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Sample records for clic drive beam

  1. 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...

  2. Simulations for CLIC Drive Beam Linac

    CERN Document Server

    Aksoy, Avni

    2012-01-01

    The Drive Beam Linac of the Compact Linear Collider (CLIC) has to accelerate an electron beam with 4.2 A up to 2.4 GeV in almost fully-loaded structures. The pulse contains about 70000 bunches, one in every second rf bucket, and has a length of 140 $\\mu$s. The beam stability along the beamline is of concern for such a high current and pulse length. We present different options for the lattice of the linac based on FODO, triplet and doublet cells and compare the transverse instability for each lattice including the effects of beam jitter, alignment and beam-based correction. Additionally longitudinal stability is discussed for different bunch compressors using FODO type of lattice.

  3. 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.

  4. Simulation of Phase Stability at the Flat Top of the CLIC Drive Beam

    CERN Document Server

    Gerbershagen, A; Burrows, P

    2011-01-01

    The drive beam phase stability is one of the critical issues of the Compact Linear Collider (CLIC). In this paper the generation and propagation of drive beam phase errors is studied for effects that vary during the drive beam pulse. This includes the influence of drive beam current and phase errors as well as of drive beam accelerator RF phase and amplitude errors on the drive beam phase after the compressor chicanes and the analysis of the propagation of these errors through the drive beam combination scheme. The impact of the imperfections on the main beam is studied including the possible correction with help of a feedforward system.

  5. 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.

  6. A Study of the Beam Physics in the CLIC Drive Beam Decelerator

    CERN Document Server

    Adli, Erik; Stapnes, Steinar

    2009-01-01

    CLIC is a study for a Multi-TeV e+e- linear collider, in which the rf power for the main linacs is extracted from 100 ampere electron drive beams, by the use of specially designed power extraction structures. Up to 90% of the beam energy is extracted from the drive beams along one kilometer long decelerator sectors, rendering the beam transport challenging. We have identified two major challenges for robust beam transport: the significant transverse wakes in the power extraction structures, and the large energy spread induced by the power extraction process. By beam dynamics studies we have qualified power extraction structure designs, leading to the present CLIC baseline structure in which the transverse wakes are sufficiently mitigated. We have further shown that the beam energy spread induced by the deceleration implies that standard 1-to-1 correction might not ensure satisfactory drive beam transport. As alternative, we propose a decelerator orbit correction scheme based on dispersion-free steering and ex...

  7. 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...

  8. 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.

  9. $2\\times250$ 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...

  10. 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 ...

  11. 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...

  12. 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...

  13. Two 352 MHz push pull linac pairs to generate two drive beams for CLIC multibunch operation

    International Nuclear Information System (INIS)

    The present note describes a drive beam generation scheme for multibunch operation at 1 TeV continuous mode and the luminosity of 1034 cm-2s-1. This rather conventional scheme is essentially based on acceleration with 352 MHz superconducting cavities. Contrary to a previous proposal for single bunch operation, an independent push pull linac pair per drive beam is foreseen mainly for the following reasons. Twice as many drive bunchlets per 352 MHz period halves the required charge per bunchlet. With two trains, the bunchlet deceleration variation inside one train is reduced. A good drive beam to RF efficiencies are obtained through matching of the train energy profile to the decelerating wake pattern in the drive linac. The reduced wake variation makes it feasible to preshape the train energy profile to the required ramp by simple phase shifting of the 352 MHz voltage in the superconducting cavities in conjunction with a small harmonics correction. The layout of the system consists of the 30 GHz accelerating structures, 30 GHz transfer structures, fourth harmonics (1408 MHz) superconducting structures, push pull fundamental (352 MHz) linac pair and switch yards. Emphasis has been put on wall-plug to main beam efficiency and minimum capital cost to the extent possible for the concept chosen. The issues of studies are harmonic synthesis of an optimum acceleration ramp, beam loading compensation for fundamental frequency cavities, acceleration of 22 bunchlets, fourth harmonic cavities, wall plug to main beam efficiency and RF deflectors. The main disadvantage of the scheme seem to be: a) high bunchlet charge of 45 n C. b) overall efficiency of only 10.1%, essentially because of the limited stored RF energy in the 352 MHz structures, which limits the number of drive bunchlet trains per pulse. c) significant amount of RF and cryogenics hardware for complete drive beam generation complex. The main advantage appears to be: a) no long drive beam transport lines, no 180 and

  14. 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.

  15. Beam position monitoring at CLIC

    OpenAIRE

    Prochnow, Jan Erik

    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 gener...

  16. Study and Experimental Characterization of a Novel Photo Injector for the CLIC Drive Beam

    CERN Document Server

    Mete, Oznur; Rivkin, Leonid

    2011-01-01

    Abstract In this thesis, the transverse and longitudinal beam properties of the PHIN photoinjector are characterized. The ob jective of the research is to demonstrate the reliable and stable production of a 1.3 µs long bunch train, with 2.33 nC charge per bunch and 4.5 µC of total charge, by the PHIN photoinjector. The results of this thesis are the important steps towards the feasibility demonstration of a photoinjector as the Compact Linear Collider’s drive beam source. The PHIN photoinjector has been conceptualized by a collaboration between “Laboratoire de l’Accélérateur Linéaire (LAL)”, “Rutherford Appleton Laboratory (RAL)” and “Organisation Européenne pour la Recherche Nucléaire (CERN)”. Within this collaboration, LAL and RAL have committed to the design and the construction of the RF gun and laser, respectively. The photocathode production as well as the overall coordination and commissioning were under the responsibility of CERN. The pro ject is in the framework of the second...

  17. 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...

  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. 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.

  20. 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...

  1. 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...

  2. Positron source investigation by using CLIC drive beam for Linac-LHC based e+p collider

    Science.gov (United States)

    Arιkan, Ertan; Aksakal, Hüsnü

    2012-08-01

    Three different methods which are alternately conventional, Compton backscattering and Undulator based methods employed for the production of positrons. The positrons to be used for e+p collisions in a Linac-LHC (Large Hadron Collider) based collider have been studied. The number of produced positrons as a function of drive beam energy and optimum target thickness has been determined. Three different targets have been used as a source investigation which are W75-Ir25, W75-Ta25, and W75-Re25 for three methods. Estimated number of the positrons has been performed with FLUKA simulation code. Then, these produced positrons are used for following Adiabatic matching device (AMD) and capture efficiency is determined. Then e+p collider luminosity corresponding to the methods mentioned above have been calculated by CAIN code.

  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. 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...

  5. 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.

  6. 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.

  7. CLIC a Two-Beam Multi-TeV $e\\pm$ Linear Collider

    CERN Document Server

    Delahaye, J P; Assmann, R W; Becker, F; Bossart, Rudolf; Braun, H; Burkhardt, H; Carron, G; Coosemans, Williame; Corsini, R; D'Amico, T E; Döbert, Steffen; Fartoukh, Stéphane David; Ferrari, A; Geschonke, Günther; Godot, J C; Groening, L; Guignard, Gilbert; Hutchins, S; Jeanneret, J B; Jensen, E; Jowett, John M; Kamitani, T; Millich, Antonio; Pearce, P; Perriollat, F; Pittin, R; Potier, J P; Riche, A; Rinolfi, Louis; Risselada, Thys; Royer, P; Ruggiero, F; Schulte, Daniel; Suberlucq, Guy; Syratchev, I V; Thorndahl, L; Trautner, H; Verdier, A; Wuensch, Walter; Zhou, F; Zimmermann, Frank; Napoly, O

    2000-01-01

    The CLIC study of a high-energy (0.5 - 5 TeV), high-luminosity (1034 - 1035 cm-2 sec-1) e± linear collider is presented. Beam acceleration using high frequency (30 GHz) normal-conducting structures operating at high accelerating fields (150 MV/m) significantly reduces the length and, in consequence, the cost of the linac. Using parameters derived from general scaling laws for linear colliders, the beam stability is shown to be similar to lower frequency designs in spite of the strong wake-field dependency on frequency. A new cost-effective and efficient drive beam generation scheme for RF power production by the so-called "Two-Beam Acceleration" method is described. It uses a thermionic gun and a fully-loaded normal-conducting linac operating at low frequency (937 MHz) to generate and accelerate the drive beam bunches, and RF multiplication by funnelling in compressor rings to produce the desired bunch structure. Recent 30 GHz hardware developments and CLIC Test Facility (CTF) results are described.

  8. 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.

  9. 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.

  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. 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.

  12. CTF3 Drive Beam Injector Optimisation

    CERN Document Server

    AUTHOR|(CDS)2082899; Doebert, S

    2015-01-01

    In the Compact Linear Collider (CLIC) the RF power for the acceleration of the Main Beam is extracted from a high-current Drive Beam that runs parallel to the main linac. The main feasibility issues of the two-beam acceleration scheme are being demonstrated at CLIC Test Facility 3 (CTF3). The CTF3 Drive Beam injector consists of a thermionic gun followed by the bunching system and two accelerating structures all embedded in solenoidal magnetic field and a magnetic chicane. Three sub-harmonic bunchers (SHB), a prebuncher and a travelling wave buncher constitute the bunching system. The phase coding process done by the sub-harmonic bunching system produces unwanted satellite bunches between the successive main bunches. The beam dynamics of the CTF3 Drive Beam injector is reoptimised with the goal of improving the injector performance and in particular decreasing the satellite population, the beam loss in the magnetic chicane and the beam emittance in transverse plane compare to the original model based on P. Ur...

  13. Thermal joining studies of CLIC accelerating structures and Establishment of a test bench and studies of thermomechanical behaviour of a CLIC two beam module

    CERN Document Server

    Rossi, Fabrizio

    2013-01-01

    The assembly procedure of the CLIC accelerating structures is constituted of several steps, involving ultra-precision machining, heating cycles at very high temperatures and many quality controls necessary to fulfil the very tight technical requirements. Diverse issues are related to the diffusion bonding process of CLIC accelerating structures; due to diffusion creep mechanisms occurring at high temperature and low stress, residual deformations might be present at the end of the joining process. A theoretical and experimental approach is presented here in order to understand this issue further and feedback on the design process. As a second issue tackled here, the final alignment of CLIC is also affected by the power dissipation occurring in the module during the normal operation modes and resulting in time-varying non-uniform thermal fields. The thermo-mechanical models of CLIC two-beam modules developed in the past are then useful to predict the structural deformations affecting the final alignment of the ...

  14. 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.

  15. Experimental Study of the Effect of Beam Loading on RF Breakdown Rate in CLIC High-Gradient Accelerating Structures

    CERN Document Server

    Tecker, F; Kelisani, M; Doebert, S; Grudiev, A; Quirante, J; Riddone, G; Syratchev, I; Wuensch, W; Kononenko, O; Solodko, A; Lebet, S

    2013-01-01

    RF breakdown is a key issue for the multi-TeV highluminosity e+e- Compact Linear Collider (CLIC). Breakdowns in the high-gradient accelerator structures can deflect the beam and decrease the desired luminosity. The limitations of the accelerating structures due to breakdowns have been studied so far without a beam present in the structure. The presence of the beam modifies the distribution of the electrical and magnetic field distributions, which determine the breakdown rate. Therefore an experiment has been designed for high power testing a CLIC prototype accelerating structure with a beam present in the CLIC Test Facility (CTF3). A special beam line allows extracting a beam with nominal CLIC beam current and duration from the CTF3 linac. The paper describes the beam optics design for this experimental beam line and the commissioning of the experiment with beam.

  16. 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.

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

    OpenAIRE

    Burt, Graeme; Ambattu, Praveen; Dexter, Amos; Abram, Thomas; Dolgashev, V.; Tantawi, S.; Jones, R. M.

    2008-01-01

    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 m...

  18. CTF3 Drive Beam Accelerating Structures

    CERN Document Server

    Jensen, E

    2002-01-01

    The 3 GHz drive beam accelerator of the CLIC Test Facility CTF3, currently under construction at CERN, will be equipped with 16 novel SICA (Slotted Iris – Constant Aperture) accelerating structures. The slotted irises couple out the potentially disruptive induced transverse HOM energy to integrated silicon carbide loads (dipole mode Q's below 20). The use of nose cones for detuning allows a constant inner aperture (34 mm). The structures will be 1.2 m long and consist of 34 cells. A first 6 cell prototype structure has been tested successfully up to power levels of 100 MW (nominal: 30 MW), corresponding to surface electric field levels of 180 MV/m.

  19. Recent Improvements to the Control of the CTF3 High-Current Drive Beam

    CERN Document Server

    Constance, B; Gamba, D; Skowronski, P K

    2013-01-01

    In order to demonstrate the feasibility of the CLIC multiTeV linear collider option, the drive beam complex at the CLIC Test Facility (CTF3) at CERN is providing highcurrent electron pulses for a number of related experiments. By means of a system of electron pulse compression and bunch frequency multiplication, a fully loaded, 120 MeV linac is used to generate 140 ns electron pulses of around 28 Amperes. Subsequent deceleration of this high-current drive beam demonstrates principles behind the CLIC acceleration scheme, and produces 12 GHz RF power for experimental purposes. As the facility has progressed toward routine operation, a number of studies aimed at improving the drive beam performance have been carried out. Additional feedbacks, automated steering programs, and improved control of optics and dispersion have contributed to a more stable, reproducible drive beam with consequent benefits for the experiments.

  20. 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%.

  1. 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.

  2. 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...

  3. 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...

  4. 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.

  5. 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. \

  6. 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.

  7. 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.

  8. 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...

  9. 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...

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

    International Nuclear Information System (INIS)

    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 suggest that

  12. 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

  13. Monte Carlo simulations to estimate the damage potential of electron beam and tests of beam loss detector based on quartz Cherenkov radiator read out by a silicon photomultiplier on CLIC Test Facility 3(CTF3)

    CERN Document Server

    Orfanelli, Styliani; Gazis, E

    The Compact Linear Collider (CLIC) study is a feasibility study aiming at the development of an electron/positron linear collider with a centre of mass energy in the multi-TeV energy range. Each Linac will have a length of 21 km, which means that very high accelerating gradients (>100 MV/m) are required. To achieve the high accelerating gradients, a novel two-beam acceleration scheme, in which RF power is transferred from a high-current, low-energy drive beam to the low-current, high energy main accelerating beam is designed. A Beam Loss Monitoring (BLM) system will be designed for CLIC to meet the requirements of the accelerator complex. Its main role as part of the machine protection scheme will be to detect potentially dangerous beam instabilities and prevent subsequent injection into the main beam or drive beam decelerators. The first part of this work describes the GEANT4 Monte Carlo simulations performed to estimate the damage potential of high energy electron beams impacting a copper target. The second...

  14. 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.

  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 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.

  17. CLIC and CTF3

    CERN Document Server

    Tecker, F

    2008-01-01

    The CLIC study has been exploring the scheme for an electron-positron Collider (CLIC) with high luminosity (10$^{34}$ - 10$^{35}$ cm2/s) and a nominal centre-of-mass energy of 3 TeV in order to make the multi-TeV range accessible for physics. The CLIC Test Facility CTF3, built at CERN by an international collaboration, aims at demonstrating the feasibility of the CLIC scheme by 2010. CTF3 consists of a 150 MeV electron linac followed by a 42 m long delay loop and an 84 m combiner ring, followed by a two-beam test stand and a test decelerator. The linac and delay loop have been previously commissioned, while the combiner ring has been recently completed. After a presentation of the recent CLIC parameters, the status of the test facility, the experimental results achieved and the future plans will be presented.

  18. 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.

  19. Beam dynamic simulation and optimization of the CLIC positron source and the capture linac

    Science.gov (United States)

    Bayar, C.; Doebert, S.; Ciftci, A. K.

    2016-03-01

    The CLIC Positron Source is based on the hybrid target composed of a crystal and an amorphous target. Simulations have been performed from the exit of the amorphous target to the end of pre-injector linac which captures and accelerates the positrons to an energy of 200 MeV. Simulations are performed by the particle tracking code PARMELA. The magnetic field of the AMD is represented in PARMELA by simple coils. Two modes are applied in this study. The first one is accelerating mode based on acceleration after the AMD. The second one is decelerating mode based on deceleration in the first accelerating structure. It is shown that the decelerating mode gives a higher yield for the e+ beam in the end of the Pre-Injector Linac.

  20. The CERN study of a 2 TeV e+e- collider CLIC

    International Nuclear Information System (INIS)

    Progress with the CERN study of a 2 TeV e+e- linear collider (CLIC) is reported. The CLIC Test Facility for drive beam generation is giving first results. Results are also reported from development work on 30 GHz prototype accelerating structures (including RF quadrupole configurations) from a 30 GHz transfer structure for RF power generation in the CLIC two-beam scheme, from a prototype system for submicron automatic alignment and from theoretical work on wake-field stabilization, alignment tolerances, compensation of the beams energy spread and the final focus system

  1. Conceptual Design of the Drive Beam for a PWFA-LC

    Energy Technology Data Exchange (ETDEWEB)

    Pei, S.; Hogan, M.J.; Raubenheimer, T.O.; Seryi, A.; /SLAC; Braun, H.H.; Corsini, R.; Delahaye, J.P.; /DESY

    2009-08-03

    Plasma Wake-Field Acceleration (PWFA) has demonstrated acceleration gradients above 50 GeV/m. Simulations have shown drive/witness bunch configurations that yield small energy spreads in the accelerated witness bunch and high energy transfer efficiency from the drive bunch to the witness bunch, ranging from 30% for a Gaussian drive bunch to 95% for bunch with triangular shaped longitudinal profile. These results open the opportunity for a linear collider that could be compact, efficient and more cost effective than the present microwave technologies. A concept of a PWFA-based Linear Collider (PWFA-LC) has been developed by the PWFA collaboration. Here we will describe the conceptual design and optimization of the drive beam, which includes the drive beam linac and distribution system. We apply experience of the CLIC drive beam design and demonstration in the CLIC Test Facility (CTF3) to this study. We discuss parameter optimization of the drive beam linac structure and evaluate the drive linac efficiency in terms of the drive beam distribution scheme and the klystron/modulator requirements.

  2. 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...

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hajari, Sh. Sanaye, E-mail: ssanayeh@cern.ch [Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); European Organization for Nuclear Research (CERN), BE Department, CH-1211 Geneva 23 (Switzerland); Shaker, H. [Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); European Organization for Nuclear Research (CERN), BE Department, CH-1211 Geneva 23 (Switzerland); Doebert, S. [European Organization for Nuclear Research (CERN), BE Department, CH-1211 Geneva 23 (Switzerland)

    2015-11-01

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

  5. Transverse Beam Polarizationas an Alternate View into New Physics at CLIC

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, Thomas G.; /SLAC

    2011-08-12

    In e{sup +}e{sup -} collisions, transverse beam polarization can be a useful tool in studying the properties of particles associated with new physics beyond the Standard Model(SM). However, unlike in the case of measurements associated with longitudinal polarization, the formation of azimuthal asymmetries used to probe this physics in the case of transverse polarization requires both e{sup {+-}} beams to be simultaneously polarized. In this paper we discuss the further use of transverse polarization as a probe of new physics models at a high energy, {radical}s = 3 TeV version of CLIC. In particular, we show (i) how measurements of the sign of these asymmetries is sufficient to discriminate the production of spin-0 supersymmetric states from the spin-1/2 Kaluza-Klein excitations of Universal Extra Dimensions. Simultaneously, the contribution to this asymmetry arising from the potentially large SM W{sup +}W{sup -} background can be made negligibly small. We then show (ii) how measurements of such asymmetries and their associated angular distributions on the peak of a new resonant Z{prime}-like state can be used to extract precision information on the Z{prime} couplings to the SM fermions.

  6. 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...

  7. 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.

  8. 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...

  9. 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 ...

  10. Emittance optimisation in the Drive Beam Recombination Complex at CTF3

    CERN Document Server

    Gamba, D

    2014-01-01

    According to the Conceptual Design Report, the power to accelerate the main colliding beams of CLIC is taken from parallel high intensity (100 A), low energy (2.37 GeV) beams. These beams are generated by long trains, accelerated by conventional klystrons and then time-compressed in the so called Drive-Beam Recombination Complex (DBRC). A scaled version of the DBRC has been built at the CLIC Test Facility (CTF3) at CERN in order to prove its principle and study any arising feasibility issues. One of the main constraints is the emittance control during the recombination process. This work presents an overview of the studies ongoing at CTF3, keeping in view possible improvements of the nominal CLIC design. In particular, a generic feedback algorithm to solve (quasi-)linear systems has been implemented and used in order to optimize the process by tuning the energy of the beam and steer the orbits in the different lines, as well matching the design dispersion. Current results and possible room for further optimiz...

  11. 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...

  12. 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&...

  13. 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].

  14. 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.

  15. 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...

  16. CERN: Making CLIC tick

    International Nuclear Information System (INIS)

    While the Large Hadron Collider (LHC) scheme for counter-rotating proton beams in a new superconducting ring to be built in CERN's existing 27-kilometre LEP tunnel is being pushed as the Laboratory's main construction project for the 1990s, research and development continues in parallel for an eventual complementary attack on new physics frontiers with CERN's Linear Collider - CLIC - firing TeV electron and positron beams at each other

  17. 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 ...

  18. 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...

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

    International Nuclear Information System (INIS)

    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+e- collider based on CLIC technology and to describe the essential features of a detector that are required to deliver the full physics potential of this machine. The experimental conditions at CLIC are significantly more challenging than those at previous electron-positron colliders due to the much higher levels of beam-induced backgrounds and the 0.5 ns bunch-spacing. Consequently, a large part of this report is devoted to understanding the impact of the machine environment on the detector with the aim of demonstrating, with the example of realistic detector concepts, that high precision physics measurements can be made at CLIC. Since the impact of background increases with energy, this document concentrates on the detector requirements and physics measurements at the highest CLIC center-of-mass energy of 3 TeV. One essential output of this report is the clear demonstration that a wide range of high precision physics measurements can be made at CLIC with detectors which are challenging, but considered

  20. 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

  1. Laser Wire Scanner Basic Process and Perspectives for the CTF's and CLIC Machines

    CERN Document Server

    Lefèvre, T

    2002-01-01

    In a laser wire scanner, the basic idea is to replace the solid wire classically used in a standard wire scanner by a narrow laser beam. The basic process involved is the Thomson-Compton scattering process, where photons are scattered from the laser beam by the incoming electrons. By counting the number of scattered photons or degraded electrons as a function of laser position the bunch profile can be reconstructed. In this note the Compton scattering mechanism is first presented. In the framework of the CLIC project, a laser wire scanner (LWS) could be used as a non-interfering beam profile measurement both on the Drive Beam for a high current electron beam and on the Main Beam for very small electron beam sizes. A design for a LWS on the CTF2 and CTF3 machines is proposed and some considerations for the use of a LWS on the CLIC main beam are also mentioned.

  2. The PHIN photoinjector for the CTF3 Drive beam

    CERN Document Server

    Losito, R; Braun, H; Champault, N; Chevallay, E; Divall, M; Fedosseev, V; Hirst, G; Kumar, A; Kurdi, G; Martin, W; Masi, A; Mercier, B; Musgrave, I; Prevost, C; Ross, I; Roux, R; Springate, E; Suberlucq, Guy

    2006-01-01

    A new photoinjector for the CTF3 drive beam has been designed and is now being constructed by a collaboration among LAL, CCLRC and CERN within PHIN, the second Joint Research Activity of CARE. The photoinjector will provide a train of 2332 pulses at 1.5 GHz with a complex timing structure (sub-trains of 212 pulses spaced from one another by 333 ps or 999 ps) to allow the frequency multiplication scheme, which is one of the features of CLIC, to be tested in CTF3. Each pulse of 2.33 nC will be emitted by a Cs2Te photocathode deposited by a co-evaporation process to allow high quantum efficiency in operation (>3% for a minimum of 40 h). The 3 GHz, 2 1/2 cell RF gun has a 2 port coupler to minimize emittance growth due to asymmetric fields, racetrack profile of the irises and two solenoids to keep the emittance at the output below 20 p.mm.mrad. The laser has to survive very high average powers both within the pulse train (15 kW) and overall (200 W before pulse slicing). Challenging targets are also for amplitude ...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. A sensitiviy analysis for the stabilization of the CLIC main beam quadrupoles

    CERN Document Server

    Janssens, S; Artoos, K; Fernandez Carmona, P; Hauviller, C

    2010-01-01

    In particle colliders (like the LHC), particles are highly accelerated in a circular beam pipe before the collision. However, due to the curved trajectory of the particles, they are also loosing energy because of the so-called Bremsstrahlung. In order to bypass this fundamental limitation imposed by circular beams, the next generation of particle colliders will accelerate two straight beams of particles before the collision. One of them, the Compact Linear Collider, is currently under study at CERN. The machine is constituted of a huge number of accelerating structures (used to accelerate the particles) and quadrupoles (electromagnets used to focus the particles). The latter ones are required to be stable at the nanometer level. This extreme stability has to be guaranteed by active vibration isolation from all types of disturbances like ground vibrations, ventilation, cooling system, or acoustic noise. Because of the huge number of quadrupoles (about 4000), it is critical that the strategy adopted for the act...

  8. 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...

  9. 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...

  10. 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...

  11. Power threshold for neutral beam current drive

    International Nuclear Information System (INIS)

    For fully noninductive current drive in tokamaks using neutral beams, there is a power and density threshold condition, setting a minimum value for P3/2/n2. If this condition is not met, stationary state cannot occur, and a tokamak discharge will collapse. This is a consequence of the coupling between current and electron temperature, or between current drive efficiency and energy confinement time. 4 figs

  12. 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...

  13. 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.

  14. 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.

  15. 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

  16. 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.

  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. Longitudinal Beam Dynamics Studies at CTF3 And Pulse Compressor Controlling

    CERN Document Server

    Shaker, S H

    2009-01-01

    The aim of the CLIC Test Facility CTF3, built at CERN by an international collaboration, is to address the main feasibility issues of the CLIC electron-positron linear collider technology by 2010. One key-issue studied at CTF3 is the generation of the very high current drive beam, used in CLIC as the RF power source. It is particularly important to simulate and control the drive beam longitudinal dynamics in the drive beam generation complex, since it directly affects the efficiency and stability of the RF power production process. In this thesis how to use pulse compressors to achieve a high RF power in the drive beam accelerator is discussed. We also describe the ongoing effort in modelling the longitudinal evolution of the CTF3 drive beam and compare the simulations with experimental results. Our study is based on the single bunch simulation.

  19. 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.

  20. CLIC Post-Collision Line Luminosity Monitoring

    CERN Document Server

    Appleby, R B; Deacon, L; Geschwendtner, E

    2011-01-01

    The CLIC post collision line is designed to transport the un-collided beams and the products of the collided beams with a total power of 14MW to the main beam dump. Full Monte Carlo simulation has been done for the description of the CLIC luminosity monitoring in the post collision line. One method of the luminosity diagnostic is based on the detection of high energy muons produced by beamstrahlung photons in the main beam dump. The disrupted beam and the beamstrahlung photons produce at the order of 106 muons per bunch crossing per cm2, with energies higher than 10 GeV. Threshold Cherenkov counters are considered after the beam dump for the detection of these high energy muons. Another method for luminosity monitoring is presented using the direct detection of the beamstrahlung photons.

  1. The CLIC project and the design for an e+- collider

    International Nuclear Information System (INIS)

    The two-beam scheme of the CERN Linear Collider (CLIC) project is discussed. The problems in achieving the needed luminosity, caused by disruption and beam radiation are outlined. The main CLIC paramaters are presented. The supply of the RF power and problems of RF focusing caused by wakefield effects are discussed. The transfer and main LINAC structures, and the design of damping rings and the final focus are outlined. (H.W.). 25 refs.; 3 figs.; 2 tabs

  2. 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.

  3. 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.

  4. 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.

  5. Performance of particle flow calorimetry at CLIC

    International Nuclear Information System (INIS)

    The particle flow approach to calorimetry can provide unprecedented jet energy resolution at a future high energy collider, such as the International Linear Collider (ILC). However, the use of particle flow calorimetry at the proposed multi-TeV Compact Linear Collider (CLIC) poses a number of significant new challenges. At higher jet energies, detector occupancies increase, and it becomes increasingly difficult to resolve energy deposits from individual particles. The experimental conditions at CLIC are also significantly more challenging than those at previous electron–positron colliders, with increased levels of beam-induced backgrounds combined with a bunch spacing of only 0.5 ns. This paper describes the modifications made to the PandoraPFA particle flow algorithm to improve the jet energy reconstruction for jet energies above 250 GeV. It then introduces a combination of timing and pT cuts that can be applied to reconstructed particles in order to significantly reduce the background. A systematic study is performed to understand the dependence of the jet energy resolution on the jet energy and angle, and the physics performance is assessed via a study of the energy and mass resolution of W and Z particles in the presence of background at CLIC. Finally, the missing transverse momentum resolution is presented, and the fake missing momentum is quantified. The results presented in this paper demonstrate that high granularity particle flow calorimetry leads to a robust and high resolution reconstruction of jet energies and di-jet masses at CLIC.

  6. 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.

  7. 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...

  8. 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.

  9. The CLIC Vertex Detector

    International Nuclear Information System (INIS)

    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 and D achievements in the domains of sensors, readout and detector integration

  10. 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.

  11. 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.

  12. Neutral beam current drive scaling in DIII-D

    International Nuclear Information System (INIS)

    Neutral beam current drive scaling experiments have been carried out on the DIII-D tokamak at General Atomics. These experiments were performed using up to 10 MW of 80 keV hydrogen beams. Previous current drive experiments on DIII-D have demonstrated beam driven currents up to 340 kA. In the experiments reported here we achieved beam driven currents of at least 500 kA, and have obtained operation with record values of poloidal beta (εβ/sub p/ = 1.4). The beam driven current reported here is obtained from the total plasma current by subtracting an estimate of the residual Ohmic current determined from the measured loop voltage. In this report we discuss the scaling of the current drive efficiency with plasma conditions. Using hydrogen neutral beams, we find the current drive efficiency is similar in Deuterium and Helium target plasmas. Experiments have been performed with plasma electron temperatures up to T/sub e/ = 3 keV, and densities in the range 2 /times/ 1019m/sup /minus/3/ 19m/sup /minus/3/. The current drive efficiency (nIR/P) is observed to scale linearly with the energy confinement time on DIII-D to a maximum of 0.05 /times/ 1020m/sup /minus/2/ A/W. The measured efficiency is consistent with a 0-D theoretical model. In addition to comparison with this simple model, detailed analysis of several shots using the time dependent transport code ONETWO is discussed. This analysis indicates that bootstrap current contributes approximately 10--20% of the the total current. Our estimates of this effect are somewhat uncertain due to limited measurements of the radial profile of the density and temperatures. 4 refs., 1 fig., 1 tab

  13. Neutral Beam Current Drive in Spheromak plasma and plasma stability

    Science.gov (United States)

    Pearlstein, L. D.; Jayakumar, R. J.; Hudson, B.; Hill, D. N.; Lodestro, L. L.; McLean, H. S.; Fowler, T. K.; Casper, T. A.

    2007-11-01

    A key question for the Sustained Spheromak Physics Experiment (SSPX) is understanding how spheromaks can be sustained by other current drive tools such as neutral beam current drive. Another question is whether the present relationship between current and maximum spheromak magnetic field (plasma beta) is related to Alcator-like ohmic confinement limit or is a stability limit. Using the code CORSICA, the fraction of neutral beam current drive that can be achieved has been calculated for different injection angles with a fixed equilibrium. It is seen that relaxing the equilibrium with this drive simply drives the core safety factor to low values. Other equilibria where the NBI may give aligned current drive are being explored. Free-boundary equilibria calculations are underway to see what hyper-resistivity model gives the observed sustained SSPX performance and include that in the NBI calculations. Work performed under the auspices of the US DOE by University of California Lawrence Livermore National Laboratory under contract W-7405-ENG-48.

