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Sample records for clic quadrupole vacuum

  1. 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.

  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. 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...

  4. 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...

  5. 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...

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

    CERN Document Server

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

    2010-01-01

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

  7. 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...

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

    CERN Document Server

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

    2012-01-01

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

  9. Simulations and Vacuum Tests of a CLIC Accelerating Structure

    CERN Document Server

    Garion, C

    2011-01-01

    The Compact LInear Collider, under study, is based on room temperature high gradient structures. The vacuum specificities of these cavities are low conductance, large surface areas and a non-baked system. The main issue is to reach UHV conditions (typically 10-7 Pa) in a system where the residual vacuum is driven by water outgassing. A finite element model based on an analogy thermal/vacuum has been built to estimate the vacuum profile in an accelerating structure. Vacuum tests are carried out in a dedicated set-up, the vacuum performances of different configurations are presented and compared with the predictions.

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

    CERN Document Server

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

    2011-01-01

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

  11. 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...

  12. SPS, quadrupole and vacuum chamber for low-beta insertion

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    During operation of the SPS as a proton-antiproton collider, 2 low-beta insertions (in LSS4 and LSS5) reduced the beam sizes and thereby increased the luminosity. The quadrupoles close to the intersection points had special, "flower-shaped", vacuum chambers. A detailed description is given in CERN Annual Report 1981, p.121.

  13. 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...

  14. 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...

  15. Mechanical behaviour of vacuum chambers and beam screens under quench conditions in dipole and quadrupole fields

    CERN Document Server

    Rathjen, C

    2002-01-01

    A method based on analytical formulas is described to calculate bending moments, stresses, and deformations of vacuum chambers and beam screens in dipole and in quadrupole fields during a magnet quench. Solutions are given for circular and racetrack shaped structures. Without the need of time consuming calculations the solutions enable a quick design and verification of vacuum chambers and beam screens.

  16. 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...

  17. 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...

  18. CLIC OVERVIEW

    CERN Document Server

    Tomas, R

    2009-01-01

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

  19. CLIC Overview

    CERN Document Server

    Tomás, R

    2010-01-01

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

  20. Vacuum polarization and quadrupole corrections to the hyperfine splitting of P-states in muonic deuterium

    CERN Document Server

    Martynenko, A P

    2016-01-01

    On the basis of quasipotential approach in quantum electrodynamics we calculate vacuum polarization and quadrupole corrections in first and second orders of perturbation theory in hyperfine structure of P-states in muonic deuterium. All corrections are presented in integral form and evaluated analytically and numerically. The obtained results can be used for the improvement of the transition frequencies between levels 2P and 2S.

  1. Preliminary Design of the Vacuum System for FAIR Super FRS Quadrupole Magnet Cryostat

    International Nuclear Information System (INIS)

    The Super-Conducting Fragment Separator (Super FRS) of the Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt is a large-acceptance superonducting fragment separator. The separator consists of large dipole, quadrupole and hexapole superconducting magnets. The long quadrupole magnet cryostat houses the helium chamber, which has the magnet iron and NbTi superconducting coil. The magnet weighs about 30 tons. The helium chamber is enclosed in vacuum inside the magnet cryostat. Multilayer Insulation (MLI) will be wrapped around the thermal shield to reduce radiation loss. Polyster of MLI comprises the major component responsible for outgassing. In order to reduce outgassing, pumping at elevated temperatures has to be carried out. In view of the large size and weight of the magnet, a seal off approach might not be operationally feasible. Continuous pumping of the cryostat has also been examined. Pump has been kept at a distance from the magnet considering the effect of stray magnetic fields. Oil free turbo molecular pump and scroll pump combination will be used to pump down the cryostat. The ultimate heat load of the cryostat will be highly dependent on the pressure attained. Radiation and conduction plays an important role in the heat transfer at low temperatures. This paper presents the vacuum design of the long quadrupole magnet cryostat and estimates the heat load of the cryostat.

  2. 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.

  3. CLIC Detector Power Requirements

    CERN Document Server

    Gaddi, A

    2013-01-01

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

  4. 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.

  5. 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.

  6. CLIC: Status and Plan

    CERN Document Server

    Sailer, Andre

    2014-01-01

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

  7. 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.

  8. 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...

  9. 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.

  10. The CLIC Detector Concept

    CERN Document Server

    Pitters, Florian Michael

    2016-01-01

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

  11. CLIC Muon Sweeper Design

    CERN Document Server

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

    2016-01-01

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

  12. CLIC Test Facility 3

    CERN Multimedia

    Kossyvakis, I; Faus-golfe, A

    2007-01-01

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

  13. 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...

  14. 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.

  15. Simulations of the HIE-ISOLDE radio frequency quadrupole cooler and buncher vacuum using the Monte Carlo test particle code Molflow

    CERN Document Server

    Hermann, M; Vandoni, G; Kersevan, R

    2013-01-01

    The existing ISOLDE radio frequency quadrupole cooler and buncher (RFQCB) will be upgraded in the framework of the HIE-ISOLDE design study. In order to improve beam properties, the upgrade includes vacuum optimization with the aim of tayloring the overall pressure profile: increasing gas pressure at the injection to enhance cooling and reducing it at the extraction to avoid emittance blow up while the beam is being bunched. This paper describes the vacuum modelling of the present RFQCB using Test Particle Monte Carlo (Molflow+). In order to benchmark the simulation results, real pressure profiles along the existing RFQCB are measured using variable helium flux in the cooling section and compared with the pressure profiles obtained with Molflow+. Vacuum conditions of the improved future RFQCB can then be simulated to validate its design. (C) 2013 Elsevier B.V. All rights reserved.

  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. Technological challenges of CLIC

    CERN Document Server

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

    2006-01-01

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

  18. BSM physics at CLIC

    CERN Document Server

    Simoniello, Rosa

    2016-01-01

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

  19. Higgs physics at CLIC

    CERN Document Server

    Lukic, Strahinja

    2016-01-01

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

  20. Higgs physics at CLIC

    CERN Document Server

    Lukić, Strahinja

    2016-01-01

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

  1. 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...

  2. 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

  3. The Physics Prospects for CLIC

    CERN Document Server

    ELLIS, J.

    2008-01-01

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

  4. Clic ring to main Linac

    CERN Document Server

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

    2010-01-01

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

  5. The CLIC Physics Potential

    CERN Document Server

    AUTHOR|(SzGeCERN)554857

    2016-01-01

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

  6. 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.

  7. 3D FEA Computation of the CLIC Machine Detector Interface Magnets

    CERN Document Server

    Bartalesi, A

    2012-01-01

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

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

    CERN Document Server

    Samoshkin, A; Solodko, A; Riddone, G

    2011-01-01

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

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

    CERN Document Server

    Samoshkin, A; Solodko, A; Riddone, G

    2011-01-01

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

  10. Determination of diffusion coefficients of hydrogen and deuterium in Zr–2.5%Nb pressure tube material using hot vacuum extraction-quadrupole mass spectrometry

    International Nuclear Information System (INIS)

    The diffusion coefficients of hydrogen and deuterium in Zr–2.5%Nb alloy were measured in the temperature range 523 to 673 K, employing hot vacuum extraction-quadrupole mass spectrometry (HVE-QMS). One end of the Zr–2.5%Nb alloy specimens was charged electrolytically with the desired hydrogen isotope. After annealing at different temperatures for a predetermined time, the specimens were cut into thin slices, which were analyzed for their H2/D2 content using the HVE-QMS technique. The depth profile data were fitted into the equation representing the solution of Fick’s second law of diffusion. The activation energy of hydrogen/deuterium diffusion was obtained from the Arrhenius relation between the diffusion coefficient and temperature. The temperature dependent diffusion coefficient can be represented as DH = 1.41 × 10−7 exp(−36,000/RT) and DD = 6.16 × 10−8 exp(−35,262/RT) for hydrogen and deuterium, respectively

  11. Determination of diffusion coefficients of hydrogen and deuterium in Zr-2.5%Nb pressure tube material using hot vacuum extraction-quadrupole mass spectrometry

    Science.gov (United States)

    Shrivastava, Komal Chandra; Kulkarni, A. S.; Ramanjaneyulu, P. S.; Sunil, Saurav; Saxena, M. K.; Singh, R. N.; Tomar, B. S.; Ramakumar, K. L.

    2015-06-01

    The diffusion coefficients of hydrogen and deuterium in Zr-2.5%Nb alloy were measured in the temperature range 523 to 673 K, employing hot vacuum extraction-quadrupole mass spectrometry (HVE-QMS). One end of the Zr-2.5%Nb alloy specimens was charged electrolytically with the desired hydrogen isotope. After annealing at different temperatures for a predetermined time, the specimens were cut into thin slices, which were analyzed for their H2/D2 content using the HVE-QMS technique. The depth profile data were fitted into the equation representing the solution of Fick's second law of diffusion. The activation energy of hydrogen/deuterium diffusion was obtained from the Arrhenius relation between the diffusion coefficient and temperature. The temperature dependent diffusion coefficient can be represented as DH = 1.41 × 10-7 exp(-36,000/RT) and DD = 6.16 × 10-8 exp(-35,262/RT) for hydrogen and deuterium, respectively.

  12. Determination of diffusion coefficients of hydrogen and deuterium in Zr–2.5%Nb pressure tube material using hot vacuum extraction-quadrupole mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, Komal Chandra, E-mail: komal@barc.gov.in [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kulkarni, A.S.; Ramanjaneyulu, P.S. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sunil, Saurav [Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Saxena, M.K. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Singh, R.N. [Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Tomar, B.S.; Ramakumar, K.L. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2015-06-15

    The diffusion coefficients of hydrogen and deuterium in Zr–2.5%Nb alloy were measured in the temperature range 523 to 673 K, employing hot vacuum extraction-quadrupole mass spectrometry (HVE-QMS). One end of the Zr–2.5%Nb alloy specimens was charged electrolytically with the desired hydrogen isotope. After annealing at different temperatures for a predetermined time, the specimens were cut into thin slices, which were analyzed for their H{sub 2}/D{sub 2} content using the HVE-QMS technique. The depth profile data were fitted into the equation representing the solution of Fick’s second law of diffusion. The activation energy of hydrogen/deuterium diffusion was obtained from the Arrhenius relation between the diffusion coefficient and temperature. The temperature dependent diffusion coefficient can be represented as D{sub H} = 1.41 × 10{sup −7} exp(−36,000/RT) and D{sub D} = 6.16 × 10{sup −8} exp(−35,262/RT) for hydrogen and deuterium, respectively.

  13. Airfoil sampling of a pulsed Laval beam with tunable vacuum ultraviolet (VUV) synchrotron ionization quadrupole mass spectrometry: Application to low--temperature kinetics and product detection

    Energy Technology Data Exchange (ETDEWEB)

    Soorkia, Satchin; Liu, Chen-Lin; Savee, John D; Ferrell, Sarah J; Leone, Stephen R; Wilson, Kevin R

    2011-10-12

    A new pulsed Laval nozzle apparatus with vacuum ultraviolet (VUV) synchrotron photoionization quadrupole mass spectrometry is constructed to study low-temperature radicalneutralchemical reactions of importance for modeling the atmosphere of Titan and the outer planets. A design for the sampling geometry of a pulsed Laval nozzle expansion has beendeveloped that operates successfully for the determination of rate coefficients by time-resolved mass spectrometry. The new concept employs airfoil sampling of the collimated expansion withexcellent sampling throughput. Time-resolved profiles of the high Mach number gas flow obtained by photoionization signals show that perturbation of the collimated expansion by theairfoil is negligible. The reaction of C2H with C2H2 is studied at 70 K as a proof-of-principle result for both low-temperature rate coefficient measurements and product identification basedon the photoionization spectrum of the reaction product versus VUV photon energy. This approach can be used to provide new insights into reaction mechanisms occurring at kinetic ratesclose to the collision-determined limit.

  14. CLIC expands to include the Southern Hemisphere

    CERN Multimedia

    Roberto Cantoni

    2010-01-01

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

  15. CLIC vertex detector R&D

    Science.gov (United States)

    Alipour Tehrani, Niloufar

    2016-07-01

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

  16. ISR Superconducting Quadrupoles

    CERN Multimedia

    1977-01-01

    Michel Bouvier is preparing for curing the 6-pole superconducting windings inbedded in the cylindrical wall separating liquid helium from vacuum in the quadrupole aperture. The heat for curing the epoxy glue was provided by a ramp of infrared lamps which can be seen above the slowly rotating cylinder. See also 7703512X, 7702690X.

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

    CERN Document Server

    D'Amico, T E

    1999-01-01

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

  18. 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

  19. 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.

  20. CLIC inner detectors cooling simulations

    CERN Document Server

    Duarte Ramos, F.; Villarejo Bermudez, M.

    2014-01-01

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

  1. 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...

  2. 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.

  3. Precision Higgs boson measurement at CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)718111

    2016-01-01

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

  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. 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...

  6. 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.

  7. 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...

  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. 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.

  10. 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.

  11. 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.

  12. CLIC Accelerated R&D

    CERN Document Server

    Wilson, Ian H

    2005-01-01

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

  13. A Luminosity Calorimeter for CLIC

    CERN Document Server

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

    2009-01-01

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

  14. Multibunch Emittance Preservation in CLIC

    CERN Document Server

    Guignard, Gilbert

    1996-01-01

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

  15. 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.

  16. 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...

  17. Light-flavor squark reconstruction at CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)548062; Weuste, Lars

    2015-01-01

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

  18. Wakefield Damping for the CLIC Crab Cavity

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-12-01

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

  19. Wakefield damping for the CLIC crab cavity

    CERN Document Server

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

    2009-01-01

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

  20. WAKEFIELD DAMPING FOR THE CLIC CRAB CAVITY

    CERN Document Server

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

    2009-01-01

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

  1. Physics highlights at ILC and CLIC

    CERN Document Server

    Lukić, Strahinja

    2015-01-01

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

  2. New clic-g structure design

    CERN Document Server

    AUTHOR|(CDS)2082335

    2016-01-01

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

  3. CLIC preparations go up a notch

    CERN Multimedia

    2007-01-01

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

  4. 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.

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

    CERN Document Server

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

    2015-01-01

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

  6. R&D Challenges of a CLIC Vertex Detector

    CERN Document Server

    van der Kraaij, E

    2010-01-01

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

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

    CERN Document Server

    D'Amico, T E

    1999-01-01

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

  8. The CLIC feasibility demonstration in CTF3

    CERN Document Server

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

    2011-01-01

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

  9. The CLIC Post-Collision Line

    CERN Document Server

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

    2010-01-01

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

  10. 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&...

  11. 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.

  12. Silicon pixel R&D for CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)754303

    2016-01-01

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

  13. 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...

  14. Higgs and BSM physics at CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)669060

    2015-01-01

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

  15. 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.

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

    CERN Document Server

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

    2010-01-01

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

  17. Simulation of Beam-Beam Background at CLIC

    CERN Document Server

    Sailer, A

    2010-01-01

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

  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. 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 ...

  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. 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.

  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. End view of ISR Superconducting Quadrupole in its cryostat

    CERN Multimedia

    1977-01-01

    This view shows the cold mass of the prototype ISR Superconducting Quadrupole suspended to the outer vacuum tank by means of titanium alloy rods.The heat shield wrapped with superinsulation can also be seen. See also photo 7702690X.

  4. Differentially pumped dual linear quadrupole ion trap mass spectrometer

    Science.gov (United States)

    Owen, Benjamin C.; Kenttamaa, Hilkka I.

    2015-10-20

    The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

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

    CERN Document Server

    Simon, F; Roloff, P

    2013-01-01

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

  6. 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).

  7. 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).

  8. 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.

  9. 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)

  10. 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.

  11. 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.

  12. 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.

  13. AA Narrow Quadrupole

    CERN Multimedia

    1979-01-01

    The very particular lattice of the AA required 2 types of quadrupoles: narrow ones (QFN, QDN) and wide ones (QFW, QDW). This is the first one of the narrow quadrupoles, delivered by industry early in 1979.

  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. 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...

  16. 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...

  17. 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...

  18. 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.

  19. 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...

  20. 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...

  1. 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\

  2. 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.

  3. Vertex-Detector R&D for CLIC

    CERN Document Server

    Dannheim, D

    2014-01-01

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

  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. Occupancy in the CLIC_ILD Time Projection Chamber

    CERN Document Server

    KILLENBERG, M.

    2011-01-01

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

  6. 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.

  7. 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...

  8. 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.

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

    CERN Document Server

    Holma, Janne

    2012-01-01

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

  10. Update on beam loss monitoring at CTF3 for CLIC

    CERN Document Server

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

    2013-01-01

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

  11. 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.

  12. Efficient Pulsed Quadrupole

    CERN Document Server

    Petzenhauser, I.; Spiller, P.; Tenholt, C.

    2016-01-01

    In order to raise the focusing gradient in case of bunched beam lines, a pulsed quadrupole was designed. The transfer channels between synchrotrons as well as the final focusing for the target line are possible applications. The quadrupole is running in a pulsed mode, which means an immense saving of energy by avoiding standby operation. Still the high gradients demand high currents. Hence a circuit had to be developed which is able to recover a significant amount of the pulsing energy for following shots. The basic design of the electrical circuit of the quadrupole is introduced. Furthermore more energy efficient circuits are presented and the limits of adaptability are considered.

  13. 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

  14. 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.

  15. 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 ...

  16. Measurement of stau_1 pair production at CLIC

    CERN Document Server

    Muennich, A.

    2012-01-01

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

  17. Prototype Superconducting Quadrupole for the ISR low-beta insertion

    CERN Multimedia

    1977-01-01

    The picture shows the cold mass of the Quadrupole with its outer aluminium alloy rings pre-compressing the superconducting coils via the magnetic yoke split in 4 parts.The end of the inner vacuum chamber,supporting the 6-pole correction windings, can also be seen as well as the electrical connections. See also photos 7702690X, 7702307.

  18. 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...

  19. 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...

  20. 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...

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

    CERN Document Server

    Elsener, K; Schlatter, D; Siegrist, N

    2011-01-01

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

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

    CERN Document Server

    Killenberg, Martin

    2013-01-01

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

  3. 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.)

  4. 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.

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

    CERN Document Server

    Lutkiewicz, P; Rathjen, Ch

    2009-01-01

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

  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. Design of a highly segmented Endcap at a CLIC detector

    CERN Document Server

    Gerwig, H; Siegrist, N

    2010-01-01

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

  8. 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

  9. Vacuum electronics

    CERN Document Server

    Eichmeier, Joseph A

    2008-01-01

    Nineteen experts from the electronics industry, research institutes and universities have joined forces to prepare this book. ""Vacuum Electronics"" covers the electrophysical fundamentals, the present state of the art and applications, as well as the future prospects of microwave tubes and systems, optoelectronics vacuum devices, electron and ion beam devices, light and X-ray emitters, particle accelerators and vacuum interrupters. These topics are supplemented by useful information about the materials and technologies of vacuum electronics and vacuum technology.

  10. Variable Permanent Magnet Quadrupole

    Energy Technology Data Exchange (ETDEWEB)

    Mihara, T.; Iwashita, Y.; /Kyoto U.; Kumada, M.; /NIRS, Chiba; Spencer, C.M.; /SLAC

    2007-05-23

    A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments.

  11. 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...

  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. 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...

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

    CERN Document Server

    Jeff, A; Welsch, CP

    2013-01-01

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

  15. 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...

  16. 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...

  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. The first LHC insertion quadrupole

    CERN Multimedia

    2004-01-01

    An important milestone was reached in December 2003 at the CERN Magnet Assembly Facility. The team from the Accelerator Technology - Magnet and Electrical Systems group, AT-MEL, completed the first special superconducting quadrupole for the LHC insertions which house the experiments and major collider systems. The magnet is 8 metres long and contains two matching quadrupole magnets and an orbit corrector, a dipole magnet, used to correct errors in quadrupole alignment. All were tested in liquid helium and reached the ultimate performance criteria required for the LHC. After insertion in the cryostat, the superconducting magnet will be installed as the Q9 quadrupole in sector 7-8, the first sector of the LHC to be put in place in 2004. Members of the quadrupole team, from the AT-MEL group, gathered around the Q9 quadrupole at its inauguration on 12 December 2003 in building 181.

  19. A microelectromechanical systems-enabled, miniature triple quadrupole mass spectrometer.

    Science.gov (United States)

    Wright, Steven; Malcolm, Andrew; Wright, Christopher; O'Prey, Shane; Crichton, Edward; Dash, Neil; Moseley, Richard W; Zaczek, Wojciech; Edwards, Peter; Fussell, Richard J; Syms, Richard R A

    2015-03-17

    Miniaturized mass spectrometers are becoming increasingly capable, enabling the development of many novel field and laboratory applications. However, to date, triple quadrupole tandem mass spectrometers, the workhorses of quantitative analysis, have not been significantly reduced in size. Here, the basis of a field-deployable triple quadrupole is described. The key development is a highly miniaturized ion optical assembly in which a sequence of six microengineered components is employed to generate ions at atmospheric pressure, provide a vacuum interface, effect ion guiding, and perform fragmentation and mass analysis. Despite its small dimensions, the collision cell efficiently fragments precursor ions and yields product ion spectra that are very similar to those recorded using conventional instruments. The miniature triple quadrupole has been used to detect thiabendazole, a common pesticide, in apples at a level of 10 ng/g. PMID:25708099

  20. MQXFS1 Quadrupole Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio, Giorgio [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); et al.

    2016-04-14

    This report presents the reference design of MQXFS1, the first 1.5 m prototype of the low-beta quadrupoles (MQXF) for the LHC High Luminosity Upgrade. The MQXF quadrupoles have 150 mm aperture, coil peak field of about 12 T, and use $Nb_{3}Sn$ conductor. The design is based on the LARP HQ quadrupoles, which had 120 mm aperture. MQXFS1 has 1st generation cable cross-section and magnetic design.

  1. 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.

  2. 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.

  3. 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.

  4. Superconducting Quadrupole for the ISR High Luminosity insertion:end view

    CERN Multimedia

    1977-01-01

    Connection end view of the prototype quadrupole before insertion of the inner vacuum chamber with inbedded 6-pole windings. The main components of the structure can be seen: (from inside outwards) the superconducting quadrupole coils surrounded by glass epoxy bandage rings and stainless steel spacers, the low-carbon steel yoke quadrants and the aluminium alloy shrinking rings. See also photos 7702690X, 7702307, 7702308, 7812604X.

  5. Analysis of SUSY Heavy Higgs events at CLIC

    CERN Document Server

    Quevillon, J

    2009-01-01

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

  6. Physics requirements for Scalar Muons searches at CLIC

    CERN Document Server

    Battaglia, M

    2010-01-01

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

  7. 8th CLIC/CTF3 Collaboration Meeting

    CERN Document Server

    2003-01-01

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

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

    CERN Document Server

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

    2011-01-01

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

  9. 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...

  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. 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.

  12. 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.

  13. 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

  14. 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.

