bar b h_ih_i, t \\bar t h_ih_i$ with $h_i=h, H, A$. We evaluate the total cross-section for both $b\\bar bh_ih_i$, $t\\bar th_ih_i$ and calculate the total number of events considering the complete set of Feynman diagrams at tree-level. We vary the triple couplings $\\kappa\\lambda_{hhh}$, $\\kappa\\lambda_{Hhh}$, $\\kappa\\lambda_{hAA}$, $\\kappa\\lambda_{HAA}$, $\\kappa\\lambda_{hHH}$ and $\\kappa\\lambda_{HHH}$ within the range $\\kappa=-1$ and +2. The numerical computation is done for the energies expected at the ILC with a center-of-mass energy 500, 1000, 1600 $GeV$ and a luminosity 1000 $fb^{-1}$. The channels $e^{+}e^{-}\\to b \\bar b h_ih_i$ and $e^{+}e^{-}\\to t \\bar t h_ih_i$ are also discussed to a center-of-mass energy of 3...

  16. Personality and serotonin transporter genotype interact with social context to affect immunity and viral set-point in simian immunodeficiency virus disease.

    Science.gov (United States)

    Capitanio, John P; Abel, Kristina; Mendoza, Sally P; Blozis, Shelley A; McChesney, Michael B; Cole, Steve W; Mason, William A

    2008-07-01

    From the beginning of the AIDS epidemic, stress has been a suspected contributor to the wide variation seen in disease progression, and some evidence supports this idea. Not all individuals respond to a stressor in the same way, however, and little is known about the biological mechanisms by which variations in individuals' responses to their environment affect disease-relevant immunologic processes. Using the simian immunodeficiency virus/rhesus macaque model of AIDS, we explored how personality (Sociability) and genotype (serotonin transporter promoter) independently interact with social context (Stable or Unstable social conditions) to influence behavioral expression, plasma cortisol concentrations, SIV-specific IgG, and expression of genes associated with Type I interferon early in infection. SIV viral RNA set-point was strongly and negatively correlated with survival as expected. Set-point was also associated with expression of interferon-stimulated genes, with CXCR3 expression, and with SIV-specific IgG titers. Poorer immune responses, in turn, were associated with display of sustained aggression and submission. Personality and genotype acted independently as well as in interaction with social condition to affect behavioral responses. Together, the data support an "interactionist" perspective [Eysenck, H.J., 1991. Personality, stress and disease: an interactionist perspective. Psychol. Inquiry 2, 221-232] on disease. Given that an important goal of HIV treatment is to maintain viral set-point as low as possible, our data suggest that supplementing anti-retroviral therapy with behavioral or pharmacologic modulation of other aspects of an organism's functioning might prolong survival, particularly among individuals living under conditions of threat or uncertainty.

  17. Measurement of the forward charged particle pseudorapidity density in pp collisions at √s=8 TeV using a displaced interaction point

    International Nuclear Information System (INIS)

    The pseudorapidity density of charged particles dNch/dη is measured by the TOTEM experiment in proton–proton collisions at √s=8 TeV within the range 3.9<η<4.7 and -6.95<η<-6.9. Data were collected in a low intensity LHC run with collisions occurring at a distance of 11.25 m from the nominal interaction point. The data sample is expected to include 96–97 % of the inelastic proton–proton interactions. The measurement reported here considers charged particles with pT>0 MeV/c, produced in inelastic interactions with at least one charged particle in -7<η<-6 or 3.7<η<4.8. The dNch/dη has been found to decrease with |η|, from 5.11 ± 0.73 at η=3.95 to 1.81 ± 0.56 at η=-6.925. Several Monte Carlo generators are compared to the data and are found to be within the systematic uncertainty of the measurement

  18. Measurement of the forward charged particle pseudorapidity density in pp collisions at √s=8 TeV using a displaced interaction point

    Energy Technology Data Exchange (ETDEWEB)

    Antchev, G. [INRNE-BAS, Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia (Bulgaria); Aspell, P. [CERN, Geneva (Switzerland); Atanassov, I. [CERN, Geneva (Switzerland); INRNE-BAS, Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia (Bulgaria); Avati, V.; Baechler, J. [CERN, Geneva (Switzerland); and others

    2015-03-17

    The pseudorapidity density of charged particles dN{sub ch}/dη is measured by the TOTEM experiment in proton–proton collisions at √s=8 TeV within the range 3.9<η<4.7 and -6.95<η<-6.9. Data were collected in a low intensity LHC run with collisions occurring at a distance of 11.25 m from the nominal interaction point. The data sample is expected to include 96–97 % of the inelastic proton–proton interactions. The measurement reported here considers charged particles with p{sub T}>0 MeV/c, produced in inelastic interactions with at least one charged particle in -7<η<-6 or 3.7<η<4.8. The dN{sub ch}/dη has been found to decrease with |η|, from 5.11 ± 0.73 at η=3.95 to 1.81 ± 0.56 at η=-6.925. Several Monte Carlo generators are compared to the data and are found to be within the systematic uncertainty of the measurement.

  19. Measurement of the forward charged particle pseudorapidity density in pp collisions at √(s) = 8 TeV using a displaced interaction point

    Energy Technology Data Exchange (ETDEWEB)

    Antchev, G. [Bulgarian Academy of Sciences, INRNE-BAS, Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria); Aspell, P. [CERN, Geneva (Switzerland); Atanassov, I. [CERN, Geneva (Switzerland); Bulgarian Academy of Sciences, INRNE-BAS, Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria); Avati, V. [CERN, Geneva (Switzerland); Baechler, J. [CERN, Geneva (Switzerland); Berardi, V. [INFN Sezione di Bari, Bari (Italy); Dipartimento Interateneo di Fisica di Bari, Bari (Italy); Berretti, M. [Universita degli Studi di Siena (Italy); Gruppo Collegato INFN di Siena, Siena (Italy); CERN, Geneva (Switzerland); Bossini, E. [Universita degli Studi di Siena (Italy); Gruppo Collegato INFN di Siena, Siena (Italy); Bottigli, U. [Universita degli Studi di Siena (Italy); Gruppo Collegato INFN di Siena, Siena (Italy); Bozzo, M. [INFN Sezione di Genova, Genoa (Italy); Universita degli Studi di Genova, Genoa (Italy); Bruecken, E. [Helsinki Institute of Physics, Helsinki (Finland); University of Helsinki, Department of Physics, Helsinki (Finland); Buzzo, A. [INFN Sezione di Genova, Genoa (Italy); Cafagna, F.S. [INFN Sezione di Bari, Bari (Italy); Catanesi, M.G. [INFN Sezione di Bari, Bari (Italy); Covault, C. [Case Western Reserve University, Department of Physics, Cleveland, OH (United States); Csanad, M. [MTA Wigner Research Center, RMKI, Budapest (Hungary); Eoetvoes University, Department of Atomic Physics, Budapest (Hungary); Csoergo, T. [MTA Wigner Research Center, RMKI, Budapest (Hungary); Deile, M. [CERN, Geneva (Switzerland); Doubek, M. [Czech Technical University, Prague (Czech Republic); Eggert, K. [Case Western Reserve University, Department of Physics, Cleveland, OH (United States); Eremin, V. [Ioffe Physical-Technical Institute of Russian Academy of Sciences, St. Petersburg (Russian Federation); Ferro, F. [INFN Sezione di Genova, Genoa (Italy); Fiergolski, A. [INFN Sezione di Bari, Bari (Italy); Warsaw University of Technology, Warsaw (Poland); Garcia, F. [Helsinki Institute of Physics, Helsinki (Finland); Georgiev, V. [University of West Bohemia, Plzen (Czech Republic); Giani, S. [CERN, Geneva (Switzerland); Grzanka, L. [AGH University of Science and Technology, Krakow (Poland); Polish Academy of Science, Institute of Nuclear Physics, Krakow (Poland); Hammerbauer, J. [University of West Bohemia, Plzen (Czech Republic); Heino, J. [Helsinki Institute of Physics, Helsinki (Finland); Hilden, T. [Helsinki Institute of Physics, Helsinki (Finland); University of Helsinki, Department of Physics, Helsinki (Finland); Karev, A. [CERN, Geneva (Switzerland); Kaspar, J. [Institute of Physics of the Academy of Sciences of the Czech Republic, Prague (Czech Republic); CERN, Geneva (Switzerland); Kopal, J. [Institute of Physics of the Academy of Sciences of the Czech Republic, Prague (Czech Republic); CERN, Geneva (Switzerland); Kundrat, V. [Institute of Physics of the Academy of Sciences of the Czech Republic, Prague (Czech Republic); Lami, S. [INFN Sezione di Pisa, Pisa (Italy); Latino, G. [Universita degli Studi di Siena (Italy); Gruppo Collegato INFN di Siena, Siena (Italy); Lauhakangas, R. [Helsinki Institute of Physics, Helsinki (Finland); Leszko, T. [Warsaw University of Technology, Warsaw (Poland); Lippmaa, E. [National Institute of Chemical Physics and Biophysics NICPB, Tallinn (Estonia); Lippmaa, J. [National Institute of Chemical Physics and Biophysics NICPB, Tallinn (Estonia); Lokajicek, M.V. [Institute of Physics of the Academy of Sciences of the Czech Republic, Prague (Czech Republic); Losurdo, L. [Universita degli Studi di Siena (IT); Gruppo Collegato INFN di Siena, Siena (IT); Lo Vetere, M. [INFN Sezione di Genova, Genoa (IT); Universita degli Studi di Genova, Genoa (IT); Lucas Rodriguez, F. [CERN, Geneva (CH); Macri, M. [INFN Sezione di Genova, Genoa (IT); Maeki, T. [Helsinki Institute of Physics, Helsinki (FI); Mercadante, A. [INFN Sezione di Bari, Bari (IT); Minafra, N. [Dipartimento Interateneo di Fisica di Bari, Bari (IT); CERN, Geneva (CH); Minutoli, S. [INFN Sezione di Genova, Genoa (IT); Nemes, F. [MTA Wigner Research Center, RMKI, Budapest (HU); Eoetvoes University, Department of Atomic Physics, Budapest (HU); Niewiadomski, H. [CERN, Geneva (CH); Oliveri, E. [Universita degli Studi di Siena (IT); Gruppo Collegato INFN di Siena, Siena (IT); Oljemark, F. [Helsinki Institute of Physics, Helsinki (FI); University of Helsinki, Department of Physics, Helsinki (FI); Orava, R. [Helsinki Institute of Physics, Helsinki (FI); University of Helsinki, Department of Physics, Helsinki (FI); Oriunno, M. [SLAC National Accelerator Laboratory, Stanford, CA (US); Oesterberg, K. [Helsinki Institute of Physics, Helsinki (FI); University of Helsinki, Department of Physics, Helsinki (FI); Palazzi, P. [Universita degli Studi di Siena (IT); Gruppo Collegato INFN di Siena, Siena (IT); Peroutka, Z. [University of West Bohemia, Plzen (CZ); Prochazka, J. [Institute of Physics of the Academy of Sciences of the Czech Republic, Prague (CZ); Quinto, M. [INFN Sezione di Bari, Bari (IT); Dipartimento Interateneo di Fisica di Bari, Bari (IT); Radermacher, E. [CERN, Geneva (CH); Radicioni, E. [INFN Sezione di Bari, Bari (IT); Ravotti, F. [CERN, Geneva (CH); Robutti, E. [INFN Sezione di Genova, Genoa (IT); Ropelewski, L. [CERN, Geneva (CH); Ruggiero, G. [CERN, Geneva (CH); Saarikko, H. [Helsinki Institute of Physics, Helsinki (FI); University of Helsinki, Department of Physics, Helsinki (FI); Scribano, A. [Universita degli Studi di Siena (IT); Gruppo Collegato INFN di Siena, Siena (IT); Smajek, J. [CERN, Geneva (CH); Snoeys, W. [CERN, Geneva (CH); Sodzawiczny, T. [CERN, Geneva (CH); Sziklai, J. [MTA Wigner Research Center, RMKI, Budapest (HU); Taylor, C. [Case Western Reserve University, Department of Physics, Cleveland, OH (US); Turini, N. [Universita degli Studi di Siena (IT); Gruppo Collegato INFN di Siena, Siena (IT); Vacek, V. [Czech Technical University, Prague (CZ); Welti, J. [Helsinki Institute of Physics, Helsinki (FI); University of Helsinki, Department of Physics, Helsinki (FI); Whitmore, J. [Penn State University, Department of Physics, University Park, PA (US); Wyszkowski, P. [AGH University of Science and Technology, Krakow (PL); Zielinski, K. [AGH University of Science and Technology, Krakow (PL); Collaboration: TOTEM Collaboration

    2015-03-01

    The pseudorapidity density of charged particles dN{sub ch}/dη is measured by the TOTEM experiment in proton-proton collisions at √(s) = 8 TeV within the range 3.9 < η < 4.7 and -6.95 < η < -6.9. Data were collected in a low intensity LHC run with collisions occurring at a distance of 11.25 m from the nominal interaction point. The data sample is expected to include 96-97 % of the inelastic proton-proton interactions. The measurement reported here considers charged particles with p{sub T} > 0 MeV/c, produced in inelastic interactions with at least one charged particle in -7 < η < -6 or 3.7 < η < 4.8. The dN{sub ch}/dη has been found to decrease with vertical stroke η vertical stroke, from 5.11 ± 0.73 at η = 3.95 to 1.81 ± 0.56 at η = -6.925. Several Monte Carlo generators are compared to the data and are found to be within the systematic uncertainty of the measurement. (orig.)