  14. 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...

  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. 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

  17. A CLIC-Prototype Higgs Factory

    OpenAIRE

    Belusevic, Radoje; Higo, Toshiyasu

    2012-01-01

    We propose that a pair of electron linacs with high accelerating gradients and an optical FEL be built at an existing laboratory. The linacs would employ CLIC-type rf cavities and a klystron-based power source; a two-beam scheme could be implemented at a later stage. The proposed facility would serve primarily as an e+e-/gamma-gamma Higgs-boson factory. The rich set of final states in e+e- and gamma-gamma collisions would play an essential role in measuring the mass, spin, parity, two-photon ...

  18. Performance of Particle Flow Calorimetry at CLIC

    CERN Document Server

    Marshall, J.S.; Thomson, M.A.

    2013-01-01

    The experimental conditions at CLIC are also significantly more challenging than those at previous electron-positron colliders, with increased levels of beam-induced backgrounds combined with a bunch spacing of only 0.5 ns. This paper describes the modifications made to the PandoraPFA particle flow algorithm to improve the jet energy reconstruction for jet energies above 250 GeV. It then introduces a combination of timing and pT cuts that can be applied to reconstructed particles in order to significantly reduce the background. A systematic study is...

  19. Crossed-beam energy transfer in direct-drive implosions

    Energy Technology Data Exchange (ETDEWEB)

    Seka, W; Edgell, D H; Michel, D T; Froula, D H; Goncharov, V N; Craxton, R S; Divol, L; Epstein, R; Follett, R; Kelly, J H; Kosc, T Z; Maximov, A V; McCrory, R L; Meyerhofer, D D; Michel, P; Myatt, J F; Sangster, T C; Shvydky, A; Skupsky, S

    2012-05-22

    Direct-drive-implosion experiments on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have showed discrepancies between simulations of the scattered (non-absorbed) light levels and measured ones that indicate the presence of a mechanism that reduces laser coupling efficiency by 10%-20%. This appears to be due to crossed-beam energy transfer (CBET) that involves electromagnetic-seeded, low-gain stimulated Brillouin scattering. CBET scatters energy from the central portion of the incoming light beam to outgoing light, reducing the laser absorption and hydrodynamic efficiency of implosions. One-dimensional hydrodynamic simulations including CBET show good agreement with all observables in implosion experiments on OMEGA. Three strategies to mitigate CBET and improve laser coupling are considered: the use of narrow beams, multicolor lasers, and higher-Z ablators. Experiments on OMEGA using narrow beams have demonstrated improvements in implosion performance.

  20. The CLIC Physics Potential

    CERN Document Server

    Robson, Aidan

    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.

  1. Wakefield monitor development for CLIC accelerating structure

    CERN Document Server

    Peauger, F; Girardot, P; Andersson, A; Riddone, G; Samoshkin, A; Solodko, A; Zennaro, R; Ruber, R

    2010-01-01

    Abstract To achieve high luminosity in CLIC, the accelerating structures must be aligned to an accuracy of 5 μm with respect to the beam trajectory. Position detectors called Wakefield Monitors (WFM) are integrated to the structure for a beam based alignment. This paper describes the requirements of such monitors. Detailed RF design and electromagnetic simulations of the WFM itself are presented. In particular, time domain computations are performed and an evaluation of the resolution is done for two higher order modes at 18 and 24 GHz. The mechanical design of a prototype accelerating structure with WFM is also presented as well as the fabrication status of three complete structures. The objective is to implement two of them in CTF3 at CERN for a feasibility demonstration with beam and high power rf.

  2. 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.

  3. CLIC Pre-damping and Damping Ring Kickers: Initial Ideas to Achieve Stability Requirements

    CERN Document Server

    Barnes, M J; Uythoven, J

    2010-01-01

    The Compact Linear Collider (CLIC) study is exploring the scheme for an electron-positron collider with high luminosity (1034-1035 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 the presence of Pre-Damping Rings (PDR) and Damping Rings (DR) to achieve the very low emittance, through synchrotron radiation, needed for the luminosity requirements of CLIC. In order to limit the beam emittance blow-up due to oscillations the combined flat top ripple and droop of the field pulse, for the DR extraction kickers, must be less than 0.02 %. In addition, the allowed beam coupling impedance is also very low: a few Ohms longitudinally and a few MW/m transversally. This paper discusses initial ideas for achieving the demanding requirements for the PDR and DR kickers.

  4. Conceptual Design of the CLIC Damping Rings

    CERN Document Server

    Papaphilippou, Y; Barnes, M; Calatroni, S; Chiggiato, P; Corsini, R; Grudiev, A; Koukovini, E; Lefevre, T; Martini, M; Modena, M; Mounet, N; Perin, A; Renier, Y; Russenschuck, S; Rumolo, G; Schoerling, D; Schulte, D; Schmickler, H; Taborelli, M; Vandoni, G; Zimmermann, F; Zisopoulos, P; Boland, M; Palmer, M; Bragin, A; Levichev, E; Syniatkin, S; Zolotarev, K; Vobly, P; Korostelev, M; Vivoli, A; Belver-Aguilar, C; Faus-Golfe, A; Rinolfi, L; Bernhard, A; Pivi, M; Smith, S; Rassool, R; Wootton, K

    2012-01-01

    The CLIC Damping rings are designed to produce unprecedentedly low-emittances of 500 nm and 5 nm normalized at 2.86 GeV, with high bunch charge, necessary for the performance of the collider. The large beam brightness triggers a number of beam dynamics and technical challenges. Ring parameters such as energy, circumference, lattice, momentum compaction, bending and superconducting wiggler fields are carefully chosen in order to provide the target emittances under the influence of intrabeam scattering but also reduce the impact of collective effects such as space-charge and coherent synchrotron radiation. Mitigation techniques for two stream instabilities have been identified and tested. The low vertical emittance is achieved by modern orbit and coupling correction techniques. Design considerations and plans for technical systems, such as wigglers, transfer systems, vacuum, RF cavities, instrumentation and feedback are finally reviewed.

  5. Impedance effects in the CLIC damping rings

    CERN Document Server

    Koukovini-Platia, E; Mounet, N; Rumolo, G; Salvant, B

    2011-01-01

    Due to the unprecedented brilliance of the beams, the performance of the Compact Linear Collider (CLIC) damping rings (DR) is affected by collective effects. Single bunch instability thresholds based on a broad-band resonator model and the associated coherent tune shifts have been evaluated with the HEADTAIL code. Simulations performed for positive and negative values of chromaticity showed that higher order bunch modes can be potentially dangerous for the beam stability. This study also includes the effects of high frequency resistive wall impedance due to different coatings applied on the chambers of the wigglers for e-cloud mitigation and/or ultra-low vacuum pressure. The impact of the resistive wall wake fields on the transverse impedance budget is finally discussed.

  6. 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...

  7. 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 ...

  8. A CLIC-Prototype Higgs Factory

    CERN Document Server

    Belusevic, Radoje

    2012-01-01

    We propose that a pair of electron linacs with high accelerating gradients and an optical FEL be built at an existing laboratory. The linacs would employ CLIC-type rf cavities and a klystron-based power source; a two-beam scheme could be implemented at a later stage. The proposed facility would serve primarily as an e+e-/gamma-gamma Higgs-boson factory. The rich set of final states in e+e- and gamma-gamma collisions would play an essential role in measuring the mass, spin, parity, two-photon width and trilinear self-coupling of the Higgs-boson, as well as its couplings to fermions and gauge bosons. These quantities are difficult to determine with only one initial state. For some processes within and beyond the Standard Model, the required CM energy is considerably lower at the proposed facility than at an e+e- or proton collider.

  9. 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.

  10. Intense relativistic electron beam injector system for tokamak current drive

    International Nuclear Information System (INIS)

    We report experimental and theoretical studies of an intense relativistic electron beam (REB) injection system designed for tokamak current drive experiments. The injection system uses a standard high-voltage pulsed REB generator and a magnetically insulated transmission line (MITL) to drive an REB-accelerating diode in plasma. A series of preliminary experiments has been carried out to test the system by injecting REBs into a test chamber with preformed plasma and applied magnetic field. REBs were accelerated from two types of diodes: a conventional vacuum diode with foil anode, and a plasma diode, i.e., an REB cathode immersed in the plasma. REB current was in the range of 50 to 100 kA and REB particle energy ranged from 0.1 to 1.0 MeV. MITL power density exceeded 10 GW/cm2. Performance of the injection system and REB transport properties is documented for plasma densities from 5 x 1012 to 2 x 1014 cm-3. Injection system data are compared with numerical calculations of the performance of the coupled system consisting of the generator, MITL, and diode

  11. 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)

  12. Transient beam-loading model and compensation in Compact Linear Collider main linac

    CERN Document Server

    Kononenko, O

    2011-01-01

    A new model to compensate for the transient beam loading in the CLIC main linac is developed. It takes into account the CLIC specific power generation scheme and the exact 3D geometry of the accelerating structure including couplers. A new method of calculating unloaded and loaded voltages during the transient is proposed and a dedicated optimization scheme of the rf pulse to compensate the transient beam-loading effect is presented. It is demonstrated that the 0.03% limit on the rms relative bunch-to-bunch energy spread in the main beam after acceleration can be reached. The optimization technique has been used to increase the rf to beam efficiency while preserving the CLIC requirements and to compensate for the energy spread caused by the Balakin-Novokhatski-Smirnov damping and transient process in the subharmonic buncher. Effects of charge jitters in the drive and main beams are studied. It is shown that within the 0.1% CLIC specification limit on the rms spread in beams charge the energy spread is not sig...

  13. 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.

  14. 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...

  15. Sensitivity Analysis for the CLIC Damping Ring Inductive Adder

    CERN Document Server

    Holma, Janne

    2012-01-01

    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, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse generators for the damping ring kickers must provide extremely flat, high-voltage pulses. The specifications for the extraction kickers of the CLIC damping rings are particularly demanding: the flattop of the output pulse must be 160 ns duration, 12.5 kV and 250 A, with a combined ripple and droop of not more than ±0.02 %. An inductive adder allows the use of different modulation techniques and is therefore a very promising approach to meeting the specifications. PSpice has been utilised to carry out a sensitivity analysis of the predicted output pulse to the value of both individual and groups of circuit compon...

  16. Fabrication of Beam-rotating Actuator for Multiple-beam Disk Drive

    Science.gov (United States)

    Kim, Boung Jun; Kim, Soo Hyun; Kwak, Yoon Keun

    2002-05-01

    Current trends in computer and communication industries are towards increasingly higher resolution images and video processing techniques. However, such sophisticated processing tasks require massive storage systems such as a compact disk read only memory (CD-ROM) and digital versatile disc (DVD). Current demands in the development of such systems are higher data density storage media and an improved data transfer rate. The latter is discussed in this paper. A multiple-beam optical disk drive is presented as a method for improving the effective data transfer rate by increasing the beam spot number formed on an optical disk. The beam-rotating actuator is necessary for positioning the multiple-beam onto more than one track. Ray tracing was also employed for the real system setup. The beam-rotating actuator is made up of piezoelectric material, a high-stiffness wire hinge and a dove prism. The actuator has an approximately 1 kHz resonance frequency and a suitable operational range. The dynamic equation for the actuator is derived for the control of the real system.

  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. On structure design for the CLIC Booster Linac

    CERN Document Server

    Darvish, Esmat

    2015-01-01

    Using the SUPERFISH code we present a design for a traveling wave (TW) structure of the Booster Linac for CLIC. The structure, consisting of thirty asymmetric cells attached to the beam pipes at two ends, works in 2π/3 operating mode at working frequency 2 GHz. For the corresponding operating mode and frequency, the RF field configuration transmitted through the cavity is obtained. The results are prepared in an RF field data file to be used in the PARMELA code for further beam dynamic study.

  19. Fast-ion transport and neutral beam current drive in ASDEX upgrade

    DEFF Research Database (Denmark)

    Geiger, B.; Weiland, M.; Jacobsen, Asger Schou;

    2015-01-01

    The neutral beam current drive efficiency has been investigated in the ASDEX Upgrade tokamak by replacing on-axis neutral beams with tangential off-axis beams. A clear modification of the radial fast-ion profiles is observed with a fast-ion D-alpha diagnostic that measures centrally peaked profil...

  20. The CLIC Test Facility (CTF3) which allowed the first electron beam recombination in order to multiply the RF frequency from 3 GHz up to 15 GHz.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Photo 0210005_11: The CTF3 linac accelerates an electron beam up to 350 MeV. Photo 0210005_1: At the front, the yellow dipole is used for the spectrometer line. At the back, a doublet of blue quadrupole for the matching. Photo 0210005_03: The CTF3 transfer line between the electron linac and the isochronous ring. Photo 0210005_04: One arc of the EPA isochronous ring. Photo 0210005_06: The CTF3 bunching system. The first RF wave guide feeds the Pre-Buncher while the second RF wave guide feeds the Buncher. They provide a bunched electron beam at 4 MeV. The blue magnet is a solenoid around the Buncher. Photo 0210005_07: A LIL accelerating structure used for CTF3. It is 4.5 meters long and provides an energy gain of 45 MeV. One can see 3 quadrupoles around the RF structure.

  1. CLIC-ACM: Acquisition and Control System

    CERN Document Server

    Bielawski, B; Magnoni, S

    2014-01-01

    CLIC [1] (Compact Linear Collider) is a world-wide collaboration to study the next terascale lepton collider, relying upon a very innovative concept of two-beamacceleration. In this scheme, the power is transported to the main accelerating structures by a primary electron beam. The Two Beam Module (TBM) is a compact integration with a high filling factor of all components: RF, Magnets, Instrumentation, Vacuum, Alignment and Stabilization. This paper describes the very challenging aspects of designing the compact system to serve as a dedicated Acquisition & Control Module (ACM) for all signals of the TBM. Very delicate conditions must be considered, in particular radiation doses that could reach several kGy in the tunnel. In such severe conditions shielding and hardened electronics will have to be taken into consideration. In addition, with more than 300 ADC&DAC channels per ACM and about 21000 ACMs in total, it appears clearly that power consumption will be an important issue. It is also obvious that...

  2. 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...

  3. Precision Higgs boson measurement at CLIC

    CERN Document Server

    Pandurovic, Mila

    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.

  4. 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...

  5. 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.

  6. 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.

  7. 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\

  8. 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].

  9. 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...

  10. 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...

  11. 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...

  12. First magnetic test of a superconducting Nb$_{3}$Sn Wiggler magnet for CLIC

    CERN Document Server

    Schoerling, D; Fessia, P; Karppinen, M; Mazet, J; Russenschuck, S; Peiffer, P; Grau, A

    2012-01-01

    To achieve high luminosity at the collision point of the Compact Linear Collider (CLIC) the normalized horizontal and vertical emittances of the electron and positron beams must be reduced to 500 nm and4 nm before the beams enter the 1.5 TeV linear accelerators. An effective way to accomplish ultra-low emittances with only small effects on the electron polarization is using damping rings operating at 2.86GeV equipped with superconducting wiggler magnets. Only superconducting wiggler magnets meet the demanding magnetic specifications of the CLIC damping rings. Although Nb-Ti damping wiggler magnets fulfill the specifications of CLIC, Nb3Sn wiggler magnets would reach higher magnetic fields leading to even better beam properties for CLIC. Moreover, they have at the same time higher thermal and magnetic margins. Therefore, Nb3Sn wiggler magnets are under investigation at CERN despite the challenging manufacturing process. This paper presents first results of Nb3Sn coils and short model tests and outlines the fur...

  13. Photoinjector beam quality improvement by shaping the wavefront of a drive laser with oblique incidence

    Institute of Scientific and Technical Information of China (English)

    HE Zhi-Gang; WANG Xiao-Hui; JIA Qi-Ka

    2012-01-01

    To increase the quantum efficiency (QE) of a copper photocathode and reduce the thermal emittance of an electron beam,a drive laser with oblique incidence was adopted in a BNL type photocathode rf gun.The disadvantageous effects on the beam quality caused by oblique incidence were analyzed qualitatively.A simple way to solve the problens through wavefront shaping was introduced and the beam quality was improved.

  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. 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%.

  16. 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.

  17. Preliminary Design of an Inductive Adder for CLIC Damping Rings

    CERN Document Server

    Holma, J

    2011-01-01

    The Compact Linear Collider (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 damping rings will produce ultra-low emittance beam, with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse power modulators for the damping rings kickers must provide extremely flat, high-voltage, pulses: specifications call for a 160 ns duration flattop of 12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 %. A solid-state modulator, the inductive adder, is a very promising approach to meeting the demanding specifications; this topology allows the use of both digital and analogue modulation. To effectively use modulation techniques to achieve such low ripple and droop requires an in-depth knowledge of the behaviour of the solid-state switching components and their gate drivers, as well as a good understanding of the overa...

  18. 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...

  19. High illumination uniformity scheme with 32 beams configuration for direct-drive inertial confinement fusion

    Science.gov (United States)

    Li, Li; Gu, Chun; Xu, Lixin; Zhou, Shenlei

    2016-04-01

    The self-adapting algorithms are improved to optimize a beam configuration in the direct drive laser fusion system with the solid state lasers. A configuration of 32 laser beams is proposed for achieving a high uniformity illumination, with a root-mean-square deviation at 10-4 level. In our optimization, the parameters such as beam number, beam arrangement, and beam intensity profile are taken into account. The illumination uniformity robustness versus the parameters such as intensity profile deviations, power imbalance, intensity profile noise, the pointing error, and the target position error is also discussed. In this study, the model is assumed a solid-sphere illumination, and refraction effects of incident light on the corona are not considered. Our results may have a potential application in the design of the direct-drive laser fusion of the Shen Guang-II Upgrading facility (SG-II-U, China).

  20. Numerical simulations of driving beam dynamics in the plasma wakefield accelerator

    International Nuclear Information System (INIS)

    Novel plasma based acceleration devices have become the subject of active research because of their ability to support acceleration gradients in excess of 10 GeV/m. The plasma wakefield accelerator (PWFA) is one such device which consists of an intense electron beam (the primary beam) whose purpose is to excite a plasma wave which, in turn, accelerates a trailing electron bunch (the secondary beam). Two issues of current interest in the PWFA are (1) the equilibrium and stability of the driving beam and (2) the effect of the wakefield on the quality of the trailing electron bunch. In the UCLA experiment, a question of particular interest is the equilibrium state of the driving electron beam. Two intriguing suggestions have been made. The first is that in the limit that the beam density greatly exceeds the plasma density, the plasma electrons will be completely expelled from the axis. The second is that, in parameter regimes of interest, the driving beam will experience a severe radial pinching force. In order to investigate these assertions, the authors first consider the envelope equation for an electron beam propagating in a plasma with nb ≥ np. They then compare numerical solutions of this equation to results obtained via two-dimensional axisymmetric (r,z) particle simulation using the GRIEZR particle simulation code

  1. Beam dynamics simulations for linacs driving short-wavelength FELs

    International Nuclear Information System (INIS)

    The fast code HOMDYN has been recently developed, in the framework of the TTF (Tesla test facility) collaboration, in order to study the beam dynamics of linacs delivering high brightness beams as those needed for short wavelength Fel experiments. These linacs are typically driven by radio-frequency photo-injectors, where correlated time dependent space charge effects are of great relevance: these effects cannot be studied by standard beam optics codes (TRACE3D, etc.) and they have been modeled so far by means of multi-particle (Pic or quasistatic) codes requiring heavy cpu time and memory allocations. HOMDYN is able to describe the beam generation at the photo-cathode and the emittance compensation process in the injector even running on a laptop with very modest running rimes (less than a minute). In this paper it is showed how this capability of the code is exploited so to model a whole linac up to the point where the space charge dominated regime is of relevance (200 MeV)

  2. Ground Motion Mitigation in the Main Linac of CLIC

    International Nuclear Information System (INIS)

    Full text: The future linear collider CLIC (Compact Linear Collider) is CERN's propose for a successor of the LHC (Large Hadron Collider). The design of CLIC requires ultralow particle beam emittances, which makes the accelerator very sensitive to ground motion. Without countermeasure, the beam quality would be already unacceptable after a few seconds. In our work we present a feedback algorithm, which mitigates the parasitic effects of ground motion in the main linac of CLIC efficiently. We use an adaptive controller, which is composed of two parts: a system identification unit and a SVD control algorithm. The system identification unit calculates on-line estimates of the time changing accelerator behaviour. This precise model, which can adapt to system changes, is used by the control algorithm. If the system identification unit would not be used, drifting accelerator parameter would cause a mismatch between the real accelerator behaviour and the model used by the controller, which would result in a poor controller performance. Standard system identification algorithms cannot be used in an accelerator environment. The indispensable system excitation cause a not tolerable emittance growth, if it is applied thoughtless. Instead a special excitation scheme consisting of interleaved beam bumps was implemented, which keeps the emittance growth at an acceptable level. However, this special excitation has the disadvantage that not the complete system can be identified anymore. To still get an all over model of the system, we use the identification data and interpolate them with the help of a beam oscillation amplitude model, derived for the main linac of CLIC. The control algorithm uses the identified system data, which are the orbit response matrix R. With the help of the SVD decomposition of R, a very efficient filter can be created. This filter reconstructs the ground motion components, which are causing the majority of the emittance growth. At the same time the

  3. 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...

  4. DC Breakdown experiments for CLIC

    CERN Document Server

    Descoeudres, A; Taborelli, M

    2008-01-01

    For the production of the Compact Linear Collider (CLIC) RF accelerating structures, a material capable of sustaining high electric field, with a low breakdown rate and showing low damages after breakdowns is needed. A DC breakdown study is underway at CERN in order to test candidate materials and surface preparations. The saturated breakdown fields of several metals and alloys have been measured, ranging from 100 MV/m for Al to 850 MV/m for stainless steel, being around 170 MV/m for Cu and 430 MV/m for Mo for example. The conditioning speed of Mo can be significantly improved by removing oxides at the surface with a vacuum heat treatment, typically at 875±C for 2 hours. DC breakdown rate measurements have been done with Cu and Mo electrodes, showing similar results as in RF experiments: the breakdown probability seems to exponentially increase with the applied field. Measurements of time delays before breakdown show two different populations of breakdowns, immediate and delayed breakdowns, indicating that t...

  5. Proposition d'une méthode d'alignement de l'accélérateur linéaire CLIC

    CERN Document Server

    Touzé, Thomas; Mainaud-Durand, H

    2011-01-01

    The compact linear collider (CLIC) is the particles accelerator project proposed by the european organization for nuclear research (CERN) for high energy physics after the large hadron collider (LHC). Because of the nanometric 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. 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 prealignment but shows the way to the last developments that have to be done for that purpose. A metho...

  6. 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.

  7. 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.

  8. 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.

  9. Neutral Beam Heating and Current Drive in MAST

    Science.gov (United States)

    Akers, R.; Challis, C.; Appel, L.; Conway, N.; Cunningham, G.; Gryaznevich, M.; Lloyd, B.; Patel, A.; Tabasso, A.; Tournianski, M.

    2002-11-01

    Primary auxiliary heating on MAST (R 0.8m, a 0.6m) is provided by two ORNL neutral-beam injectors, oriented in the mid-plane, each with a tangency radius of 0.7m. Centrally peaked heating profiles at electron densities routinely exceeding the Greenwald limit are generated by injecting in the range 40 co-injection heated discharges and for low current (Ip 300kA), low-density (ne>0.5x1019m-3) co and counter injection heated plasmas where NBCD is being investigated.

  10. 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.

  11. 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.

  12. 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...

  13. 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...

  14. ADAPTIVE CONTROL OF FLEXIBLE BEAM WITH UNKNOWN DEAD-ZONE IN THE DRIVING MOTOR

    Institute of Scientific and Technical Information of China (English)

    Wang Xingsong; Hong Henry; Su Chunyi

    2004-01-01

    Adaptive control of a flexible beam system preceded by an unknown dead-zone in the driving motor is investigated in state space form. By introducing an important lemma for simplifying error equation between the flexible beam model and the matching reference model, a robust adaptive control scheme is developed by involving the dead-zone inverse terms. The new adaptive control law ensures global stability of the entire system and achieves desired tracking precision even when the slopes of the dead-zone are not equal. Simulations performed on a typical flexible beam system illustrate and clarify the validity of this approach.

  15. 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...

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

    CERN Document Server

    Firu, Elena

    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. On-Line Dispersion Free Steering for the Main Linac of CLIC

    CERN Document Server

    Pfingstner, J

    2013-01-01

    For future linear colliders as well as for light sources, ground motion effects are a severe problem for the accelerator performance. After a few minutes, orbit feedback systems are not sufficient to mitigate all ground motion effects and additional long term methods will have to be deployed. In this paper, the long term ground motion effects in the main linac of the Compact Linear Collider (CLIC) are analysed via simulation studies. The primary growth of the projected emittance is identified to originate from chromatic dilutions due to dispersive beam orbits. To counter this effect, an on-line identification algorithm is applied to measure the dispersion parasitically. This dispersion estimate is used to correct the beam orbit with an iterative dispersion free steering algorithm. The presented results are not only of interest for the CLIC project, but for all linacs in which the dispersive orbit has to be corrected over time.

  18. Thermo-mechanical Analysis of the CLIC Post-Linac Energy Collimators

    CERN Document Server

    Resta-Lopez, J; Latina, A

    2012-01-01

    The post-linac energy collimation system of the Compact Linear Collider (CLIC) has been designed for passive protection of the Beam Delivery System (BDS) against miss-steered beams due to failure modes in the main linac. In this paper, a thermo-mechanical analysis of the CLIC energy collimators is presented. This study is based on simulations using the codes FLUKA and ANSYS when an entire bunch train hits the collimators. Different failure mode scenarios in the main linac are considered. The aim is to improve the collimator in order to make a reliable and robust design so that survives without damage the impact of a full bunch train in case of likely events generating energy errors.

  19. Neutral beam heating and current drive system and its role in ITER-FEAT operation scenarios

    International Nuclear Information System (INIS)

    The NB H and CD system, providing 33 MW in deuterium beams at 1 MeV from two injectors, in addition to 40 MW RF power, contributes to heating a plasma to sub-ignition through the L-H mode transition followed by finite-Q driven-burn (Q≥10), and achievement of a hybrid operation with an extended-duration (∼1000 s) or steady-state operation with Q≤5. To achieve such operations, the NB provides non-inductive current drive by injecting the beams tangentially into the plasma with the capability of on- and off-axis current drive. The present engineering design is under the constraints of the beam envelope, vacuum confinement, neutron shielding, tolerances, and clearances required with the toroidal field coils. The on- and off-axis current drive is to be achieved by tilting the beam axis vertically. Each beam axis of the NB injectors can be tilted independently, providing flexibility in the control of heating and the driven current profile. (author)

  20. Beam loading compensation of traveling wave linacs through the time dependence of the rf drive

    International Nuclear Information System (INIS)

    Beam loading in traveling-wave linear accelerating structures leads to unacceptable spread of particle energies across an extended train of bunched particles due to beam-induced field and dispersion. Methods for modulating the rf power driving linacs are effective at reducing energy spread, but for general linacs do not have a clear analytic foundation. We report here methods for calculating how to modulate the rf drive in arbitrarily nonuniform traveling-wave linacs within the convective-transport (power-diffusion) model that results in no additional energy spread due to beam loading (but not dispersion). Varying group velocity, loss factor, and cell quality factor within a structure, and nonzero particle velocity, are handled.

  1. 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].

  2. 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.

  3. High performance electronics for alignment regulation on the CLIC 30GHz modules

    International Nuclear Information System (INIS)

    CERN is studying a linear collider (CLIC) to obtain electron-positron collisions with centre-of-mass energies in the TeV range. To demonstrate the feasibility of CLIC, a test facility (CTF2) is being constructed. CTF2 consists of 4 identical modules, each 1.4 m long module consists of 2 linac with a girder and a doublet or a triplet quadrupole. Girders are elements that support mechanically the cavities of the accelerator while the main objective of the quadrupole is to focus particle beams. The alignment system has 2 principal utilities. The first is to pre-align the elements to make the beam pass through the aperture and produce signals in beam position monitors. In respect to these signals the girders and the quadrupoles are moved for making the definitive alignment. The second utility is to maintain the elements in this position. The alignment control system of CTF2 must regulate the position of the girders and quadrupoles with a precision < 10 μm. In fact an accuracy of 1 μ has been obtained on CTF2. Thanks to its flexibility and its simplicity, the system is expected to adapt easily to CLIC even if it means to control modules that involve up to a maximum of 384 motors and 896 sensors

  4. 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...

  5. CLIC crab cavity design optimisation for maximum luminosity

    International Nuclear Information System (INIS)

    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.

  6. 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.

  7. 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.

  8. CLIC simulations from the start of the linac to the interaction point

    CERN Document Server

    Schulte, Daniel; Blair, G A; D'Amico, T E; Leros, Nicolas; Redaelli, S; Risselada, Thys; Zimmermann, Frank

    2002-01-01

    Simulations for linear colliders are traditionally performed separately for the different sub-systems, like damping ring, bunch compressor, linac, and beam delivery. The beam properties are usually passed from one sub-system to the other via bunch charge, RMS transverse emittances, RMS bunch length, average energy and RMS energy spread. It is implicitly assumed that the detailed 6D correlations in the beam distribution are not relevant for the achievable luminosity. However, it has recently been shown that those correlations can have a strong effect on the beam-beam interaction. We present first results on CLIC simulations that integrate linac, beam delivery, and beam-beam interaction. These integrated simulations also allow a better simulation of time-dependent effects, like ground perturbations and interference between several beam-based feedbacks.

  9. Evaluation of Components for the High Precision Inductive Adder for the CLIC Damping Rings

    CERN Document Server

    Holma, J

    2012-01-01

    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 damping rings will produce, through synchrotron radiation, ultra-low emittance beam with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse generators for the damping ring kickers must provide extremely flat high-voltage pulses. The specifications for the extraction kickers of the CLIC damping rings are particularly demanding: the flattop of the output pulse must be 160 ns duration, 12.5 kV and 250 A, with a combined ripple and droop of not more than ±0.02 %. An inductive adder allows the use of different modulation techniques and is therefore a very promising approach to meeting the specifications. In addition to semiconductors working in their saturated region, semiconductors working in their linear region are needed for applying analogue modulation techniques. Simulat...

  10. Wakefield and surface electromagnetic field optimisation of manifold damped accelerating structures for CLIC

    International Nuclear Information System (INIS)

    The main travelling wave linacs of the compact linear collider (CLIC) operate at a frequency of 11.9942 GHz with a phase advance per cell of 2π/3. In order to minimise the overall footprint of the accelerator, large accelerating gradients are sought. The present baseline design for the main linacs of CLIC demands an average electric field of 100 MV/m. To achieve this in practical cavities entails the dual challenges of minimising the potential for electrical breakdown and ensuring the beam excited wakefield is sufficiently suppressed. We present a design to meet both of these conditions, together with a description of the structure, CLICDDSA, expressively designed to experimentally test the ability of the structure to cope with high powers.

  11. 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.

  12. 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...

  13. 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.