  15. Vacuum Technology

    Energy Technology Data Exchange (ETDEWEB)

    Biltoft, P J

    2004-10-15

    The environmental condition called vacuum is created any time the pressure of a gas is reduced compared to atmospheric pressure. On earth we typically create a vacuum by connecting a pump capable of moving gas to a relatively leak free vessel. Through operation of the gas pump the number of gas molecules per unit volume is decreased within the vessel. As soon as one creates a vacuum natural forces (in this case entropy) work to restore equilibrium pressure; the practical effect of this is that gas molecules attempt to enter the evacuated space by any means possible. It is useful to think of vacuum in terms of a gas at a pressure below atmospheric pressure. In even the best vacuum vessels ever created there are approximately 3,500,000 molecules of gas per cubic meter of volume remaining inside the vessel. The lowest pressure environment known is in interstellar space where there are approximately four molecules of gas per cubic meter. Researchers are currently developing vacuum technology components (pumps, gauges, valves, etc.) using micro electro mechanical systems (MEMS) technology. Miniature vacuum components and systems will open the possibility for significant savings in energy cost and will open the doors to advances in electronics, manufacturing and semiconductor fabrication. In conclusion, an understanding of the basic principles of vacuum technology as presented in this summary is essential for the successful execution of all projects that involve vacuum technology. Using the principles described above, a practitioner of vacuum technology can design a vacuum system that will achieve the project requirements.

  16. Vacuum mechatronics

    Science.gov (United States)

    Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo

    1989-01-01

    The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

  17. Vacuum Virtues

    Science.gov (United States)

    Rathey, Allen

    2007-01-01

    Upright vacuums, like cars, vary in quality, features and performance. Like automobiles, some uprights are reliable, others may be problematic, and some become a problem as a result of neglect or improper use. So, how do education institutions make an informed choice and, having done so, ensure that an upright vacuum goes the distance? In this…

  18. Vacuum extraction

    DEFF Research Database (Denmark)

    Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne;

    2012-01-01

    with daily work in the obstetric field were tested. Methods. The Delphi method was used for development of the scale. In a simulated vacuum extraction scenario first-year residents and obstetric chief physicians were rated using the developed OSATS scale for vacuum extraction to test construct validity...... of the scale. Main outcome measures. Consensus for the content of the scale. To test the scale Cronbachs alpha, interclass correlation and differential item function was calculated in the prospective study. Results. 89% completed the first and 61% completed the second Delphi round. Hereafter, consensus......Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validationof the developed OSATS scale for vacuum...

  19. Research of Force Effects During Mass-dynamic Interaction in Vacuum

    OpenAIRE

    Samokhvalov, Vladimir

    2013-01-01

    This article presents the results of the experimental research of rotating mass force effects in vacuum having a variable quadrupole moment on solids. During the research the values of forces, exciting repulsion of solids from rotating mass were measured.

  20. 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 ...

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

    CERN Document Server

    Seidel, Katja; Tesar, Michal; Poss, Stephane

    2013-01-01

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

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

    CERN Document Server

    Guignard, Gilbert

    1998-01-01

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

  3. 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

  4. 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.

  5. 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.

  6. Silicon pixel-detector R&D for CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)718101

    2016-01-01

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

  7. Vacuum Chambers for LEP sections

    CERN Multimedia

    1983-01-01

    The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

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

    CERN Document Server

    Raatikainen, R; Niinikoski, T; Riddone, G

    2011-01-01

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

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

    CERN Document Server

    Shaker, Hamed

    2016-01-01

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

  10. RFQ Vacuum brazing at CERN

    CERN Document Server

    Mathot, S

    2008-01-01

    The aim of this paper is to describe the vacuum brazing procedure used at CERN for the brazing of Radio Frequency Quadrupole (RFQ). The RFQ is made of high precision machined OFE copper pieces assembled together. Vacuum brazing is one of the most promising techniques used to join the individual components leading to vacuum tightness and high precision alignment. The RFQ modules brazed at CERN are made of four 100 or 120 cm long vanes (two major and two minor vanes). Our brazing procedure consists of two steps. The first step involves the brazing of the four vanes in a horizontal position. The second step consists of brazing the vacuum stainless steel flanges to the copper structure in a vertical position. The paper describes the problems encountered with the alignment and the vacuum tightness. The difficulties related to the stress relaxation of the machined copper pieces during the brazing heat treatment are discussed. In addition, the solutions developed to improve the alignment of the brazed RFQ’s are...

  11. 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%.

  12. 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%.

  13. Vacuum chamber

    International Nuclear Information System (INIS)

    A detailed description is given of the vacuum chamber of the so-called experimental equipment DEMAS (double-arm-time-of-flight spectrometer) at the heavy ion accelerator U-400 at the JINR-Dubna. (author)

  14. Cosmic vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Chernin, Artur D [P.K. Shternberg State Astronomical Institute at the M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

    2001-11-30

    Recent observational studies of distant supernovae have suggested the existence of cosmic vacuum whose energy density exceeds the total density of all the other energy components in the Universe. The vacuum produces the field of antigravity that causes the cosmological expansion to accelerate. It is this accelerated expansion that has been discovered in the observations. The discovery of cosmic vacuum radically changes our current understanding of the present state of the Universe. It also poses new challenges to both cosmology and fundamental physics. Why is the density of vacuum what it is? Why do the densities of the cosmic energy components differ in exact value but agree in order of magnitude? On the other hand, the discovery made at large cosmological distances of hundreds and thousands Mpc provides new insights into the dynamics of the nearby Universe, the motions of galaxies in the local volume of 10 - 20 Mpc where the cosmological expansion was originally discovered. (reviews of topical problems)

  15. Vacuum II

    CERN Document Server

    Franchetti, G

    2013-01-01

    This paper continues the presentation of pumps begun in ‘Vacuum I’. The main topic here is gauges and partial-pressure measurements. Starting from the kinetics of gases, the various strategies for measuring vacuum pressures are presented at an introductory level, with some reference to hardware devices. Partial-pressure measurement techniques are introduced, showing that the principles of ion selection have a direct similarity to particle dynamics in accelerators.

  16. 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.

  17. 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...

  18. 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

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. A compact beam focusing and steering element using quadrupoles with independently excited poles

    Energy Technology Data Exchange (ETDEWEB)

    Grime, Geoffrey W., E-mail: g.grime@surrey.ac.uk [University of Surrey, Ion Beam Centre, Advanced Technology Institute, Guildford GU2 7XH (United Kingdom)

    2013-07-01

    Beam steering elements for accelerator beam transport are conventionally and conveniently incorporated into beamlines by fitting magnetic dipole elements around the vacuum tube of the line. Two steerers in each plane (X and Y) together with a quadrupole doublet constitute a module providing full control of the direction, position and focus of the beam. In some installations however, there may be insufficient space on the beamline to mount separate steerer elements. To provide steering capabilities in such a situation we have used a magnetic quadrupole doublet with the coils of each pole independently excited to synthesise the desired combination of quadrupole, horizontal dipole and vertical dipole fields. This paper describes the quadrupole steerer and its multichannel power supply and presents calculated magnetic field distributions together with raytracing simulation of its performance.

  5. Quadrupole Induced Resonant Particle Transport

    Science.gov (United States)

    Gilson, Erik; Fajans, Joel

    1999-11-01

    We have performed experiments that explore the effects of a magnetic quadrupole field on a pure electron plasma confined in a Malmberg-Penning trap. A model that we have developed describes the shape of the plasma and shows that a certain class of resonant particles follows trajectories that take them out of the plasma. Even though the quadrupole field destroys the cylindrical symmetry of the system, our theory predicts that if the electrons are off resonance, then the lifetime of the plasma will not be greatly affected by the quadrupole field. Our preliminary experimental results show that the shape of the plasma and the plasma lifetime agree with our model. We are investigating the scaling of this behavior with various experimental parameters such as the plasma length, density, and strength of the quadrupole field. In addition to being an example of resonant particle transport, this effect may find practical applications in experiments that plan to use magnetic quadrupole neutral atom traps to confine anti-hydrogen created in double-well positron/anti-proton Malmberg-Penning traps. (ATHENA Collaboration.)

  6. 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].

  7. 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)

  8. Effective quadrupole-quadrupole interaction from density functional theory

    Science.gov (United States)

    Alhassid, Y.; Bertsch, G. F.; Fang, L.; Sabbey, B.

    2006-09-01

    The density functional theory of nuclear structure provides a many-particle wave function that is useful for static properties, but an extension of the theory is necessary to describe correlation effects or other dynamic properties. We propose a procedure to extend the theory by mapping the properties of a self-consistent mean-field theory onto an effective shell-model Hamiltonian with quadrupole-quadrupole interaction. In this initial study, we consider the sd-shell nuclei Ne20, Mg24, Si28, and Ar36. The method is first tested with the USD shell-model Hamiltonian, using its mean-field approximation to construct an effective Hamiltonian and partially recover correlation effects. We find that more than half of the correlation energy is due to the quadrupole interaction. We then follow a similar procedure but using the SLy4 Skyrme energy functional as our starting point and truncating the space to the spherical sd shell. The constructed shell-model Hamiltonian is found to satisfy minimal consistency requirements to reproduce the properties of the mean-field solution. The quadrupolar correlation energies computed with the mapped Hamiltonian are reasonable compared with those computed by other methods. The method also provides a well-defined renormalization of the quadrupole operator in the shell-model space, the “effective charge” of the phenomenological shell model.

  9. Vacuum Incalescence

    CERN Document Server

    Intravaia, F

    2016-01-01

    In quantum theory the vacuum is defined as a state of minimum energy that is devoid of particles but still not completely empty. It is perhaps more surprising that its definition depends on the geometry of the system and on the trajectory of an observer through space-time. Along these lines we investigate the case of an atom flying at constant velocity near a planar surface. Using general concepts of statistical mechanics it is shown that the motion-modified interaction with the electromagnetic vacuum is formally equivalent to the interaction with a thermal field having an effective temperature determined by the atom's velocity and distance from the surface. This result suggests new ways to experimentally investigate the properties of the quantum vacuum in non-equilibrium systems and effects such as quantum friction.

  10. Nuclear Quadrupole Moments and Nuclear Shell Structure

    Science.gov (United States)

    Townes, C. H.; Foley, H. M.; Low, W.

    1950-06-23

    Describes a simple model, based on nuclear shell considerations, which leads to the proper behavior of known nuclear quadrupole moments, although predictions of the magnitudes of some quadrupole moments are seriously in error.

  11. 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.

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

    CERN Document Server

    Killenberg, M.

    2011-01-01

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

  13. 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...

  14. 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\

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-11-01

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

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

    CERN Document Server

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

    2010-01-01

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

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

    CERN Document Server

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

    2011-01-01

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

  18. Vacuum Valve

    CERN Multimedia

    1974-01-01

    This valve was used in the Intersecting Storage Rings (ISR) to protect against the shock waves that would be caused if air were to enter the vacuum tube. Some of the ISR chambers were very fragile, with very thin walls - a design required by physicists on the lookout for new particles.

  19. Deuteron Magnetic Quadrupole Moment From Chiral Effective Field Theory

    CERN Document Server

    Liu, C -P; Mereghetti, E; Timmermans, R G E; van Kolck, U

    2012-01-01

    We calculate the magnetic quadrupole moment (MQM) of the deuteron at leading order in the systematic expansion provided by chiral effective field theory. We take into account parity and time-reversal violation which, at the quark-gluon level, results from the QCD vacuum angle and dimension-six operators that originate from physics beyond the Standard Model. We show that the deuteron MQM can be expressed in terms of five low-energy constants that appear in the parity- and time-reversal-violating nuclear potential and electromagnetic current, four of which also contribute to the electric dipole moments of light nuclei. We conclude that the deuteron MQM has an enhanced sensitivity to the QCD vacuum angle and that its measurement would be complementary to the proposed measurements of light-nuclear EDMs.

  20. LHC interaction region quadrupole cryostat design and fabrication

    CERN Document Server

    Nicol, T H; Huang, Y; Page, Thomas M

    2002-01-01

    The cryostat of a Large Hadron Collider (LHC) Interaction Region (IR) quadrupole magnet consists of all components of the inner triplet except the magnet assembly itself. It serves to support the magnet accurately and reliably within the vacuum vessel, to house all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. It must function reliably during storage, shipping and handling, normal magnet operation, quenches, and seismic excitations, and must be able to be manufactured at low cost. The major components of the cryostat are the vacuum vessel, thermal shield, multilayer insulation system, cryogenic piping, and suspension system. The overall design of a cryostat for superconducting accelerator magnets requires consideration of fluid flow, proper selection of materials for their thermal and structural performance at both ambient and operating temperature, and knowledge of the environment to which the magnets will be subjected over the course of their...

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

    Directory of Open Access Journals (Sweden)

    Stella M Valenzuela

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

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

    CERN Document Server

    Nurminen, Janne

    2012-01-01

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

  3. Development of a $Nb_{3}$Sn quadrupole magnet model

    CERN Document Server

    Devred, Arnaud; Gourdin, C; Juster, F P; Peyrot, M; Rey, J M; Rifflet, J M; Streiff, J M; Védrine, P

    2001-01-01

    One possible application of Nb/sub 3/Sn, whose superconducting properties far exceed those of NbTi, is the fabrication of short and powerful quadrupole magnets for the crowded interaction regions of large particle accelerators. To learn about Nb/sub 3/Sn technology and to evaluate fabrication techniques, DAPNIA/STCM at CEA/Saclay has undertaken an R&D program aimed at designing and building a 1 m-long, 56 mm single-aperture quadrupole magnet model. The model relies on the same coil geometry as the LHC arc quadrupole magnets, but has no iron yoke. It is expected to produce a nominal field gradient of 211 T/m at 11870 A. The coils are wound from Rutherford-type cables insulated with quartz fiber tapes, before being heat-treated and vacuum-impregnated with epoxy resin. Laminated, austenitic collars, locked around the coil assembly by means of keys restrain the Lorentz forces. After reviewing the conceptual design of the magnet model, we report on the cable and cable insulation development programs and we pre...

  4. CLIC 3TeV Beamsize Optimization with Radiation Effects

    CERN Document Server

    Blanco, OR; Tomas, R

    2013-01-01

    Oide effect and radiation in bending magnets are reviewed aiming to include this in the optical design process to minimize the beam size. The Oide double integral is expressed in simpler terms in order to speed up calculations. Part of the Oide function is used to evaluate how prone is a quadrupole magnet to contribute to the beam size increase, concluding in larger magnets with lower gradients. Radiation in bending magnets is reviewed for linear lattices, solving the case when the dispersion is different from zero and using the result to compare with theoretical results and a tracking code. An agreement between the theory, the implemented approximation included in MAPCLASS2 and the six-dimensional radiation in PLACET has been found.

  5. Extreme quadrupole deformation and clusterization

    Directory of Open Access Journals (Sweden)

    Antonenko N.

    2012-12-01

    Full Text Available We discuss a simple symmetry-adapted method for the determination of the shape isomers, and for the study of their possible fragmentation. In other words the connection between the quadrupole (collective and dipole (cluster degrees of freedom is considered in terms of an easily applicable, yet microscopic method. The energetics is taken into account by the double-folding method. Special attention is focused on those cases in which the theoretical predictions have a direct comparison with experimental observation.

  6. Sign-Selected Quadrupole Train

    International Nuclear Information System (INIS)

    The design of the Sign-Selected Quadrupole Train for E-815 (NuTeV) is set forth. The relevant physics requirements are explained. The optics of the beam are presented, along with an explanation of the proton dumping scheme. A discussion of rates and backgrounds follows, with special care given to backgrounds from scraping and obstructions. The relevant tolerances for beam construction are given and justified by simulations of the beamline. This leads to a discussion of the beam monitoring

  7. Vacuum Performance Improvement of the HL-2A Tokamak

    Institute of Scientific and Technical Information of China (English)

    LIUDequan; CAOZeng; CUIChenghe; RANHong; LUPing; XIEYanfeng; XUZenghua

    2003-01-01

    There are many inner items in vacuum vessel, and hundreds of seals on the vessel borts in the HL-2A tokamak, so it is difficult to get excellent vacuum. During the engineering test in 2002, the results of quadrupole mass spectrometer showed thatthe partial pressures of oxygen and H2O were higher than normal value, some leaks on theupper MP3 coil jackets and port seals had been detected. In order to carry out good discharge experiment, the good vacuum and wall condition must be maintained.

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

    CERN Document Server

    Rinolfi, Louis

    2005-01-01

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

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

    CERN Document Server

    Lukic, Strahinja

    2013-01-01

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

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

    CERN Document Server

    Lukic, Strahinja

    2013-01-01

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

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

    CERN Document Server

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

    2011-01-01

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

  12. 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

  13. 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.

  14. 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.

  15. 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...

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

    CERN Document Server

    AUTHOR|(SzGeCERN)754272

    2015-01-01

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

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

    CERN Document Server

    Dubrovskiy, A; Bathe, BN; Srivastava, S

    2013-01-01

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

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

    CERN Document Server

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

    2013-01-01

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

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

    CERN Document Server

    Kirca, Z; Cakir, O

    2003-01-01

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

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

    CERN Document Server

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

    2011-01-01

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

  1. 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. \

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

    CERN Document Server

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

    2011-01-01

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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

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

    CERN Document Server

    Coosemans, Williame

    1998-01-01

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

  9. 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.

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

    CERN Document Server

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

    2010-01-01

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

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

    CERN Document Server

    WEUSTE, L.

    2011-01-01

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

  12. 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 ...

  13. 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.

  14. 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.

  15. 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.

  16. Quadrupole scattering in PrAl2

    Science.gov (United States)

    Sablik, M. J.; Pureur, P.; Creuzet, G.; Fert, A.; Levy, P. M.

    1983-10-01

    We derive the spontaneous anisotropy of the resistivity of the ferromagnetic compound PrAl2 from magnetoresistance measurements on a single crystal of PrAl2. We ascribe this spontaneous anisotropy of the resistivity to scattering of the conduction electrons by the thermal quadrupole disorder and we account for our experimental results by using the theoretical model previously developed by us. We find that quadrupole scattering gives a very important contribution to the total magnetic disorder (spin and quadrupole) resistivity but that only a small part of this quadrupole contribution is anisotropic.

  17. Development of integrated superconducting quadrupole doublet modules for operation in the SIS100 accelerator

    Science.gov (United States)

    Meier, J.; Bleile, A.; Ceballos Velasco, J.; Fischer, E.; Hess, G.; Macavei, J.; Spiller, P.

    2015-12-01

    The FAIR project (Facility for Antiproton and Ion Research) evolves and builds an international accelerator- and experimental facility for basic research activities in various fields of modern physics. Within the course of this project, integrated quadrupole doublet modules are in development. The quadrupole doublet modules provide a pair of superconducting main quadrupoles (focusing and defocusing), corrector magnets, cryogenic collimators and beam position monitors as integrated sets of ion-optical elements. Furthermore LHe cooled beam pipes and vacuum cold-warm transitions are used as ultra-high vacuum components for beam transportation. Superconducting bus bars are used for 13 kA current supply of the main quadrupole magnets. All components are integrated as one common cold mass into one cryostat. High temperature super conductor local current leads will be applied for the low current supply of corrector magnets. The quadrupole doublet modules will be operated in the SIS100 heavy ion accelerator, the core component of the FAIR project. A first version of a corrector magnet has already been manufactured at the Joint Institute for Nuclear Research (JINR), Russia, and is now ready for testing. The ion-optical lattice structure of SIS100 requires multiple configurations of named components. Eleven different configurations, organized in four categories, provide the required quadrupole doublet module setups. The high integration level of multiple ion-optical, mechanical and cryogenic functions, based on requirements of operation safety, is leading towards a sophisticated mechanical structure and cooling solution, to satisfy the demanding requirements on position preservation during thermal cycling. The mechanical and cryogenic design solutions will be discussed.

  18. A Vibrating Wire System For Quadrupole Fiducialization

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Zachary

    2010-12-13

    A vibrating wire system is being developed to fiducialize the quadrupoles between undulator segments in the LCLS. This note provides a detailed analysis of the system. The LCLS will have quadrupoles between the undulator segments to keep the electron beam focused. If the quadrupoles are not centered on the beam axis, the beam will receive transverse kicks, causing it to deviate from the undulator axis. Beam based alignment will be used to move the quadrupoles onto a straight line, but an initial, conventional alignment must place the quadrupole centers on a straight line to 100 {micro}m. In the fiducialization step of the initial alignment, the position of the center of the quadrupole is measured relative to tooling balls on the outside of the quadrupole. The alignment crews then use the tooling balls to place the magnet in the tunnel. The required error on the location of the quadrupole center relative to the tooling balls must be less than 25 {micro}m. In this note, we analyze a system under construction for the quadrupole fiducialization. The system uses the vibrating wire technique to position a wire onto the quadrupole magnetic axis. The wire position is then related to tooling balls using wire position detectors. The tooling balls on the wire position detectors are finally related to tooling balls on the quadrupole to perform the fiducialization. The total 25 {micro}m fiducialization error must be divided between these three steps. The wire must be positioned onto the quadrupole magnetic axis to within 10 {micro}m, the wire position must be measured relative to tooling balls on the wire position detectors to within 15 {micro}m, and tooling balls on the wire position detectors must be related to tooling balls on the quadrupole to within 10 {micro}m. The techniques used in these three steps will be discussed. The note begins by discussing various quadrupole fiducialization techniques used in the past and discusses why the vibrating wire technique is our method

  19. Prototype Superconducting Quadrupole for the ISR high-luminosity (low beta)insertion:end view.

    CERN Multimedia

    1977-01-01

    In this picture, taken before the insertion of the inner vacuum chamber with inbedded 6-pole superconducting windings, one can see the main components of the magnet structure: (from inside outwards) the superconducting quadrupole coils surronded by glass epoxy bandage rings and stainless steel spacers, the low-carbon steel yoke quadrants and the aluminium alloy shrinking rings. See also photos 7702307, 7702688X, 7702690X.

  20. High sensitivity quadrupole mass spectrometry of neutrals sputtered by UV-laser ablation of polymers

    Science.gov (United States)

    Lazare, Sylvain; Guan, Weiping; Drilhole, David

    1996-04-01

    Laser Ablation-Sputtered Neutrals Spectrometry is developed as a portable system which consists of a commercial gas analyser (quadrupole mass spectrometer with e-beam ionization) in ultrahigh vacuum. ArF and KrF ablation of 20 polymers yielded mass spectra (1-200), rich in information, and mass intensity versus etching time for depth profiling analysis. The sensitivity is very high (100 ng of polymer can be probed) and microablation can be recorded by LA-SNMS.

  1. 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$\

  2. Vacuum phenomenon.

    Science.gov (United States)

    Yanagawa, Youichi; Ohsaka, Hiromichi; Jitsuiki, Kei; Yoshizawa, Toshihiko; Takeuchi, Ikuto; Omori, Kazuhiko; Oode, Yasumasa; Ishikawa, Kouhei

    2016-08-01

    This article describes the theory of the formation of the vacuum phenomenon (VP), the detection of the VP, the different medical causes, the different locations of the presentation of the VP, and the differential diagnoses. In the human body, the cavitation effect is recognized on radiological studies; it is called the VP. The mechanism responsible for the formation of the VP is as follows: if an enclosed tissue space is allowed to expand as a rebound phenomenon after an external impact, the volume within the enclosed space will increase. In the setting of expanding volume, the pressure within the space will decrease. The solubility of the gas in the enclosed space will decrease as the pressure of the space decreases. Decreased solubility allows a gas to leave a solution. Clinically, the pathologies associated with the VP have been reported to mainly include the normal joint motion, degeneration of the intervertebral discs or joints, and trauma. The frequent use of CT for trauma patients and the high spatial resolution of CT images might produce the greatest number of chances to detect the VP in trauma patients. The VP is observed at locations that experience a traumatic impact; thus, an analysis of the VP may be useful for elucidating the mechanism of an injury. When the VP is located in the abdomen, it is important to include perforation of the digestive tract in the differential diagnosis. The presence of the VP in trauma patients does not itself influence the final outcome. PMID:27147527

  3. Leybold vacuum handbook

    CERN Document Server

    Diels, K; Diels, Kurt

    1966-01-01

    Leybold Vacuum Handbook presents a collection of data sets that are essential for numerical calculation of vacuum plants and vacuum processes. The title first covers vacuum physics, which includes gas kinetics, flow phenomena, vacuum gauges, and vapor removal. Next, the selection presents data on vacuum, high vacuum process technology, and gas desorption and gettering. The text also deals with materials, vapor pressure, boiling and melting points, and gas permeability. The book will be of great interest to engineers and technicians that deals with vacuum related technologies.