  20. Benchmark calculations of the complete configuration-interaction limit of Born-Oppenheimer diagonal corrections to the saddle points of isotopomers of the H +H2 reaction

    Science.gov (United States)

    Mielke, Steven L.; Schwenke, David W.; Peterson, Kirk A.

    2005-06-01

    We present a detailed ab initio study of the effect that the Born-Oppenheimer diagonal correction (BODC) has on the saddle-point properties of the H3 system and its isotopomers. Benchmark values are presented that are estimated to be within 0.1cm-1 of the complete configuration-interaction limit. We consider the basis set and correlation treatment requirements for accurate BODC calculations, and both are observed to be more favorable than for the Born-Oppenheimer energies. The BODC raises the H+H2 barrier height by 0.1532kcal/mol and slightly narrows the barrier—with the imaginary frequency increasing by ˜2%.

  1. Measurement of σ (e+e− → Hνν)×BR(H → ττ) at CLIC @ 350 GeV

    CERN Document Server

    Münnich, A

    2012-01-01

    This detector benchmark study evaluates the statistical precision with which the H → ττ branching ratio times cross section can be measured at CLIC running at s = 350 GeV. Only the hadronic decay of τs are considered. Results for MH = 126 GeV and 500 fb−1 of integrated luminosity are obtained using full de- tector simulation and including beam-induced backgrounds resulting in a statistical accuracy of cross section times branching ratio of 6.2%.

  2. Age and Type of Instruction (CLIC vs. Traditional EFL) in Lexical Development

    Science.gov (United States)

    Augustín-Llach, María Pilar

    2016-01-01

    The present paper compares the vocabulary development of a group of CLIL and of traditional EFL learners along three years. The observation that a CLIL approach might provide with larger benefits in the long-run vocabulary is the starting point of this study. We had learners in the two groups complete a letter-writing task. These writings were…

  3. Disruption of RB/E2F-1 interaction by single point mutations in E2F-1 enhances S-phase entry and apoptosis.

    Science.gov (United States)

    Shan, B; Durfee, T; Lee, W H

    1996-01-01

    The retinoblastoma protein (RB) has been proposed to function as a negative regulator of cell proliferation by complexing with cellular proteins such as the transcription factor E2F. To study the biological consequences of the RB/E2F-1 interaction, point mutants of E2F-1 which fail to bind to RB were isolated by using the yeast two-hybrid system. Sequence analysis revealed that within the minimal 18-amino acid peptide of E2F-1 required for RB binding, five residues, Tyr (position 411), Glu (419), and Asp-Leu-Phe (423-425), are critical. These amino acids are conserved among the known E2F family members. While mutation of any of these five amino acids abolished binding to RB, all mutants retained their full transactivation potential. Expression of mutated E2F-1, when compared with that of wild-type, significantly accelerated entry into S phase and subsequent apoptosis. These results provide direct genetic evidence for the biological significance of the RB/E2F interaction and strongly suggest that the interplay between RB and E2F is critical for proper cell cycle progression. Images Fig. 3 Fig. 4 PMID:8570615

  4. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions...... interaction between a human operator and an artificial actor or agent. We can apply insights from puppetry to develop culturally-aware robots. Here we describe the development of a robotic marionette theatre wherein robotic controllers assume the role of human puppeteers. The system has been built, tested......, and demonstrated in public settings. We then describe INTERACT, a proposed research project that stages the robotic marionettes in a live performance. The interdisciplinary project brings humanities research to bear on scientific and technological inquiry, and culminates in the development a live performance which...

  5. Interactions

    DEFF Research Database (Denmark)

    The main theme of this anthology is the unique interaction between mathematics, physics and philosophy during the beginning of the 20th century. Seminal theories of modern physics and new fundamental mathematical structures were discovered or formed in this period. Significant physicists such as ......The main theme of this anthology is the unique interaction between mathematics, physics and philosophy during the beginning of the 20th century. Seminal theories of modern physics and new fundamental mathematical structures were discovered or formed in this period. Significant physicists...... also key figures in the philosophical discussions of nature and science - from philosophical tendencies like logical empiricism via critical rationalism to various neo-Kantian trends....

  6. Physics performances for Scalar Electron, Scalar Muon and Scalar Neutrino searches at 3 TeV and 1.4 TeV at CLIC

    CERN Document Server

    Battaglia, Marco; Marshall, John S; Thomson, Mark; Sailer, Andre; Poss, Stephan; van der Kraaij, Erik

    2013-01-01

    The determination of scalar lepton and gaugino masses is an important part of the programme of spectroscopic studies of Supersymmetry at a high energy e+e- linear collider. In this article we present results of a study of the processes: e+e- -> eR eR -> e+e- chi0 chi, e+e- -> muR muR -> mu mu- chi0 chi0, e+e- -> eL eL -> e e chi0 chi0 and e+e- -> snu_e snu_e -> e e chi+ chi-in two Supersymmetric benchmark scenarios at 3 TeV and 1.4 TeV at CLIC. We characterize the detector performance, lepton energy resolution and boson mass resolution. We report the accuracy of the production cross section measurements and the eR muR, snu_e, chi+ and chi0 mass determination, estimate the systematic errors affecting the mass measurement and discuss the requirements on the detector time stamping capability and beam polarization. The analysis accounts for the CLIC beam energy spectrum and the dominant beam-induced background. The detector performances are incorporated by full simulation and reconstruction of the events within t...

  7. Measurement of the branching ratios for the Standard Model Higgs decays into muon pairs and into Z boson pairs at a 1.4 TeV CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)701211; Bozovic-Jelisavcic, Ivanka; Grefe, Christian; Kacarevic, Goran; Lukic, Strahinja; Pandurovic, Mila; Roloff, Philipp Gerhard; Smiljanic, Ivan

    2016-01-01

    The measurement of the Higgs production cross-section times the branching ratios for its decays into μ+μ- and ZZ* pairs at a 1.4 TeV CLIC collider is investigated in this paper. The Standard Model Higgs boson with a mass of 126 GeV is dominantly produced via WW fusion in e+e- collisions at 1.4 TeV centre-of-mass energy. Analyses for both decay channels are based on a full simulation of the CLIC_ILD detector. All relevant physics and beam-induced background processes are taken into account. An integrated luminosity of 1.5 ab 1 and unpolarised beams are assumed. For the H-->ZZ* decay, the purely hadronic final state (ZZ*--> qq ̄qq ̄) is considered as well as ZZ* decays into two jets and two leptons (ZZ*--> qq ̄l+l- ). It is shown that the branching ratio for the Higgs decay into a muon pair times the Higgs production cross-section can be measured with 38% statistical uncertainty. It is also shown that the statistical uncertainty of the Higgs branching fraction for decay into a Z boson pair times the Hi...

  8. Arboreal ant colonies as 'hot-points' of cryptic diversity for myrmecophiles: the weaver ant Camponotus sp. aff. textor and its interaction network with its associates.

    Directory of Open Access Journals (Sweden)

    Gabriela Pérez-Lachaud

    Full Text Available INTRODUCTION: Systematic surveys of macrofaunal diversity within ant colonies are lacking, particularly for ants nesting in microhabitats that are difficult to sample. Species associated with ants are generally small and rarely collected organisms, which makes them more likely to be unnoticed. We assumed that this tendency is greater for arthropod communities in microhabitats with low accessibility, such as those found in the nests of arboreal ants that may constitute a source of cryptic biodiversity. MATERIALS AND METHODS: We investigated the invertebrate diversity associated with an undescribed, but already threatened, Neotropical Camponotus weaver ant. As most of the common sampling methods used in studies of ant diversity are not suited for evaluating myrmecophile diversity within ant nests, we evaluated the macrofauna within ant nests through exhaustive colony sampling of three nests and examination of more than 80,000 individuals. RESULTS: We identified invertebrates from three classes belonging to 18 taxa, some of which were new to science, and recorded the first instance of the co-occurrence of two brood parasitoid wasp families attacking the same ant host colony. This diversity of ant associates corresponded to a highly complex interaction network. Agonistic interactions prevailed, but the prevalence of myrmecophiles was remarkably low. CONCLUSIONS: Our data support the hypothesis of the evolution of low virulence in a variety of symbionts associated with large insect societies. Because most myrmecophiles found in this work are rare, strictly specific, and exhibit highly specialized biology, the risk of extinction for these hitherto unknown invertebrates and their natural enemies is high. The cryptic, far unappreciated diversity within arboreal ant nests in areas at high risk of habitat loss qualifies these nests as 'hot-points' of biodiversity that urgently require special attention as a component of conservation and management

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

    CERN Document Server

    CERN. Geneva

    2008-01-01

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

  10. Thermal Fatigue of Polycrystalline Copper in CLIC Accelerating Structures: Surface Roughening and Hardening as a Function of Grain Orientation

    CERN Document Server

    Aicheler, M

    2010-01-01

    The ac­cel­er­at­ing struc­tures of CLIC will be sub­mit­ted to 2 x 1010 ther­mal-me­chan­i­cal fa­tigue cy­cles, aris­ing from Radio Fre­quen­cy (RF) in­duced eddy cur­rents, caus­ing local su­per­fi­cial cyclic heat­ing. In order to as­sess the ef­fects of su­per­fi­cial fa­tigue, high tem­per­a­ture an­nealed OFE Cop­per sam­ples were ther­mal­ly fa­tigued with the help of pulsed laser ir­ra­di­a­tion. They un­der­went post­mortem Elec­tron Backscat­tered Diffrac­tion (EBSD) mea­sure­ments andμhard­ness ob­ser­va­tions. Pre­vi­ous work has con­firmed that sur­face rough­en­ing de­pends on the ori­en­ta­tion of near-sur­face grains*,**. It is clear­ly ob­served that, through ther­mal cy­cling, the in­crease of hard­ness of a crys­tal­lo­graph­ic di­rec­tion is re­lat­ed to the amount of sur­face rough­en­ing in­duced by fa­tigue. Near-sur­face grains, ori­ent­ed [1 0 0] with re­spect to the sur­face, ex­hibit­ing ver...

  11. A theology of matter. The strong interaction at strong resonance at the meeting point of I and not-I. Conjectures about oscillating strings and fluctuating vacuum energy

    International Nuclear Information System (INIS)

    This book shows that matter and consciousness are intertwined and mutually produce. Quantum vacuum fluctuations ensure that the latent energy of each event is present as zero-point energy simultaneously at all points of the cosmos.

  12. Reannotation of the CELO genome characterizes a set of previously unassigned open reading frames and points to novel modes of host interaction in avian adenoviruses

    Directory of Open Access Journals (Sweden)

    Washietl Stefan

    2003-11-01

    Full Text Available Abstract Background The genome of the avian adenovirus Chicken Embryo Lethal Orphan (CELO has two terminal regions without detectable homology in mammalian adenoviruses that are left without annotation in the initial analysis. Since adenoviruses have been a rich source of new insights into molecular cell biology and practical applications of CELO as gene a delivery vector are being considered, this genome appeared worth revisiting. We conducted a systematic reannotation and in-depth sequence analysis of the CELO genome. Results We describe a strongly diverged paralogous cluster including ORF-2, ORF-12, ORF-13, and ORF-14 with an ATPase/helicase domain most likely acquired from adeno-associated parvoviruses. None of these ORFs appear to have retained ATPase/helicase function and alternative functions (e.g. modulation of gene expression during the early life-cycle must be considered in an adenoviral context. Further, we identified a cluster of three putative type-1-transmembrane glycoproteins with IG-like domains (ORF-9, ORF-10, ORF-11 which are good candidates to substitute for the missing immunomodulatory functions of mammalian adenoviruses. ORF-16 (located directly adjacent displays distant homology to vertebrate mono-ADP-ribosyltransferases. Members of this family are known to be involved in immuno-regulation and similiar functions during CELO life cycle can be considered for this ORF. Finally, we describe a putative triglyceride lipase (merged ORF-18/19 with additional domains, which can be expected to have specific roles during the infection of birds, since they are unique to avian adenoviruses and Marek's disease-like viruses, a group of pathogenic avian herpesviruses. Conclusions We could characterize most of the previously unassigned ORFs pointing to functions in host-virus interaction. The results provide new directives for rationally designed experiments.

  13. Tipping Point

    Medline Plus

    Full Text Available ... en español Blog About OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by ... danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe ...

  14. The Interaction of Arp2/3 Complex with Actin: Nucleation, High Affinity Pointed End Capping, and Formation of Branching Networks of Filaments

    Science.gov (United States)

    Dyche Mullins, R.; Heuser, John A.; Pollard, Thomas D.

