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Sample records for lhc luminosity upgrade

  1. Flat bunch creation and acceleration: a possible path for the LHC luminosity upgrade

    SciTech Connect

    Bhat, C.M.; /Fermilab

    2009-05-01

    Increasing the collider luminosity by replacing bunches having Gaussian line-charge distribution with flat bunches, but with same beam-beam tune shift at collision, has been studied widely in recent years. But, creation of 'stable' flat bunches (and their acceleration) using a multiple harmonic RF system has not been fully explored. Here, we review our experience with long flat bunches in the barrier RF buckets at Fermilab.We presentsome preliminary results from beam dynamics simulations and recent beam studies in the LHC injectors to create stable flat bunches using double harmonic RF systems. The results deduced from these studies will be used to model the necessary scheme for luminosity upgrade in the LHC. We have also described a viable (and economical) way for creation and acceleration of flat bunches in the LHC. The flat bunch scheme may have many advantages over the LHC baseline scenario, particularly because of the reduced momentum spread of the bunch for increased intensities.

  2. Cryogenic test of double quarter wave crab cavity for the LHC High luminosity upgrade

    SciTech Connect

    Xiao, B.; Alberty, L.; Belomestnykh, S.; Ben-Zvi, I.; Calaga, R.; Cullen, C.; Capatina, O.; Hammons, L.; Li, Z.; Marques, C.; Skaritka, J.; Verdu-Andres, S.; Wu, Q.

    2015-05-03

    A Proof-of-Principle (PoP) Double Quarter Wave Crab Cavity (DQWCC) was designed and fabricated for the Large Hadron Collider (LHC) luminosity upgrade. A vertical cryogenic test has been done at Brookhaven National Lab (BNL). The cavity achieved 4.5 MV deflecting voltage with a quality factor above 3×109. We report the test results of this design.

  3. Performance of drift-tube detectors at high counting rates for high-luminosity LHC upgrades

    NASA Astrophysics Data System (ADS)

    Bittner, Bernhard; Dubbert, Jörg; Kortner, Oliver; Kroha, Hubert; Manfredini, Alessandro; Nowak, Sebastian; Ott, Sebastian; Richter, Robert; Schwegler, Philipp; Zanzi, Daniele; Biebel, Otmar; Hertenberger, Ralf; Ruschke, Alexander; Zibell, Andre

    2013-12-01

    The performance of pressurized drift-tube detectors at very high background rates has been studied at the Gamma Irradiation Facility (GIF) at CERN and in an intense 20 MeV proton beam at the Munich Van-der-Graaf tandem accelerator for applications in large-area precision muon tracking at high-luminosity upgrades of the Large Hadron Collider (LHC). The ATLAS muon drift-tube (MDT) chambers with 30 mm tube diameter have been designed to cope with γ and neutron background hit rates of up to 500 Hz/cm2. Background rates of up to 14 kHz/cm2 are expected at LHC upgrades. The test results with standard MDT readout electronics show that the reduction of the drift-tube diameter to 15 mm, while leaving the operating parameters unchanged, vastly increases the rate capability well beyond the requirements. The development of new small-diameter muon drift-tube (sMDT) chambers for LHC upgrades is completed. Further improvements of tracking efficiency and spatial resolution at high counting rates will be achieved with upgraded readout electronics employing improved signal shaping for high counting rates.

  4. The CMS electromagnetic calorimeter barrel upgrade for High-Luminosity LHC

    NASA Astrophysics Data System (ADS)

    Gras, Philippe; CMS Collaboration

    2015-02-01

    The High Luminosity LHC (HL-LHC) will provide unprecedented instantaneous and integrated luminosity. The lead tungstate crystals forming the barrel part of the CMS Electromagnetic Calorimeter (ECAL) will still perform well, even after the expected 3000 fb-1 at the end of HL-LHC. The scintillation light from the crystals is measured with avalanche photodiodes (APDs). Although the APDs will continue to be operational, there will be some increase in noise due to radiation-induced dark-currents. Triggering on electromagnetic objects with ~140 pileup events necessitates a change of the front-end electronics. New developments in high-speed optical links will allow single-crystal readout at 40 MHz to upgraded off-detector processors, allowing maximum flexibility and enhanced triggering possibilities. The very-front- end system will also be upgraded, to provide improved rejection of anomalous signals in the APDs as well as to mitigate the increase in APD noise. We are also considering lowering the ECAL barrel operating temperature from 18°C to about 8 ~10°C, in order to increase the scintillation light output and reduce the APD dark current.

  5. Higher order mode filter design for double quarter wave crab cavity for the LHC high luminosity upgrade

    SciTech Connect

    Xiao, B.; Belomestnykh, S.; Ben-Zvi, I.; Burt, G.; Calaga, R.; Capatina, O.; Hall, B.; Jones, T.; Skaritka, J.; Verdu-Andres, S.; Wu, Q.

    2015-05-03

    A Double Quarter Wave Crab Cavity (DQWCC) was designed for the Large Hadron Collider (LHC) luminosity upgrade. A compact Higher Order Mode (HOM) filter with wide stop band at the deflecting mode is developed for this cavity. Multiphysics finite element simulation results are presented. The integration of this design to the cavity cryomodule is described.

  6. LHC detector upgrades

    SciTech Connect

    Dan Green

    2003-09-15

    The LHC detectors are well into their construction phase. The LHC schedule shows first beam to ATLAS and CMS in 2007. Because the LHC accelerator has begun to plan for a ten fold increase in LHC design luminosity (the SLHC or super LHC) it is none too soon to begin to think about the upgrades which will be required of the present LHC detectors. In particular, the tracking systems of ATLAS and CMS will need to be completely rebuilt. Given the time needed to do the R & D, make prototypes, and construct the new detectors and given the accelerator schedule for the SLHC, work needs to begin rather soon.

  7. Conceptual Design of the Cryogenic System for the High-luminosity Upgrade of the Large Hadron Collider (LHC)

    NASA Astrophysics Data System (ADS)

    Brodzinski, K.; Claudet, S.; Ferlin, G.; Tavian, L.; Wagner, U.; Van Weelderen, R.

    The discovery of a Higgs boson at CERN in 2012 is the start of a major program of work to measure this particle's properties with the highest possible precision for testing the validity of the Standard Model and to search for further new physics at the energy frontier. The LHC is in a unique position to pursue this program. Europe's top priority is the exploitation of the full potential of the LHC, including the high-luminosity upgrade of the machine and detectors with an objective to collect ten times more data than in the initial design, by around 2030. To reach this objective, the LHC cryogenic system must be upgraded to withstand higher beam current and higher luminosity at top energy while keeping the same operation availability by improving the collimation system and the protection of electronics sensitive to radiation. This paper will present the conceptual design of the cryogenic system upgrade with recent updates in performance requirements, the corresponding layout and architecture of the system as well as the main technical challenges which have to be met in the coming years.

  8. The High-Luminosity upgrade of the LHC: Physics and Technology Challenges for the Accelerator and the Experiments

    NASA Astrophysics Data System (ADS)

    Schmidt, Burkhard

    2016-04-01

    In the second phase of the LHC physics program, the accelerator will provide an additional integrated luminosity of about 2500/fb over 10 years of operation to the general purpose detectors ATLAS and CMS. This will substantially enlarge the mass reach in the search for new particles and will also greatly extend the potential to study the properties of the Higgs boson discovered at the LHC in 2012. In order to meet the experimental challenges of unprecedented pp luminosity, the experiments will need to address the aging of the present detectors and to improve the ability to isolate and precisely measure the products of the most interesting collisions. The lectures gave an overview of the physics motivation and described the conceptual designs and the expected performance of the upgrades of the four major experiments, ALICE, ATLAS, CMS and LHCb, along with the plans to develop the appropriate experimental techniques and a brief overview of the accelerator upgrade. Only some key points of the upgrade program of the four major experiments are discussed in this report; more information can be found in the references given at the end.

  9. Mechanical Analysis of the 400 MHz RF-Dipole Crabbing Cavity Prototype for LHC High Luminosity Upgrade

    SciTech Connect

    De Silva, Subashini U.; Park, HyeKyoung; Delayen, Jean R.; Li, Z.

    2013-12-01

    The proposed LHC high luminosity upgrade requires two crabbing systems in increasing the peak luminosity, operating both vertically and horizontally at two interaction points of IP1 and IP5. The required system has tight dimensional constraints and needs to achieve higher operational gradients. A proof-of-principle 400 MHz crabbing cavity design has been successfully tested and has proven to be an ideal candidate for the crabbing system. The cylindrical proof-of-principle rf-dipole design has been adapted in to a square shaped design to further meet the dimensional requirements. The new rf-dipole design has been optimized in meeting the requirements in rf-properties, higher order mode damping, and multipole components. A crabbing system in a cryomodule is expected to be tested on the SPS beam line prior to the test at LHC. The new prototype is required to achieve the mechanical and thermal specifications of the SPS test followed by the test at LHC. This paper discusses the detailed mechanical and thermal analysis in minimizing Lorentz force detuning and sensitivity to liquid He pressure fluctuations.

  10. Prototyping of an HV-CMOS demonstrator for the High Luminosity-LHC upgrade

    NASA Astrophysics Data System (ADS)

    Vilella, E.; Benoit, M.; Casanova, R.; Casse, G.; Ferrere, D.; Iacobucci, G.; Peric, I.; Vossebeld, J.

    2016-01-01

    HV-CMOS sensors can offer important advantages in terms of material budget, granularity and cost for large area tracking systems in high energy physics experiments. This article presents the design and simulated results of an HV-CMOS pixel demonstrator for the High Luminosity-LHC. The pixel demonstrator has been designed in the 0.35 μm HV-CMOS process from ams AG and submitted for fabrication through an engineering run. To improve the response of the sensor, different wafers with moderate to high substrate resistivities are used to fabricate the design. The prototype consists of four large analog and standalone matrices with several pixel flavours, which are all compatible for readout with the FE-I4 ASIC. Details about the matrices and the pixel flavours are provided in this article.

  11. Nb$_3$Sn High Field Magnets for the High Luminosity LHC Upgrade Project

    SciTech Connect

    Ambrosio, Giorgio

    2015-01-01

    The High Luminosity upgrade of the Large Hadron Collider at CERN requires a new generation of high field superconducting magnets. High field large aperture quadrupoles (MQXF) are needed for the low-beta triplets close to the ATLAS and CMS detectors, and high field two-in-one dipoles (11 T dipoles) are needed to make room for additional collimation. The MQXF quadrupoles, with a field gradient of 140 T/m in 150 mm aperture, have a peak coil field of 12.1 T at nominal current. The 11 T dipoles, with an aperture of 60 mm, have a peak coil field of 11.6 T at nominal current. Both magnets require Nb3Sn conductor and are the first applications of this superconductor to actual accelerator magnets.

  12. Design and Analysis of TQS01, a 90 mm Nb3Sn Model Quadrupole for LHC Luminosity Upgrade Based on a Key and Bladder Assembly

    SciTech Connect

    Caspi, S.; Ambrosio, G.; Andreev, N.; Barzi, E.; Bossert, R.C.; Dietderich, D.R.; Ferracin, P.; Ghosh, A.; Gourlay, S.A.; Hafalia, A.R.; Hannaford, C.R.; Kashikhin, V.S.; Kashikhin, V.V.; Lietzke, A.F.; Mattafirri, S.; McInturff, A.D.; Novitsky, I.V.; Sabbi, G.L.; Turrioni, D.; Yamada, R.; Zlobin, A.V.