  4. SUSY Fits and their Implications for ILC and CLIC

    CERN Document Server

    Heinemeyer, S

    2016-01-01

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

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

    CERN Document Server

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

    2010-01-01

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

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

    CERN Document Server

    Gaddi, A; Ramos, F; Siegrist, N

    2012-01-01

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

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

    CERN Document Server

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

    2016-01-01

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

  8. 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

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

    OpenAIRE

    Domènech, Luisa

    2004-01-01

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

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. Pygmy Quadrupole Resonance in Skin Nuclei

    CERN Document Server

    Tsoneva, N

    2009-01-01

    The electric quadrupole response is investigated theoretically by HFB and QPM calculations along the Sn isotopic chain with special emphasis on excitations above the first collective state and below the particle threshold. Depending on the asymmetry, additional strength clustering as a group of states similar to the known PDR mode is found. The spectral distributions and electric response functions are discussed. The transition densities of these Pygmy Quadrupole Resonances (PQR) states are closely related to the neutron excess and showing special features being compatible with an oscillation of the neutron skin against the nuclear core. These features may indicate a new nuclear quadrupole mode connected to the skin configuration.

  16. On the Post-linear Quadrupole-Quadrupole Metric

    CERN Document Server

    Frutos-Alfaro, Francisco

    2015-01-01

    The Hartle-Thorne metric defines a reliable spacetime for most astrophysical purposes, for instance for the simulation of slowly rotating stars. Solving the Einstein field equations, we added terms of second order in the quadrupole moment to its post-linear version without rotation in order to compare it with solutions found by Blanchet in the frame of the multi-polar post-Minkowskian framework. We first derived the extended Hartle-Thorne metric in harmonic coordinates and then showed agreement with the corresponding post-linear metric from Blanchet. We also found a coordinate transformation from the post-linear Erez-Rosen metric to our extended Hartle-Thorne spacetime. It is well known that the Hartle-Thorne solution can be smoothly matched with an interior perfect fluid solution with physically appropriate properties. A comparison among these solutions provides a validation of them. It is clear that in order to represent realistic solutions of self-gravitating (axially symmetric) matter distributions of per...

  17. Isoscalar quadratic energy weighted sum rules and quadrupole moment of giant quadrupole resonance

    International Nuclear Information System (INIS)

    Isoscalar sum rules homogeneous quadratic in energy weighting are derived for the electric multipole operators. Except for scaling factors the sum rule values for the pure quadrupole and monopole transitions are the same as that for the corresponding linear energy weighted sum rules. Through these sum rules the electric quadrupole moment of giant quadrupole resonance is found to be -2.7 Asup(1/3) efm2. (author)

  18. Photoassociation of a cold atom-molecule pair: long-range quadrupole-quadrupole interactions

    OpenAIRE

    Lepers, M.; Dulieu, O.; Kokoouline, V.

    2010-01-01

    The general formalism of the multipolar expansion of electrostatic interactions is applied to the calculation the potential energy between an excited atom (without fine structure) and a ground state diatomic molecule at large separations. Both partners exhibit a permanent quadrupole moment, so that their mutual quadrupole-quadrupole long-range interaction is attractive enough to bind trimers. Numerical results are given for an excited Cs(6P) atom and a ground state Cs2 molecule. The prospects...

  19. AA, shims and washers on quadrupole ends

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    Due to the fact that much of the field of the quadrupoles was outside the iron (in particular with the wide quadrupoles) and that thus the fields of quadrupoles and bending magnets interacted, the lattice properties of the AA could not be predicted with the required accuracy. After a first running period in 1980, during which detailed measurements were made with proton test beams, corrections to the quadrupoles were made in 1981, in the form of laminated shims at the ends of the poles, and with steel washers. With the latter ones, further refinements were made in an iterative procedure with measurements on the circulating beam. This eventually resulted, amongst other things, in a very low chromaticity, with the Q-values being constant to within +- 0.001 over the total momentum range of 6 %. Here we see the shims and washers on a narrow qudrupole (QFN, QDN). See also 8103203, 8103204, 8103205, 8103206.

  20. Squeezed Thermal Vacuum and the Maximum Scale for Inflation

    OpenAIRE

    M. GASPERINI; Giovannini, M; Veneziano, G.

    1993-01-01

    We consider the stimulated emission of gravitons from an initial state of thermal equilibrium, under the action of the cosmic gravitational background field. We find that the low-energy graviton spectrum is enhanced if compared with spontaneous creation from the vacuum; as a consequence, the scale of inflation must be lowered, in order not to exceed the observed CMB quadrupole anisotropy. This effect is particularly important for models based on a symmetry-breaking transition which require, a...

  1. Thermal quadrupole method with internal heat sources

    OpenAIRE

    PAILHES, Jérôme; Pradere, Christophe; Battaglia, Jean-Luc; TOUTAIN, Jean; KUSIAK, Andrzej; AREGBA, Waste; Batsale, Jean-Christophe

    2012-01-01

    A new method based on the thermal quadrupoles technique for heat transfer modelling in multilayered slabs with heat sources is proposed. Classical thermal quadrupoles use hyperbolic functions and numerical problems occur according to the argument value that depends on thermophysical and geometrical properties as well as characteristics times. We propose a new formulation based on exponential function with negative argument. Using this formulation in the classical equivalent impedance network ...

  2. AA, wide quadrupole on measurement stand

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    Please look up 8101024 first. Shims and washers on the wide quadrupoles (QFW, QDW; located in the lattice where dispersion was large) served mostly for corrections of those lattice parameters which were a function of momentum. After mounting shims and washers, the quadrupoles were measured to determine their magnetic centre and to catalogue the effect of washer constellations. Raymond Brown is busy measuring a wide quad.

  3. Quadrupole Deformation of Barium Isotopes

    CERN Document Server

    Sugita, M; Furuno, K

    1998-01-01

    The B(E2:0_1^+ -> 2_1^+) values of the Ba isotopes (Z=56) exhibit a sharp increase in deformation as the neutron numbers approach the mid-shell value of N=66. This behavior is anomalous because the 2_1^+ level energies are very similar to those of the neighboring isotopes. By means of the axially-symmetric deformed Woods-Saxon (WS) hamiltonian plus the BCS method, we investigated the systematics of B(E2) of the Ba isotopes. We showed that 15% of the B(E2) values at N=66 was due to the level crossing, occurring at the deformation with beta being nearly 0.3, between the proton orbits originating from the orbits Omega=1/2^-(h11/2) and 9/2^+(g9/2) at zero deformation. The latter of these two was an intruder orbit originating from below the energy gap at Z=50, rising higher in energy with the deformation and intruding the Z=50-82 shell. These two orbits have the largest magnitude of the quadrupole moment with a different sign among the orbits near and below the Fermi surface. Occupancy and non-occupancy of these o...

  4. 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...

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

    CERN Document Server

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

    2010-01-01

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

  7. 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...

  8. 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...

  9. 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...

  10. 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...

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

    CERN Document Server

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

    2010-01-01

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

  12. 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...

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

    CERN Document Server

    Münnich, A.

    2013-01-01

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

  14. $2\\times250$ 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...

  15. The RHIC vacuum systems

    Science.gov (United States)

    Burns, R.; Hseuh, H. C.; Lee, R. C.; McIntyre, G.; Pate, D.; Smart, L.; Sondericker, J.; Weiss, D.; Welch, K.

    2003-03-01

    There are three vacuum systems in RHIC: the insulating vacuum vessels housing the superconducting magnets, the cold beam tubes surrounded by the superconducting magnets, and the warm beam tube sections at the insertion regions and the experimental regions. These systems have a cumulative length over 10 km and a total volume over 3000 m 3. Conventional ultrahigh vacuum technology was used in the design and construction of the cold and warm beam vacuum systems with great success. The long and large insulating vacuum volumes without vacuum barriers require careful management of the welding and leak checking of the numerous helium line joints. There are about 1500 vacuum gauges and pumps serial-linked to eight PLCs distributed around RHIC, which allow the monitoring and control of these devices through Ethernet networks to remote control consoles. With the exception of helium leaks through the cryogenic valve boxes into the insulating vacuum volumes, the RHIC vacuum systems have performed well beyond expectations.

  16. Indian Vacuum Society: The Indian Vacuum Society

    Science.gov (United States)

    Saha, T. K.

    2008-03-01

    The Indian Vacuum Society (IVS) was established in 1970. It has over 800 members including many from Industry and R & D Institutions spread throughout India. The society has an active chapter at Kolkata. The society was formed with the main aim to promote, encourage and develop the growth of Vacuum Science, Techniques and Applications in India. In order to achieve this aim it has conducted a number of short term courses at graduate and technician levels on vacuum science and technology on topics ranging from low vacuum to ultrahigh vacuum So far it has conducted 39 such courses at different parts of the country and imparted training to more than 1200 persons in the field. Some of these courses were in-plant training courses conducted on the premises of the establishment and designed to take care of the special needs of the establishment. IVS also regularly conducts national and international seminars and symposia on vacuum science and technology with special emphasis on some theme related to applications of vacuum. A large number of delegates from all over India take part in the deliberations of such seminars and symposia and present their work. IVS also arranges technical visits to different industries and research institutes. The society also helped in the UNESCO sponsored post-graduate level courses in vacuum science, technology and applications conducted by Mumbai University. The society has also designed a certificate and diploma course for graduate level students studying vacuum science and technology and has submitted a syllabus to the academic council of the University of Mumbai for their approval, we hope that some colleges affiliated to the university will start this course from the coming academic year. IVS extended its support in standardizing many of the vacuum instruments and played a vital role in helping to set up a Regional Testing Centre along with BARC. As part of the development of vacuum education, the society arranges the participation of

  17. Radiation hard vacuum switch

    Science.gov (United States)

    Boettcher, Gordon E.

    1990-01-01

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction.

  18. Induced CMB quadrupole from pointing offsets

    Science.gov (United States)

    Moss, Adam; Scott, Douglas; Sigurdson, Kris

    2011-01-01

    Recent claims in the literature have suggested that the WMAP quadrupole is not primordial in origin, and arises from an aliasing of the much larger dipole field because of incorrect satellite pointing. We attempt to reproduce this result and delineate the key physics leading to the effect. We find that, even if real, the induced quadrupole would be smaller than the WMAP value. We discuss reasons why the WMAP data are unlikely to suffer from this particular systematic effect, including the implications for observations of point sources. Given this evidence against the reality of the effect, the similarity between the pointing-offset-induced signal and the actual quadrupole then appears to be quite puzzling. However, we find that the effect arises from a convolution between the gradient of the dipole field and anisotropic coverage of the scan direction at each pixel. There is something of a directional conspiracy here — the dipole signal lies close to the Ecliptic Plane, and its direction, together with the WMAP scan strategy, results in a strong coupling to the Y2, -1 component in Ecliptic co-ordinates. The dominant strength of this component in the measured quadrupole suggests that one should exercise increased caution in interpreting its estimated amplitude. The Planck satellite has a different scan strategy which does not so directly couple the dipole and quadrupole in this way and will soon provide an independent measurement.

  19. Induced CMB quadrupole from pointing offsets

    Energy Technology Data Exchange (ETDEWEB)

    Moss, Adam; Scott, Douglas; Sigurdson, Kris, E-mail: adammoss@phas.ubc.ca, E-mail: dscott@phas.ubc.ca, E-mail: krs@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 Canada (Canada)

    2011-01-01

    Recent claims in the literature have suggested that the WMAP quadrupole is not primordial in origin, and arises from an aliasing of the much larger dipole field because of incorrect satellite pointing. We attempt to reproduce this result and delineate the key physics leading to the effect. We find that, even if real, the induced quadrupole would be smaller than the WMAP value. We discuss reasons why the WMAP data are unlikely to suffer from this particular systematic effect, including the implications for observations of point sources. Given this evidence against the reality of the effect, the similarity between the pointing-offset-induced signal and the actual quadrupole then appears to be quite puzzling. However, we find that the effect arises from a convolution between the gradient of the dipole field and anisotropic coverage of the scan direction at each pixel. There is something of a directional conspiracy here — the dipole signal lies close to the Ecliptic Plane, and its direction, together with the WMAP scan strategy, results in a strong coupling to the Y{sub 2,−1} component in Ecliptic co-ordinates. The dominant strength of this component in the measured quadrupole suggests that one should exercise increased caution in interpreting its estimated amplitude. The Planck satellite has a different scan strategy which does not so directly couple the dipole and quadrupole in this way and will soon provide an independent measurement.

  20. Quadrupole moments measured by nuclear orientation

    International Nuclear Information System (INIS)

    Quadrupole interactions between the nuclei and solids have been studied with the low temperature nuclear orientation technique. The first series of measurements have been effected on the orientation of 195Hgm and 197Hgm, long lived daughter states in the 195Au and 197 Au decay. The lifetimes of these states are of the same order as the spin-lattice relaxation time. The reorientation of the intermediate states has been taken into account extending the dipole relaxation mechanism to non-equidistant relaxing substates. The experimental nuclear quadrupole moments, thus deduced are slightly different from theoretical estimations. A new high precision method accessible to levels with 100 ns to 1 m lifetimes, the level mixing resonance on oriented nuclei (LMR/ON) has been elaborated in collaboration with LEUVEN university (Belgium). In this technique the nucleus is subject to a non colinear electric plus magnetic combined interaction. The quadrupole interaction of Ag[7/2, = 40 s] isomer with the electric field gradient in zinc has been established to better than 1% observing its level mixing resonances; and also the ratio of electric field gradients of silver in zinc to cadmium. The electric quadrupole moments of 106Agm, 107Agm and 109Agm have been established combining the level mixing resonances with classical low temperature quadrupole alignment measurements. The experimental values are in good agreement with theoretical calculations based on a semi-microscopical model using Yukawa potential

  1. 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.

  2. The Planck Vacuum

    Directory of Open Access Journals (Sweden)

    Daywitt W. C.

    2009-01-01

    Full Text Available This paper argues that there is a polarizable vacuum state (the Planck vacuum that is the source of the quantum vacuum; the free particles; the gravitational, fine structure, and Planck constants; the gravitational field and the spacetime of General Relativity; the Maxwell equations and the Lorentz transformation; and the particle Compton relations and the quantum theory.

  3. In-situ GaN decomposition analysis by quadrupole mass spectrometry and reflection high-energy electron diffraction

    OpenAIRE

    Fernández-Garrido, Sergio; Koblmüller, Gregor; Calleja Pardo, Enrique; Speck, James S.

    2008-01-01

    Thermal decomposition of wurtzite (0001)-oriented GaN was analyzed: in vacuum, under active N exposure, and during growth by rf plasma-assisted molecular beam epitaxy. The GaN decomposition rate was determined by measurements of the Ga desorption using in situ quadrupole mass spectrometry, which showed Arrhenius behavior with an apparent activation energy of 3.1 eV. Clear signatures of intensity oscillations during reflection high-energy electron diffraction measurements facilitated complemen...

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

    CERN Document Server

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

    2011-01-01

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

  5. 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.

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

    CERN Document Server

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

    2012-01-01

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

  8. 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.

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

    CERN Document Server

    AUTHOR|(SzGeCERN)752526

    2015-01-01

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

  10. 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.

  11. 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

  12. 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.

  13. 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.

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

    CERN Document Server

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

    2007-01-01

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

  15. Analytical transfer matrix of a quadrupole fringe

    Institute of Scientific and Technical Information of China (English)

    PENG Yue-Mei; XU Gang

    2011-01-01

    The analytical linear transfer matrices for different quadrupole fringes including quadratic,high order power and exponential models are deduced in this paper.As an example,the transfer matrices of the quadrupole BEPC Ⅱ 105Q are computed for the above three models and compared with hard edge and sliceby-slice models in cases of near 60° and 90° FODO cells.These models' results are much better than the hard edge model's,and can meet the requirement of accurate calculation.

  16. Electric quadrupole transition probabilities for atomic lithium

    International Nuclear Information System (INIS)

    Electric quadrupole transition probabilities for atomic lithium have been calculated using the weakest bound electron potential model theory (WBEPMT). We have employed numerical non-relativistic Hartree–Fock wavefunctions for expectation values of radii and the necessary energy values have been taken from the compilation at NIST. The results obtained with the present method agree very well with the Coulomb approximation results given by Caves (1975). Moreover, electric quadrupole transition probability values not existing in the literature for some highly excited levels have been obtained using the WBEPMT

  17. 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.

  18. Photoassociation of a cold atom-molecule pair: long-range quadrupole-quadrupole interactions

    CERN Document Server

    Lepers, M; Kokoouline, V

    2010-01-01

    The general formalism of the multipolar expansion of electrostatic interactions is applied to the calculation the potential energy between an excited atom and a ground state diatomic molecule at large separations. Both partners exhibit a permanent quadrupole moment, so that their mutual quadrupole-quadrupole long-range interaction is attractive enough to bind trimers. Numerical results are given for an excited Cs(6P) atom and a ground state Cs2 molecule. The prospects for achieving photoassociation of a cold atom/dimer pair is thus discussed and found promising. The formalism can be easily generalized to the long-range interaction between molecules to investigate the formation of cold tetramers.

  19. Adiabatic Rormation of a Matched-beam Distribution for an Alternating-gradient Quadrupole Lattice

    International Nuclear Information System (INIS)

    The formation of a quasiequilibrium beam distribution matched to an alternating-gradient quadrupole focusing lattice by means of the adiabatic turn-on of the oscillating focusing field is studied numerically using particle-in-cell simulations. Quiescent beam propagation over several hundred lattice periods is demonstrated for a broad range of beam intensities and vacuum phase advances describing the strength of the oscillating focusing field. Properties of the matched-beam distribution are investigated. In particular, self-similar evolution of the beam density profile is observed over a wide range of system parameters. The numerical simulations are performed using the WARP particle-in-cell code.

  20. Beam Vacuum Interconnects for the LHC Cold Arcs

    CERN Document Server

    Veness, R J M; Gröbner, Oswald; Lepeule, P; Reymermier, C; Schneider, G; Skoczen, Blazej; Kleimenok, V; Nikitin, I N

    1999-01-01

    The design of the beam vacuum interconnect is described in this paper. Features include a novel RF bridge design to maximise lateral flexibility during cryostat Cold arcs of the LHC will consist of twin aperture dipole, quadrupole and corrector magnets in cryostats, operating at 1.9 K. Beam vacuum chambers, along with all connecting elements require flexible 'interconnects' between adjacent cryostats to allow for thermal and mechanical offsets foreseen during machine operation and alignment. In addition, the beam vacuum chambers contain perforated beam screens to intercept beam induced heat loads at an intermediate temperature. These must also be connected with low impedance RF bridges in the interconnect zones.alignment and so-called 'nested' bellows to minimise the required length of the assembly.

  1. Model of an LHC superconducting quadrupole magnet

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    Model of a superconducting quadrupole magnet for the LHC project. These magnets are used to focus the beam by squeezing it into a smaller cross-section, a similar effect to a lens focusing light. However, each magnet only focuses the beam in one direction so alternating magnet arrangements are required to produce a fully focused beam.

  2. Dipole gravity waves from unbound quadrupoles

    CERN Document Server

    Felber, Franklin

    2010-01-01

    Dipole gravitational disturbances from gravitationally unbound mass quadrupoles propagate to the radiation zone with signal strength at least of quadrupole order if the quadrupoles are nonrelativistic, and of dipole order if relativistic. Angular distributions of parallel-polarized and transverse-polarized dipole power in the radiation zone are calculated for simple unbound quadrupoles, like a linear-oscillator/stress-wave pair and a particle storage ring. Laboratory tests of general relativity through measurements of dipole gravity waves in the source region are proposed. A NASA G2 flywheel module with a modified rotor can produce a post-Newtonian dc bias signal at a gradiometer up to 1 mE. At peak luminosity, the repulsive dipole impulses of proton bunches at the LHC can produce an rms velocity of a high-Q detector surface up to 4 micron/s. Far outside the source region, Newtonian lunar dipole gravity waves can produce a 1-cm displacement signal at LISA. Dipole signal strengths of astrophysical events invol...

  3. All systems go for LHC quadrupoles

    CERN Multimedia

    2003-01-01

    The series fabrication of the Main Quadrupole cold masses for the LHC has begun with the delivery of the first unit on February 12th. The superconducting dipole magnets required to bend the proton beams around the LHC are often in the news. Less famous, perhaps, but equally important are the 360 main quadrupole (MQ) magnets, which will perform the principal focusing around the 27 km ring. CERN and CEA-Saclay began collaborating on the development and prototyping of these magnets in 1989. This resulted in five highly successful quadrupole units - also known as short straight sections - one of which was integrated for testing in String 1, and two others of the final design in String 2. Once the tests had confirmed the validity of the design and realization, the fabrication of the 360 cold masses had to be transferred to industry. After highly competitive tendering, the German firm ACCEL Instruments was entrusted both with the construction of the quadrupole magnets themselves, and with their assembly into the co...

  4. Closed orbit response to quadrupole strength variation

    Energy Technology Data Exchange (ETDEWEB)

    Wolski, Andrzej; Zimmermann, Frank

    2004-01-20

    We derive two formulae relating the variation in closed orbit in a storage ring to variations in quadrupole strength, neglecting nonlinear and dispersive effects. These formulae correct results previously reported [1,2,3]. We compare the results of the formulae applied to the ATF with simulations using MAD, and consider their application to beam-based alignment.

  5. Laser-induced quadrupole-quadrupole collisional energy transfer in Xe-Kr

    Institute of Scientific and Technical Information of China (English)

    Lu Zhen-Zhong; Chen De-Ying; Fan Rong-Wei; Xia Yuan-Qin

    2011-01-01

    By considering the relative velocity distribution function and multipole expansion interaction Hamiltonian, a three-state model for calculating the cross section of laser-induced quadrupole-quadrupole collisional energy transfer is presented. Calculated results in Xe-Kr system show that in the present system, the laser-induced collision process occurs for ~4 ps, which is much shorter than the dipole-dipole laser-induced collisional energy transfer (LICET) process.The spectrum of laser-induced quadrupole-quadrupole collisional energy transfer in Xe-Kr system has wider tunable range in an order of magnitude than the dipole-dipole LICET spectra. The peak cross section decreases and moves to the quasi-static wing with increasing temperature and the full width at half peak of the profile becomes larger as the system temperature increases.