  14. Nested folded-beam suspensions with low longitudinal stiffness for comb-drive actuators

    International Nuclear Information System (INIS)

    Nested folded-beam suspensions with a low longitudinal spring constant and a high lateral spring constant have been used in comb-drive actuators. In the new design, every two flexible beams and two stiff members form a parallelogram flexure, which is considered as an ‘element’ of the nested folded-beam suspension. A set of these flexures of increasing size were placed one outside another to compose a nested structure. In this way, a serial mechanical connection between adjacent parallelogram flexures was formed; thus, a longer output stroke was obtained by combining the stroke displacements of all flexures in an additive fashion. The designed suspensions were theoretically analyzed and numerically simulated. Furthermore, comb-drive actuators with conventional and new suspensions were fabricated and tested to verify the predicted function. In the testing cases, the longitudinal spring constants of suspensions with two (conventional), three and four parallelogram flexures on each side were measured as 2.77, 1.75 and 1.36 N m−1. The ratio among these three values was approximately 6:4:3, which is consistent with the theoretical predictions and simulation results. Microfabricated folded beams in series were achieved. (paper)

  15. Fast phase switching within the bunch train of the PHIN photo-injector at CERN using fiber-optic modulators on the drive laser

    CERN Document Server

    Divall Csatari, M; Bolzon, B; Bravin, E; Chevallay, E; Dobert, S; Drozdy, A; Fedosseev, V; Hessler, C; Lefevre, T; Livesley, S; Losito, R; Mete, O; Petrarca, M; Rabiller, A N

    2011-01-01

    The future Compact Linear Collider (CLIC) e^-/e^+ collider is based on the two-beam acceleration concept, whereby interleaving electron bunches of the drive beam through a delay loop and combiner rings as well as high peak RF power at 12GHz are created locally to accelerate a second beam, the main beam. One of the main objectives of the currently operational CLIC Test Facility (CTF3) is to demonstrate beam combination from 1.5GHz to 12GHz, which requires satellite-free fast phase-switching of the drive beam with sub-ns speed. The PHIN photo-injector, with the photo-injector laser, provides flexibility in the time structure of the electron bunches produced, by direct manipulation of the laser pulses. A novel fiber modulator-based phase-switching technique allows clean and fast phase-switch at 1.5GHz. This paper describes the switching system based on fiber-optic modulators, and the measurements carried out on both the laser and the electron beam to verify the scheme.

  16. Fast phase switching within the bunch train of the PHIN photo-injector at CERN using fiber-optic modulators on the drive laser

    Science.gov (United States)

    ‘Csatari' Divall, M.; Andersson, A.; Bolzon, B.; Bravin, E.; Chevallay, E.; Döbert, S.; Drozdy, A.; Fedosseev, V.; Hessler, C.; Lefevre, T.; Livesley, S.; Losito, R.; Mete, Ö.; Petrarca, M.; Rabiller, A. N.

    2011-12-01

    The future Compact Linear Collider (CLIC) e-/e+ collider is based on the two-beam acceleration concept, whereby interleaving electron bunches of the drive beam through a delay loop and combiner rings as well as high peak RF power at 12 GHz are created locally to accelerate a second beam, the main beam. One of the main objectives of the currently operational CLIC Test Facility (CTF3) is to demonstrate beam combination from 1.5 GHz to 12 GHz, which requires satellite-free fast phase-switching of the drive beam with sub-ns speed. The PHIN photo-injector, with the photo-injector laser, provides flexibility in the time structure of the electron bunches produced, by direct manipulation of the laser pulses. A novel fiber modulator-based phase-switching technique allows clean and fast phase-switch at 1.5 GHz. This paper describes the switching system based on fiber-optic modulators, and the measurements carried out on both the laser and the electron beam to verify the scheme.

  17. 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.

  18. 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).

  19. Fast wave current drive in neutral beam heated plasmas on DIII-D

    International Nuclear Information System (INIS)

    The physics of non-inductive current drive and current profile control using the fast magnetosonic wave has been demonstrated on the DIII-D tokamak. In non-sawtoothing discharges formed by neutral beam injection (NBI), the radial profile of the fast wave current drive (FWCD) was determined by the response of the loop voltage profile to co, counter, and symmetric antenna phasings, and was found to be in good agreement with theoretical models. The application of counter FWCD increased the magnetic shear reversal of the plasma and delayed the onset of sawteeth, compared to co FWCD. The partial absorption of fast waves by energetic beam ions at high harmonics of the ion cyclotron frequency was also evident from a build up of fast particle pressure near the magnetic axis and a correlated increase in the neutron rate. The anomalous fast particle pressure and neutron rate increased with increasing NBI power and peaked when a harmonic of the deuterium cyclotron frequency passed through the center of the plasma. The experimental FWCD efficiency was highest at 2 T where the interaction between the fast waves and the beam ions was weakest; as the magnetic field strength was lowered, the FWCD efficiency decreased to approximately half of the maximum theoretical value

  20. 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.

  1. Benchmarking of neutral beam current drive codes as a basis for the integrated modelling for ITER

    International Nuclear Information System (INIS)

    Neutral beam injection is a robust method for heating and current drive because it does not depend on any resonance conditions or coupling conditions at the edge. High-energy neutral beam current drive (NBCD) was experimentally validated for central current drive in JT-60U, giving a further confidence in ITER predictions. Recent progress in diagnostics, equilibrium solvers and analysis techniques enable rather detailed comparisons with NBCD codes. However, different codes give somewhat different results. Thus, we need to clarify physics implementations in NBCD codes, such as the beam model, ionization process, fast ion diffusion in the velocity space, orbit effects and electron shielding. Also from an integrated modelling viewpoint, an NBCD code benchmark is needed to establish a more solid basis for ITER operations. A benchmark of the Fokker-Planck code ACCOME has been performed against the orbit following Monte-Carlo code OFMC. Although calculated profiles agree rather well, the OFMC profile is slightly wider than the ACCOME one. The difference in the total fast ion current is ∼ 15%. We have examined fast ion diffusion in the 2D velocity space and observed difference in the diffusion in the pitch angle space. We have also examined orbit effects using a point source of the fast ions. Comparison of OFMC runs with and without the drift term in the orbit equation shows the finite banana width effect is not negligible. We have started a new NBCD code benchmark in the frame of the ITPA Steady-State Operation Topical Group with Fokker-Planck codes and orbit following Monte-Carlo codes such as OFMC, ACCOME, SPOT, NEMO, ASTRA, TRANSP/NUBEAM, ONETWO/NUBEAM, DRIFT and TOPICS. (author)

  2. 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.

  3. 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.

  4. 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).

  5. 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).

  6. CLIC-ACM: generic modular rad-hard data acquisition system based on CERN GBT versatile link

    International Nuclear Information System (INIS)

    CLIC is a world-wide collaboration to study the next ''terascale'' lepton collider, relying upon a very innovative concept of two-beam-acceleration. This accelerator, currently under study, will be composed of the subsequence of 21000 two-beam-modules. Each module requires more than 300 analogue and digital signals which need to be acquired and controlled in a synchronous way. CLIC-ACM (Acquisition and Control Module) is the 'generic' control and acquisition module developed to accommodate the controls of all these signals for various sub-systems and related specification in term of data bandwidth, triggering and timing synchronization. This paper describes the system architecture with respect to its radiation-tolerance, power consumption and scalability

  7. 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...

  8. Measurements and Laboratory Tests on a Prototype Stripline Kicker for the CLIC Damping Rings

    CERN Document Server

    Belver-Aguilar, C; Toral, F; Barnes, MJ; Day, H

    2014-01-01

    The Pre-Damping Rings (PDRs) and Damping Rings (DRs) of CLIC are required to reduce the beam emittances to the small values required for the main linacs. The injection and extraction, from the PDRs and DRs, are performed by kicker systems. To achieve both low beam coupling impedance and reasonable broadband impedancematching to the electrical circuit, striplines have been chosen for the kicker elements. Prototype striplines have been built: tests and measurements of these striplines have started. The goal of these tests is to characterize, without beam, the electromagnetic response of the striplines. The tests have been carried out at CERN. To study the signal transmission through the striplines, the measured S-parameters have been compared with simulations. In addition, measurements of longitudinal beam coupling impedance, using the coaxial wire method, are reported and compared with simulations.

  9. 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.

  10. 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

  11. Impact of beam smoothing method on direct drive target performance for the NIF

    International Nuclear Information System (INIS)

    The impact of smoothing method on the performance of a direct drive target is modeled and examined in terms of its l-mode spectrum. In particular, two classes of smoothing methods are compared, smoothing by spectral dispersion (SSD) and the induced spatial incoherence (ISI) method. It is found that SSD using sinusoidal phase modulation (FM) results in poor smoothing at low l-modes and therefore inferior target performance at both peak velocity and ignition. Modeling of the hydrodynamic nonlinearity shows that saturation tends to reduce the difference between target performance for the smoothing methods considered. However, using SSD with more generalized phase modulation results in a smoothed spatial spectrum, and therefore target performance, which is identical to that obtained with the ISI or similar method where random phase plates are present in both methods and identical beam divergence is assumed

  12. 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...

  13. Study of non-inductive current drive using high energy neutral beam injection on JT-60U

    International Nuclear Information System (INIS)

    The negative ion based neutral beam (N-NB) current drive was experimentally studied. The N-NB driven current density was determined over a wide range of electron temperatures by using the motional Stark effect spectroscopy. Theoretical prediction of the NB current drive increasing with beam energy and electron temperature was validated. A record value of NB current drive efficiency 1.55 x 1019 Am-2W-1 was achieved simultaneously with high confinement and high beta at at a plasma current of 1.5 MA under a fully non-inductively current driven condition. The experimental validation of NB current drive theory for MHD quiescent plasmas gives greater confidence in predicting the NB current drive in future reactors. However, it was also found that MHD instabilities caused a degradation of NB current drive. A beam-driven instability expelled N-NB fast ions carrying non-inductive current from the central region. The lost N-NB driven current was estimated to be 7% of the total N-NB driven current. For the neoclassical tearing mode (NTM), comparisons of the measured neutron yield and fast ion pressure profile with transport code calculations revealed that the loss of fast ions increases with the NTM activity and that fast ions at higher energies suffer larger transport than at lower energies. (author)

  14. CLIC1 regulates dendritic cell antigen processing and presentation by modulating phagosome acidification and proteolysis

    Science.gov (United States)

    Salao, Kanin; Jiang, Lele; Li, Hui; Tsai, Vicky W.-W.; Husaini, Yasmin; Curmi, Paul M. G.; Brown, Louise J.; Brown, David A.

    2016-01-01

    ABSTRACT Intracellular chloride channel protein 1 (CLIC1) participates in inflammatory processes by regulating macrophage phagosomal functions such as pH and proteolysis. Here, we sought to determine if CLIC1 can regulate adaptive immunity by actions on dendritic cells (DCs), the key professional antigen presenting cells. To do this, we first generated bone marrow-derived DCs (BMDCs) from germline CLIC1 gene-deleted (CLIC1−/−) and wild-type (CLIC1+/+) mice, then studied them in vitro and in vivo. We found phagocytosis triggered cytoplasmic CLIC1 translocation to the phagosomal membrane where it regulated phagosomal pH and proteolysis. Phagosomes from CLIC1−/− BMDCs displayed impaired acidification and proteolysis, which could be reproduced if CLIC1+/+, but not CLIC1−/− cells, were treated with IAA94, a CLIC family ion channel blocker. CLIC1−/− BMDC displayed reduced in vitro antigen processing and presentation of full-length myelin oligodendrocyte glycoprotein (MOG) and reduced MOG-induced experimental autoimmune encephalomyelitis. These data suggest that CLIC1 regulates DC phagosomal pH to ensure optimal processing of antigen for presentation to antigen-specific T-cells. Further, they indicate that CLIC1 is a novel therapeutic target to help reduce the adaptive immune response in autoimmune diseases. PMID:27113959

  15. Direct-drive, hollow-shell implosion studies on the 60-beam, UV OMEGA laser system

    International Nuclear Information System (INIS)

    Direct-drive implosion experiments have been performed on the University of Rochester's 60-beam, 30 kJ, UV (351 nm) OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] laser system to investigate the conditions at maximum compression of polymer-shell targets with zero- or low-pressure (≤3 atm) gas fills. By using deuterium-bearing shells (CD), the imploded-core conditions have been diagnosed with both x-ray and neutron spectral measurements. The core electron temperature (kTe) and shell areal density (ρRshell) are determined from the emergent x-ray spectrum, while independent inferences of ρRshell are obtained from the measured primary (DD) and secondary (DT) neutron yields. Target performance was investigated for a range of beam-smoothing conditions [none to 0.25 THz-bandwidth smoothing by spectral dispersion along two dimensions (2-D SSD)] and a set of pulse shapes (1 ns square pulse to a 2.5 ns pulse with a 1:40 foot-to-main-pulse power ratio). The results have conclusively demonstrated the ability to compress targets to shell areal densities in the range of ∼60 to 130 mg/cm2. (c) 2000 American Institute of Physics

  16. 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...

  17. 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.

  18. 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)

  19. Present status of development of damping ring extraction kicker system for CLIC

    CERN Document Server

    Holma, Janne; Belver-Aguilar, Caroline; Faus-Golfe, Angeles; Toral, Fernando

    2012-01-01

    The CLIC damping rings will produce ultra-low emittance beam, with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse power modulators for the damping ring kickers must provide extremely flat, high-voltage pulses: specifications call for a 160 ns duration and a flattop of 12.5 kV, 250 A, with a combined ripple and droop of not more than \\pm0.02 %. The stripline design is also extremely challenging: the field for the damping ring kicker system must be homogenous to within \\pm0.01 % over a 1 mm radius, and low beam coupling impedance is required. The solid-state modulator, the inductive adder, is a very promising approach to meeting the demanding specifications for the field pulse ripple and droop. This paper describes the initial design of the inductive adder and the striplines of the kicker system.

  20. Present status of development of damping ring extraction kicker system for CLIC

    CERN Document Server

    Holma, Janne; Belver-Aguilar, Caroline; Faus-Golfe, Angeles; Toral, Fernando

    2012-01-01

    The CLIC damping rings will produce ultra-low emittance beam, with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse power modulators for the damping ring kickers must provide extremely flat, high-voltage pulses: specifications call for a 160 ns duration and a flattop of 12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 %. The stripline design is also extremely challenging: the field for the damping ring kicker system must be homogenous to within ±0.01 % over a 1 mm radius, and low beam coupling impedance is required. The solid-state modulator, the inductive adder, is a very promising approach to meeting the demanding specifications for the field pulse ripple and droop. This paper describes the initial design of the inductive adder and the striplines of the kicker system.

  1. 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.

  2. Imperfection Tolerances For On-line Dipsersion Free Steering in the Main LINAC of CLIC

    CERN Document Server

    Pfingstner, J; Schulte, D

    2013-01-01

    Long-term ground motion misaligns the elements of the main linac of CLIC over time. Especially the misaligned quadrupoles create dispersion and hence the beam quality is decreased gradually due to an effect called chromatic dilution. Over longer time periods, orbit feedback systems are not capable to fully recover the beam quality and have to be supplemented by dispersion correction algorithms. In this paper, such and dispersion correction algorithm is presented, which is an extended version of the well-known dispersion free steering algorithm. This extended algorithm can recover the beam quality over long time scaled without stopping the accelerator operation (on-line). Tolerances for different imperfections of the system have been identified and a strong sensitivity to the resolution of the wake field monitors of the main linac accelerating structures has been identified. This problem can be mitigated by using a local excitation scheme as will be shown in this work.

  3. 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...

  4. Modelling of Parasitic Inductances of a High Precision Inductive Adder for CLIC

    CERN Document Server

    Holma, J; Ovaska, S J

    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 flat-top 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. However, the output impedance of the inductive adder needs to be well matched to the system impedance. The primary leakage inductance, which cannot be computed accurately analytically, has a significant effect upon the output impedance of the inductive adder. This paper presents predictions, obtained by modelling the 3D geometry of the adder struc...

  5. 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...

  6. Design study of a new antenna system for steering microwave beam in electron cyclotron heating/current drive system

    International Nuclear Information System (INIS)

    The reflector driven in the linear motion to steer the microwave beam for electron cyclotron heating/current drive system, which has considerable merits, especially for reactor environments, has been studied in design. In a typical design, a microwave beam launched from the end of a waveguide is reflected at a concave mirror following a fixed flat mirror. The injection angle can be changed by varying a point of reflection on the concave mirror because of the transition of the normal angle of the concave mirror. The point of reflection is easily controlled by the linear motion of the concave mirror. It is notable that mirror rotation is not required, and the inside of a robust driving shaft can be used to supply the coolant to the mirror. This indicates that the antenna can be designed without a rotation axis, bearings, and a flexible cooling tube close to the plasma which may require frequent maintenance or replacement in a highly radioactive environment. This study shows that the antenna driven in the linear motion has a potential to meet certain specifications, especially with regard to antenna size, steerable range of the beam angle, and beam quality for experiments in tokamaks and for fusion reactors. In the preliminary design trial for the ITER equatorial antenna, the concaved mirror of 0.3 m in length having 1 m curvature and stroke of 0.2 m enables beam angle range of 20-40 deg. with beam radius of 0.06 m at the EC resonance

  7. 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...

  8. Modeling of the influence of the driving laser wavelength on the beam quality of transiently pumped X-ray lasers

    Science.gov (United States)

    Le Pape, S.; Zeitoun, Ph.

    2003-04-01

    A three dimensional ray tracing code (SHADOX) has been developed, as a post-processor of any hydrodynamic/atomic code, to model X-ray laser beam propagation along the amplifying medium and any optical component. In this paper we show a study aimed to investigate the influence of the long driving pulse wavelength on the transiently pumped X-ray laser propagation and amplification. Different pumping configurations have been modeled and their respective influence on the beam quality has been investigated. This work shows that the beam homogeneity is highly sensitive to both the emissive zone dimension and electron density gradient and that pumping by a double pulse in a two-color configuration (2 ω/ ω; Δt=200 ps) is favorable in terms of beam quality.

  9. Stabilization and positioning of CLIC quadrupole magnets with sub-nanometre resolution

    CERN Document Server

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

    2011-01-01

    To reach the required luminosity at the CLIC interaction point, about 2000 quadrupoles along each linear collider are needed to obtain a vertical beam size of 1 nm at the interaction point. Active mechanical stabilization is required to limit the vibrations of the magnetic axis to the nanometre level in a frequency range from 1 to 100 Hz. The approach of a stiff actuator support was chosen to isolate from ground motion and technical vibrations acting directly on the quadrupoles. The actuators can also reposition the quadrupoles between beam pulses with nanometre resolution. A first conceptual design of the active stabilization and nano positioning based on the stiff support and seismometers was validated in models and experimentally demonstrated on test benches. Lessons learnt from the test benches and information from integrated luminosity simulations using measured stabilization transfer functions lead to improvements of the actuating support, the sensors used and the system controller. The controller elect...

  10. Vertex-Detector R&D for CLIC

    CERN Document Server

    Dannheim, D

    2014-01-01

    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 sensors (planar or active HV-CMOS) 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 air flow. In this contribution the CLIC vertex-detector requirements are reviewed and the current status of R&D on readout and sensors is presented.

  11. 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.

  12. 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\

  13. Overlapping laser profiles used to mitigate the negative effects of beam uncertainties in direct-drive LMJ configurations

    International Nuclear Information System (INIS)

    A direct-drive shock ignition scheme in the context of the Laser Mega Joule facility has been considered. The irradiation uniformity provided by two laser beam configurations using a total of 10 or 20 quads to drive the first compression phase has been analyzed. Firstly, a numerical method is used to optimize the laser intensity profiles in the context of the illumination approximation model; then these profiles are used to calculate the irradiation non-uniformity of a spherical target of radius r0 = 1000 μm assuming the beam uncertainties: power imbalance 5%, pointing error 50 μm and target positioning 20 μm. These uncertainties deteriorate the quality of the irradiation increasing considerably the irradiation non-uniformity; moreover, it is found that the pointing error provides the major contribution to the degradation of the irradiation. A strategy to mitigate the negative effect induced by the beam uncertainties is proposed. It consists in using a composite profile in each beam: a first large and flat intensity profile provides a background that reduces pointing error and target positioning effects, whilst a second overlapping profile optimizes the illumination irradiation. It is found that the introduction of the flat background with an intensity of 55% with respect to the maximum intensity reduces by about 40% the non-uniformity of the irradiation due to beam uncertainties. (authors)

  14. Preliminary Design of a Bunching System for the CLIC Polarized Electron Source

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Feng

    2009-10-30

    Major parameters of the CLIC and ILC electron sources are given in Table I. It is shown that the CLIC source needs to provide 312 15-ps-long 2-GHz microbunches. There are two approaches to achieve the time structure [2]: one is to develop a 2-GHz optical pulse train, and the other to develop a 156-ns-long CW optical pulse and use an RF bunching system to generate 312 2-GHz microbunches. The former scheme may ease the RF bunching system but still need it to bunch 100-ps of microbunch down to 15-ps level. Otherwise, a huge amount of energy spread is accumulated when the beam is accelerated through downstream 2-GHz accelerator. In addition, in the former scheme, the space charge is high and surface charge is not yet proven in the parameter regime and 2-GHz mode locked laser is challenging. The latter scheme needs a high-efficiency bunching system to generate 312 15-ps microbunches with 2-GHz repetition rate but it has some notable advantages: a 156-ns CW laser technique is matured, and the charge limit behavior in the scheme is better characterized than that in the former case, as listed in the table. This note presents a design and modeling of the bunching system for the latter scheme to convert a 156-ns CW pulse to 312 15-ps long 2-GHz microbunches.

  15. Isolating and quantifying cross-beam energy transfer in direct-drive implosions on OMEGA and the National Ignition Facility

    Science.gov (United States)

    Davis, A. K.; Cao, D.; Michel, D. T.; Hohenberger, M.; Edgell, D. H.; Epstein, R.; Goncharov, V. N.; Hu, S. X.; Igumenshchev, I. V.; Marozas, J. A.; Maximov, A. V.; Myatt, J. F.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Froula, D. H.

    2016-05-01

    The angularly resolved mass ablation rates and ablation-front trajectories for Si-coated CH targets were measured in direct-drive inertial confinement fusion experiments to quantify cross-beam energy transfer (CBET) while constraining the hydrodynamic coupling. A polar-direct-drive laser configuration, where the equatorial laser beams were dropped and the polar beams were repointed from a symmetric direct-drive configuration, was used to limit CBET at the pole while allowing it to persist at the equator. The combination of low- and high-CBET conditions observed in the same implosion allowed for the effects of CBET on the ablation rate and ablation pressure to be determined. Hydrodynamic simulations performed without CBET agreed with the measured ablation rate and ablation-front trajectory at the pole of the target, confirming that the CBET effects on the pole are small. The simulated mass ablation rates and ablation-front trajectories were in excellent agreement with the measurements at all angles when a CBET model based on Randall's equations [C. J. Randall et al., Phys. Fluids 24, 1474 (1981)] was included into the simulations with a multiplier on the CBET gain factor. These measurements were performed on OMEGA and at the National Ignition Facility to access a wide range of plasma conditions, laser intensities, and laser beam geometries. The presence of the CBET gain multiplier required to match the data in all of the configurations tested suggests that additional physics effects, such as intensity variations caused by diffraction, polarization effects, or shortcomings of extending the 1-D Randall model to 3-D, should be explored to explain the differences in observed and predicted drive.

  16. 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.

  17. Interaction of the chloride intracellular ion channel protein CLIC1 with different sterols in model membranes

    International Nuclear Information System (INIS)

    Background and Aims: Sterols have been reported to modulate conformation and hence the function of several membrane proteins. One such group is the Chloride Intracellular Ion Channel (CLIC) family of proteins. The CLIC protein family consists of six evolutionarily conserved protein members in vertebrates. These proteins are unusual, existing as both monomeric soluble proteins and as membrane bound proteins. We now for the first time demonstrate that the spontaneous membrane insertion of CLIC1 is dependent on the presence of cholesterol in membranes. Our novel findings also extend to the identification of a cholesterol-binding domain within CLIC1 that facilitates the spontaneous membrane insertion of the protein into membranes containing cholesterol. Methods: CLIC1 wild type (WT) and mutant proteins were purified by Ni-NTA followed by size‐exclusion chromatography. Langmuir monolayer film balance experiments were carried out using 1-Palmitoyl-2-oleoylphosphatidylcholine (POPC) alone, or in a 5:1 mole ratio combination with either one of the following sterols: Cholesterol (CHOL), β-Sitosterol (SITO), Ergosterol (ERG), Hydroxyecdysone (HYD) or Cholestane (CHOS). WT CLIC1 or mutant versions of CLIC1 were then injected into the aqueous subphase under the lipid film. Results: In lipid monolayers lacking sterols, CLIC1 did not insert. However significant membrane insertion occurred when CLIC1 was added to membranes containing cholesterol. Substitution of membrane cholesterol with either HYD, SITO or ERG, not only increased CLIC1’s membrane interaction but also increased its rate of insertion. Conversely, CLIC1 showed no insertion into monolayers containing CHOS, which lacked the intact sterol 3β-OH group. CLIC1 mutants G18A and G22A, did not insert in POPC:CHOL monolayers whereas the C24A mutant showed membrane insertion equivalent to WT CLIC1. X-ray and Neutron reflectivity, along with Small Angle X-ray Scattering techniques were subsequently used to probe

  18. 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.

  19. 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

  20. Beam smoothing and temporal effects: optimized preparation of laser beams for direct-drive inertial confinement fusion

    International Nuclear Information System (INIS)

    Direct-drive laser fusion received a number of setbacks from the experimental observation in the 1960s and 1970s of very complex interactions in laser plasma experiments caused by a number of nonlinear and anomalous phenomena. Although smoothing methods were introduced intuitively or empirically -succeeding in reducing these difficulties - it was not until a few years ago that the 20-ps stochastic pulsation mechanism was discovered. We assume here that this 20 ps stochastic pulsation may be the major obstacle to achieving direct-drive fusion, even though it is now generally assumed that the major challenge to the achievement of direct-drive fusion is the Rayleigh-Taylor instability. While we do not discount the importance of the Rayleigh-Taylor mechanisms, we concentrate here on the analysis of the pulsation process. A method of analysis was developed, using, time-dependent real-time computations employing a genuine two-fluid model, which includes the interior electric fields and the very large amplitude longitudinal plasma oscillations that are driven by the laser field. These mechanisms, which were first suggested in 1974, reveal themselves now as self-generated von-Laue gratings, preventing the propagation of laser radiation through the outermost plasma corona and preventing energy deposition by temporal interuption caused by thermal relaxation and the subsequent reestablishment of these gratings, and so on. The abolition of this pulsation by broad-band laser irradiation or other smoothing methods is now well understood. A synopsis of these developments is presented here consistent with Rubbia's proposition of using the MJ drivers for laser fusion, the technology for which is now available. (author)

  1. Simulation of the CLIC transfer structure by means of MAFIA

    Science.gov (United States)

    Millich, Antonio

    1993-12-01

    The function of the CTS is to extract 30 GHz power from the drive beam and to make it available for the acceleration of the main beam. The simulation of a six cells section of the CTS using the MAFIA set of codes has provided the designers of the structure with a set of RF parameters at 30 GHz. The frequency domain analysis has allowed the plotting of the dispersion curves for the first few pass bands, whereas the time domain analysis has provided results on the shape and magnitude of the longitudinal and transverse wake fields and of the loss factors.

  2. Coherent electron beam density modulator for driving X-ray free electron lasers

    International Nuclear Information System (INIS)

    We propose a new compact scheme for a Free Electron Laser with more coherent properties for the X-ray beam. Higher FEL performance would be achieved using a train of electron bunches initially accelerated in a linear accelerator. Similar to the RF klystron concept, we propose developing an X-ray FEL which consists of two parts: an X-ray self-seeding electron beam density modulator and an output set of undulators. A density modulator consists of a low-Q X-ray cavity and an undulator, which is placed between the cavity mirrors. We use this undulator as a very high gain amplifier, which compensates the amplitude loss due to monochromatic X-ray reflections from the mirrors. Following the X-ray cavity, the density modulated electron beam is separated from the X-ray beam and then enters the output set of undulators. The frequency spectrum of the final X-ray beam is determined mainly by the bandwidth of the reflected elements in the X-ray cavity

  3. Coherent electron beam density modulator for driving X-ray free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Novokhatski, A., E-mail: novo@slac.stanford.edu; Decker, F.-J.; Hettel, B.; Nosochkov, Yu.; Sullivan, M.

    2015-02-21

    We propose a new compact scheme for a Free Electron Laser with more coherent properties for the X-ray beam. Higher FEL performance would be achieved using a train of electron bunches initially accelerated in a linear accelerator. Similar to the RF klystron concept, we propose developing an X-ray FEL which consists of two parts: an X-ray self-seeding electron beam density modulator and an output set of undulators. A density modulator consists of a low-Q X-ray cavity and an undulator, which is placed between the cavity mirrors. We use this undulator as a very high gain amplifier, which compensates the amplitude loss due to monochromatic X-ray reflections from the mirrors. Following the X-ray cavity, the density modulated electron beam is separated from the X-ray beam and then enters the output set of undulators. The frequency spectrum of the final X-ray beam is determined mainly by the bandwidth of the reflected elements in the X-ray cavity.

  4. Vertical comb drive microscanners for beam steering, linear scanning, and laser projection applications

    OpenAIRE

    Jung D.; Sandner T.; Kallweit D.; Schenk H.

    2012-01-01

    This paper describes in detail our concept of quasi-static micro scanning mirrors enabling large static deflections and linearized scanning using vertical out-of-plane comb drives. The vertical comb configuration is realized from a planar scanner substrate by wafer bonding. The device concept is highly flexible by design; different kinds of vertical combs (e.g. staggered and angular) can be realized without changing the technological process flow but by design modifications, only. First demon...

  5. Four Pulse Drive System for the Beam Induction Cells and Injector for DARHT Axis 2

    International Nuclear Information System (INIS)

    The proposed drive system allows for the generation of up to four (4) high-quality radiographic pulses along one line-of-sight, having arbitrary pulse spacing (approximately500 ns), using demonstrated technologies. This concept uses a four-pulse drive system to drive both a 16-MeV ensemble of 250-kV, 4-kA induction cells and a four-pulse, 4-MeV injector. The key to this approach lies in the method used to combine four pulses from different generators in a manner that does not compromise the voltage flatness requirement of ± 1%. The induction cells use core material for only a single pulse. A simple reverse bias circuit is used to reset the cores between pulses, and the insulator has been redesigned to withstand the reverse reset voltage. This approach can be installed in stages so that the facility can be used for dual axis radiography while implementing the multi-pulsing capability. A dual double-pulse format has been identified which provides a sequence of two pulses along one line-of-sight within a 2-microsec window. The 2-microsec windows can be separated by arbitrary time intervals of 2- to 10-microsec

  6. 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.)

  7. 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.

  8. 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

  9. Online Resources for High School Teachers--A CLIC Away

    Science.gov (United States)

    Holmes, Jon L.