    2006-06-01

    The US LHC Accelerator Research Program (LARP) is developing Nb{sub 3}Sn accelerator magnet technology for the LHC luminosity upgrade. Two 90 mm 'Technology Quadrupole' models (TQS01, TQC01) are being developed in close collaboration between LBNL and FNAL, using identical coil design, but two different support structures. The TQS01 structure was developed and tested at LBNL. With this approach coils are supported by an outer aluminum shell and assembled using keys and bladders. In contrast, the second model TQC01, utilize stainless steel collars and a thick stainless steel skin. This paper describes the TQS01 model magnet, its 3D ANSYS stress analysis, and anticipated instrumentation and assembly procedure.

  13. Test Results of 15 T Nb3Sn Quadrupole Magnet HQ01 with a 120 mm Bore for the LHC Luminosity Upgrade

    SciTech Connect

    Caspi, S.; Schmalzle, J.; Ambrosio, G.; Anerella, M.; Barzi, E.; Bingham, B.; Bossert, R.; Cheng, D.W.; Chlachidze, G.; Dietderich, D.R.; Felice, H.; Ferracin, P.; Ghosh, A.; Hafalia, A.R.; Hannaford, C.R.; Joseph, J.; Kashikhin, V.V.; Sabbi, G.L.; Schmalzle, J.; Wanderer,; P.l Xiaorong, W.; Zlobin, A.V.

    2011-08-03

    In support of the luminosity upgrade of the Large Hadron Collider (LHC), the US LHC Accelerator Research Program (LARP) has been developing a 1-meter long, 120 mm bore Nb{sub 3}Sn IR quadrupole magnet (HQ). With a short sample gradient of 219 T/m at 1.9 K and a conductor peak field of 15 T, the magnet will operate under higher forces and stored-energy levels than that of any previous LARP magnet models. In addition, HQ has been designed to incorporate accelerator quality features such as precise coil alignment and adequate cooling. The first 6 coils (out of the 8 fabricated so far) have been assembled and used in two separate tests-HQ01a and HQ01b. This paper presents design parameters, summary of the assemblies, the mechanical behavior as well as the performance of HQ01a and HQ01b.

  14. A double-sided silicon micro-strip Super-Module for the ATLAS Inner Detector upgrade in the High-Luminosity LHC

    NASA Astrophysics Data System (ADS)

    Gonzalez-Sevilla, S.; Affolder, A. A.; Allport, P. P.; Anghinolfi, F.; Barbier, G.; Bates, R.; Beck, G.; Benitez, V.; Bernabeu, J.; Blanchot, G.; Bloch, I.; Blue, A.; Booker, P.; Brenner, R.; Buttar, C.; Cadoux, F.; Casse, G.; Carroll, J.; Church, I.; Civera, J. V.; Clark, A.; Dervan, P.; Díez, S.; Endo, M.; Fadeyev, V.; Farthouat, P.; Favre, Y.; Ferrere, D.; Friedrich, C.; French, R.; Gallop, B.; García, C.; Gibson, M.; Greenall, A.; Gregor, I.; Grillo, A.; Haber, C. H.; Hanagaki, K.; Hara, K.; Hauser, M.; Haywood, S.; Hessey, N.; Hill, J.; Hommels, L. B. A.; Iacobucci, G.; Ikegami, Y.; Jones, T.; Kaplon, J.; Kuehn, S.; Lacasta, C.; La Marra, D.; Lynn, D.; Mahboubin, K.; Marco, R.; Martí-García, S.; Martínez-McKinney, F.; Matheson, J.; McMahon, S.; Nelson, D.; Newcomer, F. M.; Parzefall, U.; Phillips, P. W.; Sadrozinski, H. F.-W.; Santoyo, D.; Seiden, A.; Soldevila, U.; Spencer, E.; Stanitzki, M.; Sutcliffe, P.; Takubo, Y.; Terada, S.; Tipton, P.; Tsurin, I.; Ullán, M.; Unno, Y.; Villani, E. G.; Warren, M.; Weber, M.; Wilmut, I.; Wonsak, S.; Witharm, R.; Wormald, M.

    2014-02-01

    The ATLAS experiment is a general purpose detector aiming to fully exploit the discovery potential of the Large Hadron Collider (LHC) at CERN. It is foreseen that after several years of successful data-taking, the LHC physics programme will be extended in the so-called High-Luminosity LHC, where the instantaneous luminosity will be increased up to 5 × 1034 cm-2 s-1. For ATLAS, an upgrade scenario will imply the complete replacement of its internal tracker, as the existing detector will not provide the required performance due to the cumulated radiation damage and the increase in the detector occupancy. The current baseline layout for the new ATLAS tracker is an all-silicon-based detector, with pixel sensors in the inner layers and silicon micro-strip detectors at intermediate and outer radii. The super-module is an integration concept proposed for the strip region of the future ATLAS tracker, where double-sided stereo silicon micro-strip modules are assembled into a low-mass local support structure. An electrical super-module prototype for eight double-sided strip modules has been constructed. The aim is to exercise the multi-module readout chain and to investigate the noise performance of such a system. In this paper, the main components of the current super-module prototype are described and its electrical performance is presented in detail.

  15. High-field Magnet Development toward the High Luminosity LHC

    SciTech Connect

    Apollinari, Giorgio

    2014-07-01

    The upcoming Luminosity upgrade of the LHC (HL-LHC) will rely on the use of Accelerator Quality Nb3Sn Magnets which have been the focus of an intense R&D effort in the last decade. This contribution will describe the R&D and results of Nb3Sn Accelerator Quality High Field Magnets development efforts, with emphasis on the activities considered for the HL-LHC upgrades.

  16. SLHC, the High-Luminosity Upgrade (public event)

    ScienceCinema

    None

    2011-10-06

    In the morning of June 23rd a public event is organised in CERN's Council Chamber with the aim of providing the particle physics community with up-to-date information about the strategy for the LHC luminosity upgrade and to describe the current status of preparation work. The presentations will provide an overview of the various accelerator sub-projects, the LHC physics prospects and the upgrade plans of ATLAS and CMS. This event is organised in the framework of the SLHC-PP project, which receives funding from the European Commission for the preparatory phase of the LHC High Luminosity Upgrade project. Informing the public is among the objectives of this EU-funded project. A simultaneous transmission of this meeting will be broadcast, available at the following address: http://webcast.cern.ch/

  17. Mechanical studies towards a silicon micro-strip super module for the ATLAS inner detector upgrade at the high luminosity LHC

    NASA Astrophysics Data System (ADS)

    Barbier, G.; Cadoux, F.; Clark, A.; Endo, M.; Favre, Y.; Ferrere, D.; Gonzalez-Sevilla, S.; Hanagaki, K.; Hara, K.; Iacobucci, G.; Ikegami, Y.; Jinnouchi, O.; La Marra, D.; Nakamura, K.; Nishimura, R.; Perrin, E.; Seez, W.; Takubo, Y.; Takashima, R.; Terada, S.; Todome, K.; Unno, Y.; Weber, M.

    2014-04-01

    It is expected that after several years of data-taking, the Large Hadron Collider (LHC) physics programme will be extended to the so-called High-Luminosity LHC, where the instantaneous luminosity will be increased up to 5 × 1034 cm-2 s-1. For the general-purpose ATLAS experiment at the LHC, a complete replacement of its internal tracking detector will be necessary, as the existing detector will not provide the required performance due to the cumulated radiation damage and the increase in the detector occupancy. The baseline layout for the new ATLAS tracker is an all-silicon-based detector, with pixel sensors in the inner layers and silicon micro-strip detectors at intermediate and outer radii. The super-module (SM) is an integration concept proposed for the barrel strip region of the future ATLAS tracker, where double-sided stereo silicon micro-strip modules (DSM) are assembled into a low-mass local support (LS) structure. Mechanical aspects of the proposed LS structure are described.

  18. Dynamic aperture studies for the LHC high luminosity lattice

    SciTech Connect

    Maria, R. de; Giovannozzi, M.; McIntosh, E.; Nosochkov, Y. M.; Cai, Y.; Wang, M. -H.

    2015-07-14

    Since quite some time, dynamic aperture studies have been undertaken with the aim of specifying the required field quality of the new magnets that will be installed in the LHC ring in the framework of the high-luminosity upgrade. In this paper the latest results concerning the specification work will be presented, taking into account both injection and collision energies and the field quality contribution from all the magnets in the newly designed interaction regions.

  19. The ATLAS liquid argon calorimeter: One year of LHC operation and future upgrade plans for HL-LHC

    SciTech Connect

    Krieger, P. W.

    2011-07-01

    An overview of the ATLAS liquid-argon calorimeter system is provided, along with a discussion of its operation and performance during the first year of LHC running. Upgrade planning related to the proposed high-luminosity upgrade of the LHC is also discussed, with an emphasis on the forward part of the calorimeter where the effects of the higher luminosity are a particular challenge. (authors)

  20. Detector Developments for the High Luminosity LHC Era (4/4)

    ScienceCinema

    None

    2011-10-06

    Tracking Detectors - Part II. Calorimetry, muon detection, vertexing, and tracking will play a central role in determining the physics reach for the High Luminosity LHC Era. In these lectures we will cover the requirements, options, and the R&D; efforts necessary to upgrade the current LHC detectors and enabling discoveries.

  1. Detector Developments for the High Luminosity LHC Era (4/4)

    SciTech Connect

    2010-09-22

    Tracking Detectors - Part II. Calorimetry, muon detection, vertexing, and tracking will play a central role in determining the physics reach for the High Luminosity LHC Era. In these lectures we will cover the requirements, options, and the R&D; efforts necessary to upgrade the current LHC detectors and enabling discoveries.

  2. Detector Developments for the High Luminosity LHC Era (3/4)

    SciTech Connect

    2010-09-22

    Tracking Detectors - Part I. Calorimetry, muon detection, vertexing, and tracking will play a central role in determining the physics reach for the High Luminosity LHC Era. In these lectures we will cover the requirements, options, and the R&D; efforts necessary to upgrade the current LHC detectors and enabling discoveries.

  3. Detector Developments for the High Luminosity LHC Era (3/4)

    ScienceCinema

    None

    2011-10-06

    Tracking Detectors - Part I. Calorimetry, muon detection, vertexing, and tracking will play a central role in determining the physics reach for the High Luminosity LHC Era. In these lectures we will cover the requirements, options, and the R&D; efforts necessary to upgrade the current LHC detectors and enabling discoveries.

  4. Evaluation of Young’s modulus of MgB2 filaments in composite wires for the superconducting links for the high-luminosity LHC upgrade

    NASA Astrophysics Data System (ADS)

    Sugano, Michinaka; Ballarino, Amalia; Bartova, Barbora; Bjoerstad, Roger; Gerardin, Alexandre; Scheuerlein, Christian

    2016-02-01

    MgB2 wire is a promising superconductor for the superconducting links for the high-luminosity upgrade of the large Hadron collider at CERN. The mechanical properties of MgB2 must be fully quantified for the cable design, and in this study, we evaluate the Young’s modulus of MgB2 filaments in wires with a practical level of critical current. The Young’s moduli of MgB2 filaments by two different processes, in situ and ex situ, were compared. Two different evaluation methods were applied to an in situ MgB2 wire, a single-fiber tensile test and a tensile test after removing Monel. In addition, the Young’s modulus of the few-micron-thick Nb-Ni reaction layer in an ex situ processed wire was evaluated using a nanoindentation testing technique to improve the accuracy of analysis based on the rule of mixtures. The Young’s moduli of the in situ and ex situ MgB2 wires were in the range of 76-97 GPa and no distinct difference depending on the fabrication process was found.