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

    CERN Document Server

    Roloff, Philipp

    2013-01-01

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

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

    CERN Document Server

    Becker, F

    1999-01-01

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

  8. Quantum vacuum friction

    International Nuclear Information System (INIS)

    The quantum vacuum may in certain circumstances be regarded as a type of fluid medium, or aether, exhibiting energy density, pressure, stress and friction. Vacuum friction may be thought of as being responsible for the spontaneous creation of particles from the vacuum state when the system is non-stationary. Examples include the expanding universe, rotating black holes, moving mirrors, atoms passing close to surfaces, and the activities of sub-cellular biosystems. The concept of vacuum friction will be reviewed and illustrated, and some suggestions for future experiments made

  9. Experiments of Laser Pointing Stability in Air and in Vacuum to Validate Micrometric Positioning Sensor

    CERN Document Server

    Stern, G; Piedigrossi, D; Sandomierski, J; Sosin, M; Geiger, A; Guillaume, S

    2014-01-01

    Aligning accelerator components over 200m with 10 μm accuracy is a challenging task within the Compact Linear Collider (CLIC) study. A solution based on laser beam in vacuum as straight line reference is proposed. The positions of the accelerator’s components are measured with respect to the laser beam by sensors made of camera/shutter assemblies. To validate these sensors, laser pointing stability has to be studied over 200m. We perform experiments in air and in vacuum in order to know how laser pointing stability varies with the distance of propagation and with the environment. The experiments show that the standard deviations of the laser spot coordinates increase with the distance of propagation. They also show that the standard deviations are much smaller in vacuum (8 μm at 35m) than in air (2000 μm at 200m). Our experiment validates the concept of laser beam in vacuum with camera/shutter assembly for micrometric positioning over 35m. It also gives an estimation of the achievable precision.

  10. Vacuum Birefringence as a Vacuum Emission Process

    CERN Document Server

    Karbstein, Felix

    2015-01-01

    We argue that the phenomenon of vacuum birefringence in strong inhomogeneous electromagnetic fields can be most efficiently analyzed in terms of a vacuum emission process. In this contribution, we exemplarily stick to the case of vacuum birefringence in a stationary perpendicularly directed, purely magnetic background field extending over a finite spatial extent. Similar field configurations are realized in the BMV and PVLAS experiments. We demonstrate that we can reproduce the conventional constant field result. Our focus is on effects which arise when the probe photons originate in the field free region, are directed towards the magnetic field region, and detected well after the interaction with the magnetic field has taken place, again at zero field.

  11. New Approximate Kerr-like Metric with Quadrupole

    CERN Document Server

    Frutos-Alfaro, Francisco

    2015-01-01

    A new approximate metric representing the spacetime of a rotating deformed body is obtained by perturbing the Kerr metric to include the mass-quadrupole and quadrupole-quadrupole orders. It has a simple form, because is Kerr-like. Its post-linear form coincides with post-linear quadrupole-quadrupole metrics already found. Moreover, it can be transformed to an improved Hartle-Thorne metric, this guarantees its validity to be useful in studing compact object, like neutron stars, and that it is possible to find an inner solution.

  12. Approximate Kerr-Newman-like Metric with Quadrupole

    CERN Document Server

    Frutos-Alfaro, Francisco

    2016-01-01

    The Kerr metric is known to present issues when trying to find an interior solution. In this work we continue in our efforts to construct a more realistic exterior metric for astrophysical objects. A new approximate metric representing the spacetime of a charged, rotating and slightly-deformed body is obtained by perturbing the Kerr-Newman metric to include the mass-quadrupole and quadrupole-quadrupole orders. It has a simple form, because is Kerr-Newman-like. Its post-linear form without charge coincides with post-linear quadrupole-quadrupole metrics already found.

  13. Quadrupole to BPM offset determination in Indus-2

    International Nuclear Information System (INIS)

    A feasibility of finding the quadrupole to BPM offset using beam based alignment (BBA) technique in Indus-2 has been studied. The measurements of the offsets between BPM and quadrupoles could be performed by using quadratic fitting for the minima of the orbit response w. r. t. changes in the quadrupole strengths. These offsets will be integrated to the orbit data during closed orbit correction. There are 72 quadrupoles and 56 BPMs in Indus-2. However the assessment of Quad-BPM offsets is not feasible in some cases due to non-availability of BPM adjacent to quadrupole and also in some cases because of a large phase advance between quadrupole and nearby BPM. Here single corrector method is used to obtain these offsets and assumed the current of each quadrupole can be varied independently. A graphical user interface (GUI) is developed in MATLAB for the use of BBA in Indus-2. (author)

  14. 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

  15. ELETTRA vacuum system

    Science.gov (United States)

    Bernardini, M.

    1991-08-01

    A status report of the vacuum system of ELETTRA, the 2 GeV, 400 mA light source under construction in Trieste, will be described. The Vacuum project, presented at ``Synchrotron Radiation Vacuum Workshop'' at Riken (Japan 22-24 March 1990) and more recently at EVC-2, the European Vacuum Conference at Trieste (Italy 21-26 May 1990), is now in the phase of testing a prototype sector, which is 1/24 of the ring circumference. Details and some technological aspects of the fabrication will be reviewed together with the vacuum performances. Results of laboratory experiments on components, standard or not, allowed us to finalize the main choices in light of the general philosophy of the project and will be properly summarized.

  16. Static quadrupole moments in 120Te nuclei

    International Nuclear Information System (INIS)

    In recent years the region in the vicinity of tin isotopes has been intensively investigated both from experimental and theoretical perspectives. In tellurium nuclei with two protons outside the major shell, the partial level schemes are dominated by the 1g7/2 orbit leading to 6+ isomers in the vicinity of N=82 shell closure. At low spin, the Te nuclei are considered to be one of the best examples of quadrupole vibrators. For any nuclei to be vibrational namely three criteria must be satisfied : (i) the R4/2 ratio is equal to 2, (ii) a nearly degenerate two-phonon triplet of 0+, 2+ and 4+ states (iii) collective electric quadrupole transitions between states differing by one phonon and strong hindrance of E2 transition between states differing by more than one phonon

  17. AA Prototype-Quadrupole on Measurement Stand

    CERN Multimedia

    1979-01-01

    The very particular lattice of the AA required 2 types of quadrupoles: narrow ones (QFN, QDN) and wide ones (QFW, QDW). The wide ones, although rather short (steel length 0.54 m), had an unusually large aperture of 0.75 m in width, 0.68 m "good field". A prototype was built at CERN in 1978. Here we see it on its test stand, with a measurement coil inserted, Brian Pincott taking readings.

  18. AA Prototype-Quadrupole on Measurement Stand

    CERN Multimedia

    1978-01-01

    The very particular lattice of the AA required 2 types of quadrupoles: narrow ones (QFN, QDN) and wide ones (QFW, QDW). The wide ones, although not very long (steel length 0.54 m), had an unusually large aperture of 0.75 m in width, 0.68 m "good field". A prototype was built in 1978. Here we see it on its test stand, with Ray Brown positioning the measurement coil.

  19. Induced CMB quadrupole from pointing offsets

    CERN Document Server

    Moss, Adam; Sigurdson, Kris

    2010-01-01

    Recent claims in the literature have suggested that the {\\it WMAP} quadrupole is not primordial in origin, and arises from an aliasing of the much larger dipole field because of incorrect satellite pointing. We attempt to reproduce this result and delineate the key physics leading to the effect. We find that, even if real, the induced quadrupole would be smaller than claimed. We discuss reasons why the {\\it WMAP} data are unlikely to suffer from this particular systematic effect, including the implications for observations of point sources. Given this evidence against the reality of the effect, the similarity between the pointing-offset-induced signal and the actual quadrupole then appears to be quite puzzling. However, we find that the effect arises from a convolution between the gradient of the dipole field and anisotropic coverage of the scan direction at each pixel. There is something of a directional conspiracy here -- the dipole signal lies close to the Ecliptic Plane, and its direction, together with t...

  20. Table of nuclear electric quadrupole moments

    Science.gov (United States)

    Stone, N. J.

    2016-09-01

    This Table is a compilation of experimental measurements of static electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. Experimental data from all quadrupole moment measurements actually provide a value of the product of the moment and the electric field gradient [EFG] acting at the nucleus. Knowledge of the EFG is thus necessary to extract the quadrupole moment. A single recommended moment value is given for each state, based, for each element, wherever possible, upon a standard reference moment for a nuclear state of that element studied in a situation in which the electric field gradient has been well calculated. For several elements one or more subsidiary EFG/moment reference is required and their use is specified. The literature search covers the period to mid-2015.

  1. 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

  2. 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...

  3. 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 ...

  4. 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...

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

    CERN Document Server

    van Dam, S.B.

    2014-01-01

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

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

    CERN Document Server

    Grudiev, A; Wuensch, Walter

    2006-01-01

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

  7. 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...

  8. Avoiding vacuum arcs in high gradient normal conducting RF structures

    CERN Document Server

    Sjøbæk, Kyrre Ness; Adli, Erik; Grudiev, Alexej; Wuensch, Walter

    In order to build the Compact LInear Collider (CLIC), accelerating structures reaching extremely high accelerating gradients are needed. Such structures have been built and tested using normal-conducting copper, powered by X-band RF power and reaching gradients of 100 MV/m and above. One phenomenon that must be avoided in order to reliably reach such gradients, is vacuum arcs or “breakdowns”. This can be accomplished by carefully designing the structure geometry such that high surface fields and large local power flows are avoided. The research presented in this thesis presents a method for optimizing the geometry of accelerating structures so that these breakdowns are made less likely, allowing the structure to operate reliably at high gradients. This was done primarily based on a phenomenological scaling model, which predicted the maximum gradient as a function of the break down rate, pulse length, and field distribution in the structure. The model is written in such a way that it allows direct comparis...

  9. Development and manufacturing of a Nb$_{3}$Sn quadrupole magnet Model at CEA/Saclay for TESLA Interaction Region

    CERN Document Server

    Durante, Maria; Fratini, M; Leboeuf, D; Segreti, M; Védrine, Pierre; 10.1109/TASC.2004.829129

    2004-01-01

    One possible application of Nb/sub 3/Sn, whose superconducting properties far exceed those of NbTi, is the fabrication of short and powerful quadrupole magnets for the interaction regions of large particle accelerators. In some projects, as in the future linear collider TESLA, the quadrupole magnets are inside the detector solenoid and must operate in its background field. This situation gives singular Lorentz force distribution in the ends of the magnet. To learn about Nb/sub 3/Sn technology, evaluate fabrication techniques and test the interaction with a solenoidal field, DAPNIA /SACM at CEA/Saclay has started the manufacturing of a 1-m-long, 56- mm-single-aperture quadrupole magnet model. The model relies on the same coil geometry as the LHC arc quadrupole magnets, but has no iron yoke. It will produce a nominal field gradient of 211 T/m at 11,870 A. The coils are wound from Rutherford-type cables insulated with glass fiber tape, before being heat-treated and vacuum-impregnated with epoxy resin. Laminated,...

  10. Evading death by vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, A. [Universidade de Lisboa, Centro de Fisica Teorica e Computacional, Faculdade de Ciencias, Lisboa (Portugal); Ferreira, P.M.; Santos, Rui [Universidade de Lisboa, Centro de Fisica Teorica e Computacional, Faculdade de Ciencias, Lisboa (Portugal); Instituto Superior de Engenharia de Lisboa, Lisboa (Portugal); Ivanov, I.P. [Universite de Liege, IFPA, Liege (Belgium); Sobolev Institute of Mathematics, Novosibirsk (Russian Federation); Silva, Joao P. [Instituto Superior de Engenharia de Lisboa, Lisboa (Portugal); Universidade Tecnica de Lisboa, Centro de Fisica Teorica de Particulas (CFTP), Instituto Superior Tecnico, Lisboa (Portugal)

    2013-09-15

    In the Standard Model, the Higgs potential allows only one minimum at tree level. But the open possibility that there might be two scalar doublets enriches the vacuum structure, allowing for the risk that we might now be in a metastable state, which we dub the panic vacuum. Current experiments at the LHC are probing the Higgs particle predicted as a result of the spontaneous symmetry breaking. Remarkably, in the two Higgs model with a softly broken U(1) symmetry, the LHC experiments already allow to exclude many panic vacuum solutions. (orig.)

  11. Thermophoretic vacuum wand

    Science.gov (United States)

    Klebanoff, Leonard Elliott; Rader, Daniel John

    2000-01-01

    A thermophoretic vacuum wand that is particularly suited for transporting articles in a cleanroom environment so that potential particle contaminants in the air do not become adhered to the surface of the article is described. The wand includes a housing having a platen with a front surface with suction port(s) through the platen; a vacuum source for applying a negative pressure to the suction port(s); and heating device for the object. Heating the article when it is held by the vacuum wand affords thermophoretic protection that effectively prevents particles in the air from depositing onto the article.

  12. Negative Group Velocity from Quadrupole Resonance of Plasmonic Spheres

    CERN Document Server

    Han, Dezhuan; Fung, Kin Hung; Zhang, Zhao-Qing; Chan, C T

    2008-01-01

    We study the dispersions of plasmonic bands that arise from the coupling of electric quadrupole resonances in three dimensional photonic crystals (PCs) consisting of plasmonic spheres. Through analytical derivation, we show that two branches of quadrupole bands in simple cubic PCs with a small lattice constant possess negative group velocities. Distinct from double negative media in which the negative responses originates from the coupling of electric and magnetic responses (P and M), the negative dispersion induced by quadrupole resonance is an intrinsic property of quadrupole that does not require coupling to another degree of freedom. In addition, there is no simple effective medium description. In plasmonic systems composed of metallic nanoparticle clusters, the coupled quadrupole resonance may be tuned to lower optical frequencies, and the coupling strength between this quadrupole resonance and external electromagnetic (EM) waves are in the same order of the magnetic dipole M.

  13. Vacuum Camera Cooler

    Science.gov (United States)

    Laugen, Geoffrey A.

    2011-01-01

    Acquiring cheap, moving video was impossible in a vacuum environment, due to camera overheating. This overheating is brought on by the lack of cooling media in vacuum. A water-jacketed camera cooler enclosure machined and assembled from copper plate and tube has been developed. The camera cooler (see figure) is cup-shaped and cooled by circulating water or nitrogen gas through copper tubing. The camera, a store-bought "spy type," is not designed to work in a vacuum. With some modifications the unit can be thermally connected when mounted in the cup portion of the camera cooler. The thermal conductivity is provided by copper tape between parts of the camera and the cooled enclosure. During initial testing of the demonstration unit, the camera cooler kept the CPU (central processing unit) of this video camera at operating temperature. This development allowed video recording of an in-progress test, within a vacuum environment.

  14. Cosmology of gravitational vacuum

    CERN Document Server

    Burdyuzha, V; Pacheco, J

    2008-01-01

    Production of gravitational vacuum defects and their contribution to the energy density of our Universe are discussed. These topological microstructures (defects) could be produced in the result of creation of the Universe from "nothing" when a gravitational vacuum condensate has appeared. They must be isotropically distributed over the isotropic expanding Universe. After Universe inflation these microdefects are smoothed, stretched and broken up. A part of them could survive and now they are perceived as the structures of Lambda-term and an unclustered dark matter. It is shown that the parametrization noninvariance of the Wheeler-De Witt equation can be used to describe phenomenologically vacuum topological defects of different dimensions (worm-holes, micromembranes, microstrings and monopoles). The mathematical illustration of these processes may be the spontaneous breaking of the local Lorentz-invariance of the quasi-classical equations of gravity. Probably the gravitational vacuum condensate has fixed tim...

  15. A Planck Vacuum Cosmology

    Directory of Open Access Journals (Sweden)

    Daywitt W. C.

    2009-04-01

    Full Text Available Both the big-bang and the quasi-steady-state cosmologies originate in some type of Planck state. This paper presents a new cosmological theory based on the Planck- vacuum negative-energy state, a state consisting of a degenerate collection of negative- energy Planck particles. A heuristic look at the Einstein field equation provides a con- vincing argument that such a vacuum state could provide a theoretical explanation for the visible universe.

  16. Power vacuum tubes handbook

    CERN Document Server

    Whitaker, Jerry

    2012-01-01

    Providing examples of applications, Power Vacuum Tubes Handbook, Third Edition examines the underlying technology of each type of power vacuum tube device in common use today. The author presents basic principles, reports on new development efforts, and discusses implementation and maintenance considerations. Supporting mathematical equations and extensive technical illustrations and schematic diagrams help readers understand the material. Translate Principles into Specific Applications This one-stop reference is a hands-on guide for engineering personnel involved in the design, specification,

  17. Magnetic mirror structure for testing shell-type quadrupole coils

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, N.; Barzi, E.; Bossert, R.; Chlachidze, G.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Nobrega, F.; Novitski, I.; Tartaglia, N.; Turrioni, D.; /Fermilab

    2009-10-01

    This paper presents magnetic and mechanical designs and analyses of the quadrupole mirror structure to test single shell-type quadrupole coils. Several quadrupole coils made of different Nb{sub 3}Sn strands, cable insulation and pole materials were tested using this structure at 4.5 and 1.9 K. The coils were instrumented with voltage taps, spot heaters, temperature sensors and strain gauges to study their mechanical and thermal properties and quench performance. The results of the quadrupole mirror model assembly and test are reported and discussed.

  18. Noise reduction in negative-ion quadrupole mass spectrometry

    Science.gov (United States)

    Chastagner, Philippe

    1993-01-01

    A quadrupole mass spectrometer (QMS) system having an ion source, quadrupole mass filter, and ion collector/recorder system. A weak, transverse magnetic field and an electron collector are disposed between the quadrupole and ion collector. When operated in negative ion mode, the ion source produces a beam of primarily negatively-charged particles from a sample, including electrons as well as ions. The beam passes through the quadrupole and enters the magnetic field, where the electrons are deflected away from the beam path to the electron collector. The negative ions pass undeflected to the ion collector where they are detected and recorded as a mass spectrum.

  19. Self-consistent calculations of quadrupole moments of spherical nuclei

    OpenAIRE

    Saperstein E. E.; Tolokonnikov S.; Krewald S.; Kamerdzhiev S.; Voitenkov D.

    2012-01-01

    The self-consistent Theory of Finite Fermi Systems based on the Energy Density Functional by Fayans et al. with the set DF3-a of parameters fixed previously is used to calculate three kinds of quadrupole moments. At first, we examined systematically quadrupole moments of odd neighbors of semi-magic lead and tin isotopes and $N=50,N=82$ isotones. Second, we found quadrupole moments of the first $2^+$ states in the same two chains of isotopes. Finally, we evaluated quadrupole moments of odd-odd...

  20. Distinguishing the nonjet azimuth quadrupole from QCD jets and hydrodynamic flows via 2D angular correlations and quadrupole spectrum analysis

    CERN Document Server

    Trainor, Thomas A

    2016-01-01

    According to the flow narrative commonly applied to high-energy nuclear collisions a 1D cylindrical-quadrupole component of 2D angular correlations conventionally denoted by quantity $v_2$ is interpreted to represent elliptic flow: azimuth modulation of transverse or radial flow in noncentral nucleus-nucleus (A-A) collisions. The nonjet (NJ) quadrupole component exhibits various properties inconsistent with a flow or hydro interpretation, including the observation that NJ-quadrupole centrality variation in $A$-$A$ collisions has no relation to strongly-varying jet modification ("jet quenching") in those collisions commonly attributed to jet interaction with a dense flowing medium. In the present study I report isolation of quadrupole spectra from $p_t$-differential $v_2(p_t)$ data obtained at the relativistic heavy ion collider (RHIC) and large hadron collider (LHCr). I demonstrate that NJ quadrupole spectra have characteristics very different from the single-particle spectra for most hadrons, that quadrupole...

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

    CERN Document Server

    Blaising, Jean-Jacques

    2012-01-01

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

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

    CERN Document Server

    Duarte Ramos, F.

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    A. Gutiérrez-Rodríguez

    2014-01-01

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

  4. Nuclear Quadrupole Resonance Studies in MICA

    Science.gov (United States)

    Sengupta, S.; Rhadakrishna, S.; Marino, R. A.

    1986-02-01

    Aluminum-27 NQR transitions were detected in Muscovite Mica at room temperature using double resonance by level crossing (DRLC) techniques. Three lines were observed with frequencies of 572.5, 1052.0, and 1624.5 kHz. These lines are assigned to the octahedrally coordinated site, AlO4(OH)2. The corresponding quadrupole coupling constant, e2q Q/h, and asymmetry parameter, η, are 3554.8 kHz and 0.265, respectively. The remaining tetrahedrally coordinated sites, AlO4, gave no discernible signal, perhaps due to the greater 27Al- 1H distance.

  5. Precise calculations of the deuteron quadrupole moment

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Franz L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-06-01

    Recently, two calculations of the deuteron quadrupole moment have have given predictions that agree with the measured value to within 1%, resolving a long-standing discrepancy. One of these uses the covariant spectator theory (CST) and the other chiral effective field theory (cEFT). In this talk I will first briefly review the foundations and history of the CST, and then compare these two calculations with emphasis on how the same physical processes are being described using very different language. The comparison of the two methods gives new insights into the dynamics of the low energy NN interaction.

  6. A Compact High Gradient Pulsed Magnetic Quadrupole

    CERN Document Server

    Shuman, Derek; Kireeff Covo, Michel; Ritchie, Gary; Seidl, Peter

    2005-01-01

    A design for a high gradient, low inductance pulsed quadrupole magnet is presented. The magnet is a circular current dominated design with a circular iron return yoke. Features include a five turn eddy current compensated solid conductor coil design which theoretically eliminates the first four higher order multipole field components, a single layer "non-spiral bedstead" coil design which both minimizes utilization of radial space and maximizes utilization of axial space, and allows incorporation of steering and correction coils within existing radial space. The coils are wound and stretched straight in a special winder, then bent in simple fixtures to form the upturned ends, simplifying fabrication and assembly.

  7. Quadrupole Transfer Function for Emittance Measurement

    CERN Document Server

    Cameron, Peter; Jansson, Andreas; Tan, Cheng-Yang

    2008-01-01

    Historically the use of the quadrupole moment measurement has been impeded by the requirement for large dynamic range, as well as measurement sensitivity to beam position. We investigate the use of the transfer function technique [1-3] in combination with the sensitivity and 160dB revolution line rejection of the direct diode detection analog front end [4] to open the possibility of an emittance diagnostic that may be implemented without operational complication, quasi- parasitic to the operation of existing tune measurement systems. Such a diagnostic would be particularly useful as an emittance monitor during acceleration ramp development in machines like RHIC and the LHC.

  8. Status of radio frequency quadrupole accelerator at IUAC, New Delhi

    International Nuclear Information System (INIS)

    As part of the accelerator augmentation program at IUAC, a High Current Injector (HCI) is being developed to inject highly charged ions into the superconducting LINAC. The HCI consists of a superconducting (High TC) ECR source, producing the high currents of highly charged ions. The ion beams produced will be injected into a Radio Frequency Quadrupole Accelerator (RFQ) and be accelerated to 180 keV/u. RF power of about 100 kW at 48.5 MHz will be fed to the RFQ during its actual working. The ions will be further accelerated by a Drift Tube Linac (DTL), before being further velocity matched with a low beta cavity into the superconducting LINAC. RFQ at IUAC is a four rod cavity structure having individual demountable copper vanes held on vane posts with a total vane length of 2.536 m and a minimum aperture of 12mm. The vane posts hold twenty nos. of vanes. Water will flow into vanes through the vane posts. The copper plated stainless steel vacuum housing has been divided into two chambers for the ease of fabrication and copper plating. The RFQ stand has provision for alignment in all the three axes. After successfully validating all the electrical and mechanical design parameters on a prototype RFQ, the fabrication of final RFQ has been completed. Initial assembly to check the mechanical accuracies was carried out. Low power RF tests were conducted to validate the design parameters. The resonance frequency of the RFQ was measured as 44.12 MHz and Q value was measured ∼ 5500. The final assembly is in progress. This paper details the present status and future plan of RFQ. (author)

  9. Final Muon Emittance Exchange in Vacuum for a Collider

    Energy Technology Data Exchange (ETDEWEB)

    Summers, Don [Univ. of Mississippi, Oxford, MS (United States); Acosta, John [Univ. of Mississippi, Oxford, MS (United States); Cremaldi, Lucien [Univ. of Mississippi, Oxford, MS (United States); Hart, Terry [Univ. of Mississippi, Oxford, MS (United States); Oliveros, Sandra [Univ. of Mississippi, Oxford, MS (United States); Perera, Lalith [Univ. of Mississippi, Oxford, MS (United States); Wu, Wanwei [Univ. of Mississippi, Oxford, MS (United States); Neuffer, David [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-05-07

    We outline a plan for final muon ionization cooling with quadrupole doublets focusing onto short absorbers followed by emittance exchange in vacuum to achieve the small transverse beam sizes needed by a muon collider. A flat muon beam with a series of quadrupole doublet half cells appears to provide the strong focusing required for final cooling. Each quadrupole doublet has a low β region occupied by a dense, low Z absorber. After final cooling, normalized xyz emittances of (0.071, 0.141, 2.4) mm-rad are exchanged into (0.025, 0.025, 70) mm-rad. Thin electrostatic septa efficiently slice the bunch into 17 parts. The 17 bunches are interleaved into a 3.7 meter long train with RF deflector cavities. Snap bunch coalescence combines the muon bunch train longitudinally in a 21 GeV ring in 55 μs, one quarter of a synchrotron oscillation period. A linear long wavelength RF bucket gives each bunch a different energy causing the bunches to drift until they merge into one bunch and can be captured in a short wavelength RF bucket with a 13% muon decay loss and a packing fraction as high as 87%.