    1998-05-01

    The Arp2/3 complex is a stable assembly of seven protein subunits including two actin-related proteins (Arp2 and Arp3) and five novel proteins. Previous work showed that this complex binds to the sides of actin filaments and is concentrated at the leading edges of motile cells. Here, we show that Arp2/3 complex purified from Acanthamoeba caps the pointed ends of actin filaments with high affinity. Arp2/3 complex inhibits both monomer addition and dissociation at the pointed ends of actin filaments with apparent nanomolar affinity and increases the critical concentration for polymerization at the pointed end from 0.6 to 1.0 μ M. The high affinity of Arp2/3 complex for pointed ends and its abundance in amoebae suggest that in vivo all actin filament pointed ends are capped by Arp2/3 complex. Arp2/3 complex also nucleates formation of actin filaments that elongate only from their barbed ends. From kinetic analysis, the nucleation mechanism appears to involve stabilization of polymerization intermediates (probably actin dimers). In electron micrographs of quick-frozen, deep-etched samples, we see Arp2/3 bound to sides and pointed ends of actin filaments and examples of Arp2/3 complex attaching pointed ends of filaments to sides of other filaments. In these cases, the angle of attachment is a remarkably constant 70 ± 7 degrees. From these in vitro biochemical properties, we propose a model for how Arp2/3 complex controls the assembly of a branching network of actin filaments at the leading edge of motile cells.

  15. L’interaction sociale et son impact sur la valeur perçue et l’intention de revisite du point de vente

    OpenAIRE

    Mhaya, Inès; Najjar, Hechmi; Ben Jannet, Imen

    2014-01-01

    The experience of visiting supermarket takes an undeniable position in the retailing field. That’s why this paper aims to propose and validate a model that incorporates social interactions, perceived value and intention to revisit department stores. The results of 282 observations’ survey show that social interactions and perceived value make simultaneously a positive effect on the intention to return to store by consumers. Thus, it is possible to suggest recommendations in favor of retailing...

  16. 补体成分 C3及其缺失突变体蛋白的表达及与 CLIC1蛋白共定位的研究%The expression of human complement component C3 and its deletion mutants and the colocalization with CLIC1

    Institute of Scientific and Technical Information of China (English)

    王二宁; 陈丹丹; 刘晓颖; 范礼斌

    2015-01-01

    目的:研究补体成分 C3及其缺失突变体 C3(1-840)、C3(824-1663)在真核细胞内的表达及与氯离子通道蛋白(CLIC1)的共定位。方法构建 pcDNA3.1-C3-FLAG、pcDNA3.1-C3(1-840)-FLAG、pcDNA3.1-C3(824-1663)-FLAG 三个真核表达质粒(缺失突变体根据 C3的结构域及其裂解断裂位置设计),并分别转染至 HEK 293T 细胞中, Western blot 检测表达情况;上述质粒分别瞬时单转至 COS7细胞和分别与 GFP-CLIC1共转至 COS7细胞内,观察共定位情况。结果成功构建带 FLAG 标签的 C3基因及其两个缺失突变体[C3(1-840)、C3(824-1663)]的真核表达载体, Western blot 结果显示它们在 HEK 293T 细胞中均能成功表达;免疫荧光显示它们在 COS7细胞中均主要分布于细胞质,且三个真核表达载体中只有 C3(824-1663)与 CLIC1有共定位。结论补体 C3及其缺失突变体 C3(1-840)和 C3(824-1663)在 HEK 293T、COS7细胞中均能高效表达,且主要分布在细胞质内,C3(824-1663)与 CLIC1蛋白有共定位。%Objective To study the expression and cell localization of complement component C3 and its deletion mutants C3(1-840)and C3(824-1663)in eukaryotic cells and the colocalization with CLIC1.Methods To con-struct three eukaryotic expression plasmids of pcDNA3.1-C3-FLAG,pcDNA3.1-C3(1-840)-FLAG and pcDNA3.1-C3(824-1663)-FLAG(according to C3 structure domain and splitting position).The plasmids were transfected into HEK 293T cells.Then the expression was detected by Western blot,and their cellular localization was detected in COS7 cells by fluorescence microscopy.Results The eukaryotic expression plasmids of pcDNA3.1-C3-FLAG, pcDNA3.1-C3(1-840)-FLAG and pcDNA3.1-C3(824-1663)-FLAG were constructed successfully,which could be expressed in HEK 293T and COS7 cells,and the cellular localization of C3 and C3(1-840),C3(824-1663)ap-peared similar,mainly in the cytoplasm,and only C3(824-1663)co

  17. Turning Point

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Moves from the United States and North Korea give new impetus to nuclear disablement and U.S.-North Korea ties The tense situation surrounding denu-clearization on the Korean Peninsula has reached a turning point. On

  18. Sequential Convex Programming for Power Set-point Optimization in a Wind Farm using Black-box Models, Simple Turbine Interactions, and Integer Variables

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Larsen, Lars F. S.; Jørgensen, John Bagterp;

    2012-01-01

    We consider the optimization of power set-points to a large number of wind turbines arranged within close vicinity of each other in a wind farm. The goal is to maximize the total electric power extracted from the wind, taking the wake effects that couple the individual turbines in the farm...

  19. Experiment of Laser Pointing Stability on Different Surfaces to validate Micrometric Positioning Sensor

    CERN Document Server

    AUTHOR|(SzGeCERN)721924; Mainaud Durand, Helene; Piedigrossi, Didier; Sandomierski, Jacek; Sosin, Mateusz; Geiger, Alain; Guillaume, Sebastien

    2014-01-01

    CLIC requires 10 μm precision and accuracy over 200m for the pre-alignment of beam related components. A solution based on laser beam as straight line reference is being studied at CERN. It involves camera/shutter assemblies as micrometric positioning sensors. To validate the sensors, it is necessary to determine an appropriate material for the shutter in terms of laser pointing stability. Experiments are carried out with paper, metal and ceramic surfaces. This paper presents the standard deviations of the laser spot coordinates obtained on the different surfaces, as well as the measurement error. Our experiments validate the choice of paper and ceramic for the shutter of the micrometric positioning sensor. It also provides an estimate of the achievable precision and accuracy of the determination of the laser spot centre with respect to the shutter coordinate system defined by reference targets.

  20. A Point-of-Sale Communications Campaign to Provide Consumers Safety Information on Drug-Dietary Supplement Interactions:A Pilot Study

    OpenAIRE

    Perlman, Adam I.; Lebow, David G.; Raphael, Karen; Ali, Ather; Simmons, Leigh Ann

    2013-01-01

    Concurrent use of dietary supplements with over-the-counter and prescription pharmaceuticals has become increasingly common, and with this trend, so has the incidence of adverse drug–supplement interactions. In the current market, consumers have no way to distinguish between safe and potentially harmful supplements. Thus, the primary objective of this study was to test the hypothesis that messages designed to increase consumers' awareness of potential health risks of concurrent use of dietary...

  1. Solutions for correlations along the coexistence curve and at the critical point of a kagomé lattice gas with three-particle interactions

    Science.gov (United States)

    Barry, J. H.; Muttalib, K. A.; Tanaka, T.

    2008-01-01

    We consider a two-dimensional (d=2) kagomé lattice gas model with attractive three-particle interactions around each triangular face of the kagomé lattice. Exact solutions are obtained for multiparticle correlations along the liquid and vapor branches of the coexistence curve and at criticality. The correlation solutions are also determined along the continuation of the curvilinear diameter of the coexistence region into the disordered fluid region. The method generates a linear algebraic system of correlation identities with coefficients dependent only upon the interaction parameter. Using a priori knowledge of pertinent solutions for the density and elementary triplet correlation, one finds a closed and linearly independent set of correlation identities defined upon a spatially compact nine-site cluster of the kagomé lattice. Resulting exact solution curves of the correlations are plotted and discussed as functions of the temperature and are compared with corresponding results in a traditional kagomé lattice gas having nearest-neighbor pair interactions. An example of application for the multiparticle correlations is demonstrated in cavitation theory.

  2. The production and decay of the top partner T in the left–right twin Higgs model at the ILC and CLIC

    Directory of Open Access Journals (Sweden)

    Yao-Bei Liu

    2015-03-01

    Full Text Available The left–right twin Higgs model (LRTHM predicts the existence of the top partner T. In this work, we make a systematic investigation for the single and pair production of this top partner T through the processes: e+e−→tT¯+Tt¯ and TT¯, the neutral scalar (the SM-like Higgs boson h or neutral pseudoscalar boson ϕ0 associate productions e+e−→tT¯h+Tt¯h, TT¯h, tT¯ϕ0+Tt¯ϕ0 and TT¯ϕ0. From the numerical evaluations for the production cross sections and relevant phenomenological analysis we find that (a the production rates of these processes, in the reasonable parameter space, can reach the level of several or tens of femtobarns; (b for some cases, the peak value of the resonance production cross section can be enhanced significantly and reaches to the level of pb; (c the subsequent decay of T→ϕ+b→tb¯b may generate typical phenomenological features rather different from the signals from other new physics models beyond the standard model (SM; and (d since the relevant SM background is generally not large, some signals of the top partner T predicted by the LRTHM may be detectable in the future ILC and CLIC experiments.

  3. Beam instability induced by rf deflectors in the combiner ring of the CLIC test facility and mitigation by damped deflecting structures

    CERN Document Server

    Alesini, D; Biscari, C; Ghigo, A; Corsini, R

    2011-01-01

    In the CTF3 (CLIC test facility 3) run of November 2007, a vertical beam instability has been found in the combiner ring during operation. After a careful analysis, the source of the instability has been identified in the vertical deflecting modes trapped in the rf deflectors and excited by the beam passage. A dedicated tracking code that includes the induced transverse wakefield and the multibunch multipassage effects has been written and the results of the beam dynamics analysis are presented in the paper. The mechanism of the instability was similar to the beam breakup in a linear accelerator or in an energy recovery linac. The results of the code allowed identifying the main key parameters driving such instability and allowed finding the main knobs to mitigate it. To completely suppress such beam instability, two new rf deflectors have been designed, constructed, and installed in the ring. In the new structures the frequency separation between the vertical and horizontal deflecting modes has been increase...

  4. Thermal evaluation of different DC multi-conductor cable cross-sections and installation patterns for the CLIC drive-beam quadrupoles

    CERN Document Server

    Maglio, D

    2007-01-01

    The main goal of this study is to determine the thermal behaviour of different dc multi-conductor cable cross-sections and installations patterns for the CLIC drive beam quadrupoles loaded with increasing values of current intensity. A simplified two dimensional model of the heat transfer problem was prepared with a commercial CFD software, STAR-CD 4.2. The heat flux generated by Joule effect in conductors was estimated taking into account the current value per conductor and the temperature dependence of the copper electrical resistance. In parallel, a geometrical simplification of the problem has been done in order to be able to apply theoretical formulas which have been implemented by Microsoft Excel. Obtained results have been compared with those got by the dedicated software, showing between them a good correspondence for two-conductor cables and confirming, for this case, the rules given in the in the French norm NF C15-100. In case of multiconductor cables, attention is to be paid to the temperature lev...

  5. PEOPLE & POINTS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Gaming Tycoon Refutes Criticism For Shi Yuzhu,founder of China’s fastest growing online game operator,the wealth he has garnered through his controversial business is not a source of glory. For years,the 46-year-old chair- man of the New York-listed Giant Interactive Entertainment Group Inc.,along with his counterparts in the industry,has been blamed for the gaming addiction of many players,mostly teens.However,Shi

  6. Classical Interaction of a Magnet and a Point Charge: The Classical Electromagnetic Forces Responsible for the Aharonov-Bohm Phase Shift

    CERN Document Server

    Boyer, Timothy H

    2014-01-01

    A new classical electromagnetic analysis is presented suggesting that the Aharonov-Bohm phase shift is overwhelmingly likely to arise from a classical lag effect based upon classical electromagnetic forces. The analysis makes use of several aspects of classical electromagnetic theory which are unfamiliar to most physicists, including the Darwin Lagrangian, acceleration-based electric fields, internal electromagnetic momentum in a magnet, and a magnet model involving at least three mutually-interacting particles. Only when the acceleration-based electric forces acting on the passing charge are included do we find consistency with all the relativistic conservation laws: energy, linear momentum, angular momentum, and constant center-of-mass velocity. The electric forces on the passing charge lead to a lag effect which accounts quantitatively for the Aharonov-Bohm phase shift. Thus the classical analysis strongly suggests that the Aharonov-Bohm phase shift (observed when electrons pass a long solenoid which corre...

  7. Coupled Simulations of the Synchrotron Radiation and Induced Desorption Pressure Profiles for the HL-LHC Triplet Area and Interaction Points

    CERN Document Server

    Kersevan, R; Bregliozzi, G

    2014-01-01

    The HiLumi-LHC machine upgrade has officially started as an approved LHC project (see dedicated presentations at this conference on the subject). One important feature of the upgrade is the installation of very high-gradient triplet magnets for focusing the beams at the collision points of the two high-luminosity detectors ATLAS and CMS. Other important topics are new superconducting D1 and D2 magnets, installation of crab cavities and new tertiary collimators, and re-shuffling of the dispersion suppression area. Based on the current magnetic lattice set-up and beam orbits, a detailed study of the emission of synchrotron radiation (SR) and related photon-induced desorption (PID) has been carried out. A significant amount of SR photons are generated by the two off-axis beams in the common vacuum chamber of the triplet area, about 57 m in length. Ray-tracing Montecarlo codes Synrad+ and Molflow+ have been employed in this study. The related PID pressure profiles are shown, together with simulations using the co...