    2000-04-01

    "I'm a high school teacher. I don't have time to sift through all of JCE to find what I need. I don't have enough time as it is!" If you need to find things in a hurry, go to JCE HS CLIC, the JCE High School Chemed Learning Information Center, http://JChemEd.chem.wisc.edu/HS/. You will find good solid, reliable information, and you will find it fast. CLIC is open 24 hours every day, all over the world. What You Will Find at JCE CLIC We know teachers are pressed for time. During the few minutes between classes or at the end of the day, information needs to be found very quickly. Perhaps you are looking for a demo that illustrates electrochemistry using Cu, Mg, orange juice, and a clock; or a student activity on chromatography that is ready to copy and hand out; or a video to illustrate the action of aqua regia on gold, because you can't use aqua regia and can't afford gold. You can find each of these quickly at CLIC. The Journal has always provided lots of articles designed with high school teachers in mind. What the new JCE HS CLIC does is collect the recent materials at one address on JCE Online, making it quicker and easier for you to find them. Information has been gathered from both print and online versions of the Journal, from JCE Software, and from JCE Internet. It is organized as shown at the bottom of the page. Getting Access to Information You have located something that interests you, perhaps a list of tested demonstrations that pertain to consumer chemistry. Now it is time to get it. JCE subscribers (individuals and libraries) can read, download, and print the full versions of the articles as well as all supplemental materials, including student handouts and instructor's notes. You will need the username and password that are on the mailing label that comes with your Journaleach month. JCE HS CLIC home page: http://JChemEd.chem.wisc.edu/HS/ Your Suggestions, Please Our plans for JCE HS CLIC do not end with what you find now. Other resources and features

  10. CEBAF [Continuous Electron Beam Accelerator Facility] superconducting cavity rf drive system

    International Nuclear Information System (INIS)

    The CEBAF rf system consists of 418 individual rf amplifier chains. Each superconducting cavity is phase locked to the master drive reference line to within 1 degree, and the cavity field gradient is regulated to within 1 part in 104 by a state-of-the-art rf control module. Precision, continuously adjustable, modulo 3600 phase shifters are used to generate the individual phase references, and a compensated rf detector is used for level feedback. The close coupled digital system enhances system accuracy, provides self-calibration, and continuously checks the system for malfunction. Calibration curves, the operating program, and system history are stored in an on board EEPROM. The rf power is generated by a 5kW, water cooled, permanent magnet focused klystron. The klystrons are clustered in groups of 8 and powered from a common supply. rf power is transmitted to the accelerator sections by semiflexible waveguide

  11. CLIC5A, a component of the ezrin-podocalyxin complex in glomeruli, is a determinant of podocyte integrity.

    Science.gov (United States)

    Wegner, Binytha; Al-Momany, Abass; Kulak, Stephen C; Kozlowski, Kathy; Obeidat, Marya; Jahroudi, Nadia; Paes, John; Berryman, Mark; Ballermann, Barbara J

    2010-06-01

    The chloride intracellular channel 5A (CLIC5A) protein, one of two isoforms produced by the CLIC5 gene, was isolated originally as part of a cytoskeletal protein complex containing ezrin from placental microvilli. Whether CLIC5A functions as a bona fide ion channel is controversial. We reported previously that a CLIC5 transcript is enriched approximately 800-fold in human renal glomeruli relative to most other tissues. Therefore, this study sought to explore CLIC5 expression and function in glomeruli. RT-PCR and Western blots show that CLIC5A is the predominant CLIC5 isoform expressed in glomeruli. Confocal immunofluorescence and immunogold electron microscopy reveal high levels of CLIC5A protein in glomerular endothelial cells and podocytes. In podocytes, CLIC5A localizes to the apical plasma membrane of foot processes, similar to the known distribution of podocalyxin and ezrin. Ezrin and podocalyxin colocalize with CLIC5A in glomeruli, and podocalyxin coimmunoprecipitates with CLIC5A from glomerular lysates. In glomeruli of jitterbug (jbg/jbg) mice, which lack the CLIC5A protein, ezrin and phospho-ERM levels in podocytes are markedly lower than in wild-type mice. Transmission electron microscopy reveals patchy broadening and effacement of podocyte foot processes as well as vacuolization of glomerular endothelial cells. These ultrastructural changes are associated with microalbuminuria at baseline and increased susceptibility to adriamycin-induced glomerular injury compared with wild-type mice. Together, the data suggest that CLIC5A is required for the development and/or maintenance of the proper glomerular endothelial cell and podocyte architecture. We postulate that the interaction between podocalyxin and subjacent filamentous actin, which requires ezrin, is compromised in podocytes of CLIC5A-deficient mice, leading to dysfunction under unfavorable genetic or environmental conditions. PMID:20335315

  12. A prototype hybrid pixel detector ASIC for the CLIC experiment

    CERN Document Server

    Valerio, P; Arfaoui, S; Ballabriga, R; Benoit, M; Bonacini, S; Campbell, M; Dannheim, D; De Gaspari, M; Felici, D; Kulis, S; Llopart, X; Nascetti, A; Poikela, T; Wong, W S

    2014-01-01

    A prototype hybrid pixel detector ASIC specifically designed to the requirements of the vertex detector for CLIC is described and first electrical measurements are presented. The chip has been designed using a commercial 65 nm CMOS technology and comprises a matrix of 64x64 square pixels with 25 μm pitch. The main features include simultaneous 4-bit measure- ment of Time-over-Threshold (ToT) and Time-of-Arrival (ToA) with 10 ns accuracy, on-chip data compression and power pulsing capability.

  13. 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

  14. An Asset Test of the CLIC Accelerating Structure

    International Nuclear Information System (INIS)

    Transverse wakefield suppression in the CLIC (Compact Linear Collider) multibunch accelerating structure, called the TDS (Tapered Damped Structure), is achieved primarily through heavy damping. In order to verify the performance of the TDS design and the validity of the theoretical tools used to model it, a 15 GHz version of the TDS has been constructed and tested in the ASSET facility at SLAC. The test has directly demonstrated transverse wakefield suppression of over a factor 100, with an excellent agreement between the measured and the calculated wakefield

  15. 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...

  16. 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.

  17. 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...

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

    Science.gov (United States)

    Barry, R. G.

    Formal discussions within the World Climate Research Programme (WCRP) since 1997 have addressed the question of the role of the cryosphere in the climate system. An outcome has been the approval in March 2000 of a Science and Co-ordination Plan for a new Climate and Cryosphere (CliC) project by the WCRP Joint Scientific Com- mittee in March 2000. The concept of this plan (WCRP, 2001) and particular topics of concern for high-mountain hydrology are discussed here. The proposed definition of the cryosphere is that portion of the climate system consisting of the world's ice masses and snow deposits. of relevance for mountains are: ice caps and glaciers, sea- sonal snow cover, lake and river ice, and seasonally frozen ground and permafrost. Existing projects both within the framework of the WCRP, as well as of the IGBP are mainly regional and links into the global climate research effort are not sufficiently comprehensive. The WCRP GEWEX project has cryospheric components concerning the high latitude hydrological cycle, but mountain studies are currently only in Ti- bet. Other relevant programs include: the IGBP-BAHC Mountain Research Initiative, Global Land Ice Measurements from Space (GLIMS), and Permafrost and Climate in Europe (PACE), for example. Integration of existing cryospheric projects within a global research structure, together with new efforts addressing current gaps, is re- quired in order to: - enhance links between regional and global climatic components studies, - promote appropriate treatment of cryospheric processes in climate models, and - assemble and make accessible quality controlled, well documented, comprehen- sive and coherent global gridded data sets necessary for driving and validating climate models. The principal scientific questions relating to the cryosphere in mountain re- gions concern: - glacier melt contributions to global sea level change, - the energy and water cycle in regions with land ice, snow cover and frozen ground, - the

  19. A Framework for Applying Point Clouds Grabbed by Multi-Beam LIDAR in Perceiving the Driving Environment

    Directory of Open Access Journals (Sweden)

    Jian Liu

    2015-08-01

    Full Text Available The quick and accurate understanding of the ambient environment, which is composed of road curbs, vehicles, pedestrians, etc., is critical for developing intelligent vehicles. The road elements included in this work are road curbs and dynamic road obstacles that directly affect the drivable area. A framework for the online modeling of the driving environment using a multi-beam LIDAR, i.e., a Velodyne HDL-64E LIDAR, which describes the 3D environment in the form of a point cloud, is reported in this article. First, ground segmentation is performed via multi-feature extraction of the raw data grabbed by the Velodyne LIDAR to satisfy the requirement of online environment modeling. Curbs and dynamic road obstacles are detected and tracked in different manners. Curves are fitted for curb points, and points are clustered into bundles whose form and kinematics parameters are calculated. The Kalman filter is used to track dynamic obstacles, whereas the snake model is employed for curbs. Results indicate that the proposed framework is robust under various environments and satisfies the requirements for online processing.

  20. A Framework for Applying Point Clouds Grabbed by Multi-Beam LIDAR in Perceiving the Driving Environment.

    Science.gov (United States)

    Liu, Jian; Liang, Huawei; Wang, Zhiling; Chen, Xiangcheng

    2015-01-01

    The quick and accurate understanding of the ambient environment, which is composed of road curbs, vehicles, pedestrians, etc., is critical for developing intelligent vehicles. The road elements included in this work are road curbs and dynamic road obstacles that directly affect the drivable area. A framework for the online modeling of the driving environment using a multi-beam LIDAR, i.e., a Velodyne HDL-64E LIDAR, which describes the 3D environment in the form of a point cloud, is reported in this article. First, ground segmentation is performed via multi-feature extraction of the raw data grabbed by the Velodyne LIDAR to satisfy the requirement of online environment modeling. Curbs and dynamic road obstacles are detected and tracked in different manners. Curves are fitted for curb points, and points are clustered into bundles whose form and kinematics parameters are calculated. The Kalman filter is used to track dynamic obstacles, whereas the snake model is employed for curbs. Results indicate that the proposed framework is robust under various environments and satisfies the requirements for online processing. PMID:26404290

  1. 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.

  2. 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...

  3. 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.

  4. 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

  5. An automatic driving system for a Baker's garlic [Allium chinense] planter: Development of the infrared beam guidance system

    International Nuclear Information System (INIS)

    We have developed a tractor attachment type semi-automatic Baker's garlic (shallot) planter to save hard labor requirement during planting. The velocity of the tractor in operation is so slow (2 to 3m/min) that the tractor driver is forced to tie his hands for a long time. This is an obstacle to its diffusion, because farm managers have to drive their own tractors by themselves in most Japanese farmhouses, yet they have to do other jobs during the planting season. We designed a new automatic driving system that consists of one infrared beam radiator and two infrared beam receivers to solve this problem. The infrared radiator is located in front of the tractor and shows the infrared guideline of tractor path. The infrared receivers are equipped on the front of the tractor and detect the infrared from the radiator. The receivers are arranged symmetrically at 4.5 degree from the center of the tractor. So the misalignment of the tractor creates a difference in sensitivity and it is possible to distinguish the tractor direction against the infrared beam. This system was tested under the sand dune field conditions with the tractor that was converted to automatic driving. The results show the system can effectively steer about 80 m automatically with an almost straight path, and the error from the starting point is within 0.1 m

  6. 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...

  7. Effects of rf breakdown on the beam in the Compact Linear Collider prototype accelerator structure

    OpenAIRE

    Palaia, Andrea; Jacewicz, Marek; Ruber, Roger; Ziemann, Volker; Farabolini, Wilfrid

    2013-01-01

    Understanding the effects of rf breakdown in high-gradient accelerator structures on the acceleratedbeam is an extremely relevant aspect in the development of the Compact Linear Collider (CLIC) andis one of the main issues addressed at the Two-beam Test Stand at the CLIC Test Facility 3 at CERN.During a rf breakdown high currents are generated causing parasitic magnetic fields that interact withthe accelerated beam affecting its orbit. The beam energy is also affected because the power is part...

  8. 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 ...

  9. 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.

  10. RF-Breakdown kicks at the CTF3 two-beam test stand

    CERN Document Server

    Palaia, Andrea; Muranaka, Tomoko; Ruber, Roger; Ziemann, V; Farabolini, W

    2012-01-01

    The measurement of the effects of RF-breakdown on the beam in CLIC prototype accelerator structures is one of the key aspects of the CLIC two-beam acceleration scheme being addressed at the Two-beam Test Stand (TBTS) at CTF3. RF-breakdown can randomly cause energy loss and transverse kicks to the beam. Transverse kicks have been measured by means of a screen intercepting the beam after the accelerator structure. In correspondence of a RFbreakdown we detect a double beam spot which we interpret as a sudden change of the beam trajectory within a single beam pulse. To time-resolve such effect, the TBTS has been equipped with five inductive Beam Position Monitors (BPMs) and a spectrometer line to measure both relative changes of the beam trajectory and energy losses. Here we discuss the methodology used and we present the latest results of such measurements

  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. A Quantum Gas Jet for Non-Invasive Beam Profile Measurement

    CERN Document Server

    Holzer, EB; Lefevre, T; Tzoganis, V; Welsch, C; Zhang, H

    2014-01-01

    A novel instrument for accelerator beam diagnostics is being developed by using De Broglie-wave focusing to create an ultra-thin neutral gas jet. Scanning the gas jet across a particle beam while measuring the interaction products, the beam profile can be measured. Such a jet scanner will provide an invaluable diagnostic tool in beams which are too intense for the use of wire scanners, such as the proposed CLIC Drive Beam. In order to create a sufficiently thin jet, a focusing element working on the de Broglie wavelength of the Helium atom has been designed. Following the principles of the Photon Sieve, we have constructed an Atomic Sieve consisting of 5230 nano-holes etched into a thin film of silicon nitride. When a quasi-monochromatic Helium jet is incident on the sieve, an interference pattern with a single central maximum is created. The stream of Helium atoms passing through this central maximum is much narrower than a conventional gas jet. The first experiences with this device are presented here, alon...

  13. Progressive hearing loss and vestibular dysfunction caused by a homozygous nonsense mutation in CLIC5.

    Science.gov (United States)

    Seco, Celia Zazo; Oonk, Anne M M; Domínguez-Ruiz, María; Draaisma, Jos M T; Gandía, Marta; Oostrik, Jaap; Neveling, Kornelia; Kunst, Henricus P M; Hoefsloot, Lies H; del Castillo, Ignacio; Pennings, Ronald J E; Kremer, Hannie; Admiraal, Ronald J C; Schraders, Margit

    2015-02-01

    In a consanguineous Turkish family diagnosed with autosomal recessive nonsyndromic hearing impairment (arNSHI), a homozygous region of 47.4 Mb was shared by the two affected siblings on chromosome 6p21.1-q15. This region contains 247 genes including the known deafness gene MYO6. No pathogenic variants were found in MYO6, neither with sequence analysis of the coding region and splice sites nor with mRNA analysis. Subsequent candidate gene evaluation revealed CLIC5 as an excellent candidate gene. The orthologous mouse gene is mutated in the jitterbug mutant that exhibits progressive hearing impairment and vestibular dysfunction. Mutation analysis of CLIC5 revealed a homozygous nonsense mutation c.96T>A (p.(Cys32Ter)) that segregated with the hearing loss. Further analysis of CLIC5 in 213 arNSHI patients from mostly Dutch and Spanish origin did not reveal any additional pathogenic variants. CLIC5 mutations are thus not a common cause of arNSHI in these populations. The hearing loss in the present family had an onset in early childhood and progressed from mild to severe or even profound before the second decade. Impaired hearing is accompanied by vestibular areflexia and in one of the patients with mild renal dysfunction. Although we demonstrate that CLIC5 is expressed in many other human tissues, no additional symptoms were observed in these patients. In conclusion, our results show that CLIC5 is a novel arNSHI gene involved in progressive hearing impairment, vestibular and possibly mild renal dysfunction in a family of Turkish origin. PMID:24781754

  14. 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.

  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. 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...

  17. Detection of Ground Motion effects on the beam trajectory at ATF2

    CERN Document Server

    Renier, Y; Tomas, R; Schulte, D

    2012-01-01

    The ATF2 experiment is currently demonstrating the feasibility of the beam delivery system for the future linear collider. The orbit feedback is very critical to obtain the nanometer vertical beam size at the interaction point and in the case of CLIC, ground motion effects on the beam must be corrected. In this respect, as a proof of principle of a ground motion feed forward, the ground motion effects on the beam trajectory are extracted from the beam position monitor readings.

  18. Development of a 300-kV Marx generator and its application to drive a relativistic electron beam

    Indian Academy of Sciences (India)

    Y Choyal; Lalit Gupta; Preeti Vyas; Prasad Deshpande; Anamika Chaturvedi; K C Mittal; K P Maheshwari

    2005-12-01

    We have indigenously developed a twenty-stage vertical structure type Marx generator. At a matched load of $90-100 \\Omega$, for 25 kV DC charging, an output voltage pulse of 230 kV, and duration 150 ns is obtained. This voltage pulse is applied to a relativistic electron beam (REB) planar diode. For a cathode-anode gap of 7·5 mm, an REB having beam voltage 160 kV and duration 150 ns is obtained. Brass as well as aluminum explosive electron emission-type cathodes have been used.

  19. High Charge PHIN Photo Injector at CERN with Fast Phase switching within the Bunch Train for Beam Combination

    CERN Document Server

    Csatari Divall, M; Bolzon, B; Bravin, E; Chevallay, E; Dabrowski, A; Doebert, S; Drozdy, A; Fedosseev, V; Hessler, C; Lefevre, T; Livesley, S; Losito, R; Olvegaard, M; Petrarca, M; Rabiller, A N; Egger, D; Mete, O

    2011-01-01

    The high charge PHIN photo-injector was developed within the framework of the European CARE program to provide an alternative to the drive beam thermionic gun in the CTF3 (CLIC Test Facility) at CERN. In PHIN 1908 electron bunches are delivered with bunch spacing of 1.5 GHz and 2.33 nC charge per bunch. Furthermore the drive beam generated by CTF3 requires several fast 180 deg phase-shifts with respect to the 1.5 GHz bunch repetition frequency in order to allow the beam combination scheme developed at CTF3. A total of 8 subtrains, each 140 ns long and shifted in phase with respect to each other, have to be produced with very high phase and amplitude stability. A novel fiber modulator based phase-switching technique developed on the laser system provides this phase-shift between two consecutive pulses much faster and cleaner than the base line scheme, where a thermionic electron gun and sub-harmonic bunching are used. The paper describes the fiber-based switching system and the measurements verifying the schem...

  20. Optical Mixing in the Strong Coupling Regime: A New Method of Beam Conditioning at Hohlraum LEH and Direct Drive ICF Coronal Plasmas

    Science.gov (United States)

    Mardirian, Marine; Afeyan, Bedros; Huller, Stefan; Montgomery, David; Froula, Dustin; Kirkwood, Robert

    2012-10-01

    We will present theoretical and computational results on Brillouin interactions between two beams in co-, counter-, and orthogonal propagation geometries. The beams will be structured (with speckle patterns), the plasma will have inhomogeneous flow including the Mach -1 surface. As the growth rate of the instability surpasses the natural frequency of the ion wave, the strong coupling regime (SCR) is reached, where reactive quasi-modes with intensity dependent frequency shifts result. This is especially true in laser hot spots. We trace the consequences of operations in this regime with different damping rates on the ion acoustic waves. We consider convective and absolute instabilities as well as the design of experiments which could examine these new regimes of instability behavior with new 10 psec time resolved diagnostics. Whether well enough conditioned beams can result after 10's or 100's of pairwise crossings in direct and indirect drive ICF configurations, and whether SRS can thus be strongly suppressed downstream, remains to be demonstrated. But the prospects exist for such new paths to instability control in a staged manner before STUD pulses are implemented.-

  1. 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...

  2. 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.

  3. Quantifying the Growth of Cross-Beam Energy Transfer in Polar-Direct-Drive Implosions at the Omega Laser and National Ignition Facilities

    Science.gov (United States)

    Davis, A. K.

    2015-11-01

    Direct-drive inertial confinement fusion requires multiple overlapping laser beams that can drive the cross-beam energy transfer (CBET) instability. This instability is of primary concern because it can reduce the laser energy coupling and can affect the symmetry in a polar-direct-drive (PDD) configuration. An experiment was designed to determine the CBET growth by measuring the angularly resolved mass ablation rate and ablation-front trajectory in a PDD configuration. Adding a thin layer of Si over a CH shell generates two peaks in x-ray self-emission images that are measured with a time-resolved pinhole imager. The inner peak is related to the position of the ablation front and the outer peak corresponds to the position of the interface of the two layers in the plasma. The emergence of the second peak is used to measure the time for the laser to burn through the outer layer, giving the average mass ablation rate of the material. The mass ablation rate was measured by varying the thickness of the outer silicon layer. The shell trajectory and mass ablation rate measured in PDD on the pole, where CBET has little effect, were compared with simulations to validate the electron thermal-transport model. Excellent agreement was obtained when using a 2-D nonlocal transport model, and these observables could not be reproduced with flux-limited models. A similar comparison was performed on the equator where the CBET growth is large. Without the CBET model, the shell velocity and mass ablation rate were significantly overestimated by the simulation. Adding the CBET model reduced the drive on the equator and reproduced the experimental results. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944. In collaboration with, D. Cao, D. T. Michel, M. Hohenberger, R. Epstein, V. N. Goncharov, S. X. Hu, I. V. Igumenshchev, J. A. Marozas, D. D. Meyerhofer, P. B. Radha, S. P. Regan, T. C

  4. CLIC5 Stabilizes Membrane-Actin Filament Linkages at the Base of Hair Cell Stereocilia in a Molecular Complex with Radixin, Taperin, and Myosin VI

    OpenAIRE

    Salles, Felipe T.; Andrade, Leonardo R.; Tanda, Soichi; Grati, M’hamed; Plona, Kathleen L.; Gagnon, Leona H.; Johnson, Kenneth R.; Kachar, Bechara; Berryman, Mark A.

    2013-01-01

    Chloride intracellular channel 5 protein (CLIC5) was originally isolated from microvilli in complex with actin binding proteins including ezrin, a member of the Ezrin-Radixin-Moesin (ERM) family of membrane-cytoskeletal linkers. CLIC5 concentrates at the base of hair cell stereocilia and is required for normal hearing and balance in mice, but its functional significance is poorly understood. This study investigated the role of CLIC5 in postnatal development and maintenance of hair bundles. Co...

  5. Physics potential for the measurement of σ(Hνν{sup -bar})×BR(H→μ{sup +}μ{sup -}) at the 1.4 TeV CLIC collider

    Energy Technology Data Exchange (ETDEWEB)

    Milutinović-Dumbelović, G., E-mail: gordanamd@vinca.rs; Božović-Jelisavčić, I. [Vinca Institute of Nuclear Sciences, University of Belgrade, Mihajla Petrovića Alasa 12-14, 11001, Belgrade (Serbia); Grefe, C. [Universität Bonn, 53012, Bonn (Germany); CERN, 1211, Geneva 23 (Switzerland); Kačarević, G.; Lukić, S.; Pandurović, M. [Vinca Institute of Nuclear Sciences, University of Belgrade, Mihajla Petrovića Alasa 12-14, 11001, Belgrade (Serbia); Roloff, P. [CERN, 1211, Geneva 23 (Switzerland); Smiljanić, I. [Vinca Institute of Nuclear Sciences, University of Belgrade, Mihajla Petrovića Alasa 12-14, 11001, Belgrade (Serbia)

    2015-10-30

    The future compact linear collider (CLIC) offers a possibility for a rich precision physics programme, in particular in the Higgs sector through the energy staging. This is the first paper addressing the measurement of the standard model Higgs boson decay into two muons at 1.4 TeV CLIC. With respect to similar studies at future linear colliders, this paper includes several novel contributions to the statistical uncertainty of the measurement. The latter includes the equivalent photon approximation employed to describe e{sup +}e{sup -} and eγ interactions whenever the virtuality of the mediated photon is smaller than 4 GeV and realistic forward electron tagging based on energy deposition maps in the forward calorimeters, as well as several processes with the Beamstrahlung photons that results in irreducible contribution to the signal. In addition, coincidence of the Bhabha scattering with the signal and background processes is considered, altering the signal selection efficiency. The study is performed using a fully simulated CLIC-ILD detector model. It is shown that the branching ratio for the Higgs decay into a pair of muons BR(H→μ{sup +}μ{sup -}) times the Higgs production cross-section in WW-fusion σ(Hνν{sup -bar}) can be measured with 38 % statistical accuracy at √s=1.4 TeV, assuming an integrated luminosity of 1.5 ab{sup -1} with unpolarised beams. If 80 % electron beam polarisation is considered, the statistical uncertainty of the measurement is reduced to 25 %. Systematic uncertainties are negligible in comparison to the statistical uncertainty.

  6. The transverse and longitudinal beam characteristics of the PHIN photo-injector at CERN

    CERN Document Server

    Mete, Ö; Dabrowski, A; Divall, M; Döbert, S; Egger, D; Elsener, K; Fedosseev, V; Lefèvre, T; Petrarca, M

    2010-01-01

    A new photo-injector, capable to deliver a long pulse train with a high charge per bunch for CTF3, has been designed and installed by a collaboration between LAL, CCLRC and CERN within the framework of the second Joint Research Activity PHIN of the European CARE program. The demonstration of the high charge and the stability along the pulse train are the important goals for CTF3 and the CLIC drive beam. The nominal beam for CTF3 has an average current of 3.5 A, a 1.5 GHz bunch repetation frequency and a pulse length of 1.27 μs (1908 bunches). The existing CTF3 injector consists of a thermionic gun and a subharmonic bunching system. The PHIN photo-injector is being tested in a dedicated test-stand at CERN to replace the existing CTF3 injector that is producing unwanted satellite bunches during the bunching process. A phase-coding scheme is planned to be implemented to the PHIN laser system providing the required beam temporal structure by CTF3. RF photo-injectors are high-brightness, low-emittance electron so...

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. Analyzing the Anomalous Dipole Moment Type Couplings of Heavy Quarks with FCNC Interactions at the CLIC

    International Nuclear Information System (INIS)

    We examine both anomalous magnetic and dipole moment type couplings of a heavy quark via its single production with subsequent dominant standard model decay modes at the compact linear collider (CLIC). The signal and background cross sections are analyzed for heavy quark masses 600 and 700 GeV. We make the analysis to delimitate these couplings as well as to find the attainable integrated luminosities for 3σ observation limit

  12. 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.

  13. Gluino Pair Production in $e^+ e^-$ and Photon-Photon Collisions at CERN CLIC

    CERN Document Server

    Berge, S; 10.1140/epjc/s2003-01194-4

    2003-01-01

    We confront the generally small cross sections for gluino pair production in e^+e^- annihilation with the much larger ones in photon-photon scattering at a multi-TeV linear collider like CERN CLIC. The larger rates and the steeper rise of the cross section at threshold may allow for a precise gluino mass determination in high-energy photon-photon collisions for a wide range of squark masses and post-LEP SUSY benchmark points.

  14. 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.

  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. 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$\

  17. Expression, purification, crystallization and preliminary X-ray diffraction analysis of chloride intracellular channel 2 (CLIC2)

    International Nuclear Information System (INIS)

    Chloride intracellular channel 2 (CLIC2) belongs to a family of intracellular chloride-channel proteins that can exist in a soluble form. The expression, purification and crystallization in two different crystal forms of human CLIC2 is reported. The chloride intracellular channel (CLIC) family of proteins are unusual in that they can exist in either an integral membrane-channel form or a soluble form. Here, the expression, purification, crystallization and preliminary diffraction analysis of CLIC2, one of the least-studied members of this family, are reported. Human CLIC2 was crystallized in two different forms, both in the presence of reduced glutathione and both of which diffracted to better than 1.9 Å resolution. Crystal form A displayed P212121 symmetry, with unit-cell parameters a = 44.0, b = 74.7, c = 79.8 Å. Crystal form B displayed P21 symmetry, with unit-cell parameters a = 36.0, b = 66.9, c = 44.1 Å. Structure determination will shed more light on the structure and function of this enigmatic family of proteins

  18. X-band rf power production and deceleration in the two-beam test stand of the Compact Linear Collider test facility

    CERN Document Server

    Adli, E; Dubrovskiy, A; Syratchev, I; Ruber, R; Ziemann, V

    2011-01-01

    We discuss X-band rf power production and deceleration in the two-beam test stand of the CLIC test facility at CERN. The rf power is extracted from an electron drive beam by a specially designed power extraction structure. In order to test the structures at high-power levels, part of the generated power is recirculated to an input port, thus allowing for increased deceleration and power levels within the structure. The degree of recirculation is controlled by a splitter and phase shifter. We present a model that describes the system and validate it with measurements over a wide range of parameters. Moreover, by correlating rf power measurements with the energy lost by the electron beam, as measured in a spectrometer placed after the power extraction structure, we are able to identify system parameters, including the form factor of the electron beam. The quality of the agreement between model and reality gives us confidence to extrapolate the results found in the present test facility towards the parameter reg...

  19. Noninductive current drive in tokamaks

    International Nuclear Information System (INIS)

    Various current drive mechanisms may be grouped into four classes: (1) injection of energetic particle beams; (2) launching of rf waves; (3) hybrid schemes, which are combinations of various rf schemes (rf plus beams, rf and/or beam plus ohmic heating, etc.); and (4) other schemes, some of which are specific to reactor plasma conditions requiring the presence of alpha particle or intense synchrotron radiation. Particle injection schemes include current drive by neutral beams and relativistic electron beams. The rf schemes include current drive by the lower hybrid (LH) waves, the electron waves, the waves in the ion cyclotron range of frequencies, etc. Only a few of these approaches, however, have been tested experimentally, with the broadest data base available for LH waves. Included in this report are (1) efficiency criteria for current drive, (2) current drive by neutral beam injection, (3) LH current drive, (4) electron cyclotron current drive, (5) current drive by ion cyclotron waves - minority species heating, and (6) current drive by other schemes (such as hybrids and low frequency waves)

  20. Laser Wire and Beam Position Monitor tests

    CERN Document Server

    Boogert, S T; Lyapin, A; Nevay, L; Snuverink, J

    2013-01-01

    This subtask involved two main activities; Firstly the development and subsequent usage of high resolution beam position monitors (BPM) for the International Linear Collider (ILC) and Compact Linear Collider projects (CLIC); and secondly the development of a laser-wire (LW) transverse beam size measurement systems. This report describes the technical progress achieved at a large-scale test ILC compatible BPM system installed at the Accelerator Test Facility 2 (ATF2). The ATF2 is an energy-scaled demonstration system for the final focus systems required to deliver the particle beams to collision at the ILC and CLIC. The ATF2 cavity beam position monitor system is one of the largest of its kind and rivals systems used at free electron lasers. The ATF2 cavity beam position system has achieved a position resolutionof 250 nm (with signal attuenation) and 27 nm (without attenuation). The BPM system has been used routinely for lattice diagnostics, beam based alignment and wakefield measurements. Extensive experience...

  1. Progressive hearing loss and vestibular dysfunction caused by a homozygous nonsense mutation in CLIC5

    OpenAIRE

    Seco, Celia Zazo; Oonk, Anne MM; Domínguez-Ruiz, María; Draaisma, Jos MT; Gandía, Marta; Oostrik, Jaap; Neveling, Kornelia; Kunst, Henricus PM; Hoefsloot, Lies H.; del Castillo, Ignacio; Pennings, Ronald JE; Kremer, Hannie; Admiraal, Ronald JC; Schraders, Margit

    2014-01-01

    In a consanguineous Turkish family diagnosed with autosomal recessive nonsyndromic hearing impairment (arNSHI), a homozygous region of 47.4 Mb was shared by the two affected siblings on chromosome 6p21.1-q15. This region contains 247 genes including the known deafness gene MYO6. No pathogenic variants were found in MYO6, neither with sequence analysis of the coding region and splice sites nor with mRNA analysis. Subsequent candidate gene evaluation revealed CLIC5 as an excellent candidate gen...

  2. 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.

  3. A Search for Leptophilic Vector Boson Z_l at CLIC by Using Neural Networks

    CERN Document Server

    Akkoyun, S

    2012-01-01

    In this work, the possible dynamics associated with leptophilic Z_l boson at CLIC (Compact Linear Collider) have been investigated by using artificial neural networks (ANNs). These hypotetic massive boson Z_l have been shown through the process e+e- -> M+M-. Furthermore, the invariant mass distributions for final muons have been consistently predicted by using ANN. For these highly non-linear data, we have constructed consistent empirical physical formulas (EPFs) by appropriate feed- forward ANN. These ANN-EPFs can be used to derive further physical functions which could be relevant to studying Z_l.

  4. Anomalous production of top quarks at CLIC+LHC based gamma p colliders

    CERN Document Server

    Cakir, O

    2003-01-01

    The single production of top quark due to flavor changing neutral current (FCNC) interaction and its decay to bW are studied at CLIC+LHC based gamma-p colliders. We consider both t-c-gamma and t-u-gamma anomalous couplings. The anomalous charm (up) quark anomalous coupling parameter kappa_gamma^c (kappa_gamma^u) can be probed down to 9.5x10^-3 (8.0x10^-3) at a gamma-p collider with sqrt{s_ep}=6.48 TeV and L_int=100 fb^-1.