  10. Final Muon Emittance Exchange in Vacuum for a Collider

    CERN Document Server

    Summers, Don; Cremaldi, Lucien; Hart, Terry; Oliveros, Sandra; Perera, Lalith; Wu, Wanwei; Neuffer, David

    2015-01-01

    We outline a plan for final muon ionization cooling with quadrupole doublets focusing onto short absorbers followed by emittance exchange in vacuum to achieve the small transverse beam sizes needed by a muon collider. A flat muon beam with a series of quadrupole doublet half cells appears to provide the strong focusing required for final cooling. Each quadrupole doublet has a low beta region occupied by a dense, low Z absorber. After final cooling, normalized xyz emittances of (0.071, 0.141, 2.4) mm-rad are exchanged into (0.025, 0.025, 70) mm-rad. Thin electrostatic septa efficiently slice the bunch into 17 parts. The 17 bunches are interleaved into a 3.7 meter long train with RF deflector cavities. Snap bunch coalescence combines the muon bunch train longitudinally in a 21 GeV ring in 55 microseconds, one quarter of a synchrotron oscillation period. A linear long wavelength RF bucket gives each bunch a different energy causing the bunches to drift until they merge into one bunch and can be captured in a sho...

  11. Stellarator helical vacuum vessel

    International Nuclear Information System (INIS)

    A design study of a stainless steel, heavy wall, helically shaped vacuum torus has been made for use in a proposed Stellarator configuration. The study concerns itself with the shape of the vacuum vessel and the division of the vessel into components that can be machined and welded together into a helical configuration. A complication in the design requires that a circular magnet coil be located at the minor toroidal axis and that this coil be embedded within the periphery of the vacuum vessel. The vacuum vessel has a minor toroidal axis diameter of 4 meters, a 68.6-cm shell diameter, and a 1.9-cm wall thickness. It twists about the minor toroidal axis twice in 3600C. (An n value of 2). It is proposed that the unit be made of cylindrical segments with the ends of the cylinders cut at appropriate lengths and angles to form the helix. A mathematical derivation of the dimensions necessary to produce the required shapes of the segments has been made. Also, drawings of the vacuum vessel components have been produced on LANL's CTR CAD/CAM system. The procedure developed can be used for any value of n as dictated by physics requirements

  12. Vacuum welding of metals

    International Nuclear Information System (INIS)

    This new welding process has been developed by the Commissariat a l'Energie Atomique (CEA) in France. The edges of the work-pieces are melted by the impact of an electron beam produced by an electron gun. Welding is carried out in a vacuum of 10-4 to 10-8 mm of mercury. The welding machine consists, diagrammatically, of: a) a metal enclosure in which a vacuum is produced; b) a cathode for electron emission, a high-voltage generator for accelerating these electrons, a focusing device; c) a mechanical device for moving (rotating) the work-piece. Advantages of the process: 1) possible welding of highly oxidizable metals (e.g. zirconium); 2) fabrication of high-vacuum-sealed metal containers; 3) production of very deeply penetrated welds. Therefore, this new process is particularly advantageous for atomic power applications, the fabrication of electron tubes and, more generally, for all industries in which very special metals are used. (author)

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

    CERN Document Server

    Pequegnot, Anne-Laure

    2013-01-01

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

  14. 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...

  15. Fifth-order aberrations in magnetic quadrupole-octupole systems

    International Nuclear Information System (INIS)

    Explicit integral expressions are given for the fifth-order geometrical aberration coefficients in rectilinear magnetic quadrupole-octupole systems used for the transport of nonrelativistic charged particle beams. The numerical values of the fifth-order geometrical aberration coefficients for a rare earth cobalt (REC) quadrupole doublet are given as an example. 26 refs., 5 figs., 4 tabs

  16. Handbook of vacuum physics

    CERN Document Server

    1964-01-01

    Handbook of Vacuum Physics, Volume 3: Technology is a handbook of vacuum physics, with emphasis on the properties of miscellaneous materials such as mica, oils, greases, waxes, and rubber. Accurate modern tables of physical constants, properties of materials, laboratory techniques, and properties of commercial pumps, gauges, and leak detectors are presented. This volume is comprised of 12 chapters and begins with a discussion on pump oils, divided into rotary pump oils and vapor pump oils. The next chapter deals with the properties and applications of greases, including outgassing and vapor pr

  17. New Vacuum Solar Telescope

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    With its pure aperture up to 985mm, the New Vacuum Solar Telescope of China (NVST) has become the world's biggest vacuum solar telescope. The main science task of NVST is the high-resolution observation of photosphere and chromosphere including their fine structure of magnetic field on the sun. The NVST was equipped with many new technologies and powerful instruments, such as an adaptive optical system, a polarization analyzer, two vertical spectrographs, a high-resolution image system and a very narrow Ha filter (0.125A).

  18. Baryogenesis in false vacuum

    CERN Document Server

    Hamada, Yuta

    2016-01-01

    The null result in the LHC may indicate that the standard model is not drastically modified up to very high scale such as the GUT/string scale. Having this in the mind, we suggest a novel leptogenesis scenario realized in the false vacuum of the Higgs field. If the Higgs field develops the large vacuum expectation value in the early universe, the lepton number violating process is enhanced, which we use for baryogenesis. To demonstrate the scenario, several models are discussed. For example, we show that the observed baryon asymmetry is successfully generated in the standard model with a second Higgs doublet and a singlet scalar.

  19. Rescuing the nonjet (NJ) azimuth quadrupole from the flow narrative

    CERN Document Server

    Trainor, Thomas A

    2016-01-01

    According to the flow narrative commonly applied to high-energy nuclear collisions a cylindrical-quadrupole component of 1D azimuth angular correlations is conventionally denoted by quantity $v_2$ and interpreted to represent elliptic flow. Jet angular correlations may also contribute to $v_2$ data as "nonflow" depending on the method used to calculate $v_2$, but 2D graphical methods are available to insure accurate separation. The nonjet (NJ) quadrupole has various properties inconsistent with a flow interpretation, including the observation that NJ quadrupole centrality variation in A-A collisions has no relation to strongly-varying jet modification ("jet quenching") in those collisions commonly attributed to jet interaction with a flowing dense medium. In this presentation I describe isolation of quadrupole spectra from pt-differential $v_2(p_t)$ data from the RHIC and LHC. I demonstrate that quadrupole spectra have characteristics very different from the single-particle spectra for most hadrons, that quad...

  20. Design and construction of superconducting quadrupole magnets at Karlsruhe

    CERN Document Server

    Arendt, F; Turowski, P

    1977-01-01

    Two types of superconducting quadrupole magnets have been developed: 6 extremely short doublets with a quadrupole length of nearly 11 cm as beam focusing elements in the Karlsruhe superconducting proton linac; 2 quadrupoles of about 1 m length for use in the hyperon experiments at the CERN SPS. The concept for these quadrupoles is a one current block winding per pole, calculated with respect to minimum field errors. Special mechanical and winding techniques have been developed to get the high geometric accuracy required for such air coils. The short doublets must be operated in persistent current mode with a thermal superconducting switch and a required time constant of tau >10 /sup 4/ hours. The hyperon beam quadrupoles must operate reliably for a long time in an inaccessible concrete shielding. (2 refs).

  1. CP-violating effect of the Th nuclear magnetic quadrupole moment: accurate many-body study of ThO.

    Science.gov (United States)

    Skripnikov, L V; Petrov, A N; Titov, A V; Flambaum, V V

    2014-12-31

    Investigations of CP violation in the hadron sector may be done using measurements in the ThO molecule. Recent measurements in this molecule improved the limit on the electron electric dipole moment (EDM) by an order of magnitude. Another time-reversal (T) and parity (P)-violating effect in 229ThO is induced by the nuclear magnetic quadrupole moment. We perform nuclear and molecular calculations to express this effect in terms of the strength constants of T, P-odd nuclear forces, neutron EDM, QCD vacuum angle θ, quark EDM, and chromo-EDM. PMID:25615324

  2. Technology handbook of vacuum physics

    CERN Document Server

    Beck, A H

    2013-01-01

    Handbook of Vacuum Physics, Volume 3: Technology is part of a series of publications that presents articles featuring the whole spectrum of vacuum physics. This particular volume presents materials that deal with technology concerns in vacuum mechanics. The first material talks about the utilization of ceramic materials in the construction of vacuum devices. The next paper details the application of vacuum physics in soldering and brazing process. The last article deals with the utilization of vacuum technology in high frequency heating. The book will be of great use to professionals involved

  3. Tara vacuum system

    International Nuclear Information System (INIS)

    The Tara tandem mirror experiment vacuum system will be discussed including system design, specifications, and performance required for plug thermal barrier operation. A detailed description of the major pumpig systems, reflux control, plasma pumping, measurement and control, fast gas handling and quality control procedures will be presented. Data from the two 5 month periods of operation will be presented

  4. LEP vacuum chamber, prototype

    CERN Multimedia

    1983-01-01

    Final prototype for the LEP vacuum chamber, see 8305170 for more details. Here we see the strips of the NEG pump, providing "distributed pumping". The strips are made from a Zr-Ti-Fe alloy. By passing an electrical current, they were heated to 700 deg C.

  5. The quantum vacuum

    CERN Document Server

    Paraoanu, G S

    2014-01-01

    The vacuum is the lowest energy state of a field in a certain region of space. This definition implies that no particles can be present in the vacuum state. In classical physics, the only features of vacuum are those of its geometry. For example, in the general theory of relativity the geometry is a dynamical structure that guides the motion of matter, and, in turn, it is bent and curved by the presence of matter. Other than this, the classical vacuum is a structure void of any physical properties, since classically properties are strictly associated with physical objects such as particles and finite-amplitude fields. The situation is very different in quantum physics. As I will show in this paper, the difference stems form the fact that in quantum physics the properties are not strictly tied to objects. We know for example that physical properties come into existence - as values of observables - only when the object is measured. Thus, quantum physics allows us to detach properties from objects. This has cons...

  6. ISR vacuum system

    CERN Multimedia

    1970-01-01

    A pressure of 5 x 10-11 Torr has been obtained repreatedly in this pilot section of the ISR vacuum system. The pilot section is 45 m long is pumped by 9 sputter-ion pumps pf 350 l/s pumping speed, and is baked out at 200 degrees C before each pump down.

  7. LEP Vacuum Chamber

    CERN Multimedia

    1983-01-01

    This is a cut-out of a LEP vacuum chamber for dipole magnets showing the beam channel and the pumping channel with the getter (NEG) strip and its insulating supports. A water pipe connected to the cooling channel can also be seen at the back.The lead radiation shield lining is also shown. See also 8305563X.

  8. ISR vacuum system

    CERN Multimedia

    1971-01-01

    Some of the most important components of the vacuum system are shown. At the left, the rectangular box is a sputter-ion pump inside its bake-out oven. The assembly in the centre includes a sector valve, three roughing valves, a turbomolecular pump, a rotary backing pump and auxiliary equipment. At the right, the small elbow houses a Bayard-

  9. Commissioning Results of the HZB Quadrupole Resonator

    CERN Document Server

    Kleindienst, Raphael; Knobloch, Jens; Kugeler, Oliver

    2015-01-01

    Recent cavity results with niobium have demonstrated the necessity of a good understanding of both the BCS and residual resistance. For a complete picture and comparison with theory, it is essential that one can measure the RF properties as a function of field, temperature, frequency and ambient magnetic field. Standard cavity measurements are limited in their ability to change all parameters freely and in a controlled manner. On the other hand, most sample measurement setups operate at fairly high frequency, where the surface resistance is always BCS dominated. The quadrupole resonator, originally developed at CERN, is ideally suited for characterization of samples at typical cavity RF frequencies. We report on a modified version of the QPR with improved RF figures of merit for high-field operation. Experimental challenges in the commissioning run and alternate designs for simpler sample changes are shown alongside measurement results of a large grain niobium sample.

  10. Cryostat design for SSC quadrupole magnets

    International Nuclear Information System (INIS)

    The baseline design of the SSC Collider Quadrupole Magnet (CQM) cryostat is complete. The cryostat is designed to minimize cost and maximize system reliability. Many components have already been procured. Material characterization and component tests for many of the parts have been completed or are ongoing. The first CQM cryostat will be assembled in September of 1993. This paper describes the cryostat design for the CQM developed at Babcock ampersand Wilcox (B ampersand W). The CQM cryostat operates at cryogenic temperatures with a very stringent heat load budget. The cryostat supports the cold mass within the cryostat and insulates the cold mass against heating by conduction, thermal radiation and residual gas conduction. A description of the major components highlighting the key design features is given. The tradeoff studies performed for each component are summarized. The results of a static thermal analysis of the cryostat are presented

  11. Quadrupole magnet for a rapid cycling synchrotron

    Energy Technology Data Exchange (ETDEWEB)

    Witte, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, J. S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    Rapid Cycling Synchrotrons (RCS) feature interleaved warm and cold dipole magnets; the field of the warm magnets is used to modulate the average bending field depending on the particle energy. It has been shown that RCS can be an attractive option for fast acceleration of particles, for example, muons, which decay quickly. In previous studies it was demonstrated that in principle warm dipole magnets can be designed which can provide the required ramp rates, which are equivalent to frequencies of about 1 kHz. To reduce the losses it is beneficial to employ two separate materials for the yoke; it was also shown that by employing an optimized excitation coil geometry the eddy current losses are acceptable. In this paper we show that the same principles can be applied to quadrupole magnets targeting 30 T/m with a repetition rate of 1kHz and good field quality.

  12. Field reconstruction in large aperture quadrupole magnets

    Energy Technology Data Exchange (ETDEWEB)

    Lazzaro, A. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95125 Catania (Italy); Cappuzzello, F. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95125 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95125 Catania (Italy)], E-mail: cappuzzello@lns.infn.it; Cunsolo, A.; Cavallaro, M. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95125 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95125 Catania (Italy); Foti, A. [Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95125 Catania (Italy); INFN-Sezione di Catania, Via S. Sofia 64, I-95125 Catania (Italy); Orrigo, S.E.A.; Rodrigues, M.R.D.; Winfield, J.S. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95125 Catania (Italy); Berz, M. [Department of Physics and Astronomy, Michigan State University, MI 48824 (United States)

    2009-04-21

    A technique to interpolate complex three-dimensional field distributions such as those produced by large magnets is presented. It is based on a modified charge density method where the elementary sources of the magnetic field are image charges with Gaussian shape placed on a three-dimensional surface. The strengths of the charges are found as the solution of a best-fit problem, whose special features are discussed in detail. The method is tested against the measured field of the MAGNEX large acceptance quadrupole, showing a high level of accuracy together with an effective compensation of the effect of the experimental errors present in the data. In addition the model field is in general analytical and Maxwellian. As a consequence, the reliability of the presented technique to the challenging problem of trajectory reconstruction in modern large acceptance spectrometers is demonstrated.

  13. Quench Protection of the LHC Quadrupole Magnets

    CERN Document Server

    Kurfuerst, Christoph; Dehning, Bernd; Sapoinski, Mariusz

    2010-01-01

    CERNs Large Hadron Collider (LHC) is a new high energy proton accelerator and storage ring. Its design allows to reach unprecedented beam energies and beam intensities, resulting in a largely increased particle physics discovery potential. The combination of its high beam energy and intensity may lead to beam losses which can have a severe impact on the LHC equipment and damage sensitive elements. To protect those and to measure operational losses, a Beam Loss Monitoring system has been installed all along the ring. The protection is achieved by extracting the beam from the ring in case thresholds imposed on measured radiation levels are exceeded. The thresholds are estimated through particle shower simulations. The simulated geometry and physic processes need to be precise in order to determine an optimum value, which therefore assures a high availability of the LHC for operation. This study is focused on the interconnection region between the main dipole and the main quadrupole magnet of the LHC. Six monito...

  14. Atomic Quadrupole Moment Measurement Using Dynamic Decoupling.

    Science.gov (United States)

    Shaniv, R; Akerman, N; Ozeri, R

    2016-04-01

    We present a method that uses dynamic decoupling of a multilevel quantum probe to distinguish small frequency shifts that depend on m_{j}^{2}, where m_{j}^{2} is the angular momentum of level |j⟩ along the quantization axis, from large noisy shifts that are linear in m_{j}, such as those due to magnetic field noise. Using this method we measured the electric-quadrupole moment of the 4D_{5/2} level in ^{88}Sr^{+} to be 2.973_{-0.033}^{+0.026}ea_{0}^{2}. Our measurement improves the uncertainty of this value by an order of magnitude and thus helps mitigate an important systematic uncertainty in ^{88}Sr^{+} based optical atomic clocks and verifies complicated many-body quantum calculations.

  15. Diagnostic for Electron Clouds Trapped in Quadrupoles

    CERN Document Server

    Macek, Robert J

    2005-01-01

    Simulations have indicated that electron clouds generated by beam-induced multipactor can be trapped in the mirror-like fields of magnetic quadrupoles and thereby contribute significantly to the electron cloud buildup in high intensity accelerators and storage rings. This could be the most important source of electrons driving the two-stream (e-p) instability at the Los Alamos PSR and may also play a significant role in electron cloud effects at some of the new high intensity accelerator projects. We will describe the physics design and optimization of an electron-sweeping detector designed to measure the trapped electrons at various times after the beam pulse has passed. The instrument can also serve as an electro-magnetically shielded detector providing a signal obtained from electrons striking the wall during the passage of beam bunches.

  16. Realization of Radio-Frequency Quadrupole (RFQ) for accelerator program - manufacturing methodology adopted by industry

    International Nuclear Information System (INIS)

    Radio-Frequency Quadrupole (RFQ) linacs are efficient, compact, low energy ion structures, which have found numerous applications. They use electrical RF focusing and can capture, bunch, and transmit high-current ion beams. The RFQ for the Indian Ion Accelerator program is made of Oxygen free electrolytic (OFE) Copper in 4 segments of one meter each. Each segment is realized from 4 segments of 2 Minor and Major Vanes each. The Major and Minor Vanes are machined from OFE Copper blocks in stages with intermediate thermal treatments in vacuum environment for stress relieving and the coolant channel holes are drilled though the entire body. The final machining including the Vane tip modulation is done using special tools on a CNC machine. The Vane tip modulation and other geometrical parameters of the Vanes are inspected using a CMM to ascertain the required accuracy. This paper is aimed at discussing various aspects of RFQ development at BrahMos and the technologies developed

  17. Upgrade of the radio frequency quadrupole cooler and buncher for the HIE-ISOLDE project

    CERN Document Server

    Babcock, Carla

    2013-01-01

    The upgrade to the ISOLDE facility, HIE-ISOLDE, will include an upgrade to the RFQCB (radio frequency quadrupole cooler and buncher), the focus of which will be fixing the problems of alignment with the current machine, improving the integrity of the vacuum system, stabilizing the internal gas pressure, and the changes associated with a new position. The beam passage inside the RFQCB has been simulated with an independent code to highlight the importance of the internal gas pressure, to motivate design changes in the new RFQCB and to explain ways to improve the performance of the current machine. The suspected misalignment of ISCOOL has been quantified, and, using a simulation of ions passing through the external injection electrodes, the effect of the misalignment on machine acceptance has been detailed. Plans for the future RFQCB test stand and HIE-ISOLDE installation have been outlined. (C) 2013 Elsevier B.V. All rights reserved.

  18. A mass quadrupole spectrometry investigation on proton emission by nanosecond laser ablation

    Science.gov (United States)

    Caridi, F.

    2015-02-01

    A nanosecond pulsed Nd:YAG laser operating at the fundamental wavelength of 1064 nm and at an intensity of about 1010 W/cm2 was employed to irradiate hydrogenated polymers in vacuum. The produced plasma was characterized in terms of thermal and Coulomb interactions evaluating the equivalent temperature and the acceleration voltage developed in the non-equilibrium plasma core. Particles emission along the normal to the target surface was investigated by measuring, with the Hiden EQP 300 mass quadrupole spectrometer, ion energy distributions and fitting experimental data with the "Coulomb-Boltzmann-shifted" function. Time-of-flight technique was employed in order to measure the proton energy and yield. A comparison between experimental results is presented and discussed, with a special regard to the protons emission.

  19. Upgrade of the radio frequency quadrupole cooler and buncher for the HIE-ISOLDE project

    Science.gov (United States)

    Babcock, Carla; Giles, Tim

    2013-12-01

    The upgrade to the ISOLDE facility, HIE-ISOLDE, will include an upgrade to the RFQCB (radio frequency quadrupole cooler and buncher), the focus of which will be fixing the problems of alignment with the current machine, improving the integrity of the vacuum system, stabilizing the internal gas pressure, and the changes associated with a new position. The beam passage inside the RFQCB has been simulated with an independent code to highlight the importance of the internal gas pressure, to motivate design changes in the new RFQCB and to explain ways to improve the performance of the current machine. The suspected misalignment of ISCOOL has been quantified, and, using a simulation of ions passing through the external injection electrodes, the effect of the misalignment on machine acceptance has been detailed. Plans for the future RFQCB test stand and HIE-ISOLDE installation have been outlined.

  20. Tritium handling in vacuum systems

    Energy Technology Data Exchange (ETDEWEB)

    Gill, J.T. [Monsanto Research Corp., Miamisburg, OH (United States). Mound Facility; Coffin, D.O. [Los Alamos National Lab., NM (United States)

    1986-10-01

    This report provides a course in Tritium handling in vacuum systems. Topics presented are: Properties of Tritium; Tritium compatibility of materials; Tritium-compatible vacuum equipment; and Tritium waste treatment.

  1. Insertion device vacuum system designs

    International Nuclear Information System (INIS)

    Synchrotron light source insertion device vacuum systems now in operation and systems proposed for the future are reviewed. An overview of insertion devices is given and four generic vacuum chamber designs, transition section design and pumping considerations are discussed. Examples of vacuum chamber systems are presented

  2. Surge-damping vacuum valve

    Science.gov (United States)

    Bullock, Jack C.; Kelly, Benjamin E.