  8. Formations hybrides et interactions en ligne du point de vue de l'enseignant : pratiques, représentations, évolutions Blended learning and online interaction from the teacher's perspective: practice, representation and evolution

    Directory of Open Access Journals (Sweden)

    Christian Degache

    2008-10-01

    Full Text Available Les formations hybrides sont de plus en plus nombreuses dans le domaine des langues mais ne sont, une fois créées, pas toujours stables dans le temps. Devant ce constat, nous avons fait l'hypothèse, qui est au fondement du présent article, que ces évolutions sont liées au déroulement des interactions qui ont effectivement eu lieu dans le cadre de ces formations. Pour vérifier notre hypothèse, nous avons mené des entretiens, basés sur des questionnaires hétéro-administrés, avec 15 concepteurs de formations en langues pour spécialistes d'autres disciplines (Lansad conçues dans le cadre du projet Flodi. L'analyse des données ainsi obtenues a permis d'identifier les pratiques d'interaction, les représentations des concepteurs et les évolutions de formations hybrides. Elle montre que l'interaction effective est bien un facteur déterminant pour leur évolution. Par ailleurs, l'observation des évolutions passées, présentes ou futures nous a permis de distinguer quatre tendances des formations hybrides en langues : introductive (des Tice, optimisatrice, réorganisatrice et collaborative.Language training increasingly uses blended learning systems. One can state that the latter, once they are set up, often continue to be modified. We argue that these modifications are due to the interaction during the related training sessions. To verify our hypothesis we interviewed 15 designers of blended learning systems in the field of languages for specialists of other disciplines which are part of the Flodi-project, filling out questionnaires while interviewing them. An analysis of the data reveals interactional habits, course designers' representations, as well as past and foreseen modifications of the blended learning systems. The results show that interactions during training sessions did influence the evolution of the system. Moreover, we were able to distinguish between four tendencies of past, present and future modification of the

  9. Higgs Mass and Cross-Section Measurements at a 500 GeV CLIC Machine, Operating at sqrt(s) = 350 GeV and 500 GeV

    CERN Document Server

    Marshall, J

    2012-01-01

    Higgs mass and cross-section measurements have been examined to assess the capability of a 500 GeV CLIC machine, operating at centre-of-mass energies of 350 GeV and 500 GeV. A Higgs mass of 120 GeV and a luminosity of 500 fb−1 were assumed. Model-independent measurements were performed by examining the recoil of the Z in the Higgsstrahlung process, with the Z subsequently decaying to a pair of muons or electrons.

  10. From gestural pointing to vocal pointing in the brain

    OpenAIRE

    Loevenbruck, Hélène; Dohen, Marion; Vilain, Coriandre

    2008-01-01

    International audience Deixis, or pointing, is the ability to draw the viewer/listener's attention to an object, a person, a direction or an event. Pointing is involved at different stages of human communication development, in multiple modalities: first with the eyes, then with the finger, then with intonation and finally with syntax. It is ubiquitous and probably universal in human interactions. The role of index-finger pointing in language acquisition suggests that it may be a precursor...

  11. Signature of MoU between CERN and Australian Collaboration for Accelerator Science (ACAS); Roger Rassool, ACAS Director; Mark Boland, ACAS Deputy Director; Jean-Pierre Delahaye, CLIC Project Leader; in the presence of Rolf Heuer, Director-General and Emmanuel Tsesmelis, Adviser for Australia

    CERN Multimedia

    Maximilien Brice

    2010-01-01

    Signature of MoU between CERN and Australian Collaboration for Accelerator Science (ACAS); Roger Rassool, ACAS Director; Mark Boland, ACAS Deputy Director; Jean-Pierre Delahaye, CLIC Project Leader; in the presence of Rolf Heuer, Director-General and Emmanuel Tsesmelis, Adviser for Australia

  12. Mode Interaction at a Triple Zero Point of O(2)-symmetric Nonlinear Systems with Two Parameters%带两个参数的O(2)对称非线性系统的三重奇异点处的分枝

    Institute of Scientific and Technical Information of China (English)

    吴微; 孟繁友

    2000-01-01

    We consider a triple zero point of nonlinear equations with O(2)-symmetry, where the Jacobian has a zero eigenvalue of geometric multiplicity one and algebraic multiplicity three, We show that this triple zero point exhibits a new bifurcation phenomenon, that is, a mode interaction of the following three paths: bifurcation points from steady-states, steadystates and rotating waves to standing waves, rotating waves and modulated rotating waves respectively.

  13. Critical Points of Contact

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Morelli, Nicola

    2011-01-01

    In contemporary urban societies multiple networks and systems interact, overlap, exist in parallel, converge, conflict etc. creating unforeseen complexity and less transparency. By exploring how layered networks of physical movement, service information, goods delivery, commercial communication etc....... are connected (and disconnected) we get a much better understanding of how to design and intervene regardless if we are thinking about public spaces in the city or new systems of service design. The many networks orchestrating and facilitating contemporary everyday life are dependent on the strategic sites...... where the networks meet and establish contact. Thus we argue for the usefulness of the notion of Critical Point of Contact (CPC) to deepen our understanding of the actual life within networks. En route to this notion we draw upon theories within as diverse realms such as interaction design, service...

  14. C. Petrone et al.: "Magnetic measurement of the model magnet QD0 designed for the CLIC final focus beam transport line." CERN TE-MSC Internal Note, EDMS Nr: 1184196

    CERN Document Server

    Arpaia, Pasquale; Petrone, Carlo; Russenschuck, Stephan; Walckiers, Louis

    2012-01-01

    This note presents the results of the magnetic measurements performed on QD0, model magnet for the final focus transport line for CLIC (Fig. 1). This high-gradient, hybrid quadrupole has a yoke length of 0.1 m and an aperture of 8.3 mm. ND2Fe14B Permanent magnet blocks provide a gradient of 150 T/m, which can be further increased to 530 T/m when the four coils are excited to 18.3 A. The request was to measure the strength of the field and the multipole coefficients at different currents. The measurement of the field strength, by means of the single stretched wire system, was done in December 2011 in the I8 laboratory. The measurement of the multipole was done by means of the oscillating wire system [1][2].

  15. Residual analysis for spatial point processes

    DEFF Research Database (Denmark)

    Baddeley, A.; Turner, R.; Møller, Jesper;

    We define residuals for point process models fitted to spatial point pattern data, and propose diagnostic plots based on these residuals. The techniques apply to any Gibbs point process model, which may exhibit spatial heterogeneity, interpoint interaction and dependence on spatial covariates. Ou...

  16. Inhomogeneous Markov point processes by transformation

    DEFF Research Database (Denmark)

    Jensen, Eva B. Vedel; Nielsen, Linda Stougaard

    2000-01-01

    We construct parametrized models for point processes, allowing for both inhomogeneity and interaction. The inhomogeneity is obtained by applying parametrized transformations to homogeneous Markov point processes. An interesting model class, which can be constructed by this transformation approach......, is that of exponential inhomogeneous Markov point processes. Statistical inference For such processes is discussed in some detail....

  17. Residual analysis for spatial point processes

    DEFF Research Database (Denmark)

    Baddeley, A.; Turner, R.; Møller, Jesper;

    2005-01-01

    We define residuals for point process models fitted to spatial point pattern data, and we propose diagnostic plots based on them. The residuals apply to any point process model that has a conditional intensity; the model may exhibit spatial heterogeneity, interpoint interaction and dependence on ....... A plot of smoothed residuals against spatial location, or against a spatial covariate, is effective in diagnosing spatial trend or covariate effects. Q-Q plots of the residuals are effective in diagnosing interpoint interaction....

  18. Experiments of Laser Pointing Stability in Air and in Vacuum to Validate Micrometric Positioning Sensor

    CERN Document Server

    Stern, G; Piedigrossi, D; Sandomierski, J; Sosin, M; Geiger, A; Guillaume, S

    2014-01-01

    Aligning accelerator components over 200m with 10 μm accuracy is a challenging task within the Compact Linear Collider (CLIC) study. A solution based on laser beam in vacuum as straight line reference is proposed. The positions of the accelerator’s components are measured with respect to the laser beam by sensors made of camera/shutter assemblies. To validate these sensors, laser pointing stability has to be studied over 200m. We perform experiments in air and in vacuum in order to know how laser pointing stability varies with the distance of propagation and with the environment. The experiments show that the standard deviations of the laser spot coordinates increase with the distance of propagation. They also show that the standard deviations are much smaller in vacuum (8 μm at 35m) than in air (2000 μm at 200m). Our experiment validates the concept of laser beam in vacuum with camera/shutter assembly for micrometric positioning over 35m. It also gives an estimation of the achievable precision.

  19. SPIRE Point Source Photometry

    CERN Document Server

    Pearson, Chris; North, Chris; Bendo, George; Conversi, Luca; Dowell, Darren; Griffin, Matt; Jin, Terry; Laporte, Nicolas; Papageorgiou, Andreas; Schulz, Bernhard; Shupe, Dave; Smith, Anthony J; Xu, Kevin

    2014-01-01

    The different algorithms appropriate for point source photometry on data from the SPIRE instrument on-board the Herschel Space Observatory, within the Herschel Interactive Processing Environment (HIPE) are compared. Point source photometry of a large ensemble of standard calibration stars and dark sky observations is carried out using the 4 major methods within HIPE: SUSSEXtractor, DAOphot, the SPIRE Timeline Fitter and simple Aperture Photometry. Colour corrections and effective beam areas as a function of the assumed source spectral index are also included to produce a large number of photometric measurements per individual target, in each of the 3 SPIRE bands (250, 350, 500um), to examine both the accuracy and repeatability of each of the 4 algorithms. It is concluded that for flux densities down to the level of 30mJy that the SPIRE Timeline Fitter is the method of choice. However, at least in the 250 and 350um bands, all 4 methods provide photometric repeatability better than a few percent down to at appr...

  20. 全球气候研究计划(WCRP)中的气候与冰冻圈项目(CliC): 冰冻圈与气候的优先研究领域%The World Climate Research Programme (WCRP) Climate and Cryosphere Project (CliC): Priority Studies of the Cryosphere and Climate

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The cryosphere is an integral part of the global climate system, however, many aspects of the cryosphere have not been fully covered within WCRP. Issues relating to potential changes in the climate cryosphere system become more and more important in order to describes research and coordination initiatives required to integrate fully studies of impact and response of the cryosphere to climate change. The article also indicates the recent progress of CliC, and its future plan.

  1. 'Click Rural' - the rural program for rural electrification: his effects and implications the western Parana, Brazil after 20 years later; O programa de eletrificacao rural 'Clic rural': seus efeitos e implicacoes na regiao oeste do Parana 20 anos depois

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Celso Eduardo Lins de [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Dept. de Engenharia de Alimentos; Halmeman, Maria Cristina Rodrigues

    2006-07-01

    This study verified through a sampling the technical standard of attendance adopted by the greater program for rural electrification denominated 'Clic Rural' ever implanted in the state of Parana, Brazil, in the period of 1984-1992 at the concession area of COPEL - Parana Energy Company. The work was based on a field research with visits and a questionnaire applied of rural proprietaries.

  2. Articulation Points in Complex Networks

    CERN Document Server

    Tian, Liang; Shi, Da-Ning; Liu, Yang-Yu

    2016-01-01

    An articulation point in a network is a node whose removal disconnects the network. Those nodes play key roles in ensuring connectivity of many real-world networks, from infrastructure networks to protein interaction networks and terrorist communication networks. Despite their fundamental importance, a general framework of studying articulation points in complex networks is lacking. Here we develop analytical tools to study key issues pertinent to articulation points, e.g. the expected number of them and the network vulnerability against their removal, in an arbitrary complex network. We find that a greedy articulation point removal process provides us a novel perspective on the organizational principles of complex networks. Moreover, this process is associated with two fundamentally different types of percolation transitions with a rich phase diagram. Our results shed light on the design of more resilient infrastructure networks and the effective destruction of terrorist communication networks.

  3. Adaptive Pointing Design and Evaluation of a Precision Enhancing Technique for Absolute Pointing Devices

    OpenAIRE

    König, Werner A.; Gerken, Jens; Dierdorf, Stefan; Reiterer, Harald

    2009-01-01

    We present Adaptive Pointing, a novel approach to addressing the common problem of accuracy when using absolute pointing devices for distant interaction. First, we discuss extensively some related work concerning the problem-domain of pointing accuracy when using absolute or relative pointing devices. As a result, we introduce a novel classification scheme to more clearly discriminate between different approaches. Second, the Adaptive Pointing technique is presented and described in detail. ...