  5. 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.

  6. 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.

  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. The chloride intracellular channel protein CLIC5 is expressed at high levels in hair cell stereocilia and is essential for normal inner ear function.

    Science.gov (United States)

    Gagnon, Leona H; Longo-Guess, Chantal M; Berryman, Mark; Shin, Jung-Bum; Saylor, Katherine W; Yu, Heping; Gillespie, Peter G; Johnson, Kenneth R

    2006-10-01

    Although CLIC5 is a member of the chloride intracellular channel protein family, its association with actin-based cytoskeletal structures suggests that it may play an important role in their assembly or maintenance. Mice homozygous for a new spontaneous recessive mutation of the Clic5 gene, named jitterbug (jbg), exhibit impaired hearing and vestibular dysfunction. The jbg mutation is a 97 bp intragenic deletion that causes skipping of exon 5, which creates a translational frame shift and premature stop codon. Western blot and immunohistochemistry results confirmed the predicted absence of CLIC5 protein in tissues of jbg/jbg mutant mice. Histological analysis of mutant inner ears revealed dysmorphic stereocilia and progressive hair cell degeneration. In wild-type mice, CLIC5-specific immunofluorescence was detected in stereocilia of both cochlear and vestibular hair cells and also along the apical surface of Kolliker's organ during cochlear development. Refined immunolocalization in rat and chicken vestibular hair cells showed that CLIC5 is limited to the basal region of the hair bundle, similar to the known location of radixin. Radixin immunostaining appeared reduced in hair bundles of jbg mutant mice. By mass spectrometry and immunoblotting, CLIC5 was shown to be expressed at high levels in stereocilia of the chicken utricle, in an approximate 1:1 molar ratio with radixin. These results suggest that CLIC5 associates with radixin in hair cell stereocilia and may help form or stabilize connections between the plasma membrane and the filamentous actin core. PMID:17021174

  9. Very forward detectors for ILC and CLIC detectors

    International Nuclear Information System (INIS)

    The instrumentation of the Very Forward Regions in experiments at future linear e+e- colliders is a challenge due to high radiation fields and high rates. Two calorimeters are foreseen to perform a fast and a precise luminosity measurement and and extend the detector coverage to very low polar angles. For the calorimeter near the beampipe dedicated GaAs:Cr sensors with very good radiation tolerance were developed. For the luminometer, outside the strong radiation field, silicon sensors are foreseen. Two prototypes of sensor planes are assembled with specially developed front-end and ADC ASICS with different feedback schemes of the front-end ASIC. The performance of the full system was studied with a 4 GeV electron beam at DESY. A report of the testbeam results on relevant parameters is given.

  10. 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...

  11. 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...

  12. Prospects for the measurement of the Higgs Yukawa couplings to b and c quarks, and muons at CLIC

    Czech Academy of Sciences Publication Activity Database

    Grefe, C.; Laštovička, Tomáš; Strube, J.

    2013-01-01

    Roč. 73, č. 2 (2013), s. 1-7. ISSN 1434-6044 Institutional support: RVO:68378271 Keywords : Higgs * branching * ratio * Yukawa * couplings * quarks * muons * CLIC * inear collider Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.436, year: 2013

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

    Energy Technology Data Exchange (ETDEWEB)

    Blue, Brent Edward; /SLAC /UCLA

    2005-10-10

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

  14. Results from the CLIC X-BAND structure test program at the NLCTA

    CERN Document Server

    Adolphsen, Chris; Dolgashev, Valery; Laurent, Lisa; Tantawi, Sami; Wang, Faya; Wang, W Juwen; Doebert, Steffen; Grudiev, Alexej; Riddone, Germana; Wuensh, Walter; Zennaro, Riccardo; Higashi, Yasuo; Higo, Toshiyasu

    2010-01-01

    As part of a SLAC-CERN-KEK col­lab­o­ra­tion on high gra­di­ent X-band struc­ture re­search, sev­er­al pro­to­type struc­tures for the CLIC lin­ear col­lid­er study have been test­ed using two of the high power (300 MW) X-band rf sta­tions in the NLCTA fa­cil­i­ty at SLAC. These struc­tures dif­fer in terms of their man­u­fac­tur­ing (brazed disks and clamped quad­rants), gra­di­ent pro­file (amount by which the gra­di­ent in­creas­es along the struc­ture which op­ti­mizes ef­fi­cien­cy and max­i­mizes sus­tain­able gra­di­ent) and HOM damp­ing (use of slots or waveg­uides to rapid­ly dis­si­pate dipole mode en­er­gy). The CLIC goal in the next few years is to demon­strate the fea­si­bil­i­ty of a CLIC-ready base­line de­sign and to in­ves­ti­gate al­ter­na­tives which could bring even high­er ef­fi­cien­cy. This paper sum­ma­rizes the high gra­di­ent test re­sults from the NLCTA in sup­port of this ef­fort.

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

    Science.gov (United States)

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

    2015-11-01

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

  16. Physics potential for the measurement of σ (Hνanti ν) x BR(H → μ{sup +}μ{sup -}) at the 1.4 TeV CLIC collider

    Energy Technology Data Exchange (ETDEWEB)

    Milutinovic-Dumbelovic, G.; Bozovic-Jelisavcic, I.; Kacarevic, G.; Lukic, S.; Pandurovic, M.; Smiljanic, I. [University of Belgrade, Vinca Institute of Nuclear Sciences, Belgrade (Serbia); Grefe, C. [Universitaet Bonn, Bonn (Germany); CERN, Geneva (Switzerland); Roloff, P. [CERN, Geneva (Switzerland)

    2015-11-15

    The future compact linear collider (CLIC) offers a possibility for a rich precision physics programme, in particular in the Higgs sector through the energy staging. This is the first paper addressing the measurement of the standard model Higgs boson decay into two muons at 1.4 TeV CLIC. With respect to similar studies at future linear colliders, this paper includes several novel contributions to the statistical uncertainty of the measurement. The latter includes the equivalent photon approximation employed to describe e{sup +}e{sup -} and eγ interactions whenever the virtuality of the mediated photon is smaller than 4 GeV and realistic forward electron tagging based on energy deposition maps in the forward calorimeters, as well as several processes with the Beamstrahlung photons that results in irreducible contribution to the signal. In addition, coincidence of the Bhabha scattering with the signal and background processes is considered, altering the signal selection efficiency. The study is performed using a fully simulated CLICILD detector model. It is shown that the branching ratio for the Higgs decay into a pair of muons BR(H → μ{sup +}μ{sup -}) times the Higgs production cross-section in WW-fusion σ (Hνanti ν) can be measured with 38 % statistical accuracy at √(s) = 1.4 TeV, assuming an integrated luminosity of 1.5 ab{sup -1} with unpolarised beams. If 80 % electron beam polarisation is considered, the statistical uncertainty of the measurement is reduced to 25 %. Systematic uncertainties are negligible in comparison to the statistical uncertainty. (orig.)

  17. Electric drives

    CERN Document Server

    Boldea, Ion

    2005-01-01

    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  18. CLIC5 stabilizes membrane-actin filament linkages at the base of hair cell stereocilia in a molecular complex with radixin, taperin, and myosin VI.

    Science.gov (United States)

    Salles, Felipe T; Andrade, Leonardo R; Tanda, Soichi; Grati, M'hamed; Plona, Kathleen L; Gagnon, Leona H; Johnson, Kenneth R; Kachar, Bechara; Berryman, Mark A

    2014-01-01

    Chloride intracellular channel 5 protein (CLIC5) was originally isolated from microvilli in complex with actin binding proteins including ezrin, a member of the Ezrin-Radixin-Moesin (ERM) family of membrane-cytoskeletal linkers. CLIC5 concentrates at the base of hair cell stereocilia and is required for normal hearing and balance in mice, but its functional significance is poorly understood. This study investigated the role of CLIC5 in postnatal development and maintenance of hair bundles. Confocal and scanning electron microscopy of CLIC5-deficient jitterbug (jbg) mice revealed progressive fusion of stereocilia as early as postnatal day 10. Radixin (RDX), protein tyrosine phosphatase receptor Q (PTPRQ), and taperin (TPRN), deafness-associated proteins that also concentrate at the base of stereocilia, were mislocalized in fused stereocilia of jbg mice. TPRQ and RDX were dispersed even prior to stereocilia fusion. Biochemical assays showed interaction of CLIC5 with ERM proteins, TPRN, and possibly myosin VI (MYO6). In addition, CLIC5 and RDX failed to localize normally in fused stereocilia of MYO6 mutant mice. Based on these findings, we propose a model in which these proteins work together as a complex to stabilize linkages between the plasma membrane and subjacent actin cytoskeleton at the base of stereocilia. PMID:24285636

  19. The Climate and Cryosphere Project (CliC): Helping bring sea ice Models and Observations together.

    Science.gov (United States)

    Lytle, V.; Goodison, B.; Worby, A.; Ryabinin, V.; Prick, A.; Villinger, T.

    2007-12-01

    The Climate and Cryosphere Project is sponsored by the World Climate Research Program (WCRP) and the Scientific Committee for Antarctic Research (SCAR). One of the four themes within the CliC project is the Marine Cryosphere Theme (MarC). This paper will review the recent projects and workshops held within this Theme and how they relate to other, international initiatives. Recent recommendations on sea ice thickness are being implemented, and groups have been formed to work towards improvements in models, particularly in their representation of the Southern Ocean. SOPHOCLES (Southern Ocean Physical Oceanography and Cryosphere Processes and Climate) will work with other modeling groups to improve the representation of the Southern Ocean in climate models. This will include cooperation with other modeling and observational groups to develop metrics to help evaluate models. In the Arctic, we are working to help develop, standardize, and implement observation and measurement protocols for Arctic sea ice in coastal, seasonal, and perennial ice zones.

  20. Simulation Study of Cool-Down of the CLIC Wiggler Magnets

    CERN Document Server

    Liu, L; van Weelderen, R; Xiong, L

    2013-01-01

    The cryogenic system for the CLIC wiggler magnets is under design. The cooldown process is one of the main dimensioning factors for the system. In this paper, the heat transfer model used to simulate the cool-down process is presented. Different configurations are then investigated and a detailed analysis of the corresponding temperature evolutions along the magnet strings is calculated. The temperature profiles are evaluated for the flowing helium as well as for the magnets allowing a detailed analysis of the temperature gradients. The impact of some key parameters, like the mass-flow rate, the diameter of the cooling channels and of the thermal coupling between the helium and the magnets is also investigated.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Wakefield Simulation of CLIC PETS Structure Using Parallel 3D Finite Element Time-Domain Solver T3P

    Energy Technology Data Exchange (ETDEWEB)

    Candel, A.; Kabel, A.; Lee, L.; Li, Z.; Ng, C.; Schussman, G.; Ko, K.; /SLAC; Syratchev, I.; /CERN

    2009-06-19

    In recent years, SLAC's Advanced Computations Department (ACD) has developed the parallel 3D Finite Element electromagnetic time-domain code T3P. Higher-order Finite Element methods on conformal unstructured meshes and massively parallel processing allow unprecedented simulation accuracy for wakefield computations and simulations of transient effects in realistic accelerator structures. Applications include simulation of wakefield damping in the Compact Linear Collider (CLIC) power extraction and transfer structure (PETS).

  6. Impaired Driving

    Science.gov (United States)

    ... help prevent injuries and deaths from alcohol-impaired driving. The Problem Risk Factors BAC Effects Prevention Additional Resources How big is the problem? In 2014, 9,967 people were killed in alcohol-impaired driving crashes, accounting for nearly one-third (31%) of ...

  7. Distracted Driving

    Science.gov (United States)

    ... 18%) in which someone was injured involved distracted driving. 1 What are the risk factors? Activities Some activities—such as texting—take the driver’s attention away from driving more frequently and for longer periods than other ...

  8. Polar drive on OMEGA

    International Nuclear Information System (INIS)

    High-convergence polar-drive experiments are being conducted on OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] using triple-picket laser pulses. The goal of OMEGA experiments is to validate modeling of oblique laser deposition, heat conduction in the presence of nonradial thermal gradients in the corona, and implosion energetics in the presence of laser-plasma interactions such as crossed-beam energy transfer. Simulated shock velocities near the equator, where the beams are obliquely incident, are within 5% of experimentally inferred values in warm plastic shells, well within the required accuracy for ignition. High, near-one-dimensional areal density is obtained in warm-plastic-shell implosions. Simulated back-lit images of the compressing core are in good agreement with measured images. Outstanding questions that will be addressed in the future relate to the role of cross-beam transfer in polar drive irradiation and increasing the energy coupled into the target by decreasing beam obliquity. (authors)

  9. Driving offences

    OpenAIRE

    Corbett, C

    2010-01-01

    Copyright @ 2010, Taylor & Francis Group. This material is posted on this site with the permission of the publishers. This chapter on driving offences will largely follow the template of earlier chapters except that owing to their vast number, a limited selection only will be examined based on their high volume, seriousness and public concern. The first section will define what driving offences are, how they developed alongside the emerging car culture, and it will consider the contempora...

  10. Klystron beam bunching

    International Nuclear Information System (INIS)

    A detailed description of electron-beam bunching phenomena in klystrons is presented. Beam harmonic current is defined, both space-charge and ballistic bunching are analyzed, Ramo's theorem is used to describe how a bunched beam drives a cavity, and a general cavity model including external coupling is provided. (author)

  11. Beam Momentum Changes due to Discharges in High-gradient Accelerator Structures

    CERN Document Server

    Palaia, Andrea; Ruber, Roger; Ekelöf, Tord

    2013-11-21

    The key questions left unanswered by the Standard Model, and the recent discovery of a Standard Model-like Higgs boson, demand an extension of the research on particle physics to the TeV energy scale. The Compact Linear Collider, CLIC, is a candidate project to achieve such goal. It is a linear lepton collider based on a novel two-beam acceleration scheme capable of high-gradient acceleration in X-band accelerator structures. The high electric fields required, however, entail the occurrence of vacuum discharges, or rf breakdowns, a phenomenon whose microscopic dynamics is not yet completely understood, and whose impact on the beam can lead to a severe degradation of the collider luminosity. The understanding of the physics of rf breakdowns has therefore become a significant issue in the design of a reliable accelerator based on CLIC technology. That is addressed experimentally through the study of accelerator structures performance during high-power operations. We report on such a study carried out on a CLIC...

  12. High power X-band RF test stand development and high power testing of the CLIC crab cavity

    OpenAIRE

    Woolley, Benjamin

    2015-01-01

    This thesis describes the development and operation of multiple high power X-band RF test facilities for high gradient acceleration and deflecting structures at CERN, as re-quired for the e+ e- collider research programme CLIC (Compact Linear Collider). Signif-icant improvements to the control system and operation of the first test stand, Xbox-1 are implemented. The development of the second X-band test stand at CERN, Xbox-2 is followed from inception to completion. The LLRF (Low Level Radio ...

  13. Wakefield Computations for the CLIC PETS using the Parallel Finite Element Time-Domain Code T3P

    Energy Technology Data Exchange (ETDEWEB)

    Candel, A; Kabel, A.; Lee, L.; Li, Z.; Ng, C.; Schussman, G.; Ko, K.; /SLAC; Syratchev, I.; /CERN

    2009-06-19

    In recent years, SLAC's Advanced Computations Department (ACD) has developed the high-performance parallel 3D electromagnetic time-domain code, T3P, for simulations of wakefields and transients in complex accelerator structures. T3P is based on advanced higher-order Finite Element methods on unstructured grids with quadratic surface approximation. Optimized for large-scale parallel processing on leadership supercomputing facilities, T3P allows simulations of realistic 3D structures with unprecedented accuracy, aiding the design of the next generation of accelerator facilities. Applications to the Compact Linear Collider (CLIC) Power Extraction and Transfer Structure (PETS) are presented.

  14. Tuning of the Compact Linear Collider Beam Delivery System

    CERN Document Server

    Garcia, H; Inntjore Levinsen, Y; Latina, A; Tomas, R; Snuverink, J

    2014-01-01

    Tuning the Compact Linear Collider (CLIC) BeamDelivery System (BDS), and in particular the Final Focus (FF), is a challenging task. In simulations without misalignments, the goal is to reach 120%o f the nominal luminosity target, in order to allow for 10% loss due to static imperfections, and another 10% loss from dynamic imperfections. Various approaches have been considered to correct the magnet misalignments, including 1-1 correction, Dispersion Free Steering (DFS), and several minimization methods utilizing multipole movers. In this paper we report on the recent advancements towards a feasible tuning approach that reaches the required luminosity target.

  15. Wakefield Monitor Experiments with X-Band Accelerating Structures

    CERN Document Server

    Lillestøl, Reidar; Corsini, Roberto; Döbert, Steffen; Farabolini, Wilfrid; Malina, Lukas; Pfingstner, Juergen; Wuensch, Walter

    2015-01-01

    The accelerating structures for CLIC must be aligned with a precision of a few um with respect to the beam trajectory in order to mitigate emittance growth due to transverse wake fields. We report on first results from wake field monitor tests in an X-band structure, with a probe beam at the CLIC Test Facility. The monitors are currently installed in the CLIC Two-Beam Module. In order to fully demonstrate the feasibility of using wakefield monitors for CLIC, the precision of the monitors must be verified using a probe beam while simultaneously filling the structure with high power rf used to drive the accelerating mode. We outline plans to perform such a demonstration in the CLIC Test Facility.

  16. Imaging Techniques for Relativistic Beams: Issues and Limitations

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, Alex H.; Wendt, Manfred; /Fermilab

    2012-02-01

    Characterizations of transverse profiles for low-power beams in the accelerators of the proposed linear colliders (ILC and CLIC) using imaging techniques are being evaluated. Assessments of the issues and limitations for imaging relativistic beams with intercepting scintillator or optical transition radiation screens are presented based on low-energy tests at the Fermilab A0 photoinjector and are planned for the Advanced Superconducting Test Accelerator at Fermilab. We have described several of the issues and limitations one encounters with the imaging of relativistic electron beams. We have reported our initial tests at the A0PI facility and our plans to extend these studies to the GeV scale at the ASTA facility. We also have plans to test these concepts with 23-GeV beams at the FACET facility at SLAC in the coming year. It appears the future remains bright for imaging techniques in ILC-relevant parameter space.

  17. High frequency beam protection

    International Nuclear Information System (INIS)

    This report describes the design and construction of a high-frequency beam protecting device. This apparatus controls a number of functions in a modulator. Furthermore it drives the phase shifter and the attenuator. (author). 6 figs

  18. Beam-Beam Effects

    OpenAIRE

    Herr, W; Pieloni, T.

    2016-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities.

  19. Beam-Beam Effects

    CERN Document Server

    Herr, W

    2014-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities.

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

    International Nuclear Information System (INIS)

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

  1. Driving things

    DEFF Research Database (Denmark)

    Nevile, Maurice Richard

    2015-01-01

    I explore how participants organise involvement with objects brought into the car, relative to the demands of driving and social activity. Objects in cars commonly include phones or other technologies, food, body care products, texts, clothing, bags and carry items, toys, and even animals....... pp.155 ((http://www.infrastructure.gov.au/roads/safety/publications/2010/pdf/rsgr_2010001.pdf)) Nevile, M., Haddington, P., Heinemann, T., Rauniomaa, M. (Eds.) Interacting with objects: Language, materiality, and social activity. Amsterdam/Philadelphia: John Benjamins. Redshaw, S. (2008). In the...

  2. Fast wave current drive

    International Nuclear Information System (INIS)

    Experiments on the fast wave in the range of high ion cyclotron harmonics in the ACT-1 device show that current drive is possible with the fast wave just as it is for the lower hybrid wave, except that it is suitable for higher plasma densities. A 1400 loop antenna launched the high ion cyclotron harmonic fast wave [ω/Ω = O(10)] into a He+ plasma with n/sub e/approx. =4 x 1012 cm-3 and B = 4.5 kG. Probe and magnetic loop diagnostics and FIR laser scattering confirmed the presence of the fast wave, and the Rogowski loop indicated that the circulating plasma current increased by up to 40A with 1 kW of coupled power, which is comparable to lower hybrid current drive in the same device with the same unidirectional fast electron beam used as the target for the RF. A phased antenna array would be used for FWCD in a tokamak without the E-beam

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

    OpenAIRE

    Belver Aguilar, Carolina

    2015-01-01

    El descubrimiento del bosón de Higgs ha iniciado una nueva era en el LHC cuyo objetivo será medir las propiedades de dicho bosón con la mayor precisión posible. Sin embargo, dada la complejidad de los protones, compuestos por quarks y gluones, existe el consenso en la Física de Altas Energías de que el próximo colisionador será un colisionador electrón-positrón. Desde un punto de vista simplista, para que electrones y positrones colisionen a muy altas energías en un colisionador circular, la ...

  4. 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.

  5. 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 �...

  6. Beam Delivery Simulation - Recent Developments and Optimization

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00232566; Boogert, Stewart Takashi; Garcia-Morales, H; Gibson, Stephen; Kwee-Hinzmann, Regina; Nevay, Laurence James; Deacon, Lawrence Charles

    2015-01-01

    Beam Delivery Simulation (BDSIM) is a particle tracking code that simulates the passage of particles through both the magnetic accelerator lattice as well as their interaction with the material of the accelerator itself. The Geant4 toolkit is used to give a full range of physics processes needed to simulate both the interaction of primary particles and the production and subsequent propagation of secondaries. BDSIM has already been used to simulate linear accelerators such as the International Linear Collider (ILC) and the Compact Linear Collider (CLIC), but it has recently been adapted to simulate circular accelerators as well, producing loss maps for the Large Hadron Collider (LHC). In this paper the most recent developments, which extend BDSIM’s functionality as well as improve its efficiency are presented. Improvement and refactorisation of the tracking algorithms are presented alongside improved automatic geometry construction for increased particle tracking speed.

  7. CTF3 Design Report

    CERN Document Server

    Ruth, Ronald D

    2003-01-01

    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.

  8. Performance of the FONT3 Fast Analogue Intra-Train Beam-Based Feedback System at ATF

    International Nuclear Information System (INIS)

    We report results of beam tests of the FONT3 intra-train position feedback system prototype at the Accelerator Test Facility (ATF) at KEK. The feedback system incorporates a novel beam position monitor (BPM) processor with latency below 5 nanoseconds, and a kicker driver amplifier with similar low latency. The 56 nanosecond-long bunchtrain in the ATF extraction line was used to test the prototype feedback system. The achieved latency of 23ns provides a demonstration of intra-train feedback on very short timescales relevant even for the CLIC Linear Collider design

  9. Measurement of Higgs couplings and mass in e+e- collisions at CLIC in the sqrt(s) range of 350 GeV - 3 TeV

    Czech Academy of Sciences Publication Activity Database

    Laštovička, Tomáš

    Trieste: S I S S A, 2013, s. 1-7, 295. ISSN 1824-8039. [EPS-HEP 2013 - The European Physical Society Conference on High Energy Physics 2013. Stockholm (SE), 17.07.2013- 24.07.2013] Institutional support: RVO:68378271 Keywords : Higgs boson * CLIC * CERN * Higgs branching ratios * Higgs mass * linear accelerator Subject RIV: BF - Elementary Particles and High Energy Physics http://pos.sissa.it/archive/conferences/180/295/EPS-HEP%202013_295.pdf

  10. Distractions in Everyday Driving

    Science.gov (United States)

    ... while driving, which is one of the reasons distracted driving is such a big problem. Driver inattention is ... you’re doing any of these things while driving, you become distracted in ways that increase your risk of crashing. ...

  11. Beam Momentum Changes due to Discharges in High-gradient Accelerator Structures

    OpenAIRE

    Palaia, Andrea

    2013-01-01

    The key questions left unanswered by the Standard Model, and the recent discovery of a Standard Model-like Higgs boson, demand an extension of the research on particle physics to the TeV energy scale. The Compact Linear Collider, CLIC, is a candidate project to achieve such goal. It is a linear lepton collider based on a novel two-beam acceleration scheme capable of high-gradient acceleration in X-band accelerator structures. The high electric fields required, however, entail the occurrence o...

  12. Deposition and drive symmetry for light ion ICF targets

    International Nuclear Information System (INIS)

    Light ion beam ICF is a concept in which intense beams of low atomic number ions would be used to drive ICF targets to ignition and gain. Three dimensional analytic approximations indicate that at least twelve beams would be required to drive an indirect drive target with adequate symmetry. Here, results from two dimensional numerical simulations are presented describing the ion deposition and drive symmetry aspects of such a target for which the ion beams are approximated as ring sources. For adequate symmetry in the two dimensional calculations, the simulations required six ring sources and two pole sources during the low power 'foot' pulse and four ring sources during the main ion beam drive pulse. If each ring represents five individual beams, this corresponds to 32 beams in the foot pulse and 20 beams in the main pulse. The corresponding two dimensional integrated LASNEX calculation, simulating the target from ion beam input to ignition and burn in the same code run, produced 591 MJ of thermonuclear yield with lithium ion beam sources containing a total input energy of 16 MJ. (author)

  13. Beam-beam effects

    Energy Technology Data Exchange (ETDEWEB)

    Zholents, A.

    1994-12-01

    The term beam-beam effects is usually used to designate different phenomena associated with interactions of counter-rotating beams in storage rings. Typically, the authors speak about beam-beam effects when such interactions lead to an increase of the beam core size or to a reduction of the beam lifetime or to a growth of particle`s population in the beam halo and a correspondent increase of the background. Although observations of beam-beam effects are very similar in most storage rings, it is very likely that every particular case is largely unique and machine-dependent. This constitutes one of the problems in studying the beam-beam effects, because the experimental results are often obtained without characterizing a machine at the time of the experiment. Such machine parameters as a dynamic aperture, tune dependencies on amplitude of particle oscillations and energy, betatron phase advance between the interaction points and some others are not well known, thus making later analysis uncertain. The authors begin their discussion with demonstrations that beam-beam effects are closely related to non linear resonances. Then, they will show that a non linearity of the space charge field is responsible for the excitation of these resonances. After that, they will consider how beam-beam effects could be intensified by machine imperfections. Then, they will discuss a leading mechanism for the formation of the beam halo and will describe a new technique for beam tails and lifetime simulations. They will finish with a brief discussion of the coherent beam-beam effects.

  14. 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.

  15. 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

  16. Extended Driving Impairs Nocturnal Driving Performances

    OpenAIRE

    Patricia Sagaspe; Jacques Taillard; Torbjorn Akerstedt; Virginie Bayon; Stéphane Espié; Guillaume Chaumet; Bernard Bioulac; Pierre Philip

    2008-01-01

    Though fatigue and sleepiness at the wheel are well-known risk factors for traffic accidents, many drivers combine extended driving and sleep deprivation. Fatigue-related accidents occur mainly at night but there is no experimental data available to determine if the duration of prior driving affects driving performance at night. Participants drove in 3 nocturnal driving sessions (3-5 am, 1-5 am and 9 pm-5 am) on open highway. Fourteen young healthy men (mean age [+/-SD] = 23.4 [+/-1.7] years)...

  17. Extended Driving Impairs Nocturnal Driving Performances

    OpenAIRE

    SAGASPE, Patricia; Taillard, Jacques; Åkerstedt, Torbjorn; BAYON, Virginie; Espié, Stéphane; Chaumet, Guillaume; Bioulac, Bernard; Philip, Pierre

    2008-01-01

    Though fatigue and sleepiness at the wheel are well-known risk factors for traffic accidents, many drivers combine extended driving and sleep deprivation. Fatigue-related accidents occur mainly at night but there is no experimental data available to determine if the duration of prior driving affects driving performance at night. Participants drove in 3 nocturnal driving sessions (3–5am, 1–5am and 9pm–5am) on open highway. Fourteen young healthy men (mean age [±SD] = 23.4 [±1.7] years) partici...

  18. Reading Text While Driving

    OpenAIRE

    Liang, Yulan; Horrey, William J.; Hoffman, Joshua D.

    2015-01-01

    Objective In this study, we investigated how drivers adapt secondary-task initiation and time-sharing behavior when faced with fluctuating driving demands. Background Reading text while driving is particularly detrimental; however, in real-world driving, drivers actively decide when to perform the task. Method In a test track experiment, participants were free to decide when to read messages while driving along a straight road consisting of an area with increased driving demands (demand zone)...

  19. HARMONIC DRIVE SELECTION

    Directory of Open Access Journals (Sweden)

    Piotr FOLĘGA

    2014-03-01

    Full Text Available The variety of types and sizes currently in production harmonic drive is a problem in their rational choice. Properly selected harmonic drive must meet certain requirements during operation, and achieve the anticipated service life. The paper discusses the problems associated with the selection of the harmonic drive. It also presents the algorithm correct choice of harmonic drive. The main objective of this study was to develop a computer program that allows the correct choice of harmonic drive by developed algorithm.

  20. 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...

  1. Beam focusing limitation from synchrotron radiation in two dimensions

    Science.gov (United States)

    Blanco, O. R.; Tomás, R.; Bambade, P.

    2016-02-01

    The Oide effect considers the synchrotron radiation in the final focusing quadrupole, and it sets a lower limit on the vertical beam size at the interaction point, particularly relevant for high-energy linear colliders. The theory of the Oide effect was derived considering only the second moment of the radiation in the focusing plane of the magnet. This article addresses the theoretical calculation of the radiation effect on the beam size considering the first and second moments of the radiation and both focusing and defocusing planes of the quadrupole. The effect for a Gaussian beam is referred to as 2D-Oide; however, an alternative beam size figure is given that could represent better the effect on the minimum achievable βy* . The CLIC 3 TeV final quadrupole (QD0) and beam parameters are used to compare the theoretical results from the Oide effect and the 2D-Oide effect with particle tracking in placet. The 2D-Oide effect is demonstrated to be important, as it increases by 17% the contribution to the beam size. Further insight into the aberrations induced by the synchrotron radiation opens the possibility to partially correct the 2D-Oide effect with octupole magnets. A beam size reduction of 4% is achieved in the simplest configuration, using a single octupole.

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

    CERN Document Server

    Liu, Shan; Cornebise, Patrick; Faus-Golfe, Angeles; Fuster-Martínez, Nuria; Griesmayer, Erich; Guler, Hayg; Kubytskyi, Viacheslav; Sylvia, Christophe; Toshiaki, Tauchi; Terunuma, Nobuhiro; Bambade, Philip

    2015-01-01

    The investigation of beam halo transverse distributions is important for the understanding of beam losses and the control of backgrounds in Future Linear Colliders (FLC). A novel in vacuum diamond sensor (DSv) scanner with four strips has been designed and developed for the investigation of the beam halo transverse distributions and also for the diagnostics of Compton recoil electrons after the interaction point (IP) of ATF2, a low energy (1.3 GeV) prototype of the final focus system for the ILC and CLIC linear collider projects. Using the DSv, a dynamic range of $\\sim10^6$ has been successfully demonstrated and confirmed for the first time by simultaneous beam core ($\\sim10^9$ electrons) and beam halo ($\\sim10^3$ electrons) measurements at ATF2. This report presents the characterization, performance studies and tests of the diamond sensors using an $\\alpha$ source as well as using the electron beams at PHIL, a low energy ($< 10$ MeV) photo-injector at LAL, and at ATF2. First beam halo measurement results ...

  3. PEPPo: Using a Polarized Electron Beam to Produce Polarized Positrons

    Energy Technology Data Exchange (ETDEWEB)

    Adeyemi, Adeleke H. [Hampton Univ., Hampton, VA (United States); et al.