    1980-01-01

    A valve having a mechanism for damping out flow surges in a vacuum system which utilizes a slotted spring-loaded disk positioned adjacent the valve's vacuum port. Under flow surge conditions, the differential pressure forces the disk into sealing engagement with the vacuum port, thereby restricting the flow path to the slots in the disk damping out the flow surge.

  3. Development of Superconducting Focusing Quadrupoles for Heavy Ion Drivers

    Energy Technology Data Exchange (ETDEWEB)

    Martovetsky, N; Manahan, R; Lietzke, A F

    2001-09-10

    Heavy Ion Fusion (HIF) is exploring a promising path to a practical inertial-confinement fusion reactor. The associated heavy ion driver will require a large number of focusing quadrupole magnets. A concept for a superconducting quadrupole array, using many simple racetrack coils, was developed at LLNL. Two, single-bore quadrupole prototypes of the same design, with distinctly different conductor, were designed, built, and tested. Both prototypes reached their short sample currents with little or no training. Magnet design, and test results, are presented and discussed.

  4. Electric quadrupole transition probabilities and line strengths of Ti11+

    International Nuclear Information System (INIS)

    Electric quadrupole transition probabilities and line strengths have been calculated using the weakest bound electron potential model for sodium-like titanium, considering many transition arrays. We employed numerical Coulomb approximation and non-relativistic Hartree–Fock wavefunctions for the expectation values of radii in determination of parameters of the model. The necessary energy values have been taken from experimental data in the literature. The calculated electric quadrupole line strengths have been compared with available data in the literature and good agreement has been obtained. Moreover, some electric quadrupole transition probability and line strength values not existing in the literature for some highly excited levels have been obtained using this method

  5. Vacuum Arc Ion Sources

    OpenAIRE

    Brown, I.

    2014-01-01

    The vacuum arc ion source has evolved into a more or less standard laboratory tool for the production of high-current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. Applications include primarily ion implantation for material surface modification research, and good performance has been obtained for the injection of high-current beams of heavy-metal ions, in particular uranium, into particle accelerators. As the use of the sourc...

  6. PARAFFIN SEPARATION VACUUM DISTILLATION

    Directory of Open Access Journals (Sweden)

    Zaid A. Abdulrahman

    2013-05-01

    Full Text Available Simulated column performance curves were constructed for existing paraffin separation vacuum distillation column in LAB plant (Arab Detergent Company/Baiji-Iraq. The variables considered in this study are the thermodynamic model option, top vacuum pressure, top and bottom temperatures, feed temperature, feed composition & reflux ratio. Also simulated columns profiles for the temperature, vapor & liquid flow rates composition were constructed. Four different thermodynamic model options (SRK, TSRK, PR, and ESSO were used, affecting the results within 1-25% variation for the most cases.The simulated results show that about 2% to 8 % of paraffin (C10, C11, C12, & C13 present at the bottom stream which may cause a problem in the LAB plant. The major variations were noticed for the top temperature & the  paraffin weight fractions at bottom section with top vacuum pressure. The bottom temperature above 240 oC is not recommended because the total bottom flow rate decreases sharply, where as  the weight fraction of paraffins decrease slightly. The study gives evidence about a successful simulation with CHEMCAD

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

    CERN Document Server

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

    2013-01-01

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

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

    CERN Document Server

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

    2011-01-01

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

  9. 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 �...

  10. Quadrupole effect on the heat conductivity of cold glasses

    International Nuclear Information System (INIS)

    At very low temperatures, the tunneling theory for amorphous solids predicts a thermal conductivity κ∝Tp, with p=2. We have studied the effect of the nuclear quadrupole moment on the thermal conductivity of glasses at very low temperatures. We developed a theory that couples the tunneling motion to the nuclear quadrupoles moment in order to evaluate the thermal conductivity. Our result suggests a cross over between two different regimes at the temperature close to the nuclear quadrupoles energy. Below this temperature we have shown that the thermal conductivity is larger than the standard tunneling result and therefore we have p<2. However, for temperatures higher than the nuclear quadrupoles energy, the result of standard tunneling model has been found

  11. PRINCIPLE OF SKEW QUADRUPOLE MODULATION TO MEASURE BETATRON COUPLING.

    Energy Technology Data Exchange (ETDEWEB)

    LUO.Y.PILAT,F.ROSER,T.ET AL.

    2004-07-05

    The measurement of the residual betatron coupling via skew quadrupole modulation is a new diagnostics technique that has been developed and tested at the Relativistic Heavy Ion Collider (RHIC) as a very promising method for the linear decoupling on the ramp. By modulating the strengths of different skew quadrupole families the two eigentunes are precisely measured with the phase lock loop system. The projections of the residual coupling coefficient onto the skew quadrupole coupling modulation directions are determined. The residual linear coupling could be corrected according to the measurement. An analytical solution for skew quadrupole modulation based on Hamiltonian perturbation approximation is given, and simulation code using smooth accelerator model is also developed. Some issues concerning the practical applications of this technique are discussed.

  12. Quadrupole Effect on the Heat Conductivity of Cold Glasses

    OpenAIRE

    Akbari, Alireza

    2007-01-01

    At very low temperatures, the tunnelling theory for amorphous solids predicts a thermal conductivity $\\kappa\\propto T^p$, with $p = 2$. We have studied the effect of the Nuclear Quadrupole moment on the thermal conductivity of glasses at very low temperatures. We developed a theory that couples the tunnelling motion to the nuclear quadrupoles moment in order to evaluate the thermal conductivity. Our result suggests a cross over between two different regimes at the temperature close to the nuc...

  13. Application of the Thermal Quadrupoles Method to Semitransparent Solids

    Science.gov (United States)

    Salazar, A.; Fuente, R.; Mendioroz, A.; Apiñaniz, E.; Celorrio, R.

    2012-11-01

    In this study, the thermal quadrupoles method is extended to semitransparent layered solids. Using this method, the surface temperature of semitransparent multilayered materials is calculated as a function of the optical and thermal properties of each layer. This result eventually leads to determination of the thermal diffusivity, thermal resistance, and/or optical absorption coefficient of layered materials using photothermal techniques. The thermal quadrupoles method is applied to determine the thermal contact resistance in glass stacks.

  14. Quadrupole collective variables in the natural Cartan-Weyl basis

    OpenAIRE

    De Baerdemacker, S.; Heyde, K.; Hellemans, V.

    2007-01-01

    The matrix elements of the quadrupole collective variables, emerging from collective nuclear models, are calculated in the natural Cartan-Weyl basis of O(5) which is a subgroup of a covering $SU(1,1)\\times O(5)$ structure. Making use of an intermediate set method, explicit expressions of the matrix elements are obtained in a pure algebraic way, fixing the $\\gamma$-rotational structure of collective quadrupole models.

  15. The quadrupole collective model from a Cartan-Weyl perspective

    OpenAIRE

    De Baerdemacker, Stijn; Heyde, Kris; Hellemans, Veerle

    2007-01-01

    The matrix elements of the quadrupole variables and canonic conjugate momenta, emerging from collective nuclear models are calculated within a $SU(1,1)\\times O(5)$ basis. Using a harmonic oscillator implementation of the SU(1,1) degree of freedom, it can be shown that the matrix elements of the quadrupole phonon creation and annihilation operators can be calculated in a pure algebraic way, making use of an intermediate state method.

  16. Quadrupole moments of odd-odd near-magic nuclei

    OpenAIRE

    Achakovskiy O.; Voitenkov D.; Kamerdzhiev S.; Tolokonnikov S.

    2012-01-01

    Ground state quadrupole moments of odd-odd near double magic nuclei are calculated in the approximation of no interaction between odd particles. Under such a simple approximation, the problem is reduced to the calculations of quadrupole moments of corresponding odd-even nuclei. These calculations are performed within the self-consistent Theory of Finite Fermi Systems based on the Energy Density Functional by Fayans et al. with the known DF3-a parameters. A reasonable agreement with the availa...

  17. Quadrupole collectivity in {sup 128}Cd

    Energy Technology Data Exchange (ETDEWEB)

    Boenig, Esther Sabine

    2014-07-07

    The regions around shell closures, especially around doubly magic nuclei, are of major interest in nuclear structure physics, as they provide a perfect test for nuclear structure theory. The neutron-rich Cd isotopes in the region of {sup 132}Sn are only two protons away from the shell closure at Z=50 and in close proximity to the N=82 magic number. Nevertheless they show an irregular behaviour regarding the excitation energy of the first excited 2{sup +} state. This is not reproduced by shell model calculations, which is astonishing due to the proximity of the shell closures. In order to shed light on the much discussed region around doubly magic {sup 132}Sn, a Coulomb excitation experiment of {sup 128}Cd has been performed at REX-ISOLDE, CERN. The reduced transition strength B(E2;0{sup +}{sub gs} → 2{sup +}{sub 1}), which is a measure of collectivity, and the spectroscopic quadrupole moment Q{sub s}(2{sup +}{sub 1}) as a measure of deformation could be determined for the first time. The results are shown as the continuation of already measured neutron-rich Cd isotopes and are compared to both beyond mean field and shell model calculations, which give different predictions for these observables.

  18. Thermal Analysis of the ILC Superconducting Quadrupole

    International Nuclear Information System (INIS)

    Critical to a particle accelerator's functioning, superconducting magnets serve to focus and aim the particle beam. The Stanford Linear Accelerator Center (SLAC) has received a prototype superconducting quadrupole designed and built by the Centro de Investigaciones Energ(acute e)ticas, Medioambientales y Tecnol(acute o)gicas (CIEMAT) to be evaluated for the International Linear Collider (ILC) project. To ensure proper functioning of the magnet, the device must be maintained at cryogenic temperatures by use of a cooling system containing liquid nitrogen and liquid helium. The cool down period of a low temperature cryostat is critical to the success of an experiment, especially a prototype setup such as this one. The magnet and the dewar each contain unique heat leaks and material properties. These differences can lead to tremendous thermal stresses. The system was analyzed mathematically, leading to ideal liquid helium and liquid nitrogen flow rates during the magnet's cool-down to 4.2 K, along with a reasonable estimate of how long this cool-down will take. With a flow rate of ten gaseous liters of liquid nitrogen per minute, the nitrogen shield will take approximately five hours to cool down to 77 K. With a gaseous helium flow rate of sixty liters per minute, the magnet will take at least nineteen hours to cool down to a temperature of 4.2 K

  19. Field measurement for large quadrupole magnets

    Energy Technology Data Exchange (ETDEWEB)

    Lazzaro, A. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy); Cappuzzello, F. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95123 Catania (Italy)], E-mail: cappuzzello@lns.infn.it; Cunsolo, A.; Cavallaro, M. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Foti, A. [Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95123 Catania (Italy); INFN-Sezione di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Orrigo, S.E.A.; Rodrigues, M.R.D.; Winfield, J.S. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy)

    2008-06-21

    The results of the field measurement of the large quadrupole magnet of the MAGNEX spectrometer are presented and analyzed in the view of the possible application of modern techniques of ray reconstruction. The experimental data are checked against the symmetry conditions expected for the magnet. The observed deviations are related both to imperfections on the magnet manufacturing and to the not ideal positioning of the measurement device. In particular a quantitative estimation of the experimental error in the alignment of the probe with respect to the magnet is achieved. The measured field is also compared with the results from three-dimensional finite elements calculation. The obtained discrepancies between the measured and calculated field are too large for a direct application of the latter to ray-reconstruction methods. Nevertheless, these calculations are reliably used to study the impact of the observed inaccuracies in the probe alignment on the overall precision of field reconstruction and to set quantitative constraints on the field interpolation algorithms.

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

    CERN Document Server

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

    2012-01-01

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

  1. 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.

  2. Vacuum ultraviolet spectroscopy I

    CERN Document Server

    Samson, James A; Lucatorto, Thomas

    1998-01-01

    This volume is for practitioners, experimentalists, and graduate students in applied physics, particularly in the fields of atomic and molecular physics, who work with vacuum ultraviolet applications and are in need of choosing the best type of modern instrumentation. It provides first-hand knowledge of the state-of-the-art equipment sources and gives technical information on how to use it, along with a broad reference bibliography.Key Features* Aimed at experimentalists who are in need of choosing the best type of modern instrumentation in this applied field* Contains a detailed chapter on la

  3. Plasmons in QED vacuum

    Science.gov (United States)

    Petrov, E. Yu.; Kudrin, A. V.

    2016-09-01

    The problem of longitudinal oscillations of an electric field and a charge polarization density in a quantum electrodynamics (QED) vacuum is considered. Within the framework of semiclassical analysis, we calculate time-periodic solutions of bosonized (1 +1 )-dimensional QED (massive Schwinger model). Applying the Bohr-Sommerfeld quantization condition, we determine the mass spectrum of charge-zero bound states (plasmons) which correspond in quantum theory to the found classical solutions. We show that the existence of such plasmons does not contradict any fundamental physical laws and study qualitatively their excitation in a (3 +1 )-dimensional real world.

  4. R&D ERL: Vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Mapes, M.; Smart, L.; Weiss, D.; Steszyn, A.; Todd, R.

    2010-01-01

    The ERL Vacuum systems are depicted in a figure. ERL has eight vacuum volumes with various sets of requirements. A summary of vacuum related requirements is provided in a table. Five of the eight volumes comprise the electron beamline. They are the 5-cell Superconducting RF Cavity, Superconducting e-gun, injection, loop and beam dump. Two vacuum regions are the individual cryostats insulating the 5-cell Superconducting RF Cavity and the Superconducting e-gun structures. The last ERL vacuum volume not shown in the schematic is the laser transport line. The beamline vacuum regions are separated by electropneumatic gate valves. The beam dump is common with loop beamline but is considered a separate volume due to geometry and requirements. Vacuum in the 5-cell SRF cavity is maintained in the {approx}10{sup -9} torr range at room temperature by two 20 l/s ion pumps and in the e-gun SRF cavity by one 60 l/s ion pump. Vacuum in the SRF cavities operated at 2{sup o}K is reduced to low 10{sup -11} torr via cryopumping of the cavity walls. The cathode of the e-gun must be protected from poisoning, which can occur if vacuum adjacent to the e-gun in the injection line exceeds 10-11 torr range in the injection warm beamline near the e-gun exit. The vacuum requirements for beam operation in the loop and beam dump are 10-9 torr range. The beamlines are evacuated from atmospheric pressure to high vacuum level with a particulate free, oil free turbomolecular pumping cart. 25 l/s shielded ion pumps distributed throughout the beamlines maintain the vacuum requirement. Due to the more demanding vacuum requirement of the injection beamline proximate to the e-gun, a vacuum bakeout of the injection beamline is required. In addition, two 200 l/s diode ion pumps and supplemental pumping provided by titanium sublimation pumps are installed in the injection line just beyond the exit of the e-gun. Due to expected gas load a similar pumping arrangement is planned for the beam dump. The

  5. Edison's vacuum coating patents

    International Nuclear Information System (INIS)

    Among the over one thousand patents bearing Thomas A. Edison's name are several for vacuum coating processes including chemical vapor deposition, evaporation, and sputter deposition. Beginning in 1880 Edison applied for patents that described carbon deposition processes that would now be called pyrolytic chemical vapor deposition. In 1884 Edison applied for a patent (granted in 1894) that described coating by evaporation in a vacuum by direct resistance heating or arc heating using a continuous current. Edison called the process 'electro vacuous deposition'. He prophetically wrote, 'the uses of the invention are almost infinite'. Edison also employed sputter deposition and in 1900 applied for a patent on a 'Process of Coating Phonograph Records'. Issued in 1902, the patent describes using a 'silent or brush electrical discharge' produced by an induction coil. The National Phonograph Company, one of Edison's many enterprises, used the sputtering process to deposit a thin layer of gold on wax phonograph cylinder masters that could then be electroplated to form molds to mass produce celluloid duplicates. The method was used for 20 years, from 1901 to 1921. It enabled the reproduction of cylinder grooves less than 0.001 in. deep at a density of 200 grooves per in. From 1913 to 1921, 10-in.-diameter Edison Diamond Disc phonograph records were made using the same method. Sputtering was abandoned in 1927, as it could not be scaled up to produce the 12 in. disks that were then introduced

  6. Of vacuum and gas

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    A new LHCb programme is delving into uncharted waters for the LHC: exploring how protons interact with noble gases inside the machine pipe. While, at first glance, it may sound risky for the overall quality of the vacuum in the machine, the procedure is safe and potentially very rich in rewards. The results could uncover the high-energy helium-proton cross-section (with all the implications thereof), explore new boundaries of the quark-gluon plasma and much more.   As the beam passes through LHCb, interactions with neon gas allow the experiment to measure the full beam profile. In this diagram, beam 1 (blue) and beam 2 (red) are measured by the surrounding VELO detector. It all begins with luminosity. In 2011, LHCb set out to further improve its notoriously precise measurements of the beam profile, using the so-called Beam-Gas Imaging (BGI) method. BGI does exactly what it says on the tin: a small amount of gas is inserted into the vacuum, increasing the rate of collisions around the interaction ...

  7. Vacuum metastability with black holes.

    OpenAIRE

    Burda, Philipp; Gregory, Ruth; Moss, Ian

    2015-01-01

    We consider the possibility that small black holes can act as nucleation seeds for the decay of a metastable vacuum, focussing particularly on the Higgs potential. Using a thin-wall bubble approximation for the nucleation process, which is possible when generic quantum gravity corrections are added to the Higgs potential, we show that primordial black holes can stimulate vacuum decay. We demonstrate that for suitable parameter ranges, the vacuum decay process dominates over the Hawking evapor...

  8. Particle contamination in vacuum systems

    International Nuclear Information System (INIS)

    Many vacuum devices, like RF cavities, are sensitive to particle contamination. This fact has motivated a considerable effort of cleanliness from the SRF community. The first results of a general study trying to identify the most contaminating steps during assembly and vacuum operation of the cavity is reported. The steps investigated here are gasket assembly, evacuation and venting of the vacuum system, and operation of sputter ion pumps. (author)

  9. Portable vacuum object handling device

    Science.gov (United States)

    Anderson, G.H.

    1983-08-09

    The disclosure relates to a portable device adapted to handle objects which are not to be touched by hand. A piston and bore wall form a vacuum chamber communicating with an adaptor sealably engageable with an object to be lifted. The piston is manually moved and set to establish vacuum. A valve is manually actuatable to apply the vacuum to lift the object. 1 fig.

  10. A highly miniaturized vacuum package for a trapped ion atomic clock

    Science.gov (United States)

    Schwindt, Peter D. D.; Jau, Yuan-Yu; Partner, Heather; Casias, Adrian; Wagner, Adrian R.; Moorman, Matthew; Manginell, Ronald P.; Kellogg, James R.; Prestage, John D.

    2016-05-01

    We report on the development of a highly miniaturized vacuum package for use in an atomic clock utilizing trapped ytterbium-171 ions. The vacuum package is approximately 1 cm3 in size and contains a linear quadrupole RF Paul ion trap, miniature neutral Yb sources, and a non-evaporable getter pump. We describe the fabrication process for making the Yb sources and assembling the vacuum package. To prepare the vacuum package for ion trapping, it was evacuated, baked at a high temperature, and then back filled with a helium buffer gas. Once appropriate vacuum conditions were achieved in the package, it was sealed with a copper pinch-off and was subsequently pumped only by the non-evaporable getter. We demonstrated ion trapping in this vacuum package and the operation of an atomic clock, stabilizing a local oscillator to the 12.6 GHz hyperfine transition of 171Y b+. The fractional frequency stability of the clock was measured to be 2 × 10-11/τ1/2.

  11. Accelerator vacuum system elements

    International Nuclear Information System (INIS)

    Some elements of vacuum systems are investigated. Considerable attention has been given to the investigation into peculiarities in pumping out of a ionoguide for transportation of an accelerated charged particles beam the spread of which often attains a considerable length. The number of pumps over the ionoguide length is experimentally determined. It is shown that as a result of ionoguide warm-up the pumping out time is considerably reduced maximum permissible pressure is decreased by two orders and lesser rate of pump pumping out is required. The investigations have shown that when operating the ionoguide there is no necessity in setting up seals between the ionoguide and magnetodischarged pump. The causes of the phenomenon in which the pressure near the pump is greater than in the end of the ionoguide, are impurities carried in by the pump into the ionoguide volume and the pumping out capacity of the pressure converter

  12. Entanglement, magnetic and quadrupole moments properties of the mixed spin Ising-Heisenberg diamond chain

    Science.gov (United States)

    Abgaryan, V. S.; Ananikian, N. S.; Ananikyan, L. N.; Hovhannisyan, V.

    2015-02-01

    Thermal entanglement, magnetic and quadrupole moments properties of the mixed spin-1/2 and spin-1 Ising-Heisenberg model on a diamond chain are considered. Magnetization and quadrupole moment plateaus are observed for the antiferromagnetic couplings. Thermal negativity as a measure of quantum entanglement of the mixed spin system is calculated. Different behavior for the negativity is obtained for the various values of Heisenberg dipolar and quadrupole couplings. The intermediate plateau of the negativity has been observed at the absence of the single-ion anisotropy and quadrupole interaction term. When dipolar and quadrupole couplings are equal there is a similar behavior of negativity and quadrupole moment.

  13. Vacuum Energy Sequestering and Graviton Loops

    CERN Document Server

    Kaloper, Nemanja

    2016-01-01

    We recently formulated a local mechanism of vacuum energy sequester. This mechanism automatically removes all matter loop contributions to vacuum energy from the stress energy tensor which sources the curvature. Here we adapt the local vacuum energy sequestering mechanism to also cancel all the vacuum energy loops involving virtual gravitons, in addition to the vacuum energy generated by matter fields alone.

  14. Purifying Aluminum by Vacuum Distillation

    Science.gov (United States)

    Du Fresne, E. R.

    1985-01-01

    Proposed method for purifying aluminum employs one-step vacuum distillation. Raw material for process impure aluminum produced in electrolysis of aluminum ore. Impure metal melted in vacuum. Since aluminum has much higher vapor pressure than other constituents, boils off and condenses on nearby cold surfaces in proportions much greater than those of other constituents.

  15. Multipurpose Vacuum Induction Processing System

    Science.gov (United States)

    Govindaraju, M.; Kulkarni, Deepak; Balasubramanian, K.

    2012-11-01

    Multipurpose vacuum processing systems are cost effective; occupy less space, multiple functional under one roof and user friendly. A multipurpose vacuum induction system was designed, fabricated and installed in a record time of 6 months time at NFTDC Hyderabad. It was designed to function as a) vacuum induction melting/refining of oxygen free electronic copper/pure metals, b) vacuum induction melting furnace for ferrous materials c) vacuum induction melting for non ferrous materials d) large vacuum heat treatment chamber by resistance heating (by detachable coil and hot zone) e) bottom discharge vacuum induction melting system for non ferrous materials f) Induction heat treatment system and g) directional solidification /investment casting. It contains provision for future capacity addition. The attachments require to manufacture multiple shaped castings and continuous rod casting can be added whenever need arises. Present capacity is decided on the requirement for 10years of development path; presently it has 1.2 ton liquid copper handling capacity. It is equipped with provision for capacity addition up to 2 ton liquid copper handling capacity in future. Provision is made to carry out the capacity addition in easy steps quickly. For easy operational maintenance and troubleshooting, design was made in easily detachable sections. High vacuum system is also is detachable, independent and easily movable which is first of its kind in the country. Detailed design parameters, advantages and development history are presented in this paper.