  4. Critical-Point Structure in Finite Nuclei

    CERN Document Server

    Leviatan, A

    2006-01-01

    Properties of quantum shape-phase transitions in finite nuclei are considered in the framework of the interacting boson model. Special emphasis is paid to the dynamics at the critical-point of a general first-order phase transition.

  5. Point-Force Energy Coupling

    Science.gov (United States)

    Burton, Tristan; Squires, Kyle

    2005-11-01

    Fully resolved simulations of particle-laden turbulent flows are computationally expensive even with a single particle. Therefore, simulations of flows with realistic numbers of particles typically treat the disperse phase as point-particles and models are used to account for the interaction between the phases. The particle trajectories are determined using a Lagrangian particle equation of motion that accounts for the fluid forces. The effect of the particulate phase on the fluid is included using point-force momentum coupling, where the opposite of the force applied to each particle by the fluid is distributed back to fluid grid points in a local region. In this work, we perform direct numerical simulation (DNS) of a particle moving at a prescribed constant or time-dependent velocity through a stationary fluid, and use the resulting force history in a corresponding point-force simulation to study point-force energy coupling. The energy input from the moving particle and the fluid dissipation in the DNS are compared to corresponding quantities in the unresolved calculation. A range of particle Reynolds numbers and ratios of the particle diameter to the unresolved grid spacing are considered to determine the conditions under which point-force momentum coupling provides accurate energy coupling.

  6. Characterizing configurations of fire ignition points through spatiotemporal point processes

    Science.gov (United States)

    Comas, C.; Costafreda-Aumedes, S.; Vega-Garcia, C.

    2014-04-01

    Human-caused forest fires are usually regarded as unpredictable but often exhibit trends towards clustering in certain locations and periods. Characterizing such configurations is crucial for understanding spatiotemporal fire dynamics and implementing preventive actions. Our objectives were to analyse the spatiotemporal point configuration and to test for spatiotemporal interaction. We characterized the spatiotemporal structure of 984 fire ignition points in a study area of Galicia, Spain, during 2007-2011 by the K-Ripley's function. Our results suggest the presence of spatiotemporal structures for time lags of less than two years and ignition point distances in the range 0-12 km. Ignition centre points at time lags of less than 100 days are aggregated for any inter-event distance. This cluster structure loses strength as the time lag increases, and at time lags of more than 365 days this cluster structure is not significant for any lag distance. Our results also suggest spatiotemporal interdependencies at time lags of less than 100 days and inter-event distances of less than 10 km. At time lags of up to 365 days spatiotemporal components are independent for any point distance. These results suggest that risk conditions occur locally and are short-lived in this study area.

  7. Point by Point: Adding up Motivation

    Science.gov (United States)

    Marchionda, Denise

    2010-01-01

    Students often view their course grades as a mysterious equation of teacher-given grades, teacher-given grace, and some other ethereal components based on luck. However, giving students the power to earn points based on numerous daily/weekly assignments and attendance makes the grading process objective and personal, freeing the instructor to…

  8. Arctic Climate Tipping Points

    OpenAIRE

    Lenton, Timothy M.

    2012-01-01

    There is widespread concern that anthropogenic global warming will trigger Arctic climate tipping points. The Arctic has a long history of natural, abrupt climate changes, which together with current observations and model projections, can help us to identify which parts of the Arctic climate system might pass future tipping points. Here the climate tipping points are defined, noting that not all of them involve bifurcations leading to irreversible change. Past abrupt climate changes in the A...

  9. Interactive two-step training and management strategy for improvement of the quality of point-of-care testing by nurses:implementation of the strategy in blood glucose measurement

    OpenAIRE

    Lehto, L. (Liisa)

    2014-01-01

    Abstract Point-of-care testing (POCT) is defined as laboratory tests performed outside the traditional clinical laboratory close to the patient at the time and place where care is received, such as hospitals and healthcare centers. The main reason for the use of POCT is that they provide rapid results and enable prompt interventions, with hopefully improved patient outcomes. All phases of laboratory procedure are included in POCT offering many opportunities for errors, which can influence ...

  10. Indexing Moving Points

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff

    2003-01-01

    We propose three indexing schemes for storing a set S of N points in the plane, each moving along a linear trajectory, so that any query of the following form can be answered quickly: Given a rectangle R and a real value t, report all K points of S that lie inside R at time t. We first present an...

  11. Nickel Curie Point Engine

    Science.gov (United States)

    Chiaverina, Chris; Lisensky, George

    2014-01-01

    Ferromagnetic materials such as nickel, iron, or cobalt lose the electron alignment that makes them attracted to a magnet when sufficient thermal energy is added. The temperature at which this change occurs is called the "Curie temperature," or "Curie point." Nickel has a Curie point of 627 K, so a candle flame is a sufficient…

  12. Sunspot Bright Points

    CERN Document Server

    Choudhary, Debi Prasad

    2010-01-01

    We used the flux calibrated images through the Broad Band Filter Imager and Stokes Polarimeter data obtained with the Solar Optical Telescope onboard the Hinode spacecraft to study the properties of bright points in and around the sunspots. The well isolated bright points were selected and classified as umbral dot, peripheral umbral dot, penumbral grains and G-band bright point depending on their location. Most of the bright points are smaller than about 150 km. The larger points are mostly associated with the penumbral features. The bright points are not uniformly distributed over the umbra but preferentially located around the penumbral boundary and in the fast decaying parts of umbra. The color temperature of the bright points, derived using the continuum irradiance, are in the range of 4600 K to 6600 K with cooler ones located in the umbra. The temperature increases as a function of distance from the center to outside. The G-band, CN-band and CaII H flux of the bright points as a function of their blue ba...

  13. Model Breaking Points Conceptualized

    Science.gov (United States)

    Vig, Rozy; Murray, Eileen; Star, Jon R.

    2014-01-01

    Current curriculum initiatives (e.g., National Governors Association Center for Best Practices and Council of Chief State School Officers 2010) advocate that models be used in the mathematics classroom. However, despite their apparent promise, there comes a point when models break, a point in the mathematical problem space where the model cannot,…

  14. SharePoint 2007 Collaboration For Dummies

    CERN Document Server

    Harvey, Greg

    2009-01-01

    If you're looking for a way to help your teams access what they need to know, work together, and get the job done, SharePoint can do just that. SharePoint 2007 Collaboration For Dummies shows you the easiest way to set up and customize SharePoint, manage your data, interact using SharePoint blogs and wikis, integrate Office programs, and make your office more productive. You'll learn what SharePoint can do and how to make it work for your business, understand the technical terms, and enable your people to collaborate on documents and spreadsheets. You'll even discover how to get SharePoint hel

  15. 6th July 2010 - United Kingdom Science and Technology Facilities Council W. Whitehorn signing the guest book with Head of International relations F. Pauss, visiting the Computing Centre with Information Technology Department Head Deputy D. Foster, the LHC superconducting magnet test hall with Technology Department P. Strubin,the Centre Control Centre with Operation Group Leader M. Lamont and the CLIC/CTF3 facility with Project Leader J.-P. Delahaye.

    CERN Multimedia

    Teams : M. Brice, JC Gadmer

    2010-01-01

    6th July 2010 - United Kingdom Science and Technology Facilities Council W. Whitehorn signing the guest book with Head of International relations F. Pauss, visiting the Computing Centre with Information Technology Department Head Deputy D. Foster, the LHC superconducting magnet test hall with Technology Department P. Strubin,the Centre Control Centre with Operation Group Leader M. Lamont and the CLIC/CTF3 facility with Project Leader J.-P. Delahaye.

  16. Do acupuncture points exist?

    Energy Technology Data Exchange (ETDEWEB)

    Yan Xiaohui; Zhang Xinyi [Department of Physics, Surface Physics Laboratory (State Key Laboratory), and Synchrotron Radiation Research Center of Fudan University, Shanghai 200433 (China); Liu Chenglin [Physics Department of Yancheng Teachers' College, Yancheng 224002 (China); Dang, Ruishan [Second Military Medical University, Shanghai 200433 (China); Huang Yuying; He Wei [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039 (China); Ding Guanghong [Shanghai Research Center of Acupuncture and Meridian, Pudong, Shanghai 201203 (China)

    2009-05-07

    We used synchrotron x-ray fluorescence analysis to probe the distribution of four chemical elements in and around acupuncture points, two located in the forearm and two in the lower leg. Three of the four acupuncture points showed significantly elevated concentrations of elements Ca, Fe, Cu and Zn in relation to levels in the surrounding tissue, with similar elevation ratios for Cu and Fe. The mapped distribution of these elements implies that each acupuncture point seems to be elliptical with the long axis along the meridian. (note)

  17. Interaction of the bovine papillomavirus type 1 E2 transcriptional control protein with the viral enhancer: purification of the DNA-binding domain and analysis of its contact points with DNA.

    OpenAIRE

    Moskaluk, C A; Bastia, D

    1988-01-01

    The E2 gene of bovine papillomavirus type 1 positively and negatively regulates the transcriptional enhancer located in the long control region of the viral genome. The DNA-binding domain of the E2 gene product was suspected to interact with the DNA sequence motif ACCN6GGT. We have shown that the carboxy-terminal 126 amino acids of the E2 protein constitute the DNA-binding domain. In this paper we described the expression of the E2 carboxy terminus in Escherichia coli and its subsequent purif...

  18. ENTREPRENEURSHIP AS SOCIAL INTERACTION

    DEFF Research Database (Denmark)

    Larsen, Henry; Lima, Patricia; Olsen, Bente;

    2013-01-01

    This paper aims to explore how entrepreneurs work with innovation; to explore and develop attention points in understanding entrepreneurship as social processes of interaction between people. Through interviews and engagement with entrepreneurs and key stakeholders, their actual social practices...

  19. Allegheny County Address Points

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains address points which represent physical address locations assigned by the Allegheny County addressing authority. Data is updated by County...

  20. Designated Wildlife Lakes - points

    Data.gov (United States)

    Minnesota Department of Natural Resources — This is a point shapefile of Designated Wildlife Lakes in Minnesota. This shapefile was created by converting lake polygons from the Designated Wildlife Lakes...

  1. Publication point indicators

    DEFF Research Database (Denmark)

    Elleby, Anita; Ingwersen, Peter

    2010-01-01

    The paper presents comparative analyses of two publication point systems, The Norwegian and the in-house system from the interdiscplinary Danish Institute for International Studies (DIIS), used as case in the study for publications published 2006, and compares central citation-based indicators...... with novel publication point indicators (PPIs) that are formalized and exemplified. Two diachronic citation windows are applied: 2006-07 and 2006-08. Web of Science (WoS) as well as Google Scholar (GS) are applied to observe the cite delay and citedness for the different document types published by DIIS......, journal articles, book chapters/conference papers and monographs. Journal Crown Indicator (JCI) calculations was based on WoS. Three PPIs are proposed: thePublication Point Ratio (PPR), which measures the sum of obtained publiacation points over the sum of the ideal pointws for the same set of documents...

  2. Triple Point Topological Metals

    Science.gov (United States)

    Zhu, Ziming; Winkler, Georg W.; Wu, QuanSheng; Li, Ju; Soluyanov, Alexey A.

    2016-07-01

    Topologically protected fermionic quasiparticles appear in metals, where band degeneracies occur at the Fermi level, dictated by the band structure topology. While in some metals these quasiparticles are direct analogues of elementary fermionic particles of the relativistic quantum field theory, other metals can have symmetries that give rise to quasiparticles, fundamentally different from those known in high-energy physics. Here, we report on a new type of topological quasiparticles—triple point fermions—realized in metals with symmorphic crystal structure, which host crossings of three bands in the vicinity of the Fermi level protected by point group symmetries. We find two topologically different types of triple point fermions, both distinct from any other topological quasiparticles reported to date. We provide examples of existing materials that host triple point fermions of both types and discuss a variety of physical phenomena associated with these quasiparticles, such as the occurrence of topological surface Fermi arcs, transport anomalies, and topological Lifshitz transitions.

  3. Transitivity on Weierstrass points

    CERN Document Server

    Laing, Zoe

    2010-01-01

    We look for Riemann surfaces whose automorphism group acts transitively on the Weierstrass points. We concentrate on hyperelliptic surfaces, surfaces with PSL(2, q) as automorphism group, Platonic surfaces and Fermat curves.

  4. National Wetlands Inventory Points

    Data.gov (United States)

    Minnesota Department of Natural Resources — Wetland point features (typically wetlands that are too small to be as area features at the data scale) mapped as part of the National Wetlands Inventory (NWI). The...

  5. On the local relaxation of solid neon upon Rydberg excitation of a NO impurity: the role of the NO(A)-Ne interaction potential and zero-point quantum delocalization.