    2015-09-01

    Polarized positron beams have been identified as either an essential or a significant ingredient for the experimental program of both the present and next generation of lepton accelerators (JLab, Super KEK B, ILC, CLIC). An experiment demonstrating a new method for producing polarized positrons has been performed at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e⁻/e⁺ pairs from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a high-Z conversion target. PEPPo demonstrated the effective transfer of spin-polarization of an 8.2 MeV/c polarized (P~85%) electron beam to positrons produced in varying thickness tungsten production targets, and collected and measured in the range of 3.1 to 6.2 MeV/c. In comparison to other methods this technique reveals a new pathway for producing either high-energy or thermal polarized positron beams using a relatively low polarized electron beam energy (~10MeV) .This presentation will describe the PEPPo concept, the motivations of the experiment and high positron polarization achieved.

  4. Dementia and driving

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000028.htm Dementia and driving To use the sharing features on ... please enable JavaScript. If your loved one has dementia, deciding when they can no longer drive may ...

  5. Beam dynamics studies and emittance optimization in the CTF3 linac at CERN

    CERN Document Server

    Urschütz, Peter; Corsini, Roberto; Döbert, Steffen; Ferrari, Arnaud; Tecker, Frank

    2006-01-01

    Small transverse beam emittances and well-known lattice functions are crucial for the 30 GHz power production in the Power Extraction and Transfer Structure (PETS) and for the commissioning of the Delay Loop of the CLIC Test Facility 3 (CTF3). Following beam dynamics simulation results, two additional solenoids were installed in the CTF3 injector in order to improve the emittance. During the runs in 2005 and 2006, an intensive measurement campaign to determine Twiss parameters and beam sizes was launched. The results obtained by means of quadrupole scans for different modes of operation suggest emittances well below the nominal .n,rms = 100 ?Î?Êm and a good agreement with PARMELA simulations.

  6. Beam dynamics in the final focus section of the future linear collider

    CERN Document Server

    AUTHOR|(SzGeCERN)739431; TOMAS, Rogelio

    The exploration of new physics in the ``Tera electron-Volt''~(TeV) scale with precision measurements requires lepton colliders providing high luminosities to obtain enough statistics for the particle interaction analysis. In order to achieve design luminosity values, linear colliders feature nanometer beam spot sizes at the Interaction~Point~(IP).\\par In addition to several effects affecting the luminosity, three main issues to achieve the beam size demagnification in the Final Focus Section (FFS) of the accelerator are the chromaticity correction, the synchrotron radiation effects and the correction of the lattice errors.\\par This thesis considers two important aspects for linear colliders: push the limits of linear colliders design, in particular the chromaticity correction and the radiation effects at 3~TeV, and the instrumentation and experimental work on beam stabilization in a test facility.\\par The current linear collider projects, CLIC~\\cite{CLICdes} and ILC~\\cite{ILCdes}, have lattices designed using...

  7. Gear bearing drive

    Science.gov (United States)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  8. Universal drive unit

    OpenAIRE

    Sehnálek, Lubomír

    2011-01-01

    This document deal with design of universal driving unit. For the final solution is required driving unit which will be controled with help of sensory unit placed on the chassis of driving unit. In theoretical part of this labour are examined possibilities of a power, electric motor operation by PWM, kind of chassis and odometry which could be taken into account. From this section is finally chosen concrete configuration which is then described in chapter concerned oneself with driving unit d...

  9. 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, ...

  10. Theoretical studies of non inductive current drive in compact toroids

    NARCIS (Netherlands)

    Farengo, R; Lifschitz, AF; Caputi, KI; Arista, NR; Clemente, RA

    2002-01-01

    Three non inductive current drive methods that can be applied to compact toroids axe studied. The use of neutral beams to drive current in field reversed configurations and spheromaks is studied using a Monte Carlo code that includes a complete ionization package and follows the exact particle orbit

  11. InterTerm: los diccionarios de internet en un solo clic

    Directory of Open Access Journals (Sweden)

    M. Gonzalo Claros

    2009-06-01

    Full Text Available En este artículo se presenta una herramienta que funciona en todos los ordenadores con tal de que se use un navegador que entienda el JavaScript estándar: InterTerm. Con ella se puede buscar una palabra en menos de un minuto en una buena colección de diccionarios y glosarios de la web. Se describe brevemente cómo utilizarlo, cómo se ven los resultados y por qué puede ser una herramienta interesante que merece ser añadida al disco duro y a los enlaces del navegador. La lista de sitios se puede modificar a voluntad del usuario, si se atreve a meterse en los entresijos del programa. Para empezar a probarlo, basta consultar la URL . ---------------------------------------------- InterTerm: Internet dictionaries at a single click. This article introduces InterTerm, a tool that runs in every type of computer using a browser with JavaScript standard. In less than a minute, this tool can search a word in a large collection of dictionaries and glossaries available in the web. This article briefly describes how to use it, how to see the results and the reasons why it's an interesting tool to install in the hard drive and to mark as a link in the browser. The user can modify the websites list if able to use the necessary skills to get into the program's ins and outs. To start testing this application, visit .

  12. High performance AC drives

    CERN Document Server

    Ahmad, Mukhtar

    2010-01-01

    This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the improvement of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on multiphase drives as well as sensorless and direct torque control of electric drives since up-to date references in these topics are provided. It will also provide few examples of modeling, analysis and control of electric drives using MATLAB/SIMULIN

  13. Simple Driving Techniques

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    2002-01-01

    -like language. Our aim is to extract a simple notion of driving and show that even in this tamed form it has much of the power of more general notions of driving. Our driving technique may be used to simplify functional programs which use function composition and will often be able to remove intermediate data......Driving was introduced as a program transformation technique by Valentin Turchin in some papers around 1980. It was intended for the programming language REFAL and used in metasystem transitions based on super compilation. In this paper we present one version of driving for a more conventional lisp...

  14. Radiation therapy apparatus having retractable beam stopper

    International Nuclear Information System (INIS)

    This invention relates to a radiation therapy apparatus which utilized a linear translation mechanism for positioning a beam stopper. An apparatus is described wherein the beam stopper is pivotally attached to the therapy machine with an associated drive motor in such a way that the beam stopper retracts linearly

  15. The application of multilayer elastic beam in MEMS safe and arming system

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guozhong, E-mail: liguozhong-bit@bit.edu.cn; Shi, Gengchen; Sui, Li [National Lab of Mechatronic Engineering and Control, Beijing Institute of Technology, Beijing 100081, P.R.CHINA (China); Yi, Futing; Wang, Bo [Institute of High Energy Physics Chinese Academy of Sciences, Beijing 100049, P.R.CHINA (China)

    2015-07-15

    In this paper, a new approach for a multilayer elastic beam to provide a driving force and driving distance for a MEMS safe and arming system is presented. In particular this is applied where a monolayer elastic beam cannot provide adequate driving force and driving distance at the same time in limited space. Compared with thicker elastic beams, the bilayer elastic beam can provide twice the driving force of a monolayer beam to guarantee the MEMS safe and arming systems work reliably without decreasing the driving distance. In this paper, the theoretical analysis, numerical simulation and experimental verification of the multilayer elastic beam is presented. The numerical simulation and experimental results show that the bilayer elastic provides 1.8–2 times the driving force of a monolayer, and a method that improves driving force without reducing the driving distance.

  16. The application of multilayer elastic beam in MEMS safe and arming system

    International Nuclear Information System (INIS)

    In this paper, a new approach for a multilayer elastic beam to provide a driving force and driving distance for a MEMS safe and arming system is presented. In particular this is applied where a monolayer elastic beam cannot provide adequate driving force and driving distance at the same time in limited space. Compared with thicker elastic beams, the bilayer elastic beam can provide twice the driving force of a monolayer beam to guarantee the MEMS safe and arming systems work reliably without decreasing the driving distance. In this paper, the theoretical analysis, numerical simulation and experimental verification of the multilayer elastic beam is presented. The numerical simulation and experimental results show that the bilayer elastic provides 1.8–2 times the driving force of a monolayer, and a method that improves driving force without reducing the driving distance

  17. Preliminary Results of Ion Beam Extraction Tests on EAST Neutral Beam Injector

    Institute of Scientific and Technical Information of China (English)

    胡纯栋

    2012-01-01

    The neutral beam injection (NBI) system is one of the most important auxiliary plasma heating and current driving methods for fusion device. A high power ion beam of 3 MW with 80 keV beam energy in 0.5 s beam duration and a long pulse ion beam of 4 s with 50 keV beam energy ion beam extraction were achieved on the EAST neutral beam injector on the teststand. The preliminary results show that the EAST-NBI system was developed successfully on schedule.

  18. Progress in direct-drive inertial confinement fusion

    International Nuclear Information System (INIS)

    Significant progress has been made in direct-drive inertial confinement fusion research at the Laboratory for Laser Energetics since the 2009 IFSA Conference [R.L. McCrory et al., J. Phys.: Conf. Ser. 244, 012004 (2010)]. Areal densities of 300 mg/cm2 have been measured in cryogenic target implosions with neutron yields 15% of 1-D predictions. A model of crossed-beam energy transfer has been developed to explain the observed scattered-light spectrum and laser-target coupling. Experiments show that its impact can be mitigated by changing the ratio of the laser beam to target diameter. Progress continues in the development of the polar-drive concept that will allow direct-drive-ignition experiments to be conducted on the National Ignition Facility using the indirect-drive-beam layout. (authors)

  19. Superluminal warp drive

    International Nuclear Information System (INIS)

    In this Letter we consider a warp drive spacetime resulting from that suggested by Alcubierre when the spaceship can only travel faster than light. Restricting to the two dimensions that retains most of the physics, we derive the thermodynamic properties of the warp drive and show that the temperature of the spaceship rises up as its apparent velocity increases. We also find that the warp drive spacetime can be exhibited in a manifestly cosmological form

  20. Universal Drive Train Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This vehicle drive train research facility is capable of evaluating helicopter and ground vehicle power transmission technologies in a system level environment. The...

  1. Laser beam riding artillery missiles guidance device is designed

    Science.gov (United States)

    Yan, Mingliang; Huo, Zhicheng; Chen, Wei

    2014-09-01

    Laser driving gun missile guidance type beam of laser information field formed by any link failure or reduced stability will directly lead to ballistic or miss out of control, and based on this, this paper designed the driving beam of laser guided missile guidance beam type forming device modulation and zoom mechanism, in order to make the missile can recognize its position in the laser beam, laser beam gun missile, by means of spatial encoding of the laser beam laser beam into information after forming device, a surface to achieve the purpose of precision guidance.

  2. Nonlinear beam-beam resonances

    International Nuclear Information System (INIS)

    Head-on collisions of bunched beams are considered, assuming the two colliding beams have opposite charges. A few experimental observations are described. The single resonance analysis is developed that is applicable to the strong-weak case of the beam-beam interaction. In this case, the strong beam is unperturbed by the beam-beam interaction; motions of the weak beam particles are then analyzed in the presence of the nonlinear electromagnetic force produced by the strong beam at the collision points. The coherent motions of the two coupled strong beams are shown to exhibit distinct nonlinear resonance behavior. 16 refs., 22 figs

  3. Piezoelectric drive circuit

    Science.gov (United States)

    Treu, Jr., Charles A.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  4. Fundamentals of electrical drives

    CERN Document Server

    Veltman, André; De Doncker, Rik W

    2007-01-01

    Provides a comprehensive introduction to various aspects of electrical drive systems. This volume provides a presentation of dynamic generic models that cover all major electrical machine types and modulation/control components of a drive as well as dynamic and steady state analysis of transformers and electrical machines.

  5. Electric Vehicle - Economical driving

    DEFF Research Database (Denmark)

    Jensen, VCE, Steen V.; Schøn, Henriette

    1999-01-01

    How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV......How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV...

  6. Measurement of Beam Loss at the Australian Synchrotron

    CERN Document Server

    Holzer, EB; Kastriotou, M; Boland, MJ; Jackson, PD; Rasool, RP; Schmidt, J; Welsch, CP

    2014-01-01

    The unprecedented requirements that new machines are setting on their diagnostic systems is leading to the development of new generation of devices with large dynamic range, sensitivity and time resolution. Beam loss detection is particularly challenging due to the large extension of new facilities that need to be covered with localized detector. Candidates to mitigate this problem consist of systems in which the sensitive part of the radiation detectors can be extended over long distance of beam lines. In this document we study the feasibility of a BLM system based on optical fiber as an active detector for an electron storage ring. The Australian Synchrotron (AS) comprises a 216m ring that stores electrons up to 3GeV. The Accelerator has recently claimed the world record ultra low transverse emittance (below pm rad) and its surroundings are rich in synchrotron radiation. Therefore, the AS provides beam conditions very similar to those expected in the CLIC/ILC damping rings. A qualitative benchmark of beam l...

  7. Superconducting wiggler magnets for beam-emittance damping rings

    CERN Document Server

    Schoerling, Daniel

    2012-01-01

    Ultra-low emittance beams with a high bunch charge are necessary for the luminosity performance of linear electron-positron colliders, such as the Compact Linear Collider (CLIC). An effective way to create ultra-low emittance beams with a high bunch charge is to use damping rings, or storage rings equipped with strong damping wiggler magnets. The remanent field of the permanent magnet materials and the ohmic losses in normal conductors limit the economically achievable pole field in accelerator magnets operated at around room temperature to below the magnetic saturation induction, which is 2.15 T for iron. In wiggler magnets, the pole field in the center of the gap is reduced further like the hyperbolic cosine of the ratio of the gap size and the period length multiplied by pi. Moreover, damping wiggler magnets require relatively large gaps because they have to accept the un-damped beam and to generate, at a small period length, a large magnetic flux density amplitude to effectively damp the beam emittance....

  8. Design principles for high current beam injection lines

    International Nuclear Information System (INIS)

    We discuss the design principles for high current injection beam lines having a high degree of beam quality preservation. These principles are applied to designing a high current e-beam injection line delivering 10 MeV e-beams from the injector to an accelerator driving LTV FELs, as proposed at CEBAF

  9. Brazing of Mo to a CuZr alloy for the production of bimetallic raw materials for the CLIC accelerating structures

    CERN Document Server

    Salvo, M; Heikkinen, Samuli; Salvo, Milena; Casalegno, Valentina; Sgobba, Stefano; Rizzo, Stefano; Izquierdo, Gonzalo Arnau; Taborelli, Mauro

    2010-01-01

    Future linear accelerators, as CLIC (Compact Linear Collider), are extremely demanding in terms of material properties. Traditionally accelerating structure is made of brazed OFE copper parts. For the high conducting regions submitted to mechanical fatigue, CuZr would represent an improved selection than pure copper while for regions where the highest electric field is applied a refractory metal, i.e. Mo, could result in a better performance. The feasibility of joining such materials, namely CuZr (UNS C15000) and pure Mo has been investigated. The joining method developed and investigated here consists in a vacuum brazing process exploiting a Cu-based brazing filler applied under appropriate vacuum conditions. Apparent shear strength (adapted from ASTM B898) on the joined samples was about 200 MPa. (C) 2010 Elsevier B.V. All rights reserved.

  10. Fast wave current drive

    Energy Technology Data Exchange (ETDEWEB)

    Goree, J.; Ono, M.; Colestock, P.; Horton, R.; McNeill, D.; Park, H.

    1985-07-01

    Fast wave current drive is demonstrated in the Princeton ACT-I toroidal device. The fast Alfven wave, in the range of high ion-cyclotron harmonics, produced 40 A of current from 1 kW of rf power coupled into the plasma by fast wave loop antenna. This wave excites a steady current by damping on the energetic tail of the electron distribution function in the same way as lower-hybrid current drive, except that fast wave current drive is appropriate for higher plasma densities.

  11. Driving When You Have Cataracts

    Science.gov (United States)

    ... when they want. I Driving is a complex skill. Our ability to drive safely can be challenged by changes in our ... drive with you to see how well you drive with your cataract. I The ... to improve your driving skills. Improving your skills could help keep you and ...

  12. Multi-beam linear accelerator EVT

    Science.gov (United States)

    Teryaev, Vladimir E.; Kazakov, Sergey Yu.; Hirshfield, Jay L.

    2016-09-01

    A novel electron multi-beam accelerator is presented. The accelerator, short-named EVT (Electron Voltage Transformer) belongs to the class of two-beam accelerators. It combines an RF generator and essentially an accelerator within the same vacuum envelope. Drive beam-lets and an accelerated beam are modulated in RF modulators and then bunches pass into an accelerating structure, comprising uncoupled with each other and inductive tuned cavities, where the energy transfer from the drive beams to the accelerated beam occurs. A phasing of bunches is solved by choice correspond distances between gaps of the adjacent cavities. Preliminary results of numerical simulations and the initial specification of EVT operating in S-band, with a 60 kV gun and generating a 2.7 A, 1.1 MV beam at its output is presented. A relatively high efficiency of 67% and high design average power suggest that EVT can find its use in industrial applications.

  13. Dual drive; Doppelt angetrieben

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, Jan

    2011-09-15

    The Opel Ampera was designed as an everyday car with an alternative drive system. A hybrid concept comprising both an electric motor and a gasoline engine ensures long mileage, but there is still the problem of high purchase cost.

  14. Safe driving for teens

    Science.gov (United States)

    ... for crashes. Drivers and passengers should use automobile safety features at all times. These include: seat belts, shoulder straps, and headrests. Only drive cars that have air bags, padded dashes, safety glass, ...

  15. Drunk Driving Campaign

    OpenAIRE

    Christoffersen, Mette Buhl; Vogel, Klara Elisa Pingel

    2014-01-01

    This project evaluates a communication product, consisting of three flush-ad posters against drunk driving. The target group of this campaign is young men in the ages 18-22 in the outskirts of Denmark. The project's scientific theoretical approach is phenomenology which will give insight in the target groups life situation, furthermore the social constructivist perspective is used to understand the target group's opinions in relation to product and subject drunk driving because of the interac...

  16. Drinking and driving

    OpenAIRE

    2003-01-01

    Alcohol misuse generates many health and social problems at a cost that society is increasingly unwilling to sustain. One of the most tragic consequences of alcohol misuse is the result of drinking and driving. Each week, impaired drivers kill 40 Canadian men, women and children and injure 1250 others. The Canadian Medical Association (CMA), in its campaign against drinking and driving, has recommended that a condition of obtaining or renewing a driver's licence include the individual's writt...

  17. Engineering Autonomous Driving Software

    OpenAIRE

    Berger, Christian; Rumpe, Bernhard

    2014-01-01

    A larger number of people with heterogeneous knowledge and skills running a project together needs an adaptable, target, and skill-specific engineering process. This especially holds for a project to develop a highly innovative, autonomously driving vehicle to participate in the 2007 DARPA Urban Challenge. In this contribution, we present essential elements of a software and systems engineering process to develop a so-called artificial intelligence capable of driving autonomously in complex u...

  18. Direct drive wind turbine

    Science.gov (United States)

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Stowell, Jesse; Costin, Daniel

    2006-07-11

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  19. Instant Google Drive starter

    CERN Document Server

    Procopio, Mike

    2013-01-01

    This book is a Starter which teaches you how to use Google Drive practically. This book is perfect for people of all skill levels who want to enjoy the benefits of using Google Drive to safely store their files online and in the cloud. It's also great for anyone looking to learn more about cloud computing in general. Readers are expected to have an Internet connection and basic knowledge of using the internet.

  20. Self-driving carsickness.

    Science.gov (United States)

    Diels, Cyriel; Bos, Jelte E

    2016-03-01

    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and productivity. However, we here show that the envisaged scenarios all lead to an increased risk of motion sickness. As such, the benefits this technology is assumed to bring may not be capitalised on, in particular by those already susceptible to motion sickness. This can negatively affect user acceptance and uptake and, in turn, limit the potential socioeconomic benefits that this emerging technology may provide. Following a discussion on the causes of motion sickness in the context of self-driving cars, we present guidelines to steer the design and development of automated vehicle technologies. The aim is to limit or avoid the impact of motion sickness and ultimately promote the uptake of self-driving cars. Attention is also given to less well known consequences of motion sickness, in particular negative aftereffects such as postural instability, and detrimental effects on task performance and how this may impact the use and design of self-driving cars. We conclude that basic perceptual mechanisms need to be considered in the design process whereby self-driving cars cannot simply be thought of as living rooms, offices, or entertainment venues on wheels. PMID:26446454

  1. Epilepsy and driving

    Directory of Open Access Journals (Sweden)

    Moetamedi M

    2000-09-01

    Full Text Available Epilepsy is a disease with high prevalence, which interferes driving and may lead to car accident; This case-control study has been done on 100 epileptic patients and 100 persons as control group, who had history of driving. We gathered our patients with face to face interview and registering their information in special forms which were prepared for this study. There were three times more accidents among epileptic cases comparing with control group and this difference was more considerable in men and in patients under 35 years old. The cause of accident were not seizure attack in more than 60% of the patients and these ordinary accidents were also more in case group. Epileptic patients with history of car accidents during driving had poor drug compliance comparing with the epileptics without history of an accident so drug compliance may be valuable in predicting accident in these patients. We have also found poor drug compliance in whom seizure attacks caused accident for them. 58% of the epileptics had not consulted their physician about driving. 43.3% of seizures during driving were of generalized type and none of the patients had inform police about their disease during getting driving license.

  2. Dangers of Texting While Driving

    Science.gov (United States)

    ... and share information, we created a dedicated website . Distracted Driving Information Clearinghouse In addition, to collect and share ... technology that could potentially reduce the problem of distracted driving, the Commission’s staff created the FCC Distracted Driving ...

  3. A beam source model for scanned proton beams

    International Nuclear Information System (INIS)

    A beam source model, i.e. a model for the initial phase space of the beam, for scanned proton beams has been developed. The beam source model is based on parameterized particle sources with characteristics found by fitting towards measured data per individual beam line. A specific aim for this beam source model is to make it applicable to the majority of the various proton beam systems currently available or under development, with the overall purpose to drive dose calculations in proton beam treatment planning. The proton beam phase space is characterized by an energy spectrum, radial and angular distributions and deflections for the non-modulated elementary pencil beam. The beam propagation through the scanning magnets is modelled by applying experimentally determined focal points for each scanning dimension. The radial and angular distribution parameters are deduced from measured two-dimensional fluence distributions of the elementary beam in air. The energy spectrum is extracted from a depth dose distribution for a fixed broad beam scan pattern measured in water. The impact of a multi-slab range shifter for energy modulation is calculated with an own Monte Carlo code taking multiple scattering, energy loss and straggling, non-elastic and elastic nuclear interactions in the slab assembly into account. Measurements for characterization and verification have been performed with the scanning proton beam system at The Svedberg Laboratory in Uppsala. Both in-air fluence patterns and dose points located in a water phantom were used. For verification, dose-in-water was calculated with the Monte Carlo code GEANT 3.21 instead of using a clinical dose engine with approximations of its own. For a set of four individual pencil beams, both with the full energy and range shifted, 96.5% (99.8%) of the tested dose points satisfied the 1%/1 mm (2%/2 mm) gamma criterion

  4. Bessel Beams

    OpenAIRE

    McDonald, Kirk T

    2000-01-01

    Scalar Bessel beams are derived both via the wave equation and via diffraction theory. While such beams have a group velocity that exceeds the speed of light, this is a manifestation of the "scissors paradox" of special relativty. The signal velocity of a modulated Bessel beam is less than the speed of light. Forms of Bessel beams that satisfy Maxwell's equations are also given.

  5. CTF3 Probe Beam LINAC Commissioning and Operations

    CERN Document Server

    Farabolini, W; Curtoni, A; Girardot, P; Peauger, F; Simon, C S; Chevallay, E; Divall Csatari, M; Lebas, N; Petrarca, M; Palaia, A; Ruber, R J M Y; Ziemann, V G

    2010-01-01

    The probe beam LINAC, CAL­IFES, of the CLIC Test Fa­cil­i­ty (CTF3) has been de­vel­oped by CEA Saclay, LAL Orsay and CERN to de­liv­er trains of short bunch­es (0.75 ps) spaced by 0.666 ps at an en­er­gy around 170 MeV with a charge of 0.6 nC to the TBTS (Two-beam Test Stand) in­tend­ed to test the high gra­di­ent CLIC ac­cel­er­at­ing struc­tures. Based on 3 for­mer LIL ac­cel­er­at­ing struc­tures and on a newly de­vel­oped RF pho­to-in­jec­tor, the whole ac­cel­er­a­tor is pow­ered with a sin­gle 3 GHz klystron de­liv­er­ing puls­es of 45 MW through a RF pulse com­pres­sion cav­i­ty and a net­work of waveg­uides, split­ters, phase-shifters and an at­ten­u­a­tor. We re­late here re­sults col­lect­ed dur­ing the var­i­ous com­mis­sion­ing and op­er­a­tion pe­ri­ods which led to nom­i­nal per­for­mances and sta­ble beam char­ac­ter­is­tics de­liv­ered to the TBTS. Progress has been made in the laser sys­tem for beam charge and sta...

  6. Progress in direct-drive inertial confinement fusion

    Directory of Open Access Journals (Sweden)

    McCrory R.L.

    2013-11-01

    Full Text Available Significant progress has been made in direct-drive inertial confinement fusion research at the Laboratory for Laser Energetics since the 2009 IFSA Conference [R.L. McCrory et al., J. Phys.: Conf. Ser. 244, 012004 (2010]. Areal densities of 300mg/cm2 have been measured in cryogenic target implosions with neutron yields 15% of 1-D predictions. A model of crossed-beam energy transfer has been developed to explain the observed scattered-light spectrum and laser–target coupling. Experiments show that its impact can be mitigated by changing the ratio of the laser beam to target diameter. Progress continues in the development of the polar-drive concept that will allow direct-drive–ignition experiments to be conducted on the National Ignition Facility using the indirect-drive-beam layout.

  7. Multiple-beam laser–plasma interactions in inertial confinement fusion

    International Nuclear Information System (INIS)

    The experimental evidence for multiple-beam laser-plasma instabilities of relevance to laser driven inertial confinement fusion at the ignition scale is reviewed, in both the indirect and direct-drive approaches. The instabilities described are cross-beam energy transfer (in both indirectly driven targets on the NIF and in direct-drive targets), multiple-beam stimulated Raman scattering (for indirect-drive), and multiple-beam two-plasmon decay instability (in direct drive). Advances in theoretical understanding and in the numerical modeling of these multiple beam instabilities are presented

  8. [Drug use and driving].

    Science.gov (United States)

    Lemaire-Hurtel, Anne-Sophie; Goullé, Jean-Pierre; Alvarez, Jean-Claude; Mura, Patrick; Verstraete, Alain G

    2015-10-01

    Some drugs are known to impair driving because they can change the vision or hearing, and/or disrupt the intellectual or motor abilities: impaired vigilance, sedation, disinhibition effect, the coordination of movement disorders and the balance. The doctor during prescribing and the pharmacist during deliverance of drug treatment should inform their patients of the potential risks of drugs on driving or operating machinery. The driver has direct responsibility, who hired him and him alone, to follow the medical advice received. The pictograms on the outer packaging of medicinal products intended to classify substances according to their risk driving: The driver can whether to observe simple precautions (level one "be prudent"), or follow the advice of a health professional (level two "be very careful"), or if it is totally not drive (level three "danger caution: do not drive"). This classification only evaluates the intrinsic danger of drugs but not the individual variability. Medicines should be taken into account also the conditions for which the medication is prescribed. It is important to inform the patient on several points. PMID:25956300

  9. Control rod drives

    International Nuclear Information System (INIS)

    Purpose: To fix a magnetic rotor to a drive shaft and at the time of non-driving, to restrain the rotor by permanent magnets thereby to hold the position of the control rod safely and accurately. Constitution: A control rod position holding device is provided in a motor or a drive shaft of a control rod drive. This device consists of a rotor and a stator, the rotor being provided on its circumference with salient-poles arranged equidistantly, and the position of the rotor being determined depending upon the transfer distance of the control rod and the conversion ratio of the converter. On the other hand, the stator has salient-poles (any of them is a permanent magnet) having the number of poles and the positional relationship equivalent to those of the rotor, and provided in the inner periphery of a cylinder using the drive shaft as a central shaft and wound with a winding. When the control rod is not driven, the poles of the rotor are attracted by the magnetic force of the confronting poles of the stator, thereby to prevent the inverse rotation of the motor shaft due to the dead weight of the control rod. When a current is caused to flow through the winding, the magnetic force of the permanent magnet, and the stator release the rotor. (Yoshino, Y.)

  10. 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

  11. Ceramic vane drive joint

    Science.gov (United States)

    Smale, Charles H. (Inventor)

    1981-01-01

    A variable geometry gas turbine has an array of ceramic composition vanes positioned by an actuating ring coupled through a plurality of circumferentially spaced turbine vane levers to the outer end of a metallic vane drive shaft at each of the ceramic vanes. Each of the ceramic vanes has an end slot of bow tie configuration including flared end segments and a center slot therebetween. Each of the vane drive shafts has a cross head with ends thereof spaced with respect to the sides of the end slot to define clearance for free expansion of the cross head with respect to the vane and the cross head being configured to uniformly distribute drive loads across bearing surfaces of the vane slot.

  12. Gears and gear drives

    CERN Document Server

    Jelaska, Damir T

    2012-01-01

    Understanding how gears are formed and how they interact or 'mesh' with each other is essential when designing equipment that uses gears or gear trains. The way in which gear teeth are formed and how they mesh is determined by their geometry and kinematics, which is the topic of this book.  Gears and Gear Drives provides the reader with comprehensive coverage of gears and gear drives. Spur, helical, bevel, worm and planetary gears are all covered, with consideration given to their classification, geometry, kinematics, accuracy control, load capacity and manufacturing. Cylindric

  13. Toyota hybrid synergy drive

    Energy Technology Data Exchange (ETDEWEB)

    Gautschi, H.

    2008-07-01

    This presentation made at the Swiss 2008 research conference on traffic by Hannes Gautschi, director of service and training at the Toyota company in Switzerland, takes a look at Toyota's hybrid drive vehicles. The construction of the vehicles and their combined combustion engines and electric generators and drives is presented and the combined operation of these components is described. Braking and energy recovery are discussed. Figures on the performance, fuel consumption and CO{sub 2} output of the hybrid vehicles are compared with those of conventional vehicles.

  14. Permanent magnet brushless drives

    OpenAIRE

    Chan, CC; Xia, W.; Jiang, JZ; Chau, KT; Zhu, ML

    1998-01-01

    The purpose of this paper is to present an optimal efficiency control scheme for constant power operation of phase decoupling (PD) PM brushless DC motor drives. The key is to adaptively adjust the advanced conduction angle to minimize the system losses for a given operation point in the constant power region. The strategy for constant power operation of PD PM brushless DC motor drives is exemplified using a 5-phase 22-pole PD PM brushless DC motor. In the sections that follow, the newly-devel...

  15. Review of the experimental papers at the IAEA conference on noninductive current drive, Culham, 1983

    International Nuclear Information System (INIS)

    Three types of noninductive current drive experiments have been reported at this conference: (1) neutral beam (2) rf current drive, and (3) relativistic electron beams (REB). If we compare the effort to develop current drive to a horse race, the neutral beam horse was first out of the gates, but it quickly found greener pastures (heating) and has dropped temporarily out of the race. The lower hybrid horse now has a big lead at the first furlong (200 m), but the bulk of the race remains to be run. The fast wave and REB horses have yet to get up speed

  16. Review of the experimental papers at the IAEA conference on noninductive current drive, Culham, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Motley, R.W.

    1983-10-01

    Three types of noninductive current drive experiments have been reported at this conference: (1) neutral beam (2) rf current drive, and (3) relativistic electron beams (REB). If we compare the effort to develop current drive to a horse race, the neutral beam horse was first out of the gates, but it quickly found greener pastures (heating) and has dropped temporarily out of the race. The lower hybrid horse now has a big lead at the first furlong (200 m), but the bulk of the race remains to be run. The fast wave and REB horses have yet to get up speed.