  16. Vacuum Enhanced Cutaneous Biopsy Instrument

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Joseph

    1999-06-25

    A syringe-like disposable cutaneous biopsy instrument equipped with a tubular blade at its lower end, and designed so that a vacuum is created during use, said vacuum serving to retain undeformed a plug of tissue cut from a patient's skin.

  17. Vacuum Alignment with more Flavors

    DEFF Research Database (Denmark)

    Ryttov, Thomas

    2014-01-01

    We study the alignment of the vacuum in gauge theories with $N_f$ Dirac fermions transforming according to a complex representation of the gauge group. The alignment of the vacuum is produced by adding a small mass perturbation to the theory. We study in detail the $N_f=2,3$ and $4$ case. For $N...

  18. ULTRARAPID VACUUM-MICROWAVE HISTOPROCESSING

    NARCIS (Netherlands)

    KOK, LP; BOON, ME

    1995-01-01

    A novel histoprocessing method for paraffin sections is presented in which the combination of vacuum and microwave exposure is the key element. By exploiting the decrease in boiling temperature under vacuum, the liquid molecules in the tissues have been successfully extracted and exchanged at relati

  19. Cryogen free superconducting splittable quadrupole magnet for linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, V.S.; Andreev, N.; Kerby, J.; Orlov, Y.; Solyak, N.; Tartaglia, M.; Velev, G.; /Fermilab

    2011-09-01

    A new superconducting quadrupole magnet for linear accelerators was fabricated at Fermilab. The magnet is designed to work inside a cryomodule in the space between SCRF cavities. SCRF cavities must be installed inside a very clean room adding issues to the magnet design, and fabrication. The designed magnet has a splittable along the vertical plane configuration and could be installed outside of the clean room around the beam pipe previously connected to neighboring cavities. For more convenient assembly and replacement a 'superferric' magnet configuration with four racetrack type coils was chosen. The magnet does not have a helium vessel and is conductively cooled from the cryomodule LHe supply pipe and a helium gas return pipe. The quadrupole generates 36 T integrated magnetic field gradient, has 600 mm effective length, and the peak gradient is 54 T/m. In this paper the quadrupole magnetic, mechanical, and thermal designs are presented, along with the magnet fabrication overview and first test results.

  20. Theoretical electric quadrupole transition probabilities for Ca, Sr and Ba

    Science.gov (United States)

    Bauschlicher, C. W., Jr.; Langhoff, S. R.; Jaffe, R. L.; Partridge, H.

    1984-01-01

    The 1D-1S quadrupole transition probabilities for Ca, Sr and Ba have been computed using extended GTO and STO valence basis sets and configuration-interaction wavefunctions that include the important core-valence correlation effects. For Ba and Sr, the relativistic contraction of the core orbitals was accounted for in the GTO calculations by a relativistic effective-core potential. The computed Einstein coefficient for Ca of 39.6/s is in excellent agreement with the recent experimental value of 40 + or - 8/s. The best Einstein coefficients for Sr (44.7/s) and Ba (2.98/s) imply increasing quadrupole line strengths down the column. Relativistic effects substantially increase the quadrupole Einstein coefficient for Ba.

  1. Quadrupole moments of odd-odd near-magic nuclei

    Directory of Open Access Journals (Sweden)

    Achakovskiy O.

    2012-12-01

    Full Text Available Ground state quadrupole moments of odd-odd near-double-magic nuclei are calculated in the approximation of non-interacting odd neutron and odd proton. Under such a simple approximation the problem is reduced to the calculations of quadrupole moments of corresponding odd-even nuclei. These calculations are performed within the self-consistent Theory of Finite Fermi Systems based on the Energy Density Functional by Fayans et al. with the known DF3-a parameters. A reasonable agreement with the available experimental data is obtained for odd-odd nuclei and odd near-magic nuclei investigated. The self-consistent approach under consideration allowed us to predict the unknown quadrupole moments of odd-even and odd-odd nuclei near the double-magic 56,78Ni, 100,132Sn nuclides.

  2. Self-consistent calculations of quadrupole moments of spherical nuclei

    Directory of Open Access Journals (Sweden)

    Saperstein E.E.

    2012-12-01

    Full Text Available The self-consistent Theory of Finite Fermi Systems based on the Energy Density Functional byFayans et al. with the set DF3-a of parameters fixed previously is used to calculate three kinds of quadrupolemoments. At first, we examined systematically quadrupole moments of odd neighbors of semi-magic lead andtin isotopes and N = 50, N = 82 isotones. Second, we found quadrupole moments of the first 2+ states in thesame two chains of isotopes. Finally, we evaluated quadrupole moments of odd-odd nuclei neighboring to doublemagic ones. Reasonable agreement with available experimental data has been obtained. Predictions are made forquadrupole moments of nuclei in the vicinity of unstable magic nuclei

  3. Bubbling the False Vacuum Away

    CERN Document Server

    Gleiser, Marcelo; Thorarinson, Joel

    2007-01-01

    We investigate the role of nonperturbative, bubble-like inhomogeneities on the decay rate of false-vacuum states in two and three-dimensional scalar field theories. The inhomogeneities are induced by setting up large-amplitude oscillations of the field about the false vacuum as, for example, after a rapid quench or in certain models of cosmological inflation. We show that, for a wide range of parameters, the presence of large-amplitude bubble-like inhomogeneities greatly accelerates the decay rate, changing it from the well-known exponential suppression of homogeneous nucleation to a power-law suppression. It is argued that this fast, power-law vacuum decay -- known as resonant nucleation -- is promoted by the presence of long-lived oscillons among the nonperturbative fluctuations about the false vacuum. A phase diagram is obtained distinguishing three possible mechanisms for vacuum decay: homogeneous nucleation, resonant nucleation, and cross-over. Possible applications are briefly discussed.

  4. The AGS Booster vacuum systems

    International Nuclear Information System (INIS)

    The AGS Booster is a synchrotron for the acceleration of both protons and heavy ions. The design pressure of low 10-11 mbar is required to minimize beam loss of the partially stripped heavy ions. To remove contaminants and to reduce outgassing, the vacuum chambers and the components located in them will be chemically cleaned, vacuum fired, baked then treated with nitric oxide. The vacuum sector will be insitu baked to a minimum of 200 degree C and pumped by the combination of sputter ion pumps and titanium sublimation pumps. This paper describes the design and the processing of this ultra high vacuum system, and the performance of some half-cell vacuum chambers. 9 refs., 7 figs

  5. Hadron Contribution to Vacuum Polarisation

    Science.gov (United States)

    Davier, M.; Hoecker, A.; Malaescu, B.; Zhang, Z.

    2016-10-01

    Precision tests of the Standard Theory require theoretical predictions taking into account higher-order quantum corrections. Among these vacuum polarisation plays a predominant role. Vacuum polarisation originates from creation and annihilation of virtual particle-antiparticle states. Leptonic vacuum polarisation can be computed from quantum electrodynamics. Hadronic vacuum polarisation cannot because of the non-perturbative nature of QCD at low energy. The problem is remedied by establishing dispersion relations involving experimental data on the cross section for e+ e- annihilation into hadrons. This chapter sets the theoretical and experimental scene and reviews the progress achieved in the last decades thanks to more precise and complete data sets. Among the various applications of hadronic vacuum polarisation calculations, two are emphasised: the contribution to the anomalous magnetic moment of the muon, and the running of the fine structure constant α to the Z mass scale. They are fundamental ingredients to high precision tests of the Standard Theory.

  6. Hadron Contribution to Vacuum Polarisation

    CERN Document Server

    Davier, M; Malaescu, B; Zhang, Z

    2016-01-01

    Precision tests of the Standard Theory require theoretical predictions taking into account higher-order quantum corrections. Among these vacuum polarisation plays a predominant role. Vacuum polarisation originates from creation and annihilation of virtual particle–antiparticle states. Leptonic vacuum polarisation can be computed from quantum electrodynamics. Hadronic vacuum polarisation cannot because of the non-perturbative nature of QCD at low energy. The problem is remedied by establishing dispersion relations involving experimental data on the cross section for e+ e− annihilation into hadrons. This chapter sets the theoretical and experimental scene and reviews the progress achieved in the last decades thanks to more precise and complete data sets. Among the various applications of hadronic vacuum polarisation calculations, two are emphasised: the contribution to the anomalous magnetic moment of the muon, and the running of the fine structure constant α to the Z mass scale. They are fundamental ingre...

  7. Thermally driven vertical displacement of IP quadrupole magnet

    International Nuclear Information System (INIS)

    The IP (interaction point) quadrupole magnets of the TRISTAN MR (main ring), QCS and QC1, at every IP sit on the common support made of steel. When all magnets are cycled through injection, acceleration, flattop and deceleration, the environmental temperature in the tunnel changes periodically following the magnet cycle. The magnet support receives the temperature cycles and the quadrupole on it moves vertically due to the thermal expansion and shrinkage of the support. Its movement was measured with the laser interferometer during the physics experiment. This displacement gives an effect on the closed orbit distortions and requires the orbit correction when it becomes serious. (author)

  8. Conceptual design of a quadrupole magnet for eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Witte, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, J. S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    eRHIC is a proposed upgrade to the existing Relativistic Heavy Ion Collider (RHIC) hadron facility at Brookhaven National Laboratory, which would allow collisions of up to 21 GeV polarized electrons with a variety of species from the existing RHIC accelerator. eRHIC employs an Energy Recovery Linac (ERL) and an FFAG lattice for the arcs. The arcs require open-midplane quadrupole magnets of up to 30 T/m gradient of good field quality. In this paper we explore initial quadrupole magnet design concepts based on permanent magnetic material which allow to modify the gradient during operation.

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

    CERN Document Server

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

    2010-01-01

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

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

    CERN Document Server

    Sailer, André; Lohse, Thomas

    2013-01-10

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

  11. 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.

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

    CERN Document Server

    Battaglia, M

    2010-01-01

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

  13. 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

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

    CERN Document Server

    Gutiérrez-Rodríguez, A; Sampayo, O A

    2009-01-01

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

  15. Vacuum Brazing of Accelerator Components

    International Nuclear Information System (INIS)

    Commonly used materials for accelerator components are those which are vacuum compatible and thermally conductive. Stainless steel, aluminum and copper are common among them. Stainless steel is a poor heat conductor and not very common in use where good thermal conductivity is required. Aluminum and copper and their alloys meet the above requirements and are frequently used for the above purpose. The accelerator components made of aluminum and its alloys using welding process have become a common practice now a days. It is mandatory to use copper and its other grades in RF devices required for accelerators. Beam line and Front End components of the accelerators are fabricated from stainless steel and OFHC copper. Fabrication of components made of copper using welding process is very difficult and in most of the cases it is impossible. Fabrication and joining in such cases is possible using brazing process especially under vacuum and inert gas atmosphere. Several accelerator components have been vacuum brazed for Indus projects at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore using vacuum brazing facility available at RRCAT, Indore. This paper presents details regarding development of the above mentioned high value and strategic components/assemblies. It will include basics required for vacuum brazing, details of vacuum brazing facility, joint design, fixturing of the jobs, selection of filler alloys, optimization of brazing parameters so as to obtain high quality brazed joints, brief description of vacuum brazed accelerator components etc.

  16. The electrical resistance of vacuum

    Science.gov (United States)

    Bringuier, E.

    2013-07-01

    This paper deals with the physics of electrical conduction in vacuum between two parallel conducting planes (planar vacuum diode). After reviewing known features of conduction in the high-voltage range, we turn to the low-voltage range. An ohmic current-voltage characteristic is calculated in the case of identical cathodic and anodic electrodes, whence an electrical resistance of the vacuum gap can be defined. The inverse resistance involves the elemental conductance 2e 2/h and the number of conductance channels between the two electrodes. The channels are thermally populated from the electrodes and the population is analytically calculable from the Poisson equation of electrostatics and the Boltzmann law of thermal equilibrium. The observed resistance of a real vacuum diode (Mullard's EB 91) is accounted for without adjusting parameters. The paper also examines the link-up between Joule's law, involving dissipation, and Ohm's law, with vacuum being contrasted with a material conducting medium; the origin of dissipation in vacuum is understood. Quantum and statistical physics are kept at the undergraduate level. Finally, the results obtained for the vacuum diode shed light upon the quantized conductance of nanoscale semiconductor wires, a topic usually handled only in graduate courses.

  17. NCSX Vacuum Vessel Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Viola, M. E.; Brown, T.; Heitzenroeder, P.; Malinowski, F.; Reiersen, W.; Sutton, L.; Goranson, P.; Nelson, B.; Cole, M.; Manuel, M.; McCorkle, D.

    2005-10-07

    The National Compact Stellarator Experiment (NCSX) is being constructed at the Princeton Plasma Physics Laboratory (PPPL) in conjunction with the Oak Ridge National Laboratory (ORNL). The goal of this experiment is to develop a device which has the steady state properties of a traditional stellarator along with the high performance characteristics of a tokamak. A key element of this device is its highly shaped Inconel 625 vacuum vessel. This paper describes the manufacturing of the vessel. The vessel is being fabricated by Major Tool and Machine, Inc. (MTM) in three identical 120º vessel segments, corresponding to the three NCSX field periods, in order to accommodate assembly of the device. The port extensions are welded on, leak checked, cut off within 1" of the vessel surface at MTM and then reattached at PPPL, to accommodate assembly of the close-fitting modular coils that surround the vessel. The 120º vessel segments are formed by welding two 60º segments together. Each 60º segment is fabricated by welding ten press-formed panels together over a collapsible welding fixture which is needed to precisely position the panels. The vessel is joined at assembly by welding via custom machined 8" (20.3 cm) wide spacer "spool pieces." The vessel must have a total leak rate less than 5 X 10-6 t-l/s, magnetic permeability less than 1.02μ, and its contours must be within 0.188" (4.76 mm). It is scheduled for completion in January 2006.

  18. ASACUSA's radio-frequency quadrupole decelerator, open to show the four-rod structure along the centre, which crosses 35 resonator chambers formed by the vertical partitions.

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    The Radio-Frequency Quadrupole, RFQD, which further decelerates antiprotons ejected from the Antiproton Decelerator (AD). Starting from a momentum of 100 MeV/c (kinetic energy 5.3 MeV), the RFQD delivers very-low-energy antiprotons, adjustable between 10 and 110 keV, to the experiment ASACUSA. In picture _02, the view from the upstream end shows its 4-rod structure, traversing 35 resonator chambers formed by the vertical partitions. The tank has an inner diameter of 390 mm and is pumped to a vacuum of a few E-8 Torr.

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

    Science.gov (United States)

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

    2016-10-01

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

  20. Velocity map imaging of a slow beam of ammonia molecules inside a quadrupole guide

    OpenAIRE

    Quintero-Pérez, Marina; Jansen, Paul; Bethlem, Hendrick L.

    2012-01-01

    Velocity map imaging inside an electrostatic quadrupole guide is demonstrated. By switching the voltages that are applied to the rods, the quadrupole can be used for guiding Stark decelerated molecules and for extracting the ions. The extraction field is homogeneous along the axis of the quadrupole while it defocuses the ions in the direction perpendicular to both the axis of the quadrupole and the axis of the ion optics. To compensate for this astigmatism, a series of planar electrodes with ...

  1. Enrichment of rare isotopes using a quadrupole mass spectrometer

    International Nuclear Information System (INIS)

    A small quadrupole mass spectrometer was operated in the static mode to enrich selected rare gas isotopes. Memory effects in the apparatus were observed and attributed to the re-emission of atoms implanted by the electron-impact ion source. Studies of the pumping mechanism led to a practical means for reducing the rate of noble gas pumping. (author)

  2. Isoscalar giant quadrupole resonance in hot and rotating nuclei

    International Nuclear Information System (INIS)

    We discuss the role of thermal shape fluctuations on isoscalar giant quadrupole resonance (ISGOR) in hot and rotating nuclei. Our results show that the GQR energies strongly reflect the shape transition in hot and rotating nuclei despite the smoothing effect of thermal fluctuation. (author)

  3. Thermal and quantal fluctuations in the pairing plus quadrupole model

    International Nuclear Information System (INIS)

    Thermal and quantal fluctuations are included in the partition function of the pairing and quadrupole model. The formalism is applied to the calculation of the thermal response functions. The effects of both thermal and quantal fluctuations to the level densities are studied. The limits and the physical content of the scheme are analyzed

  4. Alignment-to-orientation conversion and nuclear quadrupole resonance

    CERN Document Server

    Budker, D; Rochester, S M; Urban, J T

    2003-01-01

    The role of alignment-to-orientation conversion (AOC) in nuclear quadrupole resonance (NQR) is discussed. AOC is shown to be the mechanism responsible for the appearance of macroscopic orientation in a sample originally lacking any global polarization. Parallels are drawn between NQR and AOC in atomic physics.

  5. Superconducting quadrupoles for LHC : CERN/CEA-CEN Saclay Collaboration

    CERN Multimedia

    CEA Saclay and CERN Collaboration

    1994-01-01

    Agreement has been signed between CERN and CEA Saclay, concerning the construction of two prototypes of the LHC latest quadrupoles. CEA Saclay was interested with the study, the design, the construction and the testing of this magnet. The fabrication took place at the CEN Laboratory at Saclay in Paris.

  6. Measurement of an atomic quadrupole moment using dynamic decoupling

    Science.gov (United States)

    Akerman, Nitzan; Shaniv, Ravid; Ozeri, Roee

    2016-05-01

    Some of the best clocks today are ion-based optical clocks. These clocks are referenced to a narrow optical transition in a trapped ion. An example for such a narrow transition is the electric quadrupole E 2 transition between states with identical parity. An important systematic shift of such a transition is the quadrupole shift resulting from the electric field gradient inherent to the ion trap. We present a new dynamic decoupling method that rejects magnetic field noise while measuring the small quadrupole shift of the optical clock transition. Using our sequence we measured the quadrupole moment of the 4D5/2 level in a trapped 88 Sr+ ion to be 2 .973-0 . 033 + 0 . 026 ea02 , where e is the electron charge and a0 is the Bohr radius. Our measurement improves the uncertainty of this value by an order of magnitude and thus helps mitigate an important systematic uncertainty in 88 Sr+ based optical atomic clocks and verifies complicated many-body quantum calculations.

  7. Quadrupole moment of superdeformed bands in Tb-151

    NARCIS (Netherlands)

    Finck, C; Stezowski, O; Beck, FA; Appelbe, DE; Byrski, T; Courtin, S; Cullen, DM; Curien, D; de France, G; Duchene, G; Erturk, S; Gall, BJP; Garg, U; Haas, B; Khadiri, N; Kharraja, B; Kintz, N; Nourreddine, A; Prevost, D; Rigollet, C; Savajols, H; Twin, PJ; Vivien, JP; Zuber, K

    1998-01-01

    The quadrupole moments of the first two superdeformed (SD) bands in the nucleus Tb-151 have been measured with the Doppler Shift Attenuation Method (DSAM) using the EUROGAM gamma-ray spectrometer, The first excited band (B2) is identical to the yrast SD band of Dy-152 in terms of dynamical moments o

  8. ISR Superconducting Quadrupole Prototype:preparing the first test

    CERN Multimedia

    1976-01-01

    The photo shows the first prototype quadrupole (still with an adjustable stainless steel shrinking cylinder) being lifted to be inserted in a vertical cryostat for testing. It attained the design field gradient without any quench.The persons are Pierre Rey and Michel Bouvier. See also 7702690X.

  9. Inhomogeneous and interacting vacuum energy

    CERN Document Server

    De-Santiago, Josue; Wang, Yuting

    2012-01-01

    Vacuum energy is a simple model for dark energy driving an accelerated expansion of the universe. If the vacuum energy is inhomogeneous in spacetime then it must be interacting. We present the general equations for a spacetime-dependent vacuum energy in cosmology, including inhomogeneous perturbations. We show how any dark energy cosmology can be described by an interacting vacuum+matter. Different models for the interaction can lead to different behaviour (e.g., sound speed for dark energy perturbations) and hence could be distinguished by cosmological observations. As an example we present the cosmic microwave microwave background anisotropies and the matter power spectrum for two different versions of a generalised Chaplygin gas cosmology.

  10. Quantum Electrodynamics vacuum polarization solver

    CERN Document Server

    Carneiro, Pedro; Fonseca, Ricardo; Silva, Luís

    2016-01-01

    The self-consistent modeling of vacuum polarization due to virtual electron-positron fluctuations is of relevance for many near term experiments associated with high intensity radiation sources and represents a milestone in describing scenarios of extreme energy density. We present a generalized finite-difference time-domain solver that can incorporate the modifications to Maxwells equations due to virtual vacuum polarization. Our multidimensional solver reproduced in one dimensional configurations the results for which an analytic treatment is possible, yielding vacuum harmonic generation and birefringence. The solver has also been tested for two-dimensional scenarios where finite laser beam spot sizes must be taken into account. We employ this solver to explore different types of counter-propagating configurations that can be relevant for future planned experiments aiming to detect quantum vacuum dynamics at ultra-high electromagnetic field intensities.

  11. SILICON REFINING BY VACUUM TREATMENT

    Directory of Open Access Journals (Sweden)

    André Alexandrino Lotto

    2014-12-01

    Full Text Available This work aims to investigate the phosphorus removal by vacuum from metallurgical grade silicon (MGSi (98.5% to 99% Si. Melting experiments were carried out in a vacuum induction furnace, varying parameters such as temperature, time and relation area exposed to the vacuum / volume of molten silicon. The results of chemical analysis were obtained by inductively coupled plasma (ICP, and evaluated based on thermodynamic and kinetic aspects of the reaction of vaporization of the phosphorus in the silicon. The phosphorus was decreased from 33 to approximately 1.5 ppm after three hours of vacuum treatment, concluding that the evaporation step is the controlling step of the process for parameters of temperature, pressure and agitation used and refining by this process is technically feasible.

  12. APS storage ring vacuum system

    International Nuclear Information System (INIS)

    The Advanced Photon Source synchrotron radiation facility, under construction at the Argonne National Laboratory, incorporates a large ring for the storage of 7 GeV positrons for the generation of photon beams for the facility's experimental program. The Storage Ring's 1104 m circumference is divided into 40 functional sectors. The sectors include vacuum, beam transport, control, acceleration and insertion device components. The vacuum system, which is designed to operate at a pressure of 1 n Torr, consists of 240 connected sections, the majority of which are fabricated from an aluminum alloy extrusion. The sections are equipped with distributed NeG pumping, photon absorbers with lumped pumping, beam position monitors, vacuum diagnostics and valving. The details of the vacuum system design, selected results of the development program and general construction plans are presented. 11 refs., 6 figs., 3 tabs

  13. High-temperature quadrupole mass spectrometer for studying vaporization from materials heated by a CO2 laser

    International Nuclear Information System (INIS)

    To evaluate the effectiveness of mass spectrometry techniques in studying vaporization from selected materials, we designed a mass spectrometer than can be used either with a continuous wave or pulsed laser heating system or with a conventional furnace heating system. Our experimental apparatus, the components of which are described in detail, consisted of a quadrupole mass spectrometer positioned in a crossed-beam configuration, controlling electronics, a data acquisition system, a vacuum system, a cryogenic collimation system, and a laser heating system. Results of mass spectral scans taken during laser pyrolysis of polymeric materials and laser vaporization of graphite were compatible with data reported in other studies. Results of mass spectral studies of laser-induced combustion in the Ti + C system are also presented

  14. Silver/oxygen depth profile in coins by using laser ablation, mass quadrupole spectrometer and X-rays fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Cutroneo, M., E-mail: mari.cutroneo@tiscali.it [Dip. to di Fisica, Università di Messina, V. le F. Stagno D’Alcontres 31, S. Agata, Messina (Italy); Torrisi, L. [Dip. to di Fisica, Università di Messina, V. le F. Stagno D’Alcontres 31, S. Agata, Messina (Italy); INFN-Laboratori Nazionali del Sud, V. S. Sofia 62, 95123 Catania (Italy); Caridi, F. [Dip. to di Fisica, Università di Messina, V. le F. Stagno D’Alcontres 31, S. Agata, Messina (Italy); Sayed, R. [CNR V. le F. Stagno D’Alcontres 37, S. Agata, Messina (Italy); Gentile, C. [Dip. to di Fisica, Università di Messina, V. le F. Stagno D’Alcontres 31, S. Agata, Messina (Italy); Mondio, G. [Dip. to di Fisica della Materia e Ingegneria Elettronica, Messina (Italy); Serafino, T. [Centro Siciliano di Fisica Nucleare, Catania (Italy); Castrizio, E.D. [Dip.to di Scienze dell’Antichità dell’Università di Messina (Italy)

    2013-05-01

    Silver coins belonging to different historical periods were investigated to determine the Ag/O atomic ratio depth profiles. Laser ablation has been employed to remove, in high vacuum, the first superficial layers of the coins. Mass quadrupole spectrometry has been used to detect the Ag and the O atomic elements vaporized from the coin surface. The depth profile allowed to determine the thickness of the oxidation layer indicating that, in general, it is high in old coins. A complementary technique, using scanning electron microscope and the associated XRF microprobe, have been devoted to confirm the measurements of Ag/O atomic ratio measured with the laser-coupled mass spectrometry. The oxidation layer thicknesses range between about 25 and 250 microns.