    Science.gov (United States)

    Pajón-Suárez, Pedro; Rojas-Lorenzo, Germán A; Rubayo-Soneira, Jesús; Hernández-Lamoneda, Ramón; Larrégaray, Pascal

    2009-12-31

    The local relaxation of solid neon subsequent to the impulsive excitation of the NO chromophore to its A(3s sigma) Ryberg state is investigated using molecular dynamics simulations. This study makes use of empirical NO(X,A)-Ne isotropic pair potentials as well as a recently developed ab initio triatomic potential energy surface for the excited state. The role of these interaction potentials is analyzed, including many-body effects. In particular, empirical potentials, designed to reproduce correctly both the NO X-A steady-state absorption and emission bands, are shown to lead to a good description of the subpicosecond relaxation dynamics. The 600 fs expansion of the electronic bubble fairly agrees with experimental data. This relatively long time scale with respect to solid Argon, which was previously attributed to the range of the NO(A)-Ne interaction, is presumably related to the quantum nature of the medium. The time-resolved local relaxation of the Ne solid is understandably intermediate between that of classical solids (e.g., Ar) and that of quantum solids (e.g., H(2)).

  6. A fixed-point farrago

    CERN Document Server

    Shapiro, Joel H

    2016-01-01

    This text provides an introduction to some of the best-known fixed-point theorems, with an emphasis on their interactions with topics in analysis. The level of exposition increases gradually throughout the book, building from a basic requirement of undergraduate proficiency to graduate-level sophistication. Appendices provide an introduction to (or refresher on) some of the prerequisite material and exercises are integrated into the text, contributing to the volume’s ability to be used as a self-contained text. Readers will find the presentation especially useful for independent study or as a supplement to a graduate course in fixed-point theory. The material is split into four parts: the first introduces the Banach Contraction-Mapping Principle and the Brouwer Fixed-Point Theorem, along with a selection of interesting applications; the second focuses on Brouwer’s theorem and its application to John Nash’s work; the third applies Brouwer’s theorem to spaces of infinite dimension; and the fourth rests ...

  7. Projet Télétandem Brésil, trois années d'échanges franco-brésiliens en ligne : le point de vue des étudiants français Teletandem Brazil project, three years of Franco-Brazilian online interactions: the point of view of French students

    Directory of Open Access Journals (Sweden)

    Liliane Santos

    2012-10-01

    Full Text Available Le projet Télétandem Brésil (Unesp, 2006 met en relation des étudiants de portugais de l'université de Lille 3 (France et des étudiants de français de l'université de l'État de São Paulo (Brésil, pour, selon les principes du tandem, qu'ils s'engagent dans un processus d'apprentissage collaboratif dans leur langue et culture respectives fondé sur l'autonomie et la réciprocité. L'analyse des carnets de bord tenus par les étudiants tout au long de la formation, des rapports de fin de semestre, et des messages échangés entre partenaires permettra de dégager le point de vue des étudiants sur le fonctionnement du projet et du partenariat, ainsi que sur les thèmes traités avec leurs partenaires. Cela nous permettra en outre de faire quelques propositions concernant les conditions d'un partenariat réussi tant du point de vue matériel et culturel que de la relation entre les individus impliqués dans un tel projet.The telecollaborative project Teletandem Brazil (Unesp, 2006, gathering the University of Lille 3 (France and the State University of São Paulo (Brazil, enables students to take part in online exchanges. Based on the principles of autonomy and reciprocity, the project engages pairs of students in a collaborative learning of their respective languages and cultures. We analyze the students' opinions on the project, the partnership and the topics covered in the sessions in order to identify elements for a successful partnership, in terms of resources, cultural competence, and relationship between individuals.

  8. Interactions of tritium and materials

    Energy Technology Data Exchange (ETDEWEB)

    Yamawaki, Michio; Yamaguchi, Kenji; Tanaka, Satoru; Ono, Futaba (Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.); Yamamoto, Takuya

    1993-11-01

    In D-T burning fusion reactors, problems related to tritium-material interactions are vitally important. From this point of view, plasma-material interactions, blanket breeder material-tritium interactions, safety aspects of tritium-material interactions and tritium storage materials are reviewed with emphasis on the works going on in the authors' laboratories. (author) 83 refs.

  9. Holographic Three point Functions

    DEFF Research Database (Denmark)

    Bissi, Agnese

    gravitons and a point like graviton and its dual counterpart, namely two Schur polynomials and a single trace chiral primary. Secondly we compute the one loop correction to planar, non extremal three point functions of two heavy and one light operators, both from the gauge and string side in the Frolov......In this thesis it is addressed the problem of the computation of three point correlation functions within the AdS=CFT correspondence. In the context of the AdS 5=CFT4 correspondence we present three computations. First we compare the results of tree level three point functions of two giant......-Tseytlin regime. Finally we generalize the scalar product of two states belonging to the SO(6) sector of N = 4 SYM with implications on the construction of three point functions of 3 non-BPS operators from the gauge theory side. On the other hand in the AdS4=CFT3 correspondence we compare the computations...

  10. Ajustar: A interactive processor for to fit, by means of least squares, one variable polynomials (arbitrary degree) at experimental points; Ajustar: Un procesador interactivo para ajuste por minimos cuadrados de polinomios algebraicos (en una sola variable y grado arbitrario) a conjuntos de datos experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Miro, J. J.; Pena Gutierrez, J.

    1991-07-01

    In this report is offered, to scientist and technical people, a numeric tool consisting in a FORTRAN program, of interactive use, with destination to make lineal {sup l}east squares{sup ,} fittings on any set of empirical observations. The method based in the orthogonal functions (for discrete case), instead of direct solving the equations system, is used. The procedure includes also the optionally facilities of: variable change, direct interpolation, correlation non linear factor, {sup w}eights{sup o}f the points, confidence intervals (Schelle, Miller, Student), and plotting results. (Author) 10 refs.

  11. New 3-, 8-disubstituted pyrazolo[5,1-c][1,2,4]benzotriazines useful for studying the interaction with the HBp-3 area (hydrogen bond point area) in the benzodiazepine site on the gamma-aminobutyric acid type A (GABAA) receptor

    OpenAIRE

    G. Guerrini; G. CICIANI; Bruni, F.; Selleri, S.; F. Melani; Daniele, S.; Martini, C; A. Costanzo

    2011-01-01

    The pharmacophoric model using ADLR procedure, based on pyrazolo[5,1-c][1,2,4]benzotriazine system, studied in our laboratory, allowed us to identify the essential interaction points (HBp-1, HBp-2, and Lp-1) and the important areas for affinity modulation (HBp-3 and Lp-2) for binding recognition at benzodiazepine (Bzs) site of GABAA receptors (GABAA-Rs). In this work ADLR method is used to rationalize the affinity data of 23 new compounds and to improve the knowledge on HBp-3 area...

  12. FE Thermomechanics and Material Sampling Points

    NARCIS (Netherlands)

    Giessen, Erik van der

    1987-01-01

    The thermomechanics of finite elements of continuous media is discussed. The novel key concept introduced is that of material sampling points attributed to each finite element. Similar to representing the spatial interactions by a finite number of nodal quantities, the state of a finite element is r

  13. New Novae snack point

    CERN Multimedia

    2012-01-01

    Located next to the car park by the flag poles, a few metres from the Main CERN Reception (building 33), a new snack point catered by Novae will open to the public on Wednesday 8 August. More information will be available in the next issue of the Bulletin!

  14. Publication point indicators

    DEFF Research Database (Denmark)

    Elleby, Anita; Ingwersen, Peter

    2010-01-01

    The paper presents comparative analyses of two publication point systems, The Norwegian and the in-house system from the interdisciplinary Danish Institute of International Studies (DIIS), used as case in the study for publications published 2006, and compares central citation-based indicators wi...

  15. Point kinetics modeling

    International Nuclear Information System (INIS)

    A normalized form of the point kinetics equations, a prompt jump approximation, and the Nordheim-Fuchs model are used to model nuclear systems. Reactivity feedback mechanisms considered include volumetric expansion, thermal neutron temperature effect, Doppler effect and void formation. A sample problem of an excursion occurring in a plutonium solution accidentally formed in a glovebox is presented

  16. Henig Proper Efficient Points and Generalized Henig Proper Efficient Points

    Institute of Scientific and Technical Information of China (English)

    Jing Hui QIU

    2009-01-01

    Applying the theory of locally convex spaces to vector optimization,we investigate the relationship between Henig proper efficient points and generalized Henig proper efficient points. In particular,we obtain a sufficient and necessary condition for generalized Henig proper efficient points to be Henig proper efficient points. From this,we derive several convenient criteria for judging Henig proper efficient points.

  17. The quantum change point

    CERN Document Server

    Sentís, Gael; Calsamiglia, John; Chiribella, Giulio; Munoz-Tapia, Ramon

    2016-01-01

    Sudden changes are ubiquitous in nature. Identifying them is of crucial importance for a number of applications in medicine, biology, geophysics, and social sciences. Here we investigate the problem in the quantum domain, considering a source that emits particles in a default state, until a point where it switches to another state. Given a sequence of particles emitted by the source, the problem is to find out where the change occurred. For large sequences, we obtain an analytical expression for the maximum probability of correctly identifying the change point when joint measurements on the whole sequence are allowed. We also construct strategies that measure the particles individually and provide an online answer as soon as a new particle is emitted by the source. We show that these strategies substantially underperform the optimal strategy, indicating that quantum sudden changes, although happening locally, are better detected globally.

  18. Building Points - MO 2012 Stoddard Structure Points (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Missouri Structure Points are structure points generated from a two pass look over the 2007 State 2ft imagery. Unlike the structure footprints, the building point...

  19. Building Points - MO 2012 Mississippi Structure Points (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Missouri Structure Points are structure points generated from a two pass look over the 2007 State 2ft imagery. Unlike the structure footprints, the building point...

  20. Building Points - MO 2012 Scott Structure Points (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Missouri Structure Points are structure points generated from a two pass look over the 2007 State 2ft imagery. Unlike the structure footprints, the building point...

  1. Building Points - MO 2012 Dunklin Structure Points (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Missouri Structure Points are structure points generated from a two pass look over the 2007 State 2ft imagery. Unlike the structure footprints, the building point...

  2. Building Points - MO 2012 Pemiscot Structure Points (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Missouri Structure Points are structure points generated from a two pass look over the 2007 State 2ft imagery. Unlike the structure footprints, the building point...

  3. Building Points - MO 2012 New Madrid Structure Points (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Missouri Structure Points are structure points generated from a two pass look over the 2007 State 2ft imagery. Unlike the structure footprints, the building point...

  4. Tunable magnon Weyl points in ferromagnetic pyrochlores

    CERN Document Server

    Mook, Alexander; Mertig, Ingrid

    2016-01-01

    The dispersion relations of magnons in ferromagnetic pyrochlores with Dzyaloshinskii-Moriya interaction is shown to possess Weyl points, i.\\,e., pairs of topological nontrivial crossings of two magnon branches with opposite topological charge. As a consequence of their topological nature, their projections onto a surface are connected by magnon arcs, thereby resembling closely Fermi arcs of electronic Weyl semimetals. On top of this, the positions of the Weyl points in reciprocal space can be tuned widely by an external magnetic field: rotated within the surface plane, the Weyl points and magnon arcs are rotated as well; tilting the magnetic field out-of-plane shifts the Weyl points toward the center $\\bar{\\Gamma}$ of the surface Brillouin zone. The theory is valid for the class of ferromagnetic pyrochlores, i.\\,e., three-dimensional extensions of topological magnon insulators on kagome lattices. In this Letter, we focus on the $(111)$ surface, identify candidates of established ferromagnetic pyrochlores whic...

  5. Point defects in silicates

    International Nuclear Information System (INIS)

    Topaz is a wide band gap insulating crystal with four Al2F2SiO4 formula units per orthorhombic unit cell and containing isolated SiO4 tetrahedron. Electron spin resonance (ESR), UV-VIS spectrophotometry, photoluminescence, and isochronal annealing were used to study the point defects introduced by fast-neutron bombardment or by alpha decay recoils. The superoxide radical is characterized by a single hole-like spin 1/2 signal with principle g-values gxx = 2.0055, gzz = 2.0407 and the major axis of the defect points along 0.356a + 0.152b + 0.922c. The superoxide anneals near 650C. Two polarization dependent absorptions occur in the UV due to the transitions 2IIg → 2IIu and 2IIg → 2Δu. The former has an oscillator strength of 0.06. The 2.5 eV polarization dependent luminescence is due to the transition 2IIg → 2IIu. The 2Δu → 2IIu is non-radiative. The doubly occupied dangling silicon bond, the blue center, is characterized by a 2 eV polarization dependent absorption and is non-paramagnetic. The transition dipole for this absorption points in the direction 0.93a + 0.210b + 0.305c and the oscillator strength is approximately 2.0 x 10-3. The blue center anneals at 500C. This dangling bond defect is one of two models proposed for a similar 2 eV absorption in silica glass. The defects in quartz (SiO2) were introduced by the recoil nuclei after alpha decays of uranium, thorium, and their daughters in natural abundances. The accumulating damage provides a geological clock by which the age of the quartz can be found. The sample came from Yucca Flats, Nevada, the proposed site of a nuclear waste dump

  6. Ubiquitous Pointing and Drawing

    Directory of Open Access Journals (Sweden)

    Kristian Jantz

    2007-12-01

    Full Text Available This paper presents a system that enables a presenter to work directly on the projection without the typical interruption of the presentation flow being caused by a mouse or keyboard activity. The lecturer simply uses his fingers as a natural and intuitive pointing device. The system consists of an LED, a standard webcam, a video projector, and a small software system running on a notebook computer. The camera is positioned such that it views the projection area. After a few calibration clicks, the mouse emulation is functional at any place of the projection area.