  17. Possible Cryogenic Configurations for the Superconducting Magnets of the Damping Rings of the Compact Linear Collider (CLIC)

    CERN Document Server

    Perin, A; Russenschuck, S; Schoerling, D

    2012-01-01

    The Compact Linear Collider is a future electron-positron linear collider currently under study. Before being injected into the main linear accelerating structures, both the electron and the positron beams must pass through damping rings that will drastically reduce their emittance in all three dimensions. The required emittance reduction is achieved by passing the particle beams through alternating magnetic fields in superconducting wiggler magnets that result in the emission of intense synchrotron radiation. This article describes possible cooling schemes and possible cryogenic configurations to keep the magnets at operating temperature while removing the heat generated by the synchrotron radiation.

  18. Chaos in drive systems

    Directory of Open Access Journals (Sweden)

    Kratochvíl C.

    2007-10-01

    Full Text Available The purpose of this article is to provide an elementary introduction to the subject of chaos in the electromechanical drive systems. In this article, we explore chaotic solutions of maps and continuous time systems. These solutions are also bounded like equilibrium, periodic and quasiperiodic solutions.

  19. Magnetized drive fluids

    Energy Technology Data Exchange (ETDEWEB)

    Rosensweig, R.E.; Zahn, M.

    1986-04-01

    A process is described for recovering a first fluid from a porous subterranean formation which comprises injecting a displacement fluid in an effective amount to displace the first fluid, injecting a ferrofluid, applying a magnetic field containing a gradient of field intensity within the formation, driving the displacement fluid through the formation with the ferrofluid and recovering first fluid.

  20. Gaze-controlled Driving

    DEFF Research Database (Denmark)

    Tall, Martin; Alapetite, Alexandre; San Agustin, Javier;

    2009-01-01

    We investigate if the gaze (point of regard) can control a remote vehicle driving on a racing track. Five different input devices (on-screen buttons, mouse-pointing low-cost webcam eye tracker and two commercial eye tracking systems) provide heading and speed control on the scene view transmitted...

  1. Control rod drives

    International Nuclear Information System (INIS)

    Purpose: To prevent damages in control rod drives upon connection and disconnection with control rods by providing, to an extension rod, a closure and opening guide mechanism which is adapted to open and close depending upon connection and disconnection with the control rod. Constitution: In control rod drives having a driving section and a lower mechanism, the lower mechanism has a guide tube engaged into the upper cover of a reactor container and suspended therefrom into the reactor container. An opening and closure mechanism with guide blades capable of contacting the inner wall of the guide tube is secured to an extension rod for fastening the gripper which supports the control rod. Such a mechanism cap prevent damages in the control rod drives and the control rods due to the connection after disconnection of them by the buffering action between the extension rod and the control rod, as well as damages in both of them caused by rolling such as in earthquakes by the buffering action between the extension rod and the guide tube. (Moriyama, K.)

  2. Efficient driving; Effizientes Fahren

    Energy Technology Data Exchange (ETDEWEB)

    Dillmann, Gerhard; Prys, Gerhard; Klinkert, Carsten; Sauer, Juergen; Otasevic, Aleksandar; Steinbock, Robert [BMW Group, Muenchen (Germany)

    2008-11-15

    With the BMW Efficient Dynamics development strategy, the new BMW 7 Series is proving that a superior, dynamic driving experience with simultaneous reduction of fuel consumption and emissions can be combined with the premium standards of the luxury automobile class. (orig.)

  3. Efficiency studies of high frequency current drive

    International Nuclear Information System (INIS)

    Pulsed high power free-electron-lasers (FELs) offer new possibilities for the current drive in tokamaks. High intensity FELs apply to the excitation of nonlinear wave-wave processes, such as beat-waves (BW) and stimulated Raman scattering (SRS), in which large phase velocity (vph>>ve) electrostatic modes are generated. These can accelerate resonant electrons to high parallel velocities v||∼vph, which produces a slowly decaying current. Furthermore, the fast electrons with v||>>v are not toroidally trapped into banana orbits. The operation at high frequencies provides for the FEL beam an easy access into the plasma centre. This makes possible to suppress sawtooth activity by profile control and to expand the operational limits in parameter space. Raman and beat-wave methods apply particularly well to bootstrap current seeding, which may considerably enhance the overall current drive efficiency. Both Raman forward (SRS-F) and backward (SRS-B) scattering can be applied to current drive. At high, reactor relevant temperatures SRS-F is the dominant process, because SRS-B is suppressed due to heavy damping of the plasma wave. At temperatures of a few keV, SRS-B dominates because of its short gain length. In this report we shall estimate the current drive efficiency at temperatures relevant for MTX and for a tokamak reactor. We shall also consider the dependence of the efficiency on the peak intensity of FEL in these two cases. (author) 8 refs., 2 figs., 1 tab

  4. Beam-driven and bootstrap currents in JT-60 upgrade

    International Nuclear Information System (INIS)

    We recently performed beam-driven current-drive experiments with a low fraction of bootstrap currents in a wide range of plasma parameters in JT-60 upgrade. The evidence of current profile modification by the beam-driven current with tangential neutral beam injectors. A high βN, high βp and ELMy H-mode plasma with possibly fully non-inductive current-drive by beam-driven and bootstrap currents was maintained for a considerably long duration with the combined injection of quasi-perpendicular and co-tangential beams. (author) 4 refs., 7 figs

  5. The drive-wise project: driving simulator training increases real driving performance in healthy older drivers

    OpenAIRE

    Casutt, Gianclaudio; Theill, Nathan; Martin, Mike; Keller, Martin; Jäncke, Lutz

    2014-01-01

    Background: Age-related cognitive decline is often associated with unsafe driving behavior. We hypothesized that 10 active training sessions in a driving simulator increase cognitive and on-road driving performance. In addition, driving simulator training should outperform cognitive training. Methods: Ninety-one healthy active drivers (62–87 years) were randomly assigned to one of three groups: (1) a driving simulator training group, (2) an attention training group (vigilance and selective...

  6. Polar-direct-drive experiments on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Hohenberger, M. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Radha, P. B. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Myatt, J. F. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; LePape, S. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Marozas, J. A. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Marshall, F. J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Michel, D. T. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Regan, S. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Seka, W. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Shvydky, A. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Bates, J. W. [U. S. Naval Research Laboratory, Washington, DC 20375, USA; Betti, R. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Boehly, T. R. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Bonino, M. J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Casey, D. T. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Collins, T. J. B. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Craxton, R. S. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Delettrez, J. A. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Edgell, D. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Epstein, R. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Fiksel, G. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Fitzsimmons, P. [General Atomics, San Diego, California 92121, USA; Frenje, J. A. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Froula, D. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Goncharov, V. N. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Harding, D. R. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Kalantar, D. H. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Karasik, M. [U. S. Naval Research Laboratory, Washington, DC 20375, USA; Kessler, T. J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Kilkenny, J. D. [General Atomics, San Diego, California 92121, USA; Knauer, J. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Kurz, C. [General Atomics, San Diego, California 92121, USA; Lafon, M. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; LaFortune, K. N. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; MacGowan, B. J. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Mackinnon, A. J. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; MacPhee, A. G. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; McCrory, R. L. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; McKenty, P. W. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Meeker, J. F. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Nagel, S. R. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Nikroo, A. [General Atomics, San Diego, California 92121, USA; Obenschain, S. [U. S. Naval Research Laboratory, Washington, DC 20375, USA; Petrasso, R. D. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Ralph, J. E. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Rinderknecht, H. G. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Rosenberg, M. J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Schmitt, A. J. [U. S. Naval Research Laboratory, Washington, DC 20375, USA; Wallace, R. J. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Weaver, J. [U. S. Naval Research Laboratory, Washington, DC 20375, USA; Widmayer, C. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Skupsky, S. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Solodov, A. A. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Yaakobi, B. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA; Zuegel, J. D. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA

    2015-05-01

    To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, the polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] has been proposed. Ignition in PDD geometry requires direct-drive–specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments to study the energetics and preheat in PDD implosions at the NIF have been performed. These experiments utilize the NIF in its current configuration, including beam geometry, phase plates, and beam smoothing. Room-temperature, 2.2-mm-diam plastic shells filled with D2 gas were imploded with total drive energies ranging from ~500-750 kJ with peak powers of 120 to 180 TW and peak on-target irradiances at the initial target radius from 8 x 1014 to 1.2 x 1015 W/cm2. Results from these initial experiments are presented, including measurements of shell trajectory, implosion symmetry, and the level of hot-electron preheat in plastic and Si ablators. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray-trace to model oblique beams, and models for nonlocal electron transport and cross-beam energy transport (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data.

  7. Polar-direct-drive experiments on the National Ignition Facility

    International Nuclear Information System (INIS)

    To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, the polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] has been proposed. Ignition in PDD geometry requires direct-drive–specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments to study the energetics and preheat in PDD implosions at the NIF have been performed. These experiments utilize the NIF in its current configuration, including beam geometry, phase plates, and beam smoothing. Room-temperature, 2.2-mm-diam plastic shells filled with D2 gas were imploded with total drive energies ranging from ∼500 to 750 kJ with peak powers of 120 to 180 TW and peak on-target irradiances at the initial target radius from 8 × 1014 to 1.2 × 1015 W/cm2. Results from these initial experiments are presented, including measurements of shell trajectory, implosion symmetry, and the level of hot-electron preheat in plastic and Si ablators. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray-trace to model oblique beams, and models for nonlocal electron transport and cross-beam energy transport (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data

  8. Polar-direct-drive experiments on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Hohenberger, M.; Radha, P. B.; Myatt, J. F.; Marozas, J. A.; Marshall, F. J.; Michel, D. T.; Regan, S. P.; Seka, W.; Shvydky, A.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Fiksel, G.; Froula, D. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299 (United States); and others

    2015-05-15

    To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, the polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] has been proposed. Ignition in PDD geometry requires direct-drive–specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments to study the energetics and preheat in PDD implosions at the NIF have been performed. These experiments utilize the NIF in its current configuration, including beam geometry, phase plates, and beam smoothing. Room-temperature, 2.2-mm-diam plastic shells filled with D{sub 2} gas were imploded with total drive energies ranging from ∼500 to 750 kJ with peak powers of 120 to 180 TW and peak on-target irradiances at the initial target radius from 8 × 10{sup 14} to 1.2 × 10{sup 15 }W/cm{sup 2}. Results from these initial experiments are presented, including measurements of shell trajectory, implosion symmetry, and the level of hot-electron preheat in plastic and Si ablators. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray-trace to model oblique beams, and models for nonlocal electron transport and cross-beam energy transport (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data.

  9. Dielectric Wakefield Accelerator to drive the future FEL Light Source.

    Energy Technology Data Exchange (ETDEWEB)

    Jing, C.; Power, J.; Zholents, A. (Accelerator Systems Division (APS)); ( HEP); (LLC)

    2011-04-20

    X-ray free-electron lasers (FELs) are expensive instruments and a large part of the cost of the entire facility is driven by the accelerator. Using a high-energy gain dielectric wake-field accelerator (DWA) instead of the conventional accelerator may provide a significant cost saving and reduction of the facility size. In this article, we investigate using a collinear dielectric wakefield accelerator to provide a high repetition rate, high current, high energy beam to drive a future FEL x-ray light source. As an initial case study, a {approx}100 MV/m loaded gradient, 850 GHz quartz dielectric based 2-stage, wakefield accelerator is proposed to generate a main electron beam of 8 GeV, 50 pC/bunch, {approx}1.2 kA of peak current, 10 x 10 kHz (10 beamlines) in just 100 meters with the fill factor and beam loading considered. This scheme provides 10 parallel main beams with one 100 kHz drive beam. A drive-to-main beam efficiency {approx}38.5% can be achieved with an advanced transformer ratio enhancement technique. rf power dissipation in the structure is only 5 W/cm{sup 2} in the high repetition rate, high gradient operation mode, which is in the range of advanced water cooling capability. Details of study presented in the article include the overall layout, the transform ratio enhancement scheme used to increase the drive to main beam efficiency, main wakefield linac design, cooling of the structure, etc.

  10. FTIR spectrometer with solid-state drive system

    Science.gov (United States)

    Rajic, Slobodan; Seals, Roland D.; Egert, Charles M.

    1999-01-01

    An FTIR spectrometer (10) and method using a solid-state drive system with thermally responsive members (27) that are subject to expansion upon heating and to contraction upon cooling. Such members (27) are assembled in the device (10) so as to move an angled, reflective surface (22) a small distance. The sample light beam (13) is received at a detector (24) along with a reference light beam (13) and there it is combined into a resulting signal. This allows the "interference" between the two beams to occur for spectral analysis by a processor (29).

  11. Design and fabrication of a high-aspect-ratio parylene-based comb-drive actuator for large displacements at a low driving force

    International Nuclear Information System (INIS)

    This paper presents a comb-drive actuator integrated with parylene-based flexible beams for large displacements at a low driving force. Single-crystal silicon and polysilicon are the traditional materials used for comb-drive actuators in the microeletromechanical systems industry. However, the larger Young's modulus limits the displacement at a low applied voltage. This study uses the parylene beams with the characteristic of a low modulus of the elastic comb-drive actuator as a compliant suspension to create a larger displacement (>50 µm) with smaller driving forces than that of silicon. High-aspect-ratio parylene beams can be fabricated through the deposition and removal of parylene in multiple stages on a silicon micro-trench. The proposed process uses a silicon-on-insulator wafer as the substrate to fabricate suspended silicon and parylene beams as rigid and compliant structures, respectively. The test devices of parylene- and silicon-based comb-drive actuators were fabricated with 100 pairs of comb fingers with gaps of 5 µm, and compliant beams of 15 µm in width, 2000 µm in span and 50 µm in thickness. When a driving voltage of 40 V dc was applied, the parylene-based comb-drive actuator generated a displacement of up to 55 µm, whereas the silicon-based comb-drive actuator generated a displacement of 2 µm. The parylene-based comb-drive actuator can generate about 27 times of displacement than that of silicon. This design is suitable for application in devices with large in-plane displacement and low switching speed. (paper)

  12. Driving without a GPS

    DEFF Research Database (Denmark)

    Lauridsen, Karen M.

    the best way possible; and that the differences in their knowledge systems is acknowledged and used as an asset in these international programmes. With these factors in place, on the other hand, programmes with international faculty and diverse student audiences in which this diversity is exploited in...... an appropriate way, may have a considerable added value that positively impacts on the knowledge, skills and competences developed by their graduates. However, lecturers often feel at a loss because they are not sure how to do this and teaching becomes like driving in unknown territory without a GPS......, thereby contributing to a possible typology of challenges and solutions in international programmes from which all attendees may benefit. They will then not have to drive without a GPS, but will have a better background for navigating the international university. Singh, P. and C. Doherty (2004) “Global...

  13. Mitigating Distracted Driving

    OpenAIRE

    Cox, Tim; Kolberg, Kenny

    2014-01-01

    The scourge of distracted driving is not limited to any one demographic group or nation. It is global and affects every victim and victims’ families. This dire situation, caused largely by technology such as texting, requires technological solutions, including new traffic safety countermeasures. The transverse rumble strip, a countermeasure reinvented in 2009 as the temporary portable rumble strip, is already proving a significant, innovative addition to work zone safety processes and procedu...

  14. Driving on the Descartes

    Science.gov (United States)

    1972-01-01

    Astronaut John W. Young, Apollo 16 mission commander, drives the 'Rover', Lunar Roving Vehicle (LRV) to its final parking place near the end of the third extravehicular activity (EVA-3) at the Descartes landing site. Astronaut Charles M. Duke Jr., Lunar Module pilot, took this photograph looking southward. The flank of Stone Mountain can be seen on the horizon at left. The shadow of the Lunar Module 'Orion' is visible in the foreground.

  15. Driving and Neurodegenerative Diseases

    OpenAIRE

    Uc, Ergun Y.; Rizzo, Matthew

    2008-01-01

    The proportion of elderly in the general population is rising, resulting in greater numbers of drivers with neurodegenerative disorders such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). These neurodegenerative disorders impair cognition, visual perception, and motor function, leading to reduced driver fitness and greater crash risk. Yet medical diagnosis or age alone is not reliable enough to predict driver safety or crashes, or revoke the driving privileges of these drivers. Dri...

  16. Jet Reconstruction and Kinematic Fitting of the Top Quark Pair Production at CLIC at √s = 3 TeV

    CERN Document Server

    Galy-Fajou, Theo; Bay, Aurelio

    Top quark physics, due to its possible link with new physics, is a critical topic now that the Standard Model has been experimentally verified. A complete method to reconstruct top quarks pairs at the proposed Compact LInear Collider project is presented here. In this study, MC generated events of e+e− → tt have been used to tune and optimize algorithms in order to reconstruct faithfully the decay products of the top quarks. An emphasis is made on the flavour identification of the jets since it is critical to identify correctly identify the jets to remove most of the background. The reconstructed jets are fitted to the topology with the KLFitter algorithms that have been adapted for CLIC. Using a multi-variable analysis, it finds the best permutation of jets with the best set of parameters using the kinematics of the event. The results of this technique applied on a sample of 49500 e+e− → tt events (corresponding to 850 fb−1 at √s = 3 TeV) is presented here.

  17. Control rod drives

    International Nuclear Information System (INIS)

    Purpose: To enable fine positioning by using an induction motor of a simple structure as a driving source and thereby improve the reliability of control rod drives. Constitution: A step actuator is directly coupled with an induction motor, in which the induction motor is connected by way of a pulse driving control circuit to an AC power source, while the step actuator is connected to a DC power source. When a thyristor is turned ON, the motor outputs a positive torque and rotates and starts to rotate in the forward direction. When the other thyristor is turned ON, the motor is applied with braking by a reverse excitation in a manner equivalent to the change for the exciting phase sequence. When the speed is lowered to a predetermined value, braking is actuated by the torque of the step actuator and the motor stops at a zero position or balanced position. In this way, braking is actuated from the decelerating step to the stopping with no abrasion and a highly accurate positioning is possible due to the characteristics of the step actuator. (Horiuchi, T.)

  18. Control rod drive mechanisms

    International Nuclear Information System (INIS)

    Purpose: To accurately measure the loads generated upon scram and judge the absence or presence of deceleration in control rod drive mechanisms. Constitution: Control rod drive mechanisms for use in a BWR type reactor includes an index tube vertically movably, connected at the upper end to the control rod and having a drive piston at the lower end. A piezoelectric member for detecting the load generated upon uprise of the index tube is disposed and signals from the piezoelectric member is connected to a calculation processing device. A load exerted when the index tube uprises is measured by way of the piezoelectric member upon scram thereby judging the absence or presence of the decelerating operation. Therefore, the nuclear reactor can be shutdown only when it is required with no excess safety operation than required. As a result, the reactor availability can be improved and, in addition, it is also possible to mitigate the burden of in-service inspection and reduce the operators' exposure. (Kamimura, M.)

  19. Control rod drive

    International Nuclear Information System (INIS)

    Object: To provide a simple and compact construction of an apparatus for driving a drive shaft inside with a magnetic force from the outside of the primary system water side. Structure: The weight of a plunger provided with an attraction plate is supported by a plunger lift spring means so as to provide a buffer action at the time of momentary movement while also permitting the load on lift coil to be constituted solely by the load on the drive shaft. In addition, by arranging the attraction plate and lift coil so that they face each other with a small gap there-between, it is made possible to reduce the size and permit efficient utilization of the attracting force. Because of the small size, cooling can be simply carried out. Further, since there is no mechanical penetration portion, there is no possibility of leakage of the primary system water. Furthermore, concentration of load on a latch pin is prevented by arranging so that with a structure the load of the control rod to be directly beared through the scrum latch. (Kamimura, M.)

  20. Control rod drive system

    International Nuclear Information System (INIS)

    The present invention concerns an electromotive driving-type control rod driving system of a BWR type reactor, for which sliding resistance (friction) test can be performed of a movable portion of the control rod driving mechanisms. Namely, a hydraulic pressure control unit has following constitutions in addition to a conventional constitution as a sliding resistance test performing function. (1) A restricting valve is disposed downstream of the scram valve of scram pipelines to control flow rate and pressure of pressurized water flown in the pipelines. (2) A pressure gauge detects a pressure between the scram valve and the restricting valve. (3) A flow meter detects the flow rate of pipelines controlled by the restricting valve. (4) A recording pressure detector detects the pressure at the downstream of the restricting valve. (5) The recording device is attached when the sliding resistant test is performed for tracing the pressure measured by the pressure detection device. Further, the scram valve sends electric signals to a central operation chamber when it is fully closed. The central operation chamber has a function of fully opening the restricting valve by way of the electric signals. (I.S.)

  1. Beam - cavity interaction beam loading

    International Nuclear Information System (INIS)

    The interaction of a beam with a cavity and a generator in cyclic accelerators or storage rings is investigated. Application of Maxwell's equations together with the nonuniform boundary condition allows one to get an equivalent circuit for a beam-loaded cavity. The general equation for beam loading is obtained on the basis of the equivalent circuit, and the beam admittance is calculated. Formulas for power consumption by a beam-loaded cavity are derived, and the optimal tuning and coupling factor are analyzed. (author)

  2. Constructing a Distracted Driving Dataset

    OpenAIRE

    Foley, James; Ebe, Kazu; Owens, Justin M.; Angell, Linda; Hankey, Jonathan M.

    2014-01-01

    Distracted driving has become a topic of critical importance to driving safety research over the past several decades. Naturalistic driving data offer a unique opportunity to study how drivers engage with secondary tasks in real-world driving; however, the complexities involved with identifying and coding relevant epochs of naturalistic data have limited its accessibility to the general research community. Method This project was developed to help address this problem by creating an accessibl...

  3. Frozen Beams

    CERN Document Server

    Okamoto, Hiromi

    2005-01-01

    In general, the temperature of a charged particle beam traveling in an accelerator is very high. Seen from the rest frame of the beam, individual particles randomly oscillate about the reference orbit at high speed. This internal kinetic energy can, however, be removed by introducing dissipative interactions into the system. As a dissipative process advances, the beam becomes denser in phase space or, in other words, the emittance is more diminished. Ideally, it is possible to reach a "zero-emittance" state where the beam is Coulomb crystallized. The space-charge repulsion of a crystalline beam just balances the external restoring force provided by artificial electromagnetic elements. In this talk, general discussion is made of coasting and bunched crystalline beams circulating in a storage ring. Results of molecular dynamics simulations are presented to demonstrate the dynamic nature of various crystalline states. A possible method to approach such an ultimate state of matter is also discussed.

  4. LHC Report: Beam on

    CERN Multimedia

    Rossano Giachino for the LHC Team

    2012-01-01

    The powering tests described in the last edition of the Bulletin were successfully finished at the end of the first week of March opening the way for 4 TeV operations this year. The beam was back in the machine on Wednesday 14 March. The first collisions at 4 TeV are scheduled for the first week of April.   The first beam of 2012 is dumped after making a few rounds in the LHC. The magnet powering tests were followed by the machine checkout phase. Here the operations team in collaboration with the equipment groups performs a sequence of tests to ensure the readiness of the LHC for beam. The tests include driving all the LHC systems – beam dump, injection, collimation, RF, power converters, magnet circuits, vacuum, interlocks, controls, timing and synchronization – through the operational cycle. The “checkout phase” is really a massive de-bugging exercise, which is performed with the objective of ensuring the proper functioning of the whole machine and t...

  5. Active steering of laser-accelerated ion beams

    International Nuclear Information System (INIS)

    A technique for optical control of the spatial distribution of laser-accelerated ion beams is presented. An ultrashort laser pulse, tightly focused to relativistic intensities on a thin foil target, drives a beam of MeV ions. An auxiliary, nanosecond laser pulse drives a shock and locally deforms the initially flat target prior to the main pulse interaction. By changing the properties of the shock-driving laser pulse, the normal direction of the ion emitting surface is locally manipulated and the emission direction is thereby controlled. In the future, this method could be used to achieve dynamic control of the ion beam divergence

  6. Nuclear refueling platform drive system

    International Nuclear Information System (INIS)

    This patent describes a drive system. It comprises: a gantry including a bridge having longitudinal and transverse axes and supported by spaced first and second end frames joined to fist and second end frames joined to first and second drive trucks for moving the bridge along the transverse axis; first means for driving the first drive truck; second means for driving the second drive truck being independent from the first driving means; and means for controlling the first and second driving means for reducing differential transverse travel between the first and second drive trucks, due to a skewing torque acting on the bridge, to less than a predetermined maximum, the controlling means being in the form of an electrical central processing unit and including: a closed-loop first velocity control means for controlling velocity of the first drive truck by providing a first command signal to the first driver means; a close loop second velocity control means for controlling velocity of the second drive truck by providing a second command signal to the second driving means; and an auxiliary closed-loop travel control means

  7. Beam loading

    CERN Document Server

    Gamp, Alexander

    2013-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed.

  8. Offset Compound Gear Drive

    Science.gov (United States)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  9. Electric drive design methodology

    CERN Document Server

    Jufer, Marcel

    2013-01-01

    An electric drive that is designed or adapted to a specific application must take into account all the elements of the chain of constituent elements in its use and deployment. In addition to the motor, the transmission, power electronics, control, sensors, and electrical protection systems must be taken into account. The motor and the transmission can be optimized and designed to obtain the best energy efficiency assessment, in particular for dynamic nodes. An inventory and a characterization of these various components is proposed as part of this book's examination and explanation

  10. Electrical machines & drives

    CERN Document Server

    Hammond, P

    1985-01-01

    Containing approximately 200 problems (100 worked), the text covers a wide range of topics concerning electrical machines, placing particular emphasis upon electrical-machine drive applications. The theory is concisely reviewed and focuses on features common to all machine types. The problems are arranged in order of increasing levels of complexity and discussions of the solutions are included where appropriate to illustrate the engineering implications. This second edition includes an important new chapter on mathematical and computer simulation of machine systems and revised discussions o

  11. Modular droplet actuator drive

    Science.gov (United States)

    Pollack, Michael G. (Inventor); Paik, Philip (Inventor)

    2011-01-01

    A droplet actuator drive including a detection apparatus for sensing a property of a droplet on a droplet actuator; circuitry for controlling the detection apparatus electronically coupled to the detection apparatus; a droplet actuator cartridge connector arranged so that when a droplet actuator cartridge electronically is coupled thereto: the droplet actuator cartridge is aligned with the detection apparatus; and the detection apparatus can sense the property of the droplet on a droplet actuator; circuitry for controlling a droplet actuator coupled to the droplet actuator connector; and the droplet actuator circuitry may be coupled to a processor.

  12. PURE DRIVE GT

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    在2004年奥林匹克赛事中,中国的李婷,孙甜甜取得了中国网球第一个金牌一女子双打冠军。忘记不了当时李婷挥动着她的BABOLAT(百保力)网拍Pure Drive Zylon 360°激动地拥抱着孙甜甜吵闹着,幸福地哭着的情景。

  13. Progress toward direct drive laser fusion

    International Nuclear Information System (INIS)

    This chapter reviews the recent progress in the three inter-related areas of irradiation uniformity, coronal physics and ablatively driven spherical shell implosions, all of immediate relevance to direct drive laser fusion. Diagnosis of the fuel during the implosion and at final compression, including direct measurement of fuel density-radius product is made through a variety of techniques involving space, time and spectral x-ray analysis and scattered reaction product spectrometry. The 24-beam OMEGA, Nd:glass laser system operating with 2-3 kJ, 1 ns, 1.054 μm pulses has been used to examine a number of physics issues central to the success of direct drive laser fusion. This system provides the capability to irradiate spherical targets with a high degree of irradiation uniformity with precisely temporally and spatially aligned beams on target. The technical progress made in perfecting the output characteristics of OMEGA, and the formulation of an approach to define multibeam uniformity in spherical geometry, provide some optimism that the factor of 4-5 improvement in irradiation uniformity necessary for high performance targets can be attained. The coronal physics experiments performed under spherical geometric irradiation reveal shortcomings in the current understanding of electron energy transport. Includes 13 photos and 4 drawings

  14. Cross-Beam Energy Transfer Driven by Incoherent Laser Beams with Frequency Detuning

    Science.gov (United States)

    Maximov, A.; Myatt, J. F.; Short, R. W.; Igumenshchev, I. V.; Seka, W.

    2015-11-01

    In the direct-drive method of the inertial confinement fusion (ICF), the coupling of laser energy to target plasmas is strongly influenced by the effect of cross-beam energy transfer (CBET) between multiple driving laser beams. The laser -plasma interaction (LPI) model of CBET is based on the nonparaxial laser light propagation coupled with the low-frequency ion-acoustic-domain plasma response. Common ion waves driven by multiple laser beams play a very important role in CBET. The effect of the frequency detuning (colors) in the driving laser beams is studied and it is shown to significantly reduce the level of common ion waves and therefore the level of CBET. The differences between the LPI-based CBET model and the ray-based CBET model used in hydrocodes are discussed. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  15. Conceptual Design of Neutral Beam Injection System for EAST

    Science.gov (United States)

    Hu, Chundong; NBI Team

    2012-06-01

    Neutral beam injection (NBI) system with two neutral beam injections will be constructed on the Experimental Advanced Superconducting Tokamak (EAST) in two stages for high power auxiliary plasmas heating and non-inductive current drive. Each NBI can deliver 2~4 MW beam power with 50~80 keV beam energy in 10~100 s pulse length. Each elements of the NBI system are presented in this contribution.

  16. Cycloconverter drive systems. Cycloconverter gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Chiashi, M.; Osawa, H.; Endo, K. (Fuji Electric Co. Ltd., Tokyo (Japan))

    1991-10-10

    Fuji Electric has completed preparation for the production of various cycloconverter variable-speed AC drive systems used for low-speed large-capacity drives, and is ready to supply the optimum system to meet purposes. Among cycloconverter drive systems of Fuji Electric, circulating current-free cycloconverter fed synchronous motor drive is superior in respect of input power factor and equipment capacity, induction motor drive is superior in respect of maintenance, and circulating current cycloconverter fed motor drive is superior in respect of controllability. This report describes outlines, system components, comparison of performances, control systems and their characteristics, and technology for advanced performance of these various cycloconverter drive systems. Furthermore, was introduced a development of hybrid cycloconverter using a GTO thyristor which can regulate input power factor at 1. 2 refs., 14 figs., 1 tab.

  17. Control rod drives

    International Nuclear Information System (INIS)

    Purpose: To rapidly detect the position to which a control rod has been rapidly inserted into the reactor core upon scram in the control rod drives for use in LMFBR type reactors. Constitution: In control rod drives comprising an acceleration spring disposed to the outside of an extension pipe and an acceleration pipe for conducting the spring force to a control rod for rapidly dropping the rod into the reactor core, a magnet having a repulsive force is disposed to each acceleration pipe and guide pipe as decelerating and buffering means for the acceleration pipe. The position of the control rod is detected by the interaction between the magnet and the coils attached to the inside of the guide pipe or reactor lead switch. According to this invention, 85 % scram signal which has hitherto been difficult to be processed electrically can be obtained with a sufficient intensity and with no delay to thereby improve the entire safety of the reactor system. Then, the inserted position and the insertion time can accurately and rapidly be detected. (Horiuchi, T.)

  18. Turbulent current drive

    International Nuclear Information System (INIS)

    The Ohm's law is modified when turbulent processes are accounted for. Besides an hyper-resistivity, already well known, pinch terms appear in the electron momentum flux. Moreover it appears that turbulence is responsible for a source term in the Ohm's law, called here turbulent current drive. Two terms contribute to this source. The first term is a residual stress in the momentum flux, while the second contribution is an electro-motive force. A non zero average parallel wave number is needed to get a finite source term. Hence a symmetry breaking mechanism must be invoked, as for ion momentum transport. E × B shear flows and turbulence intensity gradients are shown to provide similar contributions. Moreover this source term has to compete with the collision friction term (resistivity). The effect is found to be significant for a large scale turbulence in spite of an unfavorable scaling with the ratio of the electron to ion mass. Turbulent current drive appears to be a weak effect in the plasma core, but could be substantial in the plasma edge where it may produce up to 10 % of the local current density

  19. B-factory via conversion of 1-TeV electron beams into 1-TeV photon beams

    International Nuclear Information System (INIS)

    This paper reports on the study of CP violation and rare decays of beauty particles which are pressing problems in high-energy physics. It is known that one should analyze beauty decays of at least the order of 108 or 199. Thus, numerous proposals for beauty factories are being discussed now, although some of these projects are likely to supply much smaller numbers of beauty events. At the same time, at present several projects, such as CLIC (Cern Linear Collider), expect to build linear e+e- colliders with beam energies up to 1 TeV. The aim of this work is to show that the possibility exists of using the unique features of the discussed teraelectron volt electron linacs to obtain a facility for the production of beauty via photoproduction of nuclei. Unique features of high-energy photoproduction are as follows. The rather large fraction (∼2 x 10-4) of events with beauty at Eγ ∼ 1 TeV. Beauty particles are produced with about equally large momenta ∼0.05 Eγ and at rather large transverse momenta p t ∼ mb. The following scheme can be envisioned. The 1-TeV electron beam is Compton scattered off a low-energy (∼ 1-eV) laser pulse. The laser photons are thus converted into a highly collimated beam of energy Eγ ∼ Ee, directed along the electron's original line of motion. Such schemes to produce high-energy photon beams have been discussed. These 1-TeV photons are subsequently scattered onto a nuclear target to produce b bar b pairs

  20. Beam Instabilities

    CERN Document Server

    Rumolo, G

    2014-01-01

    When a beam propagates in an accelerator, it interacts with both the external fields and the self-generated electromagnetic fields. If the latter are strong enough, the interplay between them and a perturbation in the beam distribution function can lead to an enhancement of the initial perturbation, resulting in what we call a beam instability. This unstable motion can be controlled with a feedback system, if available, or it grows, causing beam degradation and loss. Beam instabilities in particle accelerators have been studied and analysed in detail since the late 1950s. The subject owes its relevance to the fact that the onset of instabilities usually determines the performance of an accelerator. Understanding and suppressing the underlying sources and mechanisms is therefore the key to overcoming intensity limitations, thereby pushing forward the performance reach of a machine.

  1. What is strenuous? Driving itself or the driving situation?

    OpenAIRE

    Schießl, Caroline; Vollrath, Mark; Altmüller, Tobias; Dambier, Michael; Kornblum, Christian

    2006-01-01

    To avoid driver overload, assistance systems can be adapted regarding the driver’s current strain. Physiological and performance workload measures require special sensors and are problematic concerning sensitivity and specificity. Within the presented study the driver’s stress level was estimated in real-driving based on an analysis of different driving manoeuvres and environmental factors. The analyses show that different driving manoeuvres result in significantly different subjective strain...

  2. Control rod drives

    International Nuclear Information System (INIS)

    Purpose: To improve the reliability of a device for driving an LMFBR type reactor control rod by providing a buffer unit having a stationary electromagnetic coil and a movable electromagnetic coil in the device to thereby avord impact stress at scram time and to simplify the structure of the buffer unit. Constitution: A non-contact type buffer unit is constructed with a stationary electromagnetic coil, a cable for the stationary coil, a movable electromagnetic coil, a spring cable for the movable coil, and a backup coil spring or the like. Force produced at scram time is delivered without impact by the attracting or repelling force between the stationary coil and the movable coil of the buffer unit. Accordingly, since the buffer unit is of a non-contact type, there is no mechanical impact and thus no large impact stress, and as it has simple configuration, the reliability is improved and the maintenance can be conducted more easily. (Yoshihara, H.)

  3. Magnetostrictive direct drive motors

    Science.gov (United States)

    Naik, Dipak; Dehoff, P. H.

    1992-01-01

    A new rare earth alloy, Terfenol-D, combines low frequency operation and extremely high energy density with high magnetostriction. Its material properties make it suitable as a drive element for actuators requiring high output torque. The high strains, the high forces and the high controllability of Terfenol alloys provide a powerful and challenging basis for new ways to generate motion in actuators. Two prototypes of motors using Terfenol-D rods were developed at NASA Goddard. The basic principles of operation are provided of the motor along with other relevant details. A conceptual design of a torque limiting safety clutch/brake under development is illustrated. Also, preliminary design drawings of a linear actuator using Terfenol-D is shown.

  4. Do emotions drive psychosis?

    Directory of Open Access Journals (Sweden)

    João Guilherme Ribeiro

    2013-11-01

    Full Text Available Introduction: How important is the emotional life of persons who manifest psychotic symptoms? Aims: The aim of this paper is to review evidence on a causal role for emotions in psychotic processes. Methods: Selective review of literature on affective symptoms in psychoses, on emotions in the production of psychotic symptoms and on dopaminergic models of psychosis. Results: Affective symptoms are relevant across psychoses. Persons with schizophrenia have high levels of emotional reactivity and the intensification of negative affects not only is associated with but also precedes the intensification of psychotic symptoms, which is evidence that negative emotions drive the course of psychotic symptoms. Negative self‑representations are central in psychotic processes and can be the link between negative emotions and psychosis. Evidence favours the notion that persecutory delusions are consistent with negative affects and self‑representations, while grandiose delusions are consistent with a defensive amplification of positive affects and self‑representations. Shame has been proposed as the core emotional experience of psychosis, one in which the self becomes vulnerable to the external world, which is consistent with persecutory experiences. Assaults on the self, under the form of hostility in the family environment and society, are strong predictors of relapse and development of schizophrenia. Assaults on the self which induce social defeat are also strong stimulants of mesolimbic dopaminergic pathways, whose hyperactivity is associated with acute psychotic episodes and the experience of “aberrant salience”, put forward as a dopaminergic model of psychosis. Conclusions: The “defeat of the self” emerges as a central link that binds the experience of negative emotions to the expression of psychotic symptoms and its psychological and neurobiological correlates. The hypothesis gains support that the emotions related to that defeat control

  5. Do emotions drive psychosis?

    Directory of Open Access Journals (Sweden)

    João G. Ribeiro

    2012-12-01

    Full Text Available Introduction: How important is the emotional life of persons who manifest psychotic symptoms? Aims: The aim of this paper is to review evidence on a causal role for emotions in psychotic processes. Methods: Selective review of literature on affective symptoms in psychoses, on emotions in the production of psychotic symptoms and on dopaminergic models of psychosis. Results: Affective symptoms are relevant across psychoses. Persons with schizophrenia have high levels of emotional reactivity and the intensification of negative affects not only is associated with but also precedes the intensification of psychotic symptoms, which is evidence that negative emotions drive the course of psychotic symptoms. Negative self‑representations are central in psychotic processes and can be the link between negative emotions and psychosis. Evidence favours the notion that persecutory delusions are consistent with negative affects and self‑representations, while grandiose delusions are consistent with a defensive amplification of positive affects and self‑representations. Shame has been proposed as the core emotional experience of psychosis, one in which the self becomes vulnerable to the external world, which is consistent with persecutory experiences. Assaults on the self, under the form of hostility in the family environment and society, are strong predictors of relapse and development of schizophrenia. Assaults on the self which induce social defeat are also strong stimulants of mesolimbic dopaminergic pathways, whose hyperactivity is associated with acute psychotic episodes and the experience of “aberrant salience”, put forward as a dopaminergic model of psychosis. Conclusions: The “defeat of the self” emerges as a central link that binds the experience of negative emotions to the expression of psychotic symptoms and its psychological and neurobiological correlates. The hypothesis gains support that the emotions related to that defeat control

  6. Aggressive Driving Behavior: Undergraduate Students Study

    OpenAIRE

    Rungson Chomeya

    2010-01-01

    Problem statement: The main purposes of this research were (1) to study the aggressive driving behavior of graduate students, (2) to develop aggressive driving behavior standard test, (3) to compare the aggressive driving behavior between gender, years of study, academic achievement, driving confidence and driving experience and (4) to study the relationship among aggressive driving behavior, driving confidence, driving experience and accident experience. Approach: The subjects consisted of 4...

  7. Assessment of Electron-Cyclotron-Current-Drive-Assisted Operation in DEMO

    Directory of Open Access Journals (Sweden)

    Marushchenko N.B.

    2012-09-01

    Full Text Available The achievable efficiency for external current drive through electron-cyclotron (EC waves in a demonstration tokamak reactor is discussed. Two possible reactor designs, one for steady state and one for pulsed operation, are considered. It is found that for midplane injection the achievable current drive efficiency is limited by secondharmonic absorption at levels consistent with previous studies. Propagation through the second-harmonic region can be reduced by moving the launch position to the high-field side (this can be obtained by injecting the beam from an upper port in the vacuum vessel. In this case, beam tracing calculations deliver values for the EC current drive efficiency approaching those usually reported for neutral beam current drive.

  8. Automobile Driving and Aggressive Behavior

    OpenAIRE

    Novaco, Raymond W.

    1991-01-01

    Automobile driving and aggressive behavior have had an extensive association. Themes of dominance and territoriality have long been part of automobile driving, which has also involved flagrant assaultive actions. Recent episodes of roadway violence in metropolitan areas have raised community concern about aggressive behavior in driving, although common beliefs about why such violence occurs can be seen as pseudoexplanations. Various themes in the psychology of aggression are presented as they...

  9. Quantum effects in warp drives

    OpenAIRE

    Finazzi Stefano

    2013-01-01

    Warp drives are interesting configurations that, at least theoretically, provide a way to travel at superluminal speed. Unfortunately, several issues seem to forbid their realization. First, a huge amount of exotic matter is required to build them. Second, the presence of quantum fields propagating in superluminal warp-drive geometries makes them semiclassically unstable. Indeed, a Hawking-like high-temperature flux of particles is generated inside the warp-drive bubble, which causes an expon...

  10. Searching in Lists While Driving

    OpenAIRE

    Koerner, Julia

    2006-01-01

    More and more in-vehicle systems are rapidly becoming commercially available, making the driving task more and more complex. Driving performance in such multiple-task situations depends primarily on the level of task demands imposed on the driver by certain situations. The higher the perceived task difficulty, the higher the workload level of that individual. The aim of this dissertation was therefore to investigate possible trade-offs between primary task (driving) and secondary task (se...

  11. The Drive-Wise Project: Driving Simulator Training increases real driving performance in healthy older drivers

    Directory of Open Access Journals (Sweden)

    Gianclaudio Casutt

    2014-05-01

    Full Text Available Background: Age-related cognitive decline is often associated with unsafe driving behavior. We hypothesized that 10 active training sessions in a driving simulator increase cognitive and on-road driving performance. In addition, driving simulator training should outperform cognitive training.Methods: Ninety-one healthy active drivers (62 – 87 years were randomly assigned to either (1 a driving simulator training group, (2 an attention training group (vigilance and selective attention, or (3 a control group. The main outcome variables were on-road driving and cognitive performance. Seventy-seven participants (85% completed the training and were included in the analyses. Training gains were analyzed using a multiple regression analysis with planned comparisons.Results: The driving simulator training group showed an improvement in on-road driving performance compared to the attention training group. In addition, both training groups increased cognitive performance compared to the control group. Conclusion: Driving simulator training offers the potential to enhance driving skills in older drivers. Compared to the attention training, the simulator training seems to be a more powerful program for increasing older drivers’ safety on the road.

  12. Motor Integrated Variable Speed Drives

    DEFF Research Database (Denmark)

    Singh, Yash Veer

    A new trend in the variable speed drives (VSDs) is to develop fully integrated systems, which lead to low-cost products with shorter design cycles. Motor Integrated design of VSDs will reduce cable length to connect drive with machine windings and installation time for end user. The electric drives...... converter losses and its size so it can fit inside the motor housing. Weight and volume of a filter inductor has to come down drastically to make it a suitable power converter for motor integrated variable speed drives. Introduction of active power electronic switches can ensure very high performance and...

  13. Molecular beams

    International Nuclear Information System (INIS)

    This book is a timeless and rather complete theoretical and experimental treatment of electric and magnetic resonance molecular-beam experiments for studying the radio frequency spectra of atoms and molecules. The theory of interactions of the nucleus with atomic and molecular fields is extensively presented. Measurements of atomic and nuclear magnetic moments, electric multipole moments, and atomic fine and hyperfine structure are detailed. Useful but somewhat outdated chapters on gas kinetics, molecular beam design, and experimental techniques are also included

  14. Design alternatives for beam halo monitors in high intensity accelerators

    CERN Document Server

    Braun, H; Corsini, R; Lefèvre, T; Schulte, Daniel; Tecker, F A; Welsch, C P

    2005-01-01

    In future high intensity, high energy accelerators it must be ensured that particle losses are minimized as activation of the vacuum chambers or other components makes maintenance and upgrade work time consuming and costly. It is imperative to have a clear understanding of the mechanisms that can lead to halo formation and to have the possibility to test available theoretical models with an adequate experimental setup. Optical transition radiation (OTR) provides an interesting opportunity for linear real-time measurements of the transverse beam profile with a resolution which has been so far at best in the some μm range. However, the dynamic range of standard OTR systems is typically limited and needs to be improved for its application for halo measurements. In this contribution, the existing OTR system as it is installed in the CLIC test facility (CTF3) is analyzed and the contribution of each component to the final image quality discussed. Finally, possible halo measurement techniques based on OTR are pres...

  15. 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

  16. Beam instrumentation for an ISOL test stand

    International Nuclear Information System (INIS)

    TRIUMF is constructing a test bed for the first stages of the proposed TISAC accelerated radioactive beam facility. We will present the requirements for the diagnostic system for this test stand and describe the design and development work underway. Scintillators, beamstops and Faraday Cup have been tested using stable, mass analyzed, 12 keV beams of ions from mass 14 to 132. The design of a linear drive, with 10 μm resolution, for scanning wires and slits has begun. (author)

  17. Applications of neutral beam and rf technologies

    International Nuclear Information System (INIS)

    This presentation provides an update on the applications of neutral beams and radiofrequency (rf) power in the fusion program; highlights of the ion cyclotron heating (ICH) experiments now in progress, as well as the neutral beam experiments; and heating requirements of future devices and some of the available options. Some remarks on current drive are presented because this area of technology is one that is being considered for future devices

  18. Heat resistant driving coil and control rod drive mechanism

    International Nuclear Information System (INIS)

    Ceramic materials are used for each part of driving coils and used as the driving coils for a driving shaft. That is, a cylindrical bobbin having outwardly protruding flanges on the entire circumference at the upper and the lower portions is made of stainless steels. Ceramics sheets are appended as necessary to the outer circumferential surface of the bobbin. Then, ceramic electric wires are wound around the outer circumference of the bobbin by a required number of turns to constitute coils. The electric wire is prepared by coating the conductor of nickel-plated copper with ceramic coating material, disposing an insulation material to the outer circumference thereof the further coating the outside with ceramic coating material. This can improve the heat resistance and, since the control rod drives using such heat resistant driving coils can operate at a high temperature. It requires no cooling device and can simplify the reactor and its peripheral structures. (T.M.)

  19. Electric motor drive unit, especially adjustment drive for vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Litterst, P.

    1980-05-29

    An electric motor drive unit, particularly an adjustment drive for vehicles with at least two parallel drive shafts is described, which is compact and saves space, and whose manufacturing costs are low compared with those of well-known drive units of this type. The drive unit contains a suitable number of magnet systems, preferably permanent magnet systems, whose pole axes are spaced and run parallel. The two pole magnet systems have diametrically opposite shell-shaped segments, to which the poles are fixed. In at least one magnet system the two segments are connected by diametrically opposite flat walls parallel to the pole axes to form a single magnetic circuit pole housing. The segments of at least one other magnet system are arranged on this pole housing so that one of these flat walls is a magnetically conducting, connecting component of the magnetic circuit of the other magnet system.

  20. Detonation drive pellet injector

    International Nuclear Information System (INIS)

    Detonation drive pellet injector has been developed and tested. By this method the free piston is not necessary because the pellet accelerated the high pressure shock directly. In the experiment, the Teflon pellet (5 mm dia., 5 mm length) was accelerated by hydrogen, oxygen and dilution gas mixtured detonation. When the gas pressure was only 500 kPa and the mixture rates of hydrogen, oxygen and helium were 3:6:1 or 3:6:0, the Teflon pellet speed was up to 747 m/s. Typical experimental results over 300 kPa of the initial gas pressure range are 78--92% of the one-dimensional calculational values. It showed that the pellet could be accelerated by a relative low pressure gas. When the helium dilution rate is larger than 20%, it was often found the strong detonation of which speed is more than the Chapman-Jouguet speed. Then the pellet speed above 1,100 m/s was obtained

  1. Beam emittance and beam disruption

    International Nuclear Information System (INIS)

    Beam disruption during the collision of intense relativistic bunches has been studied by R. Hollebeek. In the case of oppositely charged bunches, focussing effects occur causing a decrease in the effective bunch cross section, and thereby an increase of luminosity by an enhancement factor H. The term disruption derives from the fact that the beam emittance changes markedly during the collision. 1 ref., 1 fig., 1 tab

  2. Induction-drive magnetohydrodynamic propulsion

    International Nuclear Information System (INIS)

    The use of magnetohydrodynamic propulsion for marine applications is reviewed with emphasis on induction-drive systems such as the open-quotes rippleclose quotes motor. Comparisons are made with direct-drive MHD propulsion systems. Application to pumps for hazardous fluids and liquid-metal coolants is also discussed. 13 refs., 8 figs., 2 tabs

  3. Distracted Driving Raises Crash Risk

    Science.gov (United States)

    ... a Seriously Ill Child Featured Website: NIDA for Teens Past Issues Most Viewed February 2014 Print RSS Find us on Facebook External link, please review our exit disclaimer . Subscribe Distracted Driving Raises Crash Risk Video technology and in-vehicle sensors showed that distracted driving, ...

  4. Driving Resistance from Railroad Trains

    DEFF Research Database (Denmark)

    Lindgreen, Erik Bjørn Grønning; Sorenson, Spencer C

    2005-01-01

    This report methods and parameters for calculating the driving resistance of railroad trains. Calculations and comparisons are presented for aerodynamic, rolling and total resistance for a variety of freight trains under different loading conditions, operating speed and configuration. Simplified...... methods are presented for the estimation of the driving resistance for passenger trains. This report is a supplement to the ARTEMIS rail emissions model....

  5. Warp Drive With Zero Expansion

    OpenAIRE

    Natario, Jose

    2001-01-01

    It is commonly believed that Alcubierre's warp drive works by contracting space in front of the warp bubble and expanding space behind it. We show that this expansion/contraction is but a marginal consequence of the choice made by Alcubierre, and explicitly construct a similar spacetime where no contraction/expansion occurs. Global and optical properties of warp drive spacetimes are also discussed.

  6. [Driving and health at work].

    Science.gov (United States)

    Giorgio, Marie-Thérèse

    2015-09-01

    The role of the occupational physician is to prevent occupational accidents and diseases. Therefore, he is the one to decide if a worker is fit to drive in the context of his professional activity, including in cases where no specific driving license is required (e.g. forklift truck, mobile crane). This decision is an important one, as two thirds of fatal occupational accidents occur on the road. The decision is made on the basis of both a medical examination and the regulation, which indicates all contraindications to driving. The physician's responsibility is involved, as is the employer's, as he must ensure that his employee is fit to drive and possesses a valid driving license at all times. PMID:25960440

  7. Tunable high-gradient permanent magnet quadrupoles

    International Nuclear Information System (INIS)

    A novel type of highly tunable permanent magnet (PM) based quadrupole has been designed by the ZEPTO collaboration. A prototype of the design (ZEPTO-Q1), intended to match the specification for the CLIC Drive Beam Decelerator, was built and magnetically measured at Daresbury Laboratory and CERN. The prototype utilises two pairs of PMs which move in opposite directions along a single vertical axis to produce a quadrupole gradient variable between 15 and 60 T/m. The prototype meets CLIC's challenging specification in terms of the strength and tunability of the magnet

  8. Optimal Electron Energies for Driving Chromospheric Evaporation in Solar Flares

    CERN Document Server

    Reep, Jeffrey; Alexander, David

    2015-01-01

    In the standard model of solar flares, energy deposition by a beam of electrons drives strong chromospheric evaporation leading to a significantly denser corona and much brighter emission across the spectrum. Chromospheric evaporation was examined in great detail by Fisher, Canfield, & McClymont (1985a,b,c), who described a distinction between two different regimes, termed explosive and gentle evaporation. In this work, we examine the importance of electron energy and stopping depths on the two regimes and on the atmospheric response. We find that with explosive evaporation, the atmospheric response does not depend strongly on electron energy. In the case of gentle evaporation, lower energy electrons are significantly more efficient at heating the atmosphere and driving up-flows sooner than higher energy electrons. We also find that the threshold between explosive and gentle evaporation is not fixed at a given beam energy flux, but also depends strongly on the electron energy and duration of heating. Furt...

  9. Driving the Landscape

    Science.gov (United States)

    Haff, P. K.

    2012-12-01

    Technological modification of the earth's surface (e.g., agriculture, urbanization) is an old story in human history, but what about the future? The future of landscape in an accelerating technological world, beyond a relatively short time horizon, lies hidden behind an impenetrable veil of complexity. Sufficiently complex dynamics generates not only the trajectory of a variable of interest (e.g., vegetation cover) but also the environment in which that variable evolves (e.g., background climate). There is no way to anticipate what variables will define that environment—the dynamics creates its own variables. We are always open to surprise by a change of conditions we thought or assumed were fixed or by the appearance of new phenomena of whose possible existence we had been unaware or thought unlikely. This is especially true under the influence of technology, where novelty is the rule. Lack of direct long-term predictability of landscape change does not, however, mean we cannot say anything about its future. The presence of persistence (finite time scales) in a system means that prediction by a calibrated numerical model should be good for a limited period of time barring bad luck or faulty implementation. Short-term prediction, despite its limitations, provides an option for dealing with the longer-term future. If a computer-controlled car tries to drive itself from New York to Los Angeles, no conceivable (or possible) stand-alone software can be constructed to predict a priori the space-time trajectory of the vehicle. Yet the drive is normally completed easily by most drivers. The trip is successfully completed because each in a series of very short (linear) steps can be "corrected" on the fly by the driver, who takes her cues from the environment to keep the car on the road and headed toward its destination. This metaphor differs in a fundamental way from the usual notion of predicting geomorphic change, because it involves a goal—to reach a desired

  10. Control and monitoring system for internal beam diagnostics facility of SCC

    International Nuclear Information System (INIS)

    The first Ion beam will be accelerated in K-500 Superconducting Cyclotron at VECC soon. The acceleration zone employs Main probe and Beam viewer probe for internal beam diagnostics. The ion beam, during acceleration inside the cyclotron, is needed to be maintained in median plane. The deviation of beam at various radial positions is to be monitored by Main-Probe head. The characteristics of beam e.g. size and shape information is required at the time of beam tuning. A Beam Viewer Probe, made of a borescope fitted with a fluorescent plate is used to display the beam characteristics. High resolution probe head driving systems are developed along with VB GUI to control both the drives and monitor the beam properties (e.g. magnitude, deviation, size, shape). This paper describes the control instrumentation and monitoring scheme for main probe and viewer probe. (author)

  11. Linear Back-Drive Differentials

    Science.gov (United States)

    Waydo, Peter

    2003-01-01

    Linear back-drive differentials have been proposed as alternatives to conventional gear differentials for applications in which there is only limited rotational motion (e.g., oscillation). The finite nature of the rotation makes it possible to optimize a linear back-drive differential in ways that would not be possible for gear differentials or other differentials that are required to be capable of unlimited rotation. As a result, relative to gear differentials, linear back-drive differentials could be more compact and less massive, could contain fewer complex parts, and could be less sensitive to variations in the viscosities of lubricants. Linear back-drive differentials would operate according to established principles of power ball screws and linear-motion drives, but would utilize these principles in an innovative way. One major characteristic of such mechanisms that would be exploited in linear back-drive differentials is the possibility of designing them to drive or back-drive with similar efficiency and energy input: in other words, such a mechanism can be designed so that a rotating screw can drive a nut linearly or the linear motion of the nut can cause the screw to rotate. A linear back-drive differential (see figure) would include two collinear shafts connected to two parts that are intended to engage in limited opposing rotations. The linear back-drive differential would also include a nut that would be free to translate along its axis but not to rotate. The inner surface of the nut would be right-hand threaded at one end and left-hand threaded at the opposite end to engage corresponding right- and left-handed threads on the shafts. A rotation and torque introduced into the system via one shaft would drive the nut in linear motion. The nut, in turn, would back-drive the other shaft, creating a reaction torque. Balls would reduce friction, making it possible for the shaft/nut coupling on each side to operate with 90 percent efficiency.

  12. Pulse selection control for the IR FEL photocathode drive laser

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, K.; Evans, R.; Garza, O. [and others

    1997-08-01

    The method for current control of a photocathode source is described. This system allows for full remote control of a photocathode drive laser for resulting electron beam currents ranging from less than one microamp to a full current ranging from less than one microamp to a full current of five milliamps. All current modes are obtained by gating the drive laser with a series of electro-optical cells. The system remotely generates this control signal by assuming a mode of operation with the following properties selectable: Current mode as continuous or gated, micropulse density, macropulse gate width from single shot to 1ms duration, macropulse synchronization to A/C line voltage (60 Hz) or an external trigger, 60 Hz phase and slewing through 60 Hz when applicable. All selections are derived from programmable logic devices operating from a master-oscillator resulting in a discrete, phase stable, pulse control for the drive laser.

  13. OMEGA: a 24 beam uv irradiation facility

    International Nuclear Information System (INIS)

    We report the recent completion of the uv upconversion (351 nm) of all 24 beams of the OMEGA laser which provides a unique short wavelength symmetrical irradiation facility for direct drive laser fusion experiments. Details of the characterization of illumination uniformity and initial implosion experiments will be described

  14. Semiclassical instability of warp drives

    International Nuclear Information System (INIS)

    Warp drives, at least theoretically, provide a way to travel at superluminal speeds. However, even if one succeeded in providing the necessary exotic matter to construct them, it would still be necessary to check whether they would survive to the switching on of quantum effects. In this contribution we will report on the behaviour of the Renormalized Stress-Energy Tensor (RSET) in the spacetimes associated with superluminal warp drives. We find that the RSET will exponentially grow in time close to the front wall of the superluminal bubble, hence strongly supporting the conclusion that the warp-drive geometries are unstable against semiclassical back-reaction.

  15. Phoning while driving II: a review of driving conditions influence.

    Science.gov (United States)

    Collet, C; Guillot, A; Petit, C

    2010-05-01

    The first paper examined how the variables related to driving performance were impacted by the management of holding a phone conversation. However, the conditions under which this dual task is carried out are dependent upon a set of factors that may particularly influence the risk of crash. These conditions are defined by several independent variables, classified into five main categories: i) legislation; ii) phone type (hands-free or hand-held); iii) drivers' features regarding age, gender, personal individual profile and driving experience; iv) conversation content (casual or professional) and its context (held with passengers or with a cell (mobile) phone); v) driving conditions (actual or simulated driving, road type, traffic density and weather). These independent variables determine the general conditions. The way in which these factors are combined and interact one with another thus determines the risk that drivers undergo when a cell phone is used while driving. Finally, this review defined the general conditions of driving for which managing a phone conversation is likely to elicit a high risk of car crash or, conversely, may provide a situation of lower risk, with sufficient acceptance to ensure safety. PMID:20432083

  16. High-gradient two-beam electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L. [Omega-P, Inc., New Haven, CT (United States)

    2014-11-04

    The main goal for this project was to design, build, and evaluate a detuned-cavity, collinear, two-beam accelerator structure. Testing was to be at the Yale University Beam Physics Laboratory, under terms of a sub-grant from Omega-P to Yale. Facilities available at Yale for this project include a 6-MeV S-band RF gun and associated beam line for forming and transporting a ~1 A drive beam , a 300 kV beam source for use as a test beam, and a full panoply of laboratory infrastructure and test equipment. During the first year of this project, availability and functionality of the 6-MeV drive beam and 300 kV test beam were confirmed, and the beam line was restored to a layout to be used with the two-beam accelerator project. Major efforts during the first year were also focused on computational design and simulation of the accelerator structure itself, on beam dynamics, and on beam transport. Effort during the second year was focussed on building and preparing to test the structure, including extensive cold testing. Detailed results from work under this project have been published in twelve archival journal articles, listed in Section IV of the technical report.

  17. Lithium beam characterization of cylindrical PBFA II hohlraum experiments

    International Nuclear Information System (INIS)

    Sandia National Laboratories is actively engaged in exploring indirect-drive inertial confinement fusion on the Particle Beam Fusion Accelerator (PBFA II) with pulsed-power accelerated lithium ions as the driver. Experiments utilizing cylindrical hohlraum targets were conducted in 1994. Using the incoming ion beam-induced line radiation from titanium wires surrounding these hohlraums, beam profiles during these experiments have been measured and characterized. These data, their comparison/cross-correlation with particle-based beam diagnostics, and an analysis of the beam parameters that most significantly influence target temperature are presented

  18. Beam self-excited rf cavity driver for a deflector or focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Wadlinger, E.A.

    1996-09-01

    A bunched beam from and accelerator can excite and power an rf cavity which then drives either a deflecting or focusing (including nonlinear focusing) rf cavity with and amplitude related to beam current. Rf power, generated when a bunched beam loses energy to an rf field when traversing an electric field that opposes the particle`s motion, is used to drive a separate (or the same) cavity to either focus or deflect the beam. The deflected beam can be stopped by an apertures or directed to a different area of a target depending on beam current. The beam-generated rf power can drive a radio-frequency quadrupole (RFQ) that can change the focusing properties of a beam channel as a function of beam current (space- charge force compensation or modifying the beam distribution on a target). An rf deflector can offset a beam to a downstream sextupole, effectively producing a position-dependent quadrupole field. The combination of rf deflector plus sextupole will produce a beam current dependent quadropole-focusing force. A static quadrupole magnet plus another rf deflector can place the beam back on the optic axis. This paper describes the concept, derives the appropriate equations for system analysis, and fives examples. A variation on this theme is to use the wake field generated in an rf cavity to cause growth in the beam emittance. The beam current would then be apertured by emittance defining slits.

  19. Lunar Core Drive Tubes Summary

    Data.gov (United States)

    National Aeronautics and Space Administration — Contains a brief summary and high resolution imagery from various lunar rock and core drive tubes collected from the Apollo and Luna missions to the moon.

  20. Dopaminergic Circuitry Underlying Mating Drive.

    Science.gov (United States)

    Zhang, Stephen X; Rogulja, Dragana; Crickmore, Michael A

    2016-07-01

    We develop a new system for studying how innate drives are tuned to reflect current physiological needs and capacities, and how they affect sensory-motor processing. We demonstrate the existence of male mating drive in Drosophila, which is transiently and cumulatively reduced as reproductive capacity is depleted by copulations. Dopaminergic activity in the anterior of the superior medial protocerebrum (SMPa) is also transiently and cumulatively reduced in response to matings and serves as a functional neuronal correlate of mating drive. The dopamine signal is transmitted through the D1-like DopR2 receptor to P1 neurons, which also integrate sensory information relevant to the perception of females, and which project to courtship motor centers that initiate and maintain courtship behavior. Mating drive therefore converges with sensory information from the female at the point of transition to motor output, controlling the propensity of a sensory percept to trigger goal-directed behavior. PMID:27292538