  5. Operational results from the LHC luminosity monitors

    SciTech Connect

    Miyamoto, R.; Ratti, A.; Matis, H.S.; Stezelberger, T.; Turner, W.C.; Yaver, H.; Bravin, E.

    2011-03-28

    The luminosity monitors for the high luminosity regions in the LHC have been operating to monitor and optimize the luminosity since 2009. The device is a gas ionization chamber inside the neutral particle absorber 140 m from the interaction point and monitors showers produced by high energy neutral particles from the collisions. It has the ability to resolve the bunch-by-bunch luminosity as well as to survive the extreme level of radiation in the nominal LHC operation. We present operational results of the device during proton and lead ion operations in 2010 and make comparisons with measurements of experiments. The Large Hadron Collider (LHC) at CERN can accelerate proton and lead ion beams to 7 TeV and 547 TeV and produce collisions of these particles. Luminosity measures performance of the LHC and is particularly important for experiments in high luminosity interaction points (IPs), ATLAS (IP1) and CMS (IP5). To monitor and optimize the luminosities of these IPs, BRAN (Beam RAte Neutral) detectors [1, 2] have been installed and operating since the beginning of the 2009 operation [3]. A neutral particle absorber (TAN) protects the D2 separation dipole from high energy forward neutral particles produced in the collisions [4]. These neutral particles produce electromagnetic and hadronic showers inside the TAN and their energy flux is proportional to the collision rate and hence to the luminosity. The BRAN detector is an Argon gas ionization chamber installed inside the TANs on both sides of the IP1 and IP5 and monitors the relative changes in the luminosity by detecting the ionization due to these showers. When the number of collisions per bunch crossing (multiplicity) is small, the shower rate inside the TAN is also proportional to the luminosity. Hence, the detector is designed to operate by measuring either the shower rate (counting mode for low and intermediate luminosities) or the average shower flux (pulse height mode for high luminosities). The detector is

  6. Detector Developments for the High Luminosity LHC Era (1/4)

    SciTech Connect

    2010-09-22

    Calorimetry and Muon Spectrometers - Part I : In the first part of the lecture series, the motivation for a high luminosity upgrade of the LHC will be quickly reviewed together with the challenges for the LHC detectors. In particular, the plans and ongoing research for new calorimeter detectors will be explained. The main issues in the high-luminosity era are an improved radiation tolerance, natural ageing of detector components and challenging trigger and physics requirements. The new technological solutions for calorimetry at a high-luminosity LHC will be reviewed.

  7. Detector Developments for the High Luminosity LHC Era (1/4)

    ScienceCinema

    None

    2011-10-06

    Calorimetry and Muon Spectrometers - Part I : In the first part of the lecture series, the motivation for a high luminosity upgrade of the LHC will be quickly reviewed together with the challenges for the LHC detectors. In particular, the plans and ongoing research for new calorimeter detectors will be explained. The main issues in the high-luminosity era are an improved radiation tolerance, natural ageing of detector components and challenging trigger and physics requirements. The new technological solutions for calorimetry at a high-luminosity LHC will be reviewed.

  8. SMALL ANGLE CRAB COMPENSATION FOR LHC IR UPGRADE

    SciTech Connect

    CALAGA,R.; DORDA, U.; OHMI, D.; OIDE, K.; TOMAS, R.; ZIMMERMANN, F.

    2007-06-25

    A small angle (< 1 mrad) crab scheme is an attractive option for the LHC luminosity upgrade to recover the geometric luminosity loss from the finite crossing angle [I]. The luminosity loss increases steeply to unacceptable levels as the IP beta function is reduced below its nominal value (see Fig. 1 in Ref. [2]). The crab compensation in the LHC can be accomplished using only two sets of deflecting RF cavities, placed in collision-free straight sections of the LHC to nullify the effective crossing angles at IPI & IP5. We also explore a 400 MHz superconducting cavity design and discuss the pertinent RF challenges. We present IR optics configurations with low-angle crab crossing, study the beam-beam performance and proton-beam emittance growth in the presence of crab compensation, lattice errors, and crab RF noise sources.

  9. L1Track: A fast Level 1 track trigger for the ATLAS high luminosity upgrade

    NASA Astrophysics Data System (ADS)

    Cerri, Alessandro

    2016-07-01

    With the planned high-luminosity upgrade of the LHC (HL-LHC), the ATLAS detector will see its collision rate increase by approximately a factor of 5 with respect to the current LHC operation. The earliest hardware-based ATLAS trigger stage ("Level 1") will have to provide a higher rejection factor in a more difficult environment: a new improved Level 1 trigger architecture is under study, which includes the possibility of extracting with low latency and high accuracy tracking information in time for the decision taking process. In this context, the feasibility of potential approaches aimed at providing low-latency high-quality tracking at Level 1 is discussed.

  10. Upgrading the ATLAS barrel tracker for the super-LHC

    NASA Astrophysics Data System (ADS)

    Bates, Richard L.; ATLAS ID Collaboration

    2009-08-01

    It has been proposed to increase the luminosity of the large hadron collider (LHC) at CERN by an order of magnitude, with the upgraded machine dubbed super-LHC. The ATLAS experiment will require a new tracker for this high-luminosity operation due to radiation damage and event density. In order to cope with the order of magnitude increase in pile-up backgrounds at the higher luminosity, an all-silicon tracker is being designed. The new strip detector will use significantly shorter strips than the current silicon tracker in order to minimize the occupancy. As the increased luminosity will mean a corresponding increase in radiation dose, a new generation of extremely radiation-hard silicon detectors is required. An R&D program is underway to develop silicon sensors with sufficient radiation hardness. New front-end electronics and readout systems are being designed to cope with the higher data rates. The challenges facing the sensors and the cooling and mechanical support will be discussed. A possible tracker layout will be described.

  11. Nb3Sn quadrupoles in the LHC IR Phase I upgrade

    SciTech Connect

    Zlobin, A.V.; Johnstone, J.A.; Kashikhin, V.V.; Mokhov, N.V.; Rakhno, I.L.; de Maria, R.; Peggs, S.; Robert-Demolaize, G.; Wanderer, P.; /Brookhaven

    2008-06-01

    After a number of years of operation at nominal parameters, the LHC will be upgraded to a higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet parameters and issues related to using Nb{sub 3}Sn quadrupoles including aperture, gradient, magnetic length, field quality, operation margin, et cetera are discussed.

  12. Nb3Sn Quadrupoles in the LHC IR Phase I Upgrade

    SciTech Connect

    Zlobin,A.; Johnstone, J.; Kashikhin, V.; Mokhov, N.; Rakhno, I.; deMaria, R.; Peggs, S.; Robert-Demolaize, F.; Wanderer, P.

    2008-06-23

    After a number of years of operation at nominal parameters, the LHC will be upgraded for higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet parameters and issues related to using Nb{sub 3}Sn quadrupoles including aperture, gradient, magnetic length, field quality, operation margin, et cetera are discussed.

  13. Development of a silicon-microstrip super module prototype for the high luminosity LHC

    NASA Astrophysics Data System (ADS)

    Clark, A.; Barbier, G.; Cadoux, F.; Endo, M.; Favre, Y.; Ferrere, D.; Gonzalez-Sevilla, S.; Hanagaki, K.; Hara, K.; Iacobucci, G.; Ikegami, Y.; Koriki, T.; La Marra, D.; Pohl, M.; Takubo, Y.; Terada, S.; Unno, Y.; Weber, M.

    2013-01-01

    Following the Phase II upgrade of the CERN Large Hadron Collider (LHC) currently foreseen in 2022-2023, the High Luminosity LHC (HL-LHC) is expected to deliver a peak luminosity in excess of 5×1034 cm-2 s-1 and an integrated luminosity of order 3000 fb-1 until 2033. The ATLAS Collaboration plans to replace the existing Inner Tracking Detector by a new tracker, with readout electronics as well as silicon pixel and strip sensor technology capable of maintaining the excellent tracking performance of the existing tracker in the severe radiation and high collision rate environment of the HL-LHC. The promising super-module integration concept extends the proven design of the existing barrel silicon strip tracker to the HL-LHC, with double-sided stereo silicon micro-strip modules assembled into a low mass local support structure. The Super-Module R&D program is described, with reference to HL-LHC requirements, and key prototype results are summarized.

  14. Detector Developments for the High Luminosity LHC Era (2/4)

    ScienceCinema

    None

    2011-10-06

    Calorimetry and Muon Spectromers - Part II: When upgrading the LHC to higher luminosities, the detector and trigger performance shall be preserved - if not improved - with respect to the nominal performance. The ongoing R&D; for new radiation tolerant front-end electronics for calorimeters with higher read-out bandwidth are summarized and new possibilities for the trigger systems are presented. Similar developments are foreseen for the muon spectrometers, where also radiation tolerance of the muon detectors and functioning at high background rates is important. The corresponding plans and research work for the calorimeter and muon detectors at a LHC with highest luminsity are presented.

  15. Pile up management at the high-luminosity LHC and introduction to the crab-kissing concept

    NASA Astrophysics Data System (ADS)

    Fartoukh, Stéphane

    2014-11-01

    Upgrading the integrated performance of the LHC, while preserving the quality of the physics data delivered to the experiments, is a real challenge for the high luminosity LHC (HL-LHC). This paper will give an overview of the situation in terms of performance and so-called pile up density which directly impacts on the reconstruction efficiency of the primary vertices at the interaction point. Both the present HL-LHC baseline and its possible extension with the so-called crab-kissing scheme will be discussed in this context.

  16. Radiation hardness of two CMOS prototypes for the ATLAS HL-LHC upgrade project.

    NASA Astrophysics Data System (ADS)

    Huffman, B. T.; Affolder, A.; Arndt, K.; Bates, R.; Benoit, M.; Di Bello, F.; Blue, A.; Bortoletto, D.; Buckland, M.; Buttar, C.; Caragiulo, P.; Das, D.; Dopke, J.; Dragone, A.; Ehrler, F.; Fadeyev, V.; Galloway, Z.; Grabas, H.; Gregor, I. M.; Grenier, P.; Grillo, A.; Hoeferkamp, M.; Hommels, L. B. A.; John, J.; Kanisauskas, K.; Kenney, C.; Kramberger, J.; Liang, Z.; Mandić, I.; Maneuski, D.; Martinez-Mckinney, F.; McMahon, S.; Meng, L.; Mikuž, M.; Muenstermann, D.; Nickerson, R.; Perić, I.; Phillips, P.; Plackett, R.; Rubbo, F.; Segal, J.; Seidel, S.; Seiden, A.; Shipsey, I.; Song, W.; Stanitzki, M.; Su, D.; Tamma, C.; Turchetta, R.; Vigani, L.; Volk, J.; Wang, R.; Warren, M.; Wilson, F.; Worm, S.; Xiu, Q.; Zhang, J.; Zhu, H.

    2016-02-01

    The LHC luminosity upgrade, known as the High Luminosity LHC (HL-LHC), will require the replacement of the existing silicon strip tracker and the transistion radiation tracker. Although a baseline design for this tracker exists the ATLAS collaboration and other non-ATLAS groups are exploring the feasibility of using CMOS Monolithic Active Pixel Sensors (MAPS) which would be arranged in a strip-like fashion and would take advantage of the service and support structure already being developed for the upgrade. Two test devices made with the AMS H35 process (a High voltage or HV CMOS process) have been subjected to various radiation environments and have performed well. The results of these tests are presented in this paper.