  7. Single and multispecies reference points for Baltic fish stocks

    DEFF Research Database (Denmark)

    Gislason, Henrik

    1999-01-01

    Single and multispecies models are used to examine the effect of species interaction on biological reference points for cod, herring, and sprat in the Baltic. The results demonstrate that reference points are different in single and multispecies contexts. Reference points for fishing mortality...... based on single-species yield and SSB calculations are difficult to use when natural mortality depends on the absolute abundance of the predators and their alternative prey. Reference points based on maximizing total yield from the system may lead to impractical results when species interact...... reference points. Management advice based on biomass reference points will also differ. In the single species situation the combinations of cod and pelagic fishing effort for which the equilibrium spawning- stock biomass of the three species is above the biomass reference points forms a rectangular area...

  8. Holographic Three point Functions

    DEFF Research Database (Denmark)

    Martirosyan, Ara

    . In the spirit of understanding this problem better, the thesis discusses the divergences appearing in the calculation of structure constants involving two giant and one point-like gravitons in the string theories on AdS_5 x S^5 and AdS_4 x S^7/Z_k backgrounds. Coherent state approach for the tree......The main subject of this thesis is the computation of structure constants appearing in the three-point functions for certain type of states/operators in the context of the AdS/CFT correspondence, which is one of the important parts of the dynamical problem in the dual theories of the correspondence......-level calculation of structure constants for heavy-heavy-light operators in the SU(2) x SU(2) sector of the ABJM theory is carried out both on weak and strong coupling sides of the theory. Another remarkable determinant-result is obtained in the same sector of ABJM theory using integrability techniques...

  9. Pro SharePoint 2010 Solution Development

    CERN Document Server

    Hild, E

    2010-01-01

    This book takes a practical problem-solution approach to common business challenges. You'll not only encounter interesting code samples, but also see how to combine these examples with the Microsoft collaboration platform's services. The book's solutions focus on using Visual Studio 2008 and its built-in Office development tools to construct the user interface layer. And solutions can interact with SharePoint as a service provider, taking advantage of SharePoint's many collaboration features like document repositories, collaboration sites, and search functions. This book is unique because it s

  10. Point Source Extraction with MOPEX

    CERN Document Server

    Marleau, D M F R

    2005-01-01

    MOPEX (MOsaicking and Point source EXtraction) is a package developed at the Spitzer Science Center for astronomical image processing. We report on the point source extraction capabilities of MOPEX. Point source extraction is implemented as a two step process: point source detection and profile fitting. Non-linear matched filtering of input images can be performed optionally to increase the signal-to-noise ratio and improve detection of faint point sources. Point Response Function (PRF) fitting of point sources produces the final point source list which includes the fluxes and improved positions of the point sources, along with other parameters characterizing the fit. Passive and active deblending allows for successful fitting of confused point sources. Aperture photometry can also be computed for every extracted point source for an unlimited number of aperture sizes. PRF is estimated directly from the input images. Implementation of efficient methods of background and noise estimation, and modified Simplex a...

  11. May 2002 Lidar Point Data of Southern California Coastline: Dana Point to Point La Jolla

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains lidar point data from a strip of Southern California coastline (including water, beach, cliffs, and top of cliffs) from Dana Point to Point...

  12. September 2002 Lidar Point Data of Southern California Coastline: Dana Point to Point La Jolla

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains lidar point data from a strip of Southern California coastline (including water, beach, cliffs, and top of cliffs) from Dana Point to Point...

  13. Repelling Point Bosons

    Science.gov (United States)

    McGuire, J. B.

    2011-12-01

    There is a body of conventional wisdom that holds that a solvable quantum problem, by virtue of its solvability, is pathological and thus irrelevant. It has been difficult to refute this view owing to the paucity of theoretical constructs and experimental results. Recent experiments involving equivalent ions trapped in a spatial conformation of extreme anisotropic confinement (longitudinal extension tens, hundreds or even thousands of times transverse extension) have modified the view of relevancy, and it is now possible to consider systems previously thought pathological, in particular point Bosons that repel in one dimension. It has been difficult for the experimentalists to utilize existing theory, mainly due to long-standing theoretical misunderstanding of the relevance of the permutation group, in particular the non-commutativity of translations (periodicity) and transpositions (permutation). This misunderstanding is most easily rectified in the case of repelling Bosons.

  14. The Point Mass Concept

    Directory of Open Access Journals (Sweden)

    Lehnert B.

    2011-04-01

    Full Text Available A point-mass concept has been elaborated from the equations of the gravitational field. One application of these deductions results in a black hole configuration of the Schwarzschild type, having no electric charge and no angular momentum. The critical mass of a gravitational collapse with respect to the nuclear binding energy is found to be in the range of 0.4 to 90 solar masses. A second application is connected with the spec- ulation about an extended symmetric law of gravitation, based on the options of positive and negative mass for a particle at given positive energy. This would make masses of equal polarity attract each other, while masses of opposite polarity repel each other. Matter and antimatter are further proposed to be associated with the states of positive and negative mass. Under fully symmetric conditions this could provide a mechanism for the separation of antimatter from matter at an early stage of the universe.

  15. Latent myofascial trigger points.

    Science.gov (United States)

    Ge, Hong-You; Arendt-Nielsen, Lars

    2011-10-01

    A latent myofascial trigger point (MTP) is defined as a focus of hyperirritability in a muscle taut band that is clinically associated with local twitch response and tenderness and/or referred pain upon manual examination. Current evidence suggests that the temporal profile of the spontaneous electrical activity at an MTP is similar to focal muscle fiber contraction and/or muscle cramp potentials, which contribute significantly to the induction of local tenderness and pain and motor dysfunctions. This review highlights the potential mechanisms underlying the sensory-motor dysfunctions associated with latent MTPs and discusses the contribution of central sensitization associated with latent MTPs and the MTP network to the spatial propagation of pain and motor dysfunctions. Treating latent MTPs in patients with musculoskeletal pain may not only decrease pain sensitivity and improve motor functions, but also prevent latent MTPs from transforming into active MTPs, and hence, prevent the development of myofascial pain syndrome.

  16. Virtual turning points

    CERN Document Server

    Honda, Naofumi; Takei, Yoshitsugu

    2015-01-01

    The discovery of a virtual turning point truly is a breakthrough in WKB analysis of higher order differential equations. This monograph expounds the core part of its theory together with its application to the analysis of higher order Painlevé equations of the Noumi–Yamada type and to the analysis of non-adiabatic transition probability problems in three levels. As M.V. Fedoryuk once lamented, global asymptotic analysis of higher order differential equations had been thought to be impossible to construct. In 1982, however, H.L. Berk, W.M. Nevins, and K.V. Roberts published a remarkable paper in the Journal of Mathematical Physics indicating that the traditional Stokes geometry cannot globally describe the Stokes phenomena of solutions of higher order equations; a new Stokes curve is necessary.

  17. Learning Determinantal Point Processes

    CERN Document Server

    Kulesza, Alex

    2012-01-01

    Determinantal point processes (DPPs), which arise in random matrix theory and quantum physics, are natural models for subset selection problems where diversity is preferred. Among many remarkable properties, DPPs offer tractable algorithms for exact inference, including computing marginal probabilities and sampling; however, an important open question has been how to learn a DPP from labeled training data. In this paper we propose a natural feature-based parameterization of conditional DPPs, and show how it leads to a convex and efficient learning formulation. We analyze the relationship between our model and binary Markov random fields with repulsive potentials, which are qualitatively similar but computationally intractable. Finally, we apply our approach to the task of extractive summarization, where the goal is to choose a small subset of sentences conveying the most important information from a set of documents. In this task there is a fundamental tradeoff between sentences that are highly relevant to th...

  18. Exceptional Points in three-dimensional Nanostructures

    CERN Document Server

    Kodigala, Ashok; Kanté, Boubacar

    2016-01-01

    Exceptional points (EPs) are degeneracies in open wave systems where at least two energy levels and their corresponding eigenstates coalesce. We report evidence of the existence of EPs in 3D plasmonic nanostructures. The systems are composed of coupled plasmonic nanoresonators and can be judiciously and systematically driven to EPs by controlling symmetry-compatible modes via their near-field and far-field interactions. The proposed platform opens the way to the investigation of EPs for enhanced light-matter interactions and applications in communication, sensing and imaging.

  19. Wave-Structure Interactions on Point Absorbers - an experimental study

    DEFF Research Database (Denmark)

    Jakobsen, Morten Møller

    of a wave energy device by determin- ing the loads on the device. The loads plays a key part in optimizing the power extraction, reducing the structural cost, and increasing the survivabil- ity. Experiments are carried out in small and large scale and compared to simulations and empirical functions. The WEC......We are facing a significant challenge when it comes to securing the energy needed to sustain our standard of living in the future. With the increasing global temperature and the climbing levels of carbon dioxide in our atmo- sphere we need to reduce the consumption of fossil fuels. The renewable...... been done to determine peak pressures on mono-piles worldwide, but only very little on spherical structures. In order to shed more light on the wave induced loads on a hemisphere the peak pressures are measured with the traditional drop test and during impact of so-called freak waves. 3: Implementation...

  20. Pointing Device Performance in Steering Tasks.

    Science.gov (United States)

    Senanayake, Ransalu; Goonetilleke, Ravindra S

    2016-06-01

    Use of touch-screen-based interactions is growing rapidly. Hence, knowing the maneuvering efficacy of touch screens relative to other pointing devices is of great importance in the context of graphical user interfaces. Movement time, accuracy, and user preferences of four pointing device settings were evaluated on a computer with 14 participants aged 20.1 ± 3.13 years. It was found that, depending on the difficulty of the task, the optimal settings differ for ballistic and visual control tasks. With a touch screen, resting the arm increased movement time for steering tasks. When both performance and comfort are considered, whether to use a mouse or a touch screen for person-computer interaction depends on the steering difficulty. Hence, a input device should be chosen based on the application, and should be optimized to match the graphical user interface. PMID:27216944

  1. Zero-point energy of ultracold atoms

    Science.gov (United States)

    Salasnich, Luca; Toigo, Flavio

    2016-06-01

    We analyze the divergent zero-point energy of a dilute and ultracold gas of atoms in D spatial dimensions. For bosonic atoms we explicitly show how to regularize this divergent contribution, which appears in the Gaussian fluctuations of the functional integration, by using three different regularization approaches: dimensional regularization, momentum-cutoff regularization and convergence-factor regularization. In the case of the ideal Bose gas the divergent zero-point fluctuations are completely removed, while in the case of the interacting Bose gas these zero-point fluctuations give rise to a finite correction to the equation of state. The final convergent equation of state is independent of the regularization procedure but depends on the dimensionality of the system and the two-dimensional case is highly nontrivial. We also discuss very recent theoretical results on the divergent zero-point energy of the D-dimensional superfluid Fermi gas in the BCS-BEC crossover. In this case the zero-point energy is due to both fermionic single-particle excitations and bosonic collective excitations, and its regularization gives remarkable analytical results in the BEC regime of composite bosons. We compare the beyond-mean-field equations of state of both bosons and fermions with relevant experimental data on dilute and ultracold atoms quantitatively confirming the contribution of zero-point-energy quantum fluctuations to the thermodynamics of ultracold atoms at very low temperatures.

  2. Tie-points and fixed-points in N^*

    CERN Document Server

    Dow, Alan

    2007-01-01

    A point x is a (bow) tie-point of a space X if X setminus {x} can be partitioned into (relatively) clopen sets each with x in its closure. Tie-points have appeared in the construction of non-trivial autohomeomorphisms of betaN setminus N and in the recent study of (precisely) 2-to-1 maps on betaN setminus N . In these cases the tie-points have been the unique fixed point of an involution on betaN setminus N. This paper is motivated by the search for 2-to-1 maps and obtaining tie-points of strikingly differing characteristics.

  3. Tie-points and fixed-points in N^*

    OpenAIRE

    Dow, Alan; SHELAH, Saharon

    2007-01-01

    A point x is a (bow) tie-point of a space X if X setminus {x} can be partitioned into (relatively) clopen sets each with x in its closure. Tie-points have appeared in the construction of non-trivial autohomeomorphisms of betaN setminus N and in the recent study of (precisely) 2-to-1 maps on betaN setminus N . In these cases the tie-points have been the unique fixed point of an involution on betaN setminus N. This paper is motivated by the search for 2-to-1 maps and obtaining tie-points of str...