  15. ITER diagnostic system: Vacuum interface

    Energy Technology Data Exchange (ETDEWEB)

    Patel, K.M., E-mail: Kaushal.Patel@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Udintsev, V.S.; Hughes, S.; Walker, C.I.; Andrew, P.; Barnsley, R.; Bertalot, L. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Drevon, J.M. [Bertin Technologies, BP 22, 13762 Aix-en Provence cedex 3 (France); Encheva, A. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Kashchuk, Y. [Institution “PROJECT CENTER ITER”, 1, Akademika Kurchatova pl., Moscow (Russian Federation); Maquet, Ph. [Bertin Technologies, BP 22, 13762 Aix-en Provence cedex 3 (France); Pearce, R.; Taylor, N.; Vayakis, G.; Walsh, M.J. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France)

    2013-10-15

    Diagnostics play an essential role for the successful operation of the ITER tokamak. They provide the means to observe control and to measure plasma during the operation of ITER tokamak. The components of the diagnostic system in the ITER tokamak will be installed in the vacuum vessel, in the cryostat, in the upper, equatorial and divertor ports, in the divertor cassettes and racks, as well as in various buildings. Diagnostic components that are placed in a high radiation environment are expected to operate for the life of ITER. There are approx. 45 diagnostic systems located on ITER. Some diagnostics incorporate direct or independently pumped extensions to maintain their necessary vacuum conditions. They require a base pressure less than 10{sup −7} Pa, irrespective of plasma operation, and a leak rate of less than 10{sup −10} Pa m{sup 3} s{sup −1}. In all the cases it is essential to maintain the ITER closed fuel cycle. These directly coupled diagnostic systems are an integral part of the ITER vacuum containment and are therefore subject to the same design requirements for tritium and active gas confinement, for all normal and accidental conditions. All the diagnostics, whether or not pumped, incorporate penetration of the vacuum boundary (i.e. window assembly, vacuum feedthrough etc.) and demountable joints. Monitored guard volumes are provided for all elements of the vacuum boundary that are judged to be vulnerable by virtue of their construction, material, load specification etc. Standard arrangements are made for their construction and for the monitoring, evacuating and leak testing of these volumes. Diagnostic systems are incorporated at more than 20 ports on ITER. This paper will describe typical and particular arrangements of pumped diagnostic and monitored guard volume. The status of the diagnostic vacuum systems, which are at the start of their detailed design, will be outlined and the specific features of the vacuum systems in ports and extensions

  16. Vacuum production; Produccion de vacio

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, J. L. de

    2010-07-01

    Since the advent of ultra high vacuum in 1958 has been a great demand for new as means of production and to meet the process needs to be done: industry heavy, high technology and space research areas, large accelerator systems particles or nuclear fusion. In this paper we explore the modern media production: dry vacuum pumps, turbo pumps, pump status diffusion ion pumps and cryopumps. (Author)

  17. Technical specification for vacuum systems

    International Nuclear Information System (INIS)

    The vacuum systems at the Stanford Linear Accelerator Center (SLAC) are primarily of all-metal construction and operate at pressures from 10-5 to 10-11 Torr. The primary gas loads during operation result from thermal desorption and beam-induced desorption from the vacuum chamber walls. These desorption rates can be extremely high in the case of hydrocarbons and other contaminants. These specifications place a major emphasis on eliminating contamination sources. The specifications and procedures have been written to insure the cleanliness and vacuum integrity of all SLAC vacuum systems, and to assist personnel involved with SLAC vacuum systems in choosing and designing components that are compatible with existing systems and meet the quality and reliability of SLAC vacuum standards. The specification includes requirements on design, procurement, fabrication, chemical cleaning, clean room practices, welding and brazing, helium leak testing, residual gas analyzer testing, bakeout, venting, and pumpdown. Also appended are specifications regarding acceptable vendors, isopropyl alcohol, bakeable valve cleaning procedure, mechanical engineering safety inspection, notes on synchrotron radiation, and specifications of numerous individual components

  18. Vacuum energy and cosmological evolution

    CERN Document Server

    Sola, Joan

    2014-01-01

    An expanding universe is not expected to have a static vacuum energy density. The so-called cosmological constant $\\Lambda$ should be an approximation, certainly a good one for a fraction of a Hubble time, but it is most likely a temporary description of a true dynamical vacuum energy variable that is evolving from the inflationary epoch to the present day. We can compare the evolving vacuum energy with a Casimir device where the parallel plates slowly move apart ("expand"). The total vacuum energy density cannot be measured, only the effect associated to the presence of the plates, and then also their increasing separation with time. In the universe there is a nonvanishing spacetime curvature $R$ as compared to Minkowskian spacetime that is changing with the expansion. The vacuum energy density must change accordingly, and we naturally expect $\\delta\\Lambda\\sim R\\sim H^2$. A class of dynamical vacuum models that trace such rate of change can be constructed. They are compatible with the current cosmological d...

  19. Technical specification for vacuum systems

    Energy Technology Data Exchange (ETDEWEB)

    Khaw, J. (ed.)

    1987-01-01

    The vacuum systems at the Stanford Linear Accelerator Center (SLAC) are primarily of all-metal construction and operate at pressures from 10/sup -5/ to 10/sup -11/ Torr. The primary gas loads during operation result from thermal desorption and beam-induced desorption from the vacuum chamber walls. These desorption rates can be extremely high in the case of hydrocarbons and other contaminants. These specifications place a major emphasis on eliminating contamination sources. The specifications and procedures have been written to insure the cleanliness and vacuum integrity of all SLAC vacuum systems, and to assist personnel involved with SLAC vacuum systems in choosing and designing components that are compatible with existing systems and meet the quality and reliability of SLAC vacuum standards. The specification includes requirements on design, procurement, fabrication, chemical cleaning, clean room practices, welding and brazing, helium leak testing, residual gas analyzer testing, bakeout, venting, and pumpdown. Also appended are specifications regarding acceptable vendors, isopropyl alcohol, bakeable valve cleaning procedure, mechanical engineering safety inspection, notes on synchrotron radiation, and specifications of numerous individual components. (LEW)

  20. Measurement of σ (e+e− → Hνν)×BR(H → ττ) at CLIC @ 350 GeV

    CERN Document Server

    Münnich, A

    2012-01-01

    This detector benchmark study evaluates the statistical precision with which the H → ττ branching ratio times cross section can be measured at CLIC running at s = 350 GeV. Only the hadronic decay of τs are considered. Results for MH = 126 GeV and 500 fb−1 of integrated luminosity are obtained using full de- tector simulation and including beam-induced backgrounds resulting in a statistical accuracy of cross section times branching ratio of 6.2%.

  1. Electron scale nested quadrupole Hall field in Cluster observations of magnetic reconnection

    CERN Document Server

    Jain, Neeraj

    2014-01-01

    This Letter presents the first evidence of a new and unique feature of spontaneous reconnection at multiple sites in electron current sheet, viz. nested quadrupole structure of Hall field at electron scales, in Cluster observations. The new nested quadrupole is a consequence of electron scale processes in reconnection. Whistler response of the upstream plasma to the interaction of electron flows from neighboring reconnection sites produces a large scale quadrupole Hall field enclosing the quadrupole fields of the multiple sites, thus forming a nested structure. Electron-magnetohydrodynamic simulations of an electron current sheet yields mechanism of the formation of nested quadrupole.

  2. Vacuum vessel for thermonuclear device

    International Nuclear Information System (INIS)

    In a vacuum vessel of a thermonuclear device, a rib for connecting outer and inner walls and reinforcing them has an integrated structure of an H-like shaped cross section. The vacuum vessel is formed by an assembly of plural partial vacuum vessels. The partial vacuum vessels are disposed in plurality in the poloidal direction so as to make a wall thickness at a port greater than that of other portions and provide a wall of a substantially D-like shaped cross section in the poloidal direction. Then torus circumferential electric resistance of the vacuum vessels is decreased and electromagnetic force resistance is improved since the reinforcing ribs are present, thereby enabling to provide sufficient strength and rigidity relative to a large electromagnetic force generated by plasma disruption. In addition, since all the joining is conducted by butt welding such as by electron beam welding and laser beam welding, the number of working step is reduced, and the bead width is decreased to reduce deformation, thereby reducing length of welding lines and operation time, so that low welding strain method is enabled. Further, non-destructive test for the weld portion is enabled by using radiation ray or ultrasonic-flaw detection. (N.H.)

  3. A stellarator helical vacuum vessel

    International Nuclear Information System (INIS)

    A design study of a stainless steel, heavy wall, helically shaped vacuum torus has been made for use in a proposed Stellarator configuration. The study concerns itself with the shape of the vacuum vessel and the division of the vessel into components that can be machined and welded together into a helical configuration. A complication in the design requires that a circular magnet coil be located at the minor toroidal axis and that this coil be embedded within the periphery of the vacuum vessel. The vacuum vessel has a minor toroidal axis diameter of 4 meters, a 68.6-cm shell diameter, and a 1.9-cm wall thickness. It twists about the minor toroidal axis twice in 3600. (An n value of 2). It is proposed that the unit be made of cylindrical segments with the ends of the cylinders cut at appropriate lengths and angles to form the helix. A mathematical derivation of the dimensions necessary to produce the required shapes of the segments has been made. Also, drawings of the vacuum vessel components have been produced on LANL's CTR CAD/CAM system. The procedure developed can be used for any value of n as dictated by physics requirements

  4. Vacuum Refining of Molten Silicon

    Science.gov (United States)

    Safarian, Jafar; Tangstad, Merete

    2012-12-01

    Metallurgical fundamentals for vacuum refining of molten silicon and the behavior of different impurities in this process are studied. A novel mass transfer model for the removal of volatile impurities from silicon in vacuum induction refining is developed. The boundary conditions for vacuum refining system—the equilibrium partial pressures of the dissolved elements and their actual partial pressures under vacuum—are determined through thermodynamic and kinetic approaches. It is indicated that the vacuum removal kinetics of the impurities is different, and it is controlled by one, two, or all the three subsequent reaction mechanisms—mass transfer in a melt boundary layer, chemical evaporation on the melt surface, and mass transfer in the gas phase. Vacuum refining experimental results of this study and literature data are used to study the model validation. The model provides reliable results and shows correlation with the experimental data for many volatile elements. Kinetics of phosphorus removal, which is an important impurity in the production of solar grade silicon, is properly predicted by the model, and it is observed that phosphorus elimination from silicon is significantly increased with increasing process temperature.

  5. High energy booster quadrupole cold mass development and industrialization program

    International Nuclear Information System (INIS)

    The department DAPNIA of the CEA Saclay has been involved in High Energy Physics for several decades, working on projects such as Detectors, Superconducting magnets (STCM), Thermonuclear Fusion machine (TORE SUPRA) and accelerator magnets. Considerable research and development effort have gone into the design and production of quadrupole magnets for HERA, and, over the last two years, for LHC. In January 1992 a subcontract was placed between URA and the CEA Saclay in France: from the SSC technical specification, the CEA Saclay has to design, study, fabricate, test the prototypes and develop all the production processes, as well as the tooling required to build and test in US Industry the High Energy Booster (HEB) Arc and special Quadrupole Cold Masses. This paper presents the overall program and the status of the work after 16 months

  6. Prototype of Superconducting Quadrupole for ISR Low-Beta Insertion

    CERN Multimedia

    1977-01-01

    In colliders, smaller beam cross-section means higher luminosity. Beam-size being proportional to the square-root of the "beta function" value, a small beta means small beam size, hence high luminosity. The first p-p collision in the ISR occurred in January 1971 and in 1973 a study was launched on low-beta insertions, which focus beams to even smaller sizes at the beam crossing points. In 1976 the first prototype of a superconducting quadrupole was tested. Here we see Theodor Tortschanoff with a prototype of 1.25 m magnetic length. Manufacture of 8 quadrupoles (4 of L=1.15 m, 4 of L=0.65 m) began at Alsthom in 1978. They were installed at point 8 of the ISR, enhancing luminosity there until final low-beta operation in December 1983. For details see "Yellow Report" CERN 76-16.

  7. High Gradient $Nb_3Sn$ Quadrupole Demonstrator MKQXF Engineering Design

    CERN Document Server

    Kokkinos, C; Karppinen, Mikko; CERN. Geneva. ATS Department

    2016-01-01

    A new mechanical design concept for the $Nb_3Sn$ quadrupoles has been developed with a goal of an accelerator quality magnet that can be industrially produced in large series. This concept can easily be extended to any length and applied on both 1-in-1 and 2-in-1 configurations. It is based on the pole-loading concept and collared coils using dipole-type collars. Detailed design optimisation of a demonstrator magnet based on present base-line HL-LHC IR quadrupole QXF coil geometry has been carried out including the end regions. This report describes the design concept and the fully parametric multi-physics finite element (FE) models that were used to determine the optimal assembly parameters including the effects of the manufacturing tolerances.

  8. Performance of An Adjustable Strength Permanent Magnet Quadrupole

    International Nuclear Information System (INIS)

    An adjustable strength permanent magnet quadrupole suitable for use in Next Linear Collider has been built and tested. The pole length is 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) is 68.7 Tesla. This paper describes measurements of strength, magnetic CL and field quality made using an air bearing rotating coil system. The magnetic CL stability during -20% strength adjustment proposed for beam based alignment was < 0.2 microns. Strength hysteresis was negligible. Thermal expansion of quadrupole and measurement parts caused a repeatable and easily compensated change in the vertical magnetic CL. Calibration procedures as well as CL measurements made over a wider tuning range of 100% to 20% in strength useful for a wide range of applications will be described. The impact of eddy currents in the steel poles on the magnetic field during strength adjustments will be reported

  9. Test results of LHC interaction regions quadrupoles produced by Fermilab

    CERN Document Server

    Fehér, S; Carson, J; Chichili, D R; Kerby, J; Lamm, M J; Nicol, T; Nobrega, A; Ogitsu, T; Orris, D; Page, T; Peterson, T; Rabehl, Roger Jon; Robotham, W; Scanlan, R; Schlabach, P; Strait, J; Sylvester, C D; Tartaglia, M; Tompkins, J C; Velev, G; Yadav, S; Zlobin, A V

    2005-01-01

    The US-LHC Accelerator Project is responsible for the production of the Q2 optical elements of the final focus triplets in the LHC interaction regions. As part of this program Fermilab is in the process of manufacturing and testing cryostat assemblies (LQXB) containing two identical quadrupoles (MQXB) with a dipole corrector between them. The 5.5 m long Fermilab designed MQXB have a 70 mm aperture and operate in superfluid helium at 1.9 K with a peak field gradient of 215 T/m. This paper summarizes the test results of several production MQXB quadrupoles with emphasis on quench performance and alignment studies. Quench localization studies using quench antenna signals are also presented.

  10. Quadrupole association and dissociation of hydrogen in the early Universe

    CERN Document Server

    Forrey, Robert C

    2016-01-01

    Radiative association and photodissociation rates are calculated for quadrupole transitions of H2. A complete set of bound and unbound states are included in a self-consistent master equation to obtain steady-state concentrations for a dilute system of hydrogen atoms and molecules. Phenomenological rate constants computed from the steady-state concentrations satisfy detailed balance for any combination of matter and radiation temperature. Simple formulas are derived for expressing the steady-state distributions in terms of equilibrium distributions. The rate constant for radiative association is found to be generally small for all temperature combinations. The photodissociation rate constant for quadrupole transitions is found to dominate the rate constants for other H2 photodestruction mechanisms for radiation temperatures less than or equal to 3000 K. Implications for the formation and destruction of H2 in the early universe are discussed.

  11. A twin aperture resistive quadrupole for the LHC

    CERN Document Server

    Clark, G S; de Rijk, G; Racine, M

    2000-01-01

    The European Organization for Nuclear Research (CERN) is constructing the Large Hadron Collider (LHC). The LHC's cleaning insertions require 48 twin aperture resistive quadrupoles. These 3.1 m long magnets have a gradient of 35 T/m for an inscribed circle of 46 mm diameter and an aperture separation distance of 224 mm. This magnet project is part of the Canadian contribution to the LHC. A prototype magnet was delivered in May 1998 and measured at CERN. Design changes were made based on the results. Due to the small apertures and the complicated geometry, the mechanical precision of the laminations and stacks is the main issue in the production of these quadrupoles. Series production will start in October 1999. The design and the measurement results are described in this paper. (1 refs).

  12. Quadrupole association and dissociation of hydrogen in the early Universe

    Science.gov (United States)

    Forrey, Robert C.

    2016-10-01

    Radiative association and photodissociation rates are calculated for quadrupole transitions of H2. A complete set of bound and unbound states are included in a self-consistent master equation to obtain steady-state concentrations for a dilute system of hydrogen atoms and molecules. Phenomenological rate constants computed from the steady-state concentrations satisfy detailed balance for any combination of matter and radiation temperature. Simple formulas are derived for expressing the steady-state distributions in terms of equilibrium distributions. The rate constant for radiative association is found to be generally small for all temperature combinations. The photodissociation rate constant for quadrupole transitions is found to dominate the rate constants for other H2 photodestruction mechanisms for {T}{{R}} ≤slant 3000 K. Implications for the formation and destruction of H2 in the early Universe are discussed.

  13. Performance of an Adjustable Strength Permanent Magnet Quadrupole

    CERN Document Server

    Gottschalk, Stephen C; Kangas, Kenneth; Spencer, Cherrill M; Volk, James T

    2005-01-01

    An adjustable strength permanent magnet quadrupole suitable for use in Next Linear Collider has been built and tested. The pole length is 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) is 68.7 Tesla. This paper describes measurements of strength, magnetic centerline and field quality made using an air bearing rotating coil system. The magnetic centerline stability during -20% strength adjustment proposed for beam based alignment was < 0.2 microns. Strength hysteresis was negligible. Thermal expansion of quadrupole and measurement parts caused a repeatable and easily compensated change in the vertical magnetic centerline. Calibration procedures as well as centerline measurements made over a wider tuning range of 100% to 20% in strength useful for a wide range of applications will be described. The impact of eddy currents in the steel poles on the magnetic field during strength adjustments will be reported.

  14. Measurements and correction of the PEP interaction region quadrupole magnets

    Energy Technology Data Exchange (ETDEWEB)

    Main, R.M.; Tanabe, J.T.; Halbach, K.

    1979-03-01

    Lenses for the intersection regions of PEP must be pure quadrupole over th entire magnet aperture to within 1:10/sup 4/. Correction of the magnet and its end fringe regions to this accuracy requires measurement of the field quality (relative field harmonic component amplitudes at the pole radius) to 1:10/sup 5/ through the 30th harmonic. Equipment developed for these measurements and the techniques used for field correction are described.

  15. Wooden models of an AA quadrupole between bending magnets

    CERN Multimedia

    1978-01-01

    At two points in the AA lattice, a quadrupole (QDN, defocusing, narrow) was tightly wedged between two bending magnets (BST, short, wide). This picture of wooden models lets one imagine the strong interaction between their magnetic fields. There was no way one could calculate with the necessary accuracy the magnetic effects and their consequences for the machine optics. The necessary corrections were made after measurements with a circulating beam, in a tedious iterative procedure, with corrrection coils and shims.

  16. Thermal noise in aqueous quadrupole micro- and nano-traps

    OpenAIRE

    Park, Jae Hyun; Krstić, Predrag S.

    2012-01-01

    Recent simulations and experiments with aqueous quadrupole micro-traps have confirmed a possibility for control and localization of motion of a charged particle in a water environment, also predicting a possibility of further reduction of the trap size to tens of nano-meters for trapping charged bio-molecules and DNA segments. We study the random thermal noise due to Brownian motion in water which significantly influences the trapping of particles in an aqueous environment. We derive the exac...

  17. Suitability of linear quadrupole ion traps for large Coulomb crystals

    OpenAIRE

    Tabor, D. A.; Rajagopal, V.; Lin, Y-W.; Odom, B.

    2011-01-01

    Growing and studying large Coulomb crystals, composed of tens to hundreds of thousands of ions, in linear quadrupole ion traps presents new challenges for trap implementation. We consider several trap designs, first comparing the total driven micromotion amplitude as a function of location within the trapping volume; total micromotion is an important point of comparison since it can limit crystal size by transfer of radiofrequency drive energy into thermal energy. We also compare the axial co...

  18. Radio Frequency Interference Suppression for Landmine Detection by Quadrupole Resonance

    OpenAIRE

    Liu Guoqing; Jiang Yi; Xiong Hong; Li Jian; Barrall Geoffrey A

    2006-01-01

    The quadrupole resonance (QR) technology can be used as a confirming sensor for buried plastic landmine detection by detecting the explosives within the mine. We focus herein on the detection of TNT mines via the QR sensor. Since the frequency of the QR signal is located within the AM radio frequency band, the QR signal can be corrupted by strong radio frequency interferences (RFIs). Hence to detect the very weak QR signal, RFI mitigation is essential. Reference antennas, which receive RFIs ...

  19. Short quadrupole, first at the SC, then at LEAR

    CERN Multimedia

    1982-01-01

    Quadrupoles of this type were built for the beam lines of the 600 MeV Synchro-Cylclotron. Surplus ones were installed in the LEAR injection line. The particularity of these quads is that they are very short and that a special design, resembling the "Lambertson magnet", limits and linearizes their stray field. This was achieved by the iron between the poles extending beyond the poles.

  20. Determining gaseous composition of fluid inclusions with quadrupole mass spectrometer

    Institute of Scientific and Technical Information of China (English)

    朱和平; 王莉娟

    2002-01-01

    Quadrupole mass spectrometer (QMS) is an instrument for effectively determining gaseous composition of fluid inclusion. The gaseous component is extracted from inclusions with thermal decrepitation method and then determined with the sensitive QMS instrument. The method is characterized by high sensitivity and high accuracy with the relative standard deviation (RSD, n = 6) of less than 3%. It has been successfully used for analyzing fluid inclusions. The analytical re-sults meet the requirement of geological study.