  17. Nb3Sn Quadrupoles Designs For The LHC Upgrades

    SciTech Connect

    Felice, Helene

    2008-05-19

    In preparation for the LHC luminosity upgrades, high field and large aperture Nb{sub 3}Sn quadrupoles are being studied. This development has to incorporate all the relevant features for an accelerator magnet like alignment and cooling channels. The LARP HQ model is a high field and large bore quadrupole that will meet these requirements. The 2-layer coils are surrounded by a structure based on key and bladder technology with supporting iron yoke and aluminum shell. This structure is aimed at pre-stress control, alignment and field quality. We present here the magnetic and mechanical design of HQ, along with recent progress on the development of the first 1-meter model.

  18. Upgrade of the D0 luminosity monitor readout system

    SciTech Connect

    Anderson, John; Bridges, Lloyd; Casey, Brendan; Enari, Yuji; Green, Johnny; Johnson, Marvin; Kwarciany, Rick; Miao, Chyi-Chiang; Partridge, Richard; Yoo, Hwi Dong; Wang, Jigang; /Brown U. /Fermilab

    2006-12-01

    We describe upgrades to the readout system for the D0 Luminosity Monitor. The D0 Luminosity Monitor consists of plastic scintillation detectors with fine-mesh photomultiplier readout that cover the pseudorapidity range 2.7 < |{eta}| < 4.4. The detector is designed to provide a precise measurement of the rate for non-diffractive inelastic collisions that is used to calculate the TeVatron luminosity at D0. The new readout system is based on custom VME electronics that make precise time-of-flight and charge measurements for each luminosity counter. These measurements are used to identify beam crossings with non-diffractive interactions by requiring in-time hits in both the forward and backward luminosity counters. We have also significantly increased signal/noise for the photomultiplier signals by developing a new front-end preamplifier and improving the grounding scheme.

  19. OPTIMIZATION OF OPEN MIDPLANE DIPOLE DESIGN FOR LHC IR UPGRADE.

    SciTech Connect

    GUPTA, R.; ANERELLA, M.; GHOSH, A.; HARRISON, M.; SCHMALZLE, J.; WANDERER, P.; MOKHOV, N.

    2005-05-16

    This paper presents the optimized designs of an ''open midplane dipole'' [1] for ''dipole first optics'' [2] for the proposed luminosity upgrade of the Large Hadron Collider (LHC). It was found [3] that in this design at luminosity of 10{sup 35} cm{sup -2} s{sup -1}, the peak power density in the coils can be up to two orders of magnitude higher than that at the present baseline luminosity (10{sup 34} cm{sup -2} s{sup -1}). This comes from a large quantity of spray particles from Interaction Point (IP) that is mostly concentrated at the midplane. The ''open midplane dipole'' design is the only design so far that has been found to provide reliable quench-stable operation with a lifetime of the critical components of at least ten years. In addition to a summary of magnetic, mechanical and energy deposition calculations for various iterations, the inherent benefits and challenges associated with the ''open midplane dipole'' design are also discussed. Results are presented for a recently proposed attractive option with the dipole splitted in two with a warm absorber placed between the two [4].

  20. An ionization chamber shower detector for the LHC Luminosity Monitor

    SciTech Connect

    Speziali, V.; Beche, J.F.; Burks, M.T.; Datte, P.S.; Haguenauer, M.; manfredi, P.F.; Millaud, J.E.; Placidi, M.; Ratti, L.; Re, V.; Riot, V.J.; Schmickler, H.; Turner, W.C.

    2000-10-01

    The front IR quadrupole absorbers (TAS) and the IR neutral particle absorbers (TAN) in the high luminosity insertions of the Large Hadron Collider (LHC) each absorb approximately 1.8 TeV of forward collision products on average per pp interaction (~;;235W at design luminosity 1034cm-2s-1). This secondary particle flux can be exploited to provide a useful storage ring operations tool for optimization of luminosity. A novel segmented, multi-gap, pressurized gas ionization chamber is being developed for sampling the energy deposited near the maxima of the hadronic/ electromagnetic showers in these absorbers. The system design choices have been strongly influenced by optimization of signal to noise ratio and by the very high radiation environment. The ionization chambers are instrumented with low noise, fast, pulse shaping electronics to be capable of resolving individual bunch crossings at 40 MHz. Data on each bunch are to be separately accumulated over multiple bunch crossings until the desired statistical accuracy is obtained. At design luminosity approximately 2x103 bunch crossings will suffice for a 1percent luminosity measurement. In this paper we report the first experimental results of the ionization chamber and analog electronics. Single 450GeV protons from the SPS at CERN are used to simulate the hadronic/electromagnetic showers produced by the forward collision products from the interaction regions of the LHC.

  1. LHC Abort Gap Cleaning Studies During Luminosity Operation

    SciTech Connect

    Gianfelice-Wendt, E.; Bartmann, W.; Boccardi, A.; Bracco, C.; Bravin, E.; Goddard, B.; Hofle, W.; Jacquet, D.; Jeff, A.; Kain, V.; Meddahi, M.; /CERN

    2012-05-11

    The presence of significant intensities of un-bunched beam is a potentially serious issue in the LHC. Procedures using damper kickers for cleaning both the Abort Gap (AG) and the buckets targeted for injection, are currently in operation at flat bottom. Recent observations of relatively high population of the AG during physics runs brought up the need for AG cleaning during luminosity operation. In this paper the results of experimental studies performed in October 2011 are presented.

  2. OPEN MIDPLANE DIPOLE DESIGN FOR LHC IR UPGRADE.

    SciTech Connect

    GUPTA,R.; ANERELLA,M.; HARRISON,M.; SCHMALZLE,J.; MOKHOV,N.

    2004-01-21

    The proposed luminosity upgrade of the Large Hadron Collider (LHC), now under construction, will bring a large increase in the number of secondary particles from p-p collisions at the interaction point (IP). Energy deposition will be so large that the lifetime and quench performance of interaction region (IR) magnets may be significantly reduced if conventional designs are used. Moreover, the cryogenic capacity of the LHC will have to be significantly increased as the energy deposition load on the interaction region (IR) magnets by itself will exhaust the present capacity. We propose an alternate open midplane dipole design concept for the dipole-first optics that mitigates these issues. The proposed design takes advantage of the fact that most of the energy is deposited in the midplane region. The coil midplane region is kept free of superconductor, support structure and other material. Initial energy deposition calculations show that the increase in temperature remains within the quench tolerance of the superconducting coils. In addition, most of the energy is deposited in a relatively warm region where the heat removal is economical. We present the basic concept and preliminary design that includes several innovations.

  3. Support Structure Design of the $$\\hbox{Nb}_{3}\\hbox{Sn}$$ Quadrupole for the High Luminosity LHC

    DOE PAGESBeta

    Juchno, M.; Ambrosio, G.; Anerella, M.; Cheng, D.; Felice, H.; Ferracin, P.; Perez, J. C.; Prin, H.; Schmalzle, J.

    2014-10-31

    New low-β quadrupole magnets are being developed within the scope of the High Luminosity LHC (HL-LHC) project in collaboration with the US LARP program. The aim of the HLLHC project is to study and implement machine upgrades necessary for increasing the luminosity of the LHC. The new quadrupoles, which are based on the Nb₃Sn superconducting technology, will be installed in the LHC Interaction Regions and will have to generate a gradient of 140 T/m in a coil aperture of 150 mm. In this paper, we describe the design of the short model magnet support structure and discuss results of themore » detailed 3D numerical analysis performed in preparation for the first short model test.« less

  4. Transverse emittance growth due to rf noise in the high-luminosity LHC crab cavities

    NASA Astrophysics Data System (ADS)

    Baudrenghien, P.; Mastoridis, T.

    2015-10-01

    The high-luminosity LHC (HiLumi LHC) upgrade with planned operation from 2025 onward has a goal of achieving a tenfold increase in the number of recorded collisions thanks to a doubling of the intensity per bunch (2.2e11 protons) and a reduction of β* to 15 cm. Such an increase would significantly expedite new discoveries and exploration. To avoid detrimental effects from long-range beam-beam interactions, the half crossing angle must be increased to 295 microrad. Without bunch crabbing, this large crossing angle and small transverse beam size would result in a luminosity reduction factor of 0.3 (Piwinski angle). Therefore, crab cavities are an important component of the LHC upgrade, and will contribute strongly to achieving an increase in the number of recorded collisions. The proposed crab cavities are electromagnetic devices with a resonance in the radio frequency (rf) region of the spectrum (400.789 MHz). They cause a kick perpendicular to the direction of motion (transverse kick) to restore an effective head-on collision between the particle beams, thereby restoring the geometric factor to 0.8 [K. Oide and K. Yokoya, Phys. Rev. A 40, 315 (1989).]. Noise injected through the rf/low level rf (llrf) system could cause significant transverse emittance growth and limit luminosity lifetime. In this work, a theoretical relationship between the phase and amplitude rf noise spectrum and the transverse emittance growth rate is derived, for a hadron machine assuming zero synchrotron radiation damping and broadband rf noise, excluding infinitely narrow spectral lines. This derivation is for a single beam. Both amplitude and phase noise are investigated. The potential improvement in the presence of the transverse damper is also investigated.

  5. Absolute luminosity measurements with the LHCb detector at the LHC

    NASA Astrophysics Data System (ADS)

    LHCb Collaboration

    2012-01-01

    Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic ``van der Meer scan'' method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overal precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.

  6. HERA LUMINOSITY UPGRADE SUPERCONDUCTING MAGNET PRODUCTION AT BNL.

    SciTech Connect

    PARKER,B.; ANERELLA,M.; ESCALLIER,J.; GHOSH,A.; JAIN,A.; MARONE,A.; MURATORE,J.; PRODELL,A.; THOMPSON,P.; WANDERER,P.; WU,K.C.

    2000-09-17

    Production of two types of superconducting multi-function magnets, needed for the HEX4 Luminosity Upgrade is underway at BNL. Coil winding is now completed and cryostat assembly is in progress. Magnet type GO and type GG cold masses have been satisfactorily cold tested in vertical dewars and the first fully assembled GO magnet system has been horizontally cold tested and shipped to DESY. Warm measurements confirm that the coils meet challenging harmonic content targets. In this paper we discuss GO and GG magnet design and construction solutions, field harmonic measurements and quench test results.

  7. Operation of the upgraded ATLAS Central Trigger Processor during the LHC Run 2

    NASA Astrophysics Data System (ADS)

    Bertelsen, H.; Carrillo Montoya, G.; Deviveiros, P.-O.; Eifert, T.; Galster, G.; Glatzer, J.; Haas, S.; Marzin, A.; Silva Oliveira, M. V.; Pauly, T.; Schmieden, K.; Spiwoks, R.; Stelzer, J.

    2016-02-01

    The ATLAS Central Trigger Processor (CTP) is responsible for forming the Level-1 trigger decision based on the information from the calorimeter and muon trigger processors. In order to cope with the increase of luminosity and physics cross-sections in Run 2, several components of this system have been upgraded. In particular, the number of usable trigger inputs and trigger items have been increased from 160 to 512 and from 256 to 512, respectively. The upgraded CTP also provides extended monitoring capabilities and allows to operate simultaneously up to three independent combinations of sub-detectors with full trigger functionality, which is particularly useful for commissioning, calibration and test runs. The software has also undergone a major upgrade to take advantage of all these new functionalities. An overview of the commissioning and the operation of the upgraded CTP during the LHC Run 2 is given.

  8. Status and Outlook for the RHIC Luminosity Upgrade

    NASA Astrophysics Data System (ADS)

    Bai, Mei

    2010-02-01

    electron lens to compensate the beam-beam effect is also currently explored at RHIC. This presentation will report the current performance of RHIC as well as the plans for RHIC luminosity upgrades. )

  9. Analysis of optics designs for the LHC IR upgrade

    SciTech Connect

    Sen, Tanaji; Johnstone, John; /Fermilab

    2007-06-01

    We consider the different options proposed for the LHC IR upgrade. The two main categories: quadrupoles first (as in the baseline design) and dipoles-first have complementary strengths. We analyze the potential of the proposed designs by calculating important performance parameters. We also propose a local scheme for correcting the quadratic chromaticity.

  10. Optics implications of implementing Nb3Sn magnets in the LHC phase 1 upgrade

    SciTech Connect

    Johnstone, J.A.; Kashikhin, V.V.; Mokhov, N.V.; Zlobin, A.V.; /Fermilab

    2008-06-01

    CERN has encouraged the US-LARP collaboration to participate in Phase I of the LHC luminosity upgrade by analyzing the benefits gained by using Nb3Sn technology to replace the functionality of select NbTi magnets that CERN is committed to construct. Early studies have shown that the much higher gradients (shorter magnetic lengths) and temperature margins (quench stability) of Nb3Sn magnets compared to their NbTi counterparts is favorable--allowing the insertion of additional absorbers between Q1 and Q2, for example. This paper discusses the relative merits of the NbTi and Nb3Sn options.

  11. ATLAS LAr calorimeters readout electronics upgrade R&D for sLHC

    NASA Astrophysics Data System (ADS)

    Chen, Hucheng; ATLAS Liquid Argon Calorimeter Group

    2011-04-01

    The ATLAS Liquid Argon (LAr) calorimeters consist of an electromagnetic barrel calorimeter and two end-caps with electromagnetic, hadronic and forward calorimeters. A total of 182,468 signals are digitized and processed real-time on detector, to provide energy and time deposited in each detector element at every occurrence of the Level-1 trigger. A luminosity upgrade of the LHC will occur in the years ~2020. The current readout electronics will need to be upgraded to sustain the higher radiation levels. A completely innovative readout scheme is being developed. The front-end readout will send out data continuously at each bunch crossing through high speed radiation resistant optical links, the data will be processed real-time with the possibility of implementing trigger algorithms. This article is an overview of the R&D activities and architectural studies the ATLAS LAr Calorimeter Group is developing.

  12. Radiation-hard active CMOS pixel sensors for HL-LHC detector upgrades

    NASA Astrophysics Data System (ADS)

    Backhaus, Malte

    2015-02-01

    The luminosity of the Large Hadron Collider (LHC) will be increased during the Long Shutdown of 2022 and 2023 (LS3) in order to increase the sensitivity of its experiments. A completely new inner detector for the ATLAS experiment needs to be developed to withstand the extremely harsh environment of the upgraded, so-called High-Luminosity LHC (HL-LHC). High radiation hardness as well as granularity is mandatory to cope with the requirements in terms of radiation damage as well as particle occupancy. A new silicon detector concept that uses commercial high voltage and/or high resistivity full complementary metal-oxide-semiconductor (CMOS) processes as active sensor for pixel and/or strip layers has risen high attention, because it potentially provides high radiation hardness and granularity and at the same time reduced price due to the commercial processing and possibly relaxed requirements for the hybridization technique. Results on the first prototypes characterized in a variety of laboratory as well as test beam environments are presented.

  13. Development of edgeless silicon pixel sensors on p-type substrate for the ATLAS high-luminosity upgrade

    NASA Astrophysics Data System (ADS)

    Calderini, G.; Bagolini, A.; Bomben, M.; Boscardin, M.; Bosisio, L.; Chauveau, J.; Giacomini, G.; La Rosa, A.; Marchiori, G.; Zorzi, N.

    2014-11-01

    In view of the LHC upgrade for the high luminosity phase (HL-LHC), the ATLAS experiment is planning to replace the inner detector with an all-silicon system. The n-in-p bulk technology represents a valid solution for the modules of most of the layers, given the significant radiation hardness of this option and the reduced cost. The large area necessary to instrument the outer layers will demand to tile the sensors, a solution for which the inefficient region at the border of each sensor needs to be reduced to the minimum size. This paper reports on a joint R&D project by the ATLAS LPNHE Paris group and FBK Trento on a novel n-in-p edgeless planar pixel design, based on the deep-trench process available at FBK.

  14. Steady State Heat Deposits Modeling in the Nb3Sn Quadrupole Magnets for the Upgrade of the LHC Inner Triplet

    SciTech Connect

    Bocian, D.; Ambrosio, G.; Felice, H.; Barzi, E.; Bossert, R.; Caspi, S.; Chlachidze, G.; Dietderich, D.; Feher, S.; Ferracin, P.; Hafalia, R.; /Fermilab /Lawrence Berkeley Lab /Brookhaven

    2011-09-01

    In hadron colliders such as the LHC, the energy deposited in the superconductors by the particles lost from the beams or coming from the collision debris may provoke quenches detrimental to the accelerator operation. In previous papers, a Network Model has been used to study the thermodynamic behavior of magnet coils and to calculate the quench levels in the LHC magnets for expected beam loss profiles. This model was subsequently used for thermal analysis and design optimization of Nb{sub 3}Sn quadrupole magnets, which LARP (US LHC Accelerator Research Program) is developing for possible use in the LHC luminosity upgrade. For these new magnets, the heat transport efficiency from the coil to the helium bath needs to be determined and optimized. In this paper the study of helium cooling channels and the heat evacuation scheme are presented and discussed.

  15. Upgrade of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN.

    PubMed

    Toivanen, V; Bellodi, G; Dimov, V; Küchler, D; Lombardi, A M; Maintrot, M

    2016-02-01

    Linac3 is the first accelerator in the heavy ion injector chain of the Large Hadron Collider (LHC), providing multiply charged heavy ion beams for the CERN experimental program. The ion beams are produced with GTS-LHC, a 14.5 GHz electron cyclotron resonance ion source, operated in afterglow mode. Improvement of the GTS-LHC beam formation and beam transport along Linac3 is part of the upgrade program of the injector chain in preparation for the future high luminosity LHC. A mismatch between the ion beam properties in the ion source extraction region and the acceptance of the following Low Energy Beam Transport (LEBT) section has been identified as one of the factors limiting the Linac3 performance. The installation of a new focusing element, an einzel lens, into the GTS-LHC extraction region is foreseen as a part of the Linac3 upgrade, as well as a redesign of the first section of the LEBT. Details of the upgrade and results of a beam dynamics study of the extraction region and LEBT modifications will be presented. PMID:26932084

  16. Upgrade of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN

    NASA Astrophysics Data System (ADS)

    Toivanen, V.; Bellodi, G.; Dimov, V.; Küchler, D.; Lombardi, A. M.; Maintrot, M.

    2016-02-01

    Linac3 is the first accelerator in the heavy ion injector chain of the Large Hadron Collider (LHC), providing multiply charged heavy ion beams for the CERN experimental program. The ion beams are produced with GTS-LHC, a 14.5 GHz electron cyclotron resonance ion source, operated in afterglow mode. Improvement of the GTS-LHC beam formation and beam transport along Linac3 is part of the upgrade program of the injector chain in preparation for the future high luminosity LHC. A mismatch between the ion beam properties in the ion source extraction region and the acceptance of the following Low Energy Beam Transport (LEBT) section has been identified as one of the factors limiting the Linac3 performance. The installation of a new focusing element, an einzel lens, into the GTS-LHC extraction region is foreseen as a part of the Linac3 upgrade, as well as a redesign of the first section of the LEBT. Details of the upgrade and results of a beam dynamics study of the extraction region and LEBT modifications will be presented.

  17. A proposed Drift Tubes-seeded muon track trigger for the CMS experiment at the High Luminosity-LHC

    NASA Astrophysics Data System (ADS)

    Pozzobon, N.; Lazzizzera, I.; Vanini, S.; Zotto, P.

    2016-07-01

    The LHC program at 13 and 14 TeV, after the observation of the candidate SM Higgs boson, will help clarify future subjects of study and shape the needed tools. Any upgrade of the LHC experiments for unprecedented luminosities, such as the High Luminosity-LHC ones, must then maintain the acceptance on electroweak processes that can lead to a detailed study of the properties of the candidate Higgs boson. The acceptance of the key lepton, photon and hadron triggers should be kept such that the overall physics acceptance, in particular for low-mass scale processes, can be the same as the one the experiments featured in 2012. In such a scenario, a new approach to early trigger implementation is needed. One of the major steps will be the inclusion of high-granularity tracking sub-detectors, such as the CMS Silicon Tracker, in taking the early trigger decision. This contribution can be crucial in several tasks, including the confirmation of triggers in other subsystems, and the improvement of the on-line momentum measurement resolution. A muon track-trigger for the CMS experiment at the High Luminosity-LHC is presented. A back-extrapolation of Drift Tubes trigger primitives is proposed to match tracks found at Level 1 with muon candidates. The main figures-of-merit are presented, featuring sharp thresholds and less contamination from lower momentum muons, and an expected rate reduction of a factor of 5-10 at typical thresholds with respect to the muon trigger configuration used in 2012.

  18. Upgrade of the LHC magnet interconnections thermal shielding

    SciTech Connect

    Musso, Andrea; Barlow, Graeme; Bastard, Alain; Charrondiere, Maryline; Deferne, Guy; Dib, Gaëlle; Duret, Max; Guinchard, Michael; Prin, Hervé; Craen, Arnaud Vande; Villiger, Gilles; Chrul, Anna; Damianoglou, Dimitrios; Strychalski, Michał; Wright, Loren

    2014-01-29

    The about 1700 interconnections (ICs) between the Large Hadron Collider (LHC) superconducting magnets include thermal shielding at 50-75 K, providing continuity to the thermal shielding of the magnet cryostats to reduce the overall radiation heat loads to the 1.9 K helium bath of the magnets. The IC shield, made of aluminum, is conduction-cooled via a welded bridge to the thermal shield of the adjacent magnets which is actively cooled. TIG welding of these bridges made in the LHC tunnel at installation of the magnets induced a considerable risk of fire hazard due to the proximity of the multi-layer insulation of the magnet shields. A fire incident occurred in one of the machine sectors during machine installation, but fortunately with limited consequences thanks to prompt intervention of the operators. LHC is now undergoing a 2 years technical stop during which all magnet's ICs will have to be opened to consolidate the magnet electrical connections. The IC thermal shields will therefore have to be removed and re-installed after the work is completed. In order to eliminate the risk of fire hazard when re-welding, it has been decided to review the design of the IC shields, by replacing the welded bridges with a mechanical clamping which also preserves its thermal function. An additional advantage of this new solution is the ease in dismantling for maintenance, and eliminating weld-grinding operations at removal needing radioprotection measures because of material activation after long-term operation of the LHC. This paper describes the new design of the IC shields and in particular the theoretical and experimental validation of its thermal performance. Furthermore a status report of the on-going upgrade work in the LHC is given.

  19. Upgrade of the LHC magnet interconnections thermal shielding

    NASA Astrophysics Data System (ADS)

    Musso, Andrea; Barlow, Graeme; Bastard, Alain; Charrondiere, Maryline; Chrul, Anna; Damianoglou, Dimitrios; Deferne, Guy; Dib, Gaëlle; Duret, Max; Guinchard, Michael; Prin, Hervé; Strychalski, Michał; Craen, Arnaud Vande; Villiger, Gilles; Wright, Loren

    2014-01-01

    The about 1700 interconnections (ICs) between the Large Hadron Collider (LHC) superconducting magnets include thermal shielding at 50-75 K, providing continuity to the thermal shielding of the magnet cryostats to reduce the overall radiation heat loads to the 1.9 K helium bath of the magnets. The IC shield, made of aluminum, is conduction-cooled via a welded bridge to the thermal shield of the adjacent magnets which is actively cooled. TIG welding of these bridges made in the LHC tunnel at installation of the magnets induced a considerable risk of fire hazard due to the proximity of the multi-layer insulation of the magnet shields. A fire incident occurred in one of the machine sectors during machine installation, but fortunately with limited consequences thanks to prompt intervention of the operators. LHC is now undergoing a 2 years technical stop during which all magnet's ICs will have to be opened to consolidate the magnet electrical connections. The IC thermal shields will therefore have to be removed and re-installed after the work is completed. In order to eliminate the risk of fire hazard when re-welding, it has been decided to review the design of the IC shields, by replacing the welded bridges with a mechanical clamping which also preserves its thermal function. An additional advantage of this new solution is the ease in dismantling for maintenance, and eliminating weld-grinding operations at removal needing radioprotection measures because of material activation after long-term operation of the LHC. This paper describes the new design of the IC shields and in particular the theoretical and experimental validation of its thermal performance. Furthermore a status report of the on-going upgrade work in the LHC is given.

  20. The New Transfer Line Collimation System for the LHC High Luminosity Era

    SciTech Connect

    Kain, Verena; Bracco, Chiara; Goddard, Brennan; Maciariello, Fausto; Meddahi, Malika; Mereghetti, Alessio; Steele, Genevieve; Velotti, Francesco; Gianfelice-Wendt, Eliana

    2014-07-01

    A set of passive absorbers is located at the end of each of the 3 km long injection lines to protect the LHC in case of failures during the extraction process from the LHC’s last pre-injector or the beam transfer itself. In case of an erroneous extraction, the absorbers have to attenuate the beam to a safe level and be robust enough themselves to survive the impact. These requirements are difficult to fulfil with the very bright and intense beams produced by the LHC injectors for the high luminosity era. This paper revisits the requirements for the SPS-to-LHC transfer line collimation system and the adapted strategy to fulfill these for the LHC high luminosity operation. A possible solution for the new transfer line collimation system is presented.

  1. Measurements and TCAD simulation of novel ATLAS planar pixel detector structures for the HL-LHC upgrade

    NASA Astrophysics Data System (ADS)

    Nellist, C.; Dinu, N.; Gkougkousis, E.; Lounis, A.

    2015-06-01

    The LHC accelerator complex will be upgraded between 2020-2022, to the High-Luminosity-LHC, to considerably increase statistics for the various physics analyses. To operate under these challenging new conditions, and maintain excellent performance in track reconstruction and vertex location, the ATLAS pixel detector must be substantially upgraded and a full replacement is expected. Processing techniques for novel pixel designs are optimised through characterisation of test structures in a clean room and also through simulations with Technology Computer Aided Design (TCAD). A method to study non-perpendicular tracks through a pixel device is discussed. Comparison of TCAD simulations with Secondary Ion Mass Spectrometry (SIMS) measurements to investigate the doping profile of structures and validate the simulation process is also presented.

  2. The upgrade of the CMS RPC system during the first LHC long shutdown

    NASA Astrophysics Data System (ADS)

    Tytgat, M.; Marinov, A.; Verwilligen, P.; Zaganidis, N.; Aleksandrov, A.; Genchev, V.; Iaydjiev, P.; Rodozov, M.; Shopova, M.; Sultanov, G.; Assran, Y.; Abbrescia, M.; Calabria, C.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Pugliese, G.; Benussi, L.; Bianco, S.; Caponero, M.; Colafranceschi, S.; Felli, F.; Piccolo, D.; Saviano, G.; Carrillo, C.; Berzano, U.; Gabusi, M.; Vitulo, P.; Kang, M.; Lee, K. S.; Park, S. K.; Shin, S.; Sharma, A.

    2013-02-01

    The CMS muon system includes in both the barrel and endcap region Resistive Plate Chambers (RPC). They mainly serve as trigger detectors and also improve the reconstruction of muon parameters. Over the years, the instantaneous luminosity of the Large Hadron Collider gradually increases. During the LHC Phase 1 ( ~ first 10 years of operation) an ultimate luminosity is expected above its design value of 1034 cm-2s-1 at 14 TeV. To prepare the machine and also the experiments for this, two long shutdown periods are scheduled for 2013-2014 and 2018-2019. The CMS Collaboration is planning several detector upgrades during these long shutdowns. In particular, the muon detection system should be able to maintain a low-pT threshold for an efficient Level-1 Muon Trigger at high particle rates. One of the measures to ensure this, is to extend the present RPC system with the addition of a 4th layer in both endcap regions. During the first long shutdown, these two new stations will be equipped in the region |η| < 1.6 with 144 High Pressure Laminate (HPL) double-layer RPCs operating in avalanche mode, with a similar design as the existing CMS endcap chambers. Here, we present the upgrade plans for the CMS RPC system for the fist long shutdown, including trigger simulation studies for the extended system, and details on the new HPL production, the chamber assembly and the quality control procedures.

  3. 800MHz Crab Cavity Conceptual Design For the LHC Upgrade

    SciTech Connect

    Xiao, Liling; Li, Zenghai; Ng, Cho-Kuen; Seryi, Andrei; /SLAC

    2009-05-26

    In this paper, we present an 800 MHz crab cavity conceptual design for the LHC upgrade. The cell shape is optimized for lower maximum peak surface fields as well as higher transverse R/Q. A compact coax-to-coax coupler scheme is proposed to damp the LOM/SOM modes. A two-stub antenna with a notch filter is used as the HOM coupler to damp the HOM modes in the horizontal plane and rejects the operating mode at 800MHz. Multipacting (MP) simulations show that there are strong MP particles at the disks. Adding grooves along the short axis without changing the operating mode's RF characteristics can suppress the MP activities. Possible input coupler configurations are discussed.

  4. Tevatron Collider Run II status and novel technologies for luminosity upgrades

    SciTech Connect

    Vladimir Shiltsev

    2004-07-20

    Over the past 2 years the Tevatron peak luminosity steadily progressed and reached the level of 92e30 cm-2s-1 which exceeds the original Run IIa goal. Over 0.57fb-1 have being delivered to each CDF and D0 experiments since the beginning of the Run II. In parallel to the Collider operation, we have started a project of the luminosity upgrade which should lead to peak luminosities of about 270e30 and total integrated luminosity of 4.4-8.5 fb-1 through FY2009. In this paper we describe the status of the Tevatron Collider complex, essence of the upgrades and novel accelerator technologies to be employed.

  5. An Alternative High Luminosity LHC with Flat Optics and Long-Range Beam-Beam Compensation

    SciTech Connect

    Fartoukh, Stephane; Valishev, Alexander; Shatilov, Dmitry

    2015-06-01

    In the baseline scenario of the High-Luminosity LHC (HL-LHC), the geometric loss of luminosity in the two high luminosity experiments due to collisions with a large crossing angle is recovered by tilting the bunches in the interaction region with the use of crab cavities. A possible backup scenario would rely on a reduced crossing angle together with flat optics (with different horizontal and vertical $\\beta^{\\ast}$values) for the preservation of luminosity performance. However, the reduction of crossing angle coupled with the flat optics significantly enhances the strength of long-range beam-beam interactions. This paper discusses the possibility to mitigate the long-range beam-beam effects by current bearing wire compensators (or e-lens). We develop a new HL-LHC parameter list and analyze it in terms of integrated luminosity performance as compared to the baseline. Further, we evaluate the operational scenarios using numerical simulations of single-particle dynamics with beam-beam effects.

  6. The ATLAS Diamond Beam Monitor: Luminosity detector at the LHC

    NASA Astrophysics Data System (ADS)

    Schaefer, D. M.

    2016-07-01

    After the first three years of the LHC running, the ATLAS experiment extracted its pixel detector system to refurbish and re-position the optical readout drivers and install a new barrel layer of pixels. The experiment has also taken advantage of this access to install a set of beam monitoring telescopes with pixel sensors, four each in the forward and backward regions. These telescopes are based on chemical vapor deposited (CVD) diamond sensors to survive in this high radiation environment without needing extensive cooling. This paper describes the lessons learned in construction and commissioning of the ATLAS Diamond Beam Monitor (DBM). We show results from the construction quality assurance tests and commissioning performance, including results from cosmic ray running in early 2015.

  7. UPGRADE OF RHIC VACUUM SYSTEMS FOR HIGH LUMINOSITY OPERATION.

    SciTech Connect

    HSEUH, H.C.; MAPES, M.; SMART, L.A.; TODD, R.; WEISS, D.

    2005-05-16

    With increasing ion beam intensity during recent RHIC operations, rapid pressure rises of several decades were observed at most warm sections and at a few cold sections. The pressure rises are associated with electron multi-pacting, electron stimulated desorption and beam ion induced desorption and have been one of the major intensity and luminosity limiting factors for RHIC. Improvement of the warm sections has been carried out in the last few years. Extensive in-situ bakes, additional UHV pumping and anti-grazing ridges have been implemented. Several hundred meters of NEG coated beam pipes have been installed and activated. Vacuum monitoring and logging were enhanced. Preventive measures, such as pumping before cool down to reduce monolayer condensates, were also taken to suppress the pressure rises in the cold sections. The effectiveness of these measures in reducing the pressure rises during machine studies and during physics runs are discussed and summarized.

  8. The Upgrade of the ATLAS Electron and Photon Triggers for LHC Run 2 and their Performance

    NASA Astrophysics Data System (ADS)

    Thomson, Evelyn; Atlas Collaboration

    2016-03-01

    Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software based high level trigger (HLT), both of which were upgraded during the long shutdown of the LHC in preparation for data taking in 2015. The increasing luminosity and more challenging pile-up conditions as well as the planned higher center-of-mass energy demanded the optimisation of the trigger selections at each level, to control the rates and keep efficiencies high. To improve the performance multivariate analysis techniques are introduced at the HLT. The evolution of the ATLAS electron and photon triggers and their performance will be presented, including new results from the 2015 LHC Run 2 operation. Submitted on behalf of ATLAS electron and photon combined performance group. Speaker is yet to be chosen.

  9. Developments on DC/DC converters for the LHC experiment upgrades

    NASA Astrophysics Data System (ADS)

    Abbate, C.; Alderighi, M.; Baccaro, S.; Busatto, G.; Citterio, M.; Cova, P.; Delmonte, N.; De Luca, V.; Fiore, S.; Gerardin, S.; Ghisolfi, E.; Giuliani, F.; Iannuzzo, F.; Lanza, A.; Latorre, S.; Lazzaroni, M.; Meneghesso, G.; Paccagnella, A.; Rampazzo, F.; Riva, M.; Sanseverino, A.; Silvestri, R.; Spiazzi, G.; Velardi, F.; Zanoni, E.

    2014-02-01

    Prototypes of DC/DC power and Point of Load (PoL) converters were designed and built with the aim of satisfying the foreseen working parameters of the High Luminosity (HL) LHC experiments, using both Silicon (Si) MOSFETs and/or more recent devices substantiated of better power performance, like Silicon Carbide (SiC) and Gallium Nitride (GaN) transistors. Optimization of their design, based on the comparison between the simulated and measured thermal, electrical and mechanical performance, is in progress, and many improvements with respect to the previous versions are under implementation. We discuss in this paper the results of the last modifications. In addition, many tens of discrete component samples, chosen among the devices commercially available in the three different technologies (Si, SiC and GaN), were electrically characterized and tested under γ-rays, neutron, proton and heavy ion radiation, also using a combined run method. We have also planned to test some commercial DC/DCs under the extreme conditions of radiation and magnetic field expected in the upgrades of the LHC experiments. Here we show the first results on few samples.

  10. ASSEMBLY AND TEST OF A 120 MM BORE 15 T NB3SN QUADRUPOLE FOR THE LHC UPGRADE

    SciTech Connect

    Felice, H.; Caspi, S.; Cheng, D.; Dietderich, D.; Ferracin, P.; Hafalia, R.; Joseph, J.; Lizarazo, J.; Sabbi, G. L.; Wang, X.; Anerella, M.; Ghosh, A. K.; Schmalzle, J.; Wanderer, P.; Ambrosio, G.; Bossert, R.; Zlobin, A. V.

    2010-05-23

    In support of the Large Hadron Collider (LHC) luminosity upgrade, the US LHC Accelerator Research Program (LARP) has been developing a 1-meter long, 120 mm bore Nb{sub 3}Sn IR quadrupole magnet (HQ). With a design short sample gradient of 219 T/m at 1.9 K and a peak field approaching 15 T, one of the main challenges of this magnet is to provide appropriate mechanical support to the coils. Compared to the previous LARP Technology Quadrupole and Long Quadrupole magnets, the purpose of HQ is also to demonstrate accelerator quality features such as alignment and cooling. So far, 8 HQ coils have been fabricated and 4 of them have been assembled and tested in HQ01a. This paper presents the mechanical assembly and test results of HQ01a.

  11. Changes to the Transfer Line Collimation System for the High-Luminosity LHC Beams

    SciTech Connect

    Kain, V.; Aberle, O.; Bracco, C.; Fraser, M.; Galleazzi, F.; Gianfelice-Wendt, E.; Kosmicki, A.; Maciariello, F.; Meddahi, M.; Nuiry, F. X.; Steele, G.; Velotti, F.

    2015-06-01

    The current LHC transfer line collimation system will not be able to provide enough protection for the high brightness beams in the high-luminosity LHC era. The new collimation system will have to attenuate more and be more robust than its predecessor. The active jaw length of the new transfer line collimators will therefore be 2.1 m instead of currently 1.2 m. The transfer line optics will have to be adjusted for the new collimator locations and larger beta functions at the collimators for absorber robustness reasons. In this paper the new design of the transfer line collimation system will be presented with its implications on transfer line optics and powering, maintainability, protection of transfer line magnets in case of beam loss on a collimator and protection of the LHC aperture.

  12. Second-generation coil design of the Nb3Sn low-β quadrupole for the high luminosity LHC

    DOE PAGESBeta

    Bermudez, S. Izquierdo; Ambrosio, G.; Ballarino, A.; Cavanna, E.; Bossert, R.; Cheng, D.; Dietderich, D.; Ferracin, P.; Ghosh, A.; Hagen, P.; et al

    2016-01-18

    As part of the Large Hadron Collider Luminosity upgrade (HiLumi-LHC) program, the US LARP collaboration and CERN are working together to design and build a 150 mm aperture Nb3Sn quadrupole for the LHC interaction regions. A first series of 1.5 m long coils were fabricated and assembled in a first short model. A detailed visual inspection of the coils was carried out to investigate cable dimensional changes during heat treatment and the position of the windings in the coil straight section and in the end region. The analyses allow identifying a set of design changes which, combined with a finemore » tune of the cable geometry and a field quality optimization, were implemented in a new, second-generation, coil design. In this study, we review the main characteristics of the first generation coils, describe the modification in coil lay-out, and discuss their impact on parts design and magnet analysis.« less

  13. Support Structure Design of the $\\hbox{Nb}_{3}\\hbox{Sn}$ Quadrupole for the High Luminosity LHC

    SciTech Connect

    Juchno, M.; Ambrosio, G.; Anerella, M.; Cheng, D.; Felice, H.; Ferracin, P.; Perez, J. C.; Prin, H.; Schmalzle, J.

    2014-10-31

    New low-β quadrupole magnets are being developed within the scope of the High Luminosity LHC (HL-LHC) project in collaboration with the US LARP program. The aim of the HLLHC project is to study and implement machine upgrades necessary for increasing the luminosity of the LHC. The new quadrupoles, which are based on the Nb₃Sn superconducting technology, will be installed in the LHC Interaction Regions and will have to generate a gradient of 140 T/m in a coil aperture of 150 mm. In this paper, we describe the design of the short model magnet support structure and discuss results of the detailed 3D numerical analysis performed in preparation for the first short model test.

  14. Research and development for a free-running readout system for the ATLAS LAr Calorimeters at the high luminosity LHC

    NASA Astrophysics Data System (ADS)

    Hils, Maximilian

    2016-07-01

    The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the Large Hadron Collider (LHC) at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm-2 s-1. The High Luminosity LHC (HL-LHC) programme is now developed for up to 5-7 times the design luminosity, with the goal of accumulating an integrated luminosity of 3000 fb-1. In the HL-LHC phase, the increased radiation levels and an improved ATLAS trigger system require a replacement of the Front-end (FE) and Back-end (BE) electronics of the LAr Calorimeters. Results from research and development of individual components and their radiation qualification as well as the overall system design will be presented.

  15. A time-multiplexed track-trigger for the CMS HL-LHC upgrade

    NASA Astrophysics Data System (ADS)

    Hall, G.

    2016-07-01

    A new CMS Tracker is under development for operation at the High Luminosity LHC from 2025. It includes an outer tracker based on special modules of two different types which will construct track stubs using spatially coincident clusters in two closely spaced sensor layers, to reject low transverse momentum track hits and reduce the data volume before data transmission to the Level-1 trigger. The tracker data will be used to reconstruct track segments in dedicated processors before onward transmission to other trigger processors which will combine tracker information with data originating from the calorimeter and muon detectors, to make the final L1 trigger decision. The architecture for processing the tracker data outside the detector is under study, using several alternative approaches. One attractive possibility is to exploit a Time Multiplexed design similar to the one which is currently being implemented in the CMS calorimeter trigger as part of the Phase I trigger upgrade. The novel Time Multiplexed Trigger concept is explained, the potential benefits for processing future tracker data are described and a feasible design based on currently existing hardware is outlined.

  16. Tracking for the Atlas Level 1 Trigger for the High Luminosity Lhc

    NASA Astrophysics Data System (ADS)

    Sutton, M. R.

    2014-06-01

    At the HL-LHC, the increased luminosity will result in up to 200 pile-up interactions per bunch crossing. One of the greatest challenges for ATLAS will be to keep the Level 1 Trigger pT thresholds low enough to maintain high trigger efficiency for all interesting physics. The proposed two-stage design of the ATLAS Level 1 Trigger, and the incorporation of a Level-1 track trigger is described. The requirements and implications for the tracker readout architecture, and estimates of readout latency based on a detailed discrete event simulation of the data flow in the tracker front-end electronics are also presented.

  17. CMS Tracker upgrade for HL-LHC: R&D plans, present status and perspectives

    NASA Astrophysics Data System (ADS)

    Ravera, F.

    2016-07-01

    During the high luminosity phase of the LHC (HL-LHC), the machine is expected to deliver an instantaneous luminosity of 5 ×1034cm-2s-1. A total of 3000 fb-1 of data is foreseen to be delivered, with the opening of new physics potential for the LHC experiments, but also new challenges from the point of view of both detector and electronics capabilities and radiation hardness. In order to maintain its physics reach, CMS will build a new Tracker, including a completely new Pixel Detector and Outer Tracker. The ongoing R&D activities on both pixel and strip sensors will be presented. The present status of the Inner and Outer Tracker projects will be illustrated, and the possible perspectives will be discussed.

  18. Design Study of the High Luminosity LHC Recombination Dipole (D2)

    SciTech Connect

    Sabbi, GianLuca; Wang, Xiaorong

    2014-05-26

    The interaction region design of the high-luminosity LHC requires replacing the recombination dipole magnets (D2) with new ones. The preliminary specifications include an aperture of 105 mm, with 186 mm separation between the twin-aperture axes, and an operating field in the range of 3.5 to 4.5 T. The main design challenge is to decouple the magnetic field in the two apertures and ensure good field quality. The approach adopted for the present D2 magnets, using the iron yoke as a shield between the two apertures, leads to large saturation effects. In this study, we propose an alternative approach where the iron yoke is designed primarily for low saturation, and the resulting large but current-independent cross-talk between the apertures is corrected with an asymmetric arrangement of the conductor blocks. A preliminary solution based on the LHC dipole cable is presented, and the expected harmonics for geometric, saturation and persistent current effects are provided. Finally, the feasibility of an operating field at the high end of the range considered is discussed, to minimize the D2 magnet length and facilitate the space allocation for other components.

  19. Field Tolerances for the Triplet Quadrupoles of the LHC High Luminosity Lattice

    SciTech Connect

    Nosochkov, Yuri; Cai, Y.; Jiao, Y.; Wang, M-H.; Fartoukh, S.; Giovannozzi, M.; Maria, R.de; McIntosh, E.

    2012-06-25

    It has been proposed to implement the so-called Achromatic Telescopic Squeezing (ATS) scheme in the LHC high luminosity (HL) lattice to reduce beta functions at the Interaction Points (IP) up to a factor of 8. As a result, the nominal 4.5 km peak beta functions reached in the Inner Triplets (IT) at collision will be increased by the same factor. This, therefore, justifies the installation of new, larger aperture, superconducting IT quadrupoles. The higher beta functions will enhance the effects of the triplet quadrupole field errors leading to smaller beam dynamic aperture (DA). To maintain the acceptable DA, the effects of the triplet field errors must be re-evaluated, thus specifying new tolerances. Such a study has been performed for the so-called '4444' collision option of the HL-LHC layout version SLHCV3.01, where the IP beta functions are reduced by a factor of 4 in both planes with respect to a pre-squeezed value of 60 cm at two collision points. The dynamic aperture calculations were performed using SixTrack. The impact on the triplet field quality is presented.

  20. Production of CMS FPIX detector modules and development of novel radiation-hard silicon sensors for future upgrades of the LHC

    NASA Astrophysics Data System (ADS)

    Koybasi, Ozhan

    The Compact Muon Solenoid (CMS) experiment currently taking data at the Large Hadron Collider (LHC) has the largest ever built all-silicon tracking system with a pixel detector as the innermost component. The pixel detector consists of three 53 cm long barrel layers (BPIX) at radial distances of r= 4.4, 7.3, and 10.2 cm from the interaction point complemented with two end-cap disks (FPIX) on each side of the interaction region covering radial distances from ˜6 cm to 15 cm. The development, production, and qualification of the silicon detector modules used for the construction of the CMS FPIX disks are described. The plan for the luminosity upgrade of the LHC foresees a phase I upgrade increasing the peak luminosity from 1034 cm.2s.1 (original design figure) to 2-3 x 1034 cm-2s-1 after about 5 years of operation, followed by phase II upgrade eventually reaching a value of 5x1034 cm-2 s-1 (the so-called "High Luminosity-LHC" or "HL-LHC"). At Phase I, the CMS pixel detector will be replaced by a new detector, which will have an additional fourth barrel layer at r=16 cm and two extra forward disks on each side with radial coverage of all disks increased to r =4.5-16.1 cm. Although the present non- n silicon pixel sensor technology meets the performance requirements, it is possible to achieve the same performance with the relatively new n-on-p technology, which would reduce the cost by ˜50%. The phase II upgrade, on the other hand, faces a challenge for the detector technology to be adopted for the innermost tracking layers (at r ˜ 4 cm) where the radiation fluence is expected to reach values close to 1016 neq /cm2, since the conventional planar silicon sensors are functional only up to a fluence of ˜1015 neq/cm2. The 3D silicon sensor technology is regarded as one of the most promising solutions for the radiation tolerance requirements of innermost pixel tracking layers at the HL-LHC. Improvements to the current n-on-n silicon pixel sensor design; and development

  1. Superconducting link bus design for the accelerator project for upgrade of LHC

    SciTech Connect

    Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.; /Fermilab

    2011-06-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

  2. Superconducting link bus design for the accelerator project for upgrade of LHC

    SciTech Connect

    Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.; /Fermilab

    2010-08-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

  3. Development of Nb3Sn 11 T single aperture demonstrator dipole for LHC upgrades

    SciTech Connect

    Zlobin, A.V.; Apollinari, G.; Andreev, N.; Barzi, E.; Kashikhin, V.V.; Nobrega, f.; Novitski, I.; Auchmann, B.; Karppinen, M.; Rossi, L.; /CERN

    2011-03-01

    The LHC collimation upgrade foresees additional collimators installed in dispersion suppressor regions. To obtain the necessary space for the collimators, a solution based on the substitution of LHC main dipoles for stronger dipoles is being considered. CERN and FNAL have started a joint program to demonstrate the feasibility of Nb{sub 3}Sn technology for this purpose. The goal of the first phase is the design and construction of a 2-m long single-aperture demonstrator magnet with a nominal field of 11 T at 11.85 kA with 20% margin. This paper describes the magnetic and mechanical design of the demonstrator magnet and summarizes its design parameters.

  4. Radiation-hard Active Pixel Sensors for HL-LHC Detector Upgrades based on HV-CMOS Technology

    NASA Astrophysics Data System (ADS)

    Miucci, A.; Gonella, L.; Hemperek, T.; Hügging, F.; Krüger, H.; Obermann, T.; Wermes, N.; Garcia-Sciveres, M.; Backhaus, M.; Capeans, M.; Feigl, S.; Nessi, M.; Pernegger, H.; Ristic, B.; Gonzalez-Sevilla, S.; Ferrere, D.; Iacobucci, G.; La Rosa, A.; Muenstermann, D.; George, M.; Große-Knetter, J.; Quadt, A.; Rieger, J.; Weingarten, J.; Bates, R.; Blue, A.; Buttar, C.; Hynds, D.; Kreidl, C.; Peric, I.; Breugnon, P.; Pangaud, P.; Godiot-Basolo, S.; Fougeron, D.; Bompard, F.; Clemens, J. C.; Liu, J.; Barbero, M.; Rozanov, A.; HV-CMOS Collaboration

    2014-05-01

    Luminosity upgrades are discussed for the LHC (HL-LHC) which would make updates to the detectors necessary, requiring in particular new, even more radiation-hard and granular, sensors for the inner detector region. A proposal for the next generation of inner detectors is based on HV-CMOS: a new family of silicon sensors based on commercial high-voltage CMOS technology, which enables the fabrication of part of the pixel electronics inside the silicon substrate itself. The main advantages of this technology with respect to the standard silicon sensor technology are: low material budget, fast charge collection time, high radiation tolerance, low cost and operation at room temperature. A traditional readout chip is still needed to receive and organize the data from the active sensor and to handle high-level functionality such as trigger management. HV-CMOS has been designed to be compatible with both pixel and strip readout. In this paper an overview of HV2FEI4, a HV-CMOS prototype in 180 nm AMS technology, will be given. Preliminary results after neutron and X-ray irradiation are shown.

  5. Mechanical and Thermal Prototype Testing for a Rotatable Collimator for the LHC Phase II Collimation Upgrade

    SciTech Connect

    Smith, Jeffrey Claiborne; Doyle, Eric; Keller, Lewis; Lundgren, Steven; Markiewicz, Thomas Walter; /SLAC

    2010-08-26

    The Phase II upgrade to the LHC collimation system calls for complementing the robust Phase I graphite collimators with high Z, low impedance Phase II collimators. The design for the collimation upgrade has not been finalized. One option is to use metallic rotatable collimators and testing of this design will be discussed here. The Phase II collimators must be robust in various operating conditions and accident scenarios. A prototype collimator jaw has been tested for both mechanical and thermal compliance with the design goals. Thermal expansion bench-top tests are compared to ANSYS simulation results.

  6. Readout electronics upgrade on ALICE/PHOS detector for Run 2 of LHC

    NASA Astrophysics Data System (ADS)

    Wang, D.; Zhang, F.; Feng, W.; Huang, G.; Song, Z.; Yin, Z.; Zhou, D.

    2015-02-01

    The ALICE/PHOS detector is carrying out a major upgrade of its readout electronics for the RUN 2 of LHC (2015-2017). A new architecture based on the point to point link is developed. The event readout rate can achieve 30 kHz by replacing the old parallel GTL bus with DTC links. The communication stability of the interface between front-end electronic boards and readout concentrators is significantly improved. A new FPGA firmware is designed to be compatible with the upgraded ALICE trigger system and DATE software.

  7. Performance of the ATLAS Liquid Argon Calorimeter after three years of LHC operation and plans for a future upgrade

    NASA Astrophysics Data System (ADS)

    Strizenec, P.

    2014-09-01

    The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider (LHC) at CERN. Liquid Argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudorapidity region up to 3.2, as well as for hadronic calorimetry in the range 1.4-4.9. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform azimuthal response. Copper and tungsten were chosen as passive material for the hadronic calorimetry; whereas a parallel plate geometry was adopted at large polar angles, an innovative one based on cylindrical electrodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at 88.5 K. After installation in 2004-2006, the calorimeters were extensively commissioned over the three years period prior to first collisions in 2009, using cosmic rays and single LHC beams. Since then, around 27 fb-1 of data have been collected at a unprecedented center of mass energies between 7 TeV and 8 TeV. During all these stages, the calorimeter and its electronics have been operating with performances very close to the specification ones. After 2019, the instantaneous luminosity will reach 2-3 × 1034 cm-2s-1, well above the luminosity for which the calorimeter was designed. In order to preserve its triggering capabilities, the detector will be upgraded with a new fully digital trigger system with a refined granularity. In 2023, the instantaneous luminosity will ultimately reach 5-7 × 1034 cm-2s-1, requiring a complete replacement of the readout electronics. Moreover, with an increased particle flux, several phenomena (liquid argon boiling, space charge effects...) will affect the performance of the forward calorimeter (FCal). A replacement with a new FCal with smaller LAr gaps or a new calorimeter module are considered. The performance of these new

  8. Current Lead Design for the Accelerator Project for Upgrade of LHC

    SciTech Connect

    Brandt, Jeffrey S.; Cheban, Sergey; Feher, Sandor; Kaducak, Marc; Nobrega, Fred; Peterson, Tom

    2010-01-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. In collaboration with Brookhaven National Laboratory, Fermilab is developing sub-systems for an upgrade of the LHC final focus magnet systems. A concept of main and auxiliary helium flow was developed that allows the superconductor to remain cold while the lead body warms up to prevent upper section frosting. The auxiliary flow will subsequently cool the thermal shields of the feed box and the transmission line cryostats. A thermal analysis of the current lead central heat exchange section was performed using analytic and FEA techniques. A method of remote soldering was developed that allows the current leads to be field replaceable. The remote solder joint was designed to be made without flux or additional solder, and able to be remade up to ten full cycles. A method of upper section attachment was developed that allows high pressure sealing of the helium volume. Test fixtures for both remote soldering and upper section attachment for the 13 kA lead were produced. The cooling concept, thermal analyses, and test results from both remote soldering and upper section attachment fixtures are presented.

  9. A new high-gradient correction quadrupole for the Fermilab luminosity upgrade

    SciTech Connect

    Mantsch, P.; Carson, J.; Riddiford, A.; Lamm, M.J.

    1989-03-01

    Special superconducting correction quadrupoles are needed for the luminosity upgrade of the Fermilab Tevatron Collider. These correctors are part of the low-beta system for the interaction regions at B/phi/ and D/phi/. The requirements are high gradient and low current. A quadrupole has been designed that meets the operating gradient of 0.63 T/cm at 1086 A. The one-layer quadrupole is wound with a cable consisting of five individually insulated rectangular strands. The five strands are overwrapped with Kapton and epoxy impregnated glass tape. The winding, curing and collaring of the magnet is accomplished in the same manner as Tevatron-like magnets using Rutherford style cable. Once the magnet is complete the five strands are connected in series. A prototype quadrupole has been assembled and tested. The magnet reached a plateau current of 1560 A corresponding to a gradient of 0.91 T/cm without training. The measured field harmonics are substantially better than required. 8 refs., 6 figs., 4 tabs.

  10. Fabrication and performance of a new high-gradient trim quadrupole for the Fermilab luminosity upgrade

    SciTech Connect

    Mantsch, P.M.; Carson, J.A.; Gourlay, S.A.; Lamm, M.J.; Riddiford, A.W.

    1991-05-01

    A series of 16 high-gradient trim quadrupole magnets has been designed and built for the Tevatron luminosity upgrade (Fermilab III). These quadrupoles form part of the new Low-Beta system for the two interaction regions in the Tevatron Collider. The magnets have been installed in the Tevatron lattice in anticipation of the 1991 collider run. The one-shell design uses a cable'' of individually insulated rectangular strands. The cable is overwrapped with Kapton and epoxy impregnated glass tape. The winding, curing and collaring of the magnet is accomplished in the same manner as Tevatron-like magnets using Rutherford style cable. Once the magnet is assembled, the five strands are connected in series to achieve high gradient at low current. The required gradient is 0.63 T/cm at 1086 A. The production magnets reached maximum currents of about 1.1 T/cm at 1990 A. The success of this design approach suggests other applications in beam transport where magnets of high performance and low operating cost are required. 3 refs., 6 figs., 1 tab.

  11. Mechanical qualification of the support structure for MQXF, the Nb3Sn low-β quadrupole for the high luminosity LHC

    DOE PAGESBeta

    Juchno, M.; Ambrosio, G.; Anerella, M.; Bajas, H.; Bajko, M.; Bourcey, N.; Cheng, D. W.; Felice, H.; Ferracin, P.; Grosclaude, P.; et al

    2016-01-26

    Within the scope of the High Luminosity LHC project, the collaboration between CERN and U.S. LARP is developing new low-β quadrupoles using the Nb3Sn superconducting technology for the upgrade of the LHC interaction regions. The magnet support structure of the first short model was designed and two units were fabricated and tested at CERN and at LBNL. The structure provides the preload to the collars-coils subassembly by an arrangement of outer aluminum shells pre-tensioned with water-pressurized bladders. For the mechanical qualification of the structure and the assembly procedure, superconducting coils were replaced with solid aluminum “dummy coils”, the structure wasmore » preloaded at room temperature, and then cooled-down to 77 K. Mechanical behavior of the magnet structure was monitored with the use of strain gauges installed on the aluminum shells, the dummy coils and the axial preload system. As a result, this paper reports on the outcome of the assembly and the cool-down tests with dummy coils, which were performed at CERN and at LBNL, and presents the strain gauge measurements compared to the 3D finite element model predictions.« less

  12. Compensation of the long-range beam-beam interactions as a path towards new configurations for the high luminosity LHC

    NASA Astrophysics Data System (ADS)

    Fartoukh, Stéphane; Valishev, Alexander; Papaphilippou, Yannis; Shatilov, Dmitry

    2015-12-01

    Colliding bunch trains in a circular collider demands a certain crossing angle in order to separate the two beams transversely after the collision. The magnitude of this crossing angle is a complicated function of