  4. Pointing to others: How the target gender influences pointing performance.

    Science.gov (United States)

    Cleret de Langavant, Laurent; Jacquemot, Charlotte; Cruveiller, Virginie; Dupoux, Emmanuel; Bachoud-Lévi, Anne-Catherine

    2016-01-01

    Pointing is a communicative gesture that allows individuals to share information about surrounding objects with other humans. Patients with heterotopagnosia are specifically impaired in pointing to other humans' body parts but not in pointing to themselves or to objects. Here, we describe a female patient with heterotopagnosia who was more accurate in pointing to men's body parts than to women's body parts. We replicated this gender effect in healthy participants with faster reaction times for pointing to men's body parts than to women's body parts. We discuss the role of gender stereotypes in explaining why it is more difficult to point to women than to men. PMID:27593456

  5. SharePoint 2010 Business Intelligence 24-Hour Trainer

    CERN Document Server

    Jorgensen, Adam; Knight, Devin; LeBlanc, Patrick; Schacht, Brad

    2011-01-01

    Learn to build and deliver SharePoint BI applications Written by a team of leading SharePoint and Business Intelligence (BI) experts, this unique book-and-DVD package shows you how to successfully build and deliver BI applications using SharePoint 2010. Assuming no previous SharePoint experience, the authors deliver a clear explanation of what SharePoint will do for your BI and information management capabilities. Each lesson in the book is reinforced with a helpful tutorial on the DVD and cover topics such as interactive reporting with Excel, document sharing for collaborative reporting, and

  6. Grasp interaction with tablets

    CERN Document Server

    Wolf, Katrin

    2015-01-01

    This book presents guidelines for a future device type: a tablet that allows ergonomic front- and back-of-device interaction. These guidelines help designers and developers of user interfaces to build ergonomic applications for tablet devices, in particular for devices that enable back-of-device interaction. In addition, manufacturers of tablet devices obtain arguments that back-of-device interaction is a promising extension of the interaction design space and results in increased input capabilities, enriched design possibilities, and proven usability. The guidelines are derived from empirical studies and developed to fit the users’ skills to the way the novel device type is held. Three particular research areas that are relevant to develop design guidelines for tablet interaction are investigated: ergonomic gestures, interaction areas, and pointing techniques.

  7. Random point sets and their diffraction

    CERN Document Server

    Baake, Michael

    2010-01-01

    The diffraction of various random subsets of the integer lattice $\\mathbb{Z}^{d}$, such as the coin tossing and related systems, are well understood. Here, we go one important step beyond and consider random point sets in $\\mathbb{R}^{d}$. We present several systems with an effective stochastic interaction that still allow for explicit calculations of the autocorrelation and the diffraction measure. We concentrate on one-dimensional examples for illustrative purposes, and briefly indicate possible generalisations to higher dimensions. In particular, we discuss the stationary Poisson process in $\\mathbb{R}^{d}$ and the renewal process on the line. The latter permits a unified approach to a rather large class of one-dimensional structures, including random tilings. Moreover, we present some stationary point processes that are derived from the classical random matrix ensembles as introduced in the pioneering work of Dyson and Ginibre. Their re-consideration from the diffraction point of view improves the intuiti...

  8. Z Resonance and Associated Zh Production at Future Higgs Boson Factory: ILC and CLIC

    OpenAIRE

    A. Gutiérrez-Rodríguez; Hernández-Ruíz, M. A.

    2015-01-01

    We study the prospects of the B-L model with an additional Z′ boson to be a Higgs boson factory at high-energy and high-luminosity linear electron positron colliders, such as the ILC and CLIC, through the Higgs-strahlung process e+e-→(Z,Z′)→Zh , including both the resonant and the nonresonant effects. We evaluate the total cross section of Zh and we calculate the total number of events for integrated luminosities of 500–2000 fb−1 and center of mass energies between 500 and 3000 GeV. We find t...

  9. ATLAS Point 1 Construction

    CERN Multimedia

    Inigo-Golfin, J

    After 3 years of work in point 1, a number of surface buildings have already been completed and handed over to CERN (the control, the gas and the cooling and ventilation buildings) and, probably more appealing to the public, 60,000 m3 of earth have already been excavated from underground. At present, the technical cavern USA15 and its access shaft are almost finished, leaving only the main cavern and the liaison galleries to be completed in the coming year and a half. The main cavern has been excavated down to the radiation limit and its walls and vault will presently be concreted (see below the picture of the section of the vault with the impressive shell of 1.2 m thickness). The excavation of the bench (27 vertical metres to go yet!) will proceed from August, when some additional civil engineering work in the LHC tunnel will be undertaken. Needless to say many different services are necessary around the detector, both for its installation and future operation for physics. To that end much of the heavy...

  10. "Point de suspension"

    CERN Multimedia

    2004-01-01

    CERN - Globe of Science and Innovation 20 and 21 October Acrobatics, mime, a cappella singing, projections of images, a magical setting... a host of different tools of a grandeur matching that of the Universe they relate. A camera makes a massive zoom out to reveal the multiple dimensions of Nature. Freeze the frame: half way between the infinitesimally small and the infinitesimally large, a man suspends his everyday life (hence the title "Point de Suspension", which refers to the three dots at the end of an uncompleted sentence) to take a glimpse of the place he occupies in the great history of the Universe. An unusual perspective on what it means to be a human being... This wondrous show in the Globe of Science and Innovation, specially created by the Miméscope* company for the official ceremony marking CERN's fiftieth anniversary, is a gift from the Government of the Republic and Canton of Geneva, which also wishes to share this moment of wonder with the local population. There will be three perfo...

  11. "Point de suspension"

    CERN Multimedia

    2004-01-01

    http://www.cern.ch/cern50/ CERN - Globe of Science and Innovation 20 and 21 October Acrobatics, mime, a cappella singing, projections of images, a magical setting... a host of different tools of a grandeur matching that of the Universe they relate. A camera makes a massive zoom out to reveal the multiple dimensions of Nature. Freeze the frame: half way between the infinitesimally small and the infinitesimally large, a man suspends his everyday life (hence the title "Point de Suspension", which refers to the three dots at the end of an uncompleted sentence) to take a glimpse of the place he occupies in the great history of the Universe. An unusual perspective on what it means to be a human being... This wondrous show in the Globe of Science and Innovation, specially created by the Miméscope* company for the official ceremony marking CERN's fiftieth anniversary, is a gift from the Government of the Republic and Canton of Geneva, which also wishes to share this moment of wonder with the local pop...

  12. "Point de suspension"

    CERN Multimedia

    2004-01-01

    CERN - Globe of Science and Innovation 20 and 21 October Acrobatics, mime, a cappella singing, projections of images, a magical setting... a host of different tools of a grandeur matching that of the Universe they relate. A camera makes a massive zoom out to reveal the multiple dimensions of Nature. Freeze the frame: half way between the infinitesimally small and the infinitesimally large, a man suspends his everyday life (hence the title "Point de Suspension", which refers to the three dots at the end of an uncompleted sentence) to take a glimpse of the place he occupies in the great history of the Universe. An unusual perspective on what it means to be a human being... This spectacle in the Globe of Science and Innovation, specially created by the Miméscope* company for the official ceremony marking CERN's fiftieth anniversary, is a gift from the Government of the Republic and Canton of Geneva, which also wishes to share this moment of wonder with the local population. There will be three performances for...

  13. Point 1 Updates

    CERN Multimedia

    Inigo-Golfin, J.

    The ATLAS experimental area is located in Point 1, just across the main CERN entrance, in the commune of Meyrin. There people are ever so busy to finish the different infrastructures for ATLAS. Not only has Civil Engineering finished the construction of the USA15 technical cavern, but the excavation of the main UX15 cavern has resumed below the machine tunnel, after a brief halt to allow the construction of the UJ-caverns for the power converters of the LHC machine. The excavation work should end in August 2002. The UX15 hand-over to ATLAS is expected in April 2003. On the surface civil engineering is starting to complete the last two surface buildings (SDX1 and SH1), once the services (cooling pipes, ventilation ducts and the largest item, the lift modules and its lift of course) in the shaft PX15 have been completed. But the civil engineering is not all. A lot more is under way. The site installation of the steel structures in the caverns is to begin in Autumn, along with all the cooling pipes, airconditi...

  14. Function Point Analysis Depot

    Science.gov (United States)

    Muniz, R.; Martinez, El; Szafran, J.; Dalton, A.

    2011-01-01

    The Function Point Analysis (FPA) Depot is a web application originally designed by one of the NE-C3 branch's engineers, Jamie Szafran, and created specifically for the Software Development team of the Launch Control Systems (LCS) project. The application consists of evaluating the work of each developer to be able to get a real estimate of the hours that is going to be assigned to a specific task of development. The Architect Team had made design change requests for the depot to change the schema of the application's information; that information, changed in the database, needed to be changed in the graphical user interface (GUI) (written in Ruby on Rails (RoR and the web service/server side in Java to match the database changes. These changes were made by two interns from NE-C, Ricardo Muniz from NE-C3, who made all the schema changes for the GUI in RoR and Edwin Martinez, from NE-C2, who made all the changes in the Java side.

  15. Controllable resonant tunnelling through single-point potentials: A point triode

    Energy Technology Data Exchange (ETDEWEB)

    Zolotaryuk, A.V., E-mail: azolo@bitp.kiev.ua; Zolotaryuk, Yaroslav, E-mail: yzolo@bitp.kiev.ua

    2015-03-06

    A zero-thickness limit of three-layer heterostructures under two bias voltages applied externally, where one of which is supposed to be a gate parameter, is studied. As a result, an effect of controllable resonant tunnelling of electrons through single-point potentials is shown to exist. Therefore the limiting structure may be termed a “point triode” and considered in the theory of point interactions as a new object. The simple limiting analytical expressions adequately describe the resonant behaviour in the transistor with realistic parameter values and thus one can conclude that the zero-range limit of multi-layer structures may be used in fabricating nanodevices. The difference between the resonant tunnelling across single-point potentials and the Fabry–Pérot interference effect is also emphasized. - Highlights: • The zero-thickness limit of three-layer heterostructures is described in terms of point interactions. • The effect of resonant tunnelling through these single-point potentials is established. • The resonant tunnelling is shown to be controlled by a gate voltage.

  16. Exploring Foundation Concepts in Introductory Statistics Using Dynamic Data Points

    Science.gov (United States)

    Ekol, George

    2015-01-01

    This paper analyses introductory statistics students' verbal and gestural expressions as they interacted with a dynamic sketch (DS) designed using "Sketchpad" software. The DS involved numeric data points built on the number line whose values changed as the points were dragged along the number line. The study is framed on aggregate…

  17. Non-parametric Bayesian inference for inhomogeneous Markov point processes

    DEFF Research Database (Denmark)

    Berthelsen, Kasper Klitgaard; Møller, Jesper

    is a shot noise process, and the interaction function for a pair of points depends only on the distance between the two points and is a piecewise linear function modelled by a marked Poisson process. Simulation of the resulting posterior using a Metropolis-Hastings algorithm in the "conventional" way...

  18. Design of the CLIC Quadrupole Vacuum Chambers

    CERN Document Server

    Garion, C

    2010-01-01

    The Compact Linear Collider, under study, requires vacuum chambers with a very small aperture, of the order of 8 mm in diameter, and with a length up to around 2 m for the main beam quadrupoles. To keep the very tight geometrical tolerances on the quadrupoles, no bake out is allowed. The main issue is to reach UHV conditions (typically 10-9 mbar static pressure) in a system where the vacuum performance is driven by water outgassing. For this application, a thinwalled stainless steel vacuum chamber with two ante chambers equipped with NEG strips, is proposed. The mechanical design, especially the stability analysis, is shown. The key technologies of the prototype fabrication are given. Vacuum tests are carried out on the prototypes. The test set-up as well as the pumping system conditions are presented.

  19. Fixed points for multi-class queues

    CERN Document Server

    Martin, James B

    2010-01-01

    Burke's theorem can be seen as a fixed-point result for an exponential single-server queue; when the arrival process is Poisson, the departure process has the same distribution as the arrival process. We consider extensions of this result to multi-type queues, in which different types of customer have different levels of priority. We work with a model of a queueing server which includes discrete-time and continuous-time M/M/1 queues as well as queues with exponential or geometric service batches occurring in discrete time or at points of a Poisson process. The fixed-point results are proved using interchangeability properties for queues in tandem, which have previously been established for one-type M/M/1 systems. Some of the fixed-point results have previously been derived as a consequence of the construction of stationary distributions for multi-type interacting particle systems, and we explain the links between the two frameworks. The fixed points have interesting "clustering" properties for lower-priority ...

  20. Smart Point Cloud: Definition and Remaining Challenges

    Science.gov (United States)

    Poux, F.; Hallot, P.; Neuville, R.; Billen, R.

    2016-10-01

    Dealing with coloured point cloud acquired from terrestrial laser scanner, this paper identifies remaining challenges for a new data structure: the smart point cloud. This concept arises with the statement that massive and discretized spatial information from active remote sensing technology is often underused due to data mining limitations. The generalisation of point cloud data associated with the heterogeneity and temporality of such datasets is the main issue regarding structure, segmentation, classification, and interaction for an immediate understanding. We propose to use both point cloud properties and human knowledge through machine learning to rapidly extract pertinent information, using user-centered information (smart data) rather than raw data. A review of feature detection, machine learning frameworks and database systems indexed both for mining queries and data visualisation is studied. Based on existing approaches, we propose a new 3-block flexible framework around device expertise, analytic expertise and domain base reflexion. This contribution serves as the first step for the realisation of a comprehensive smart point cloud data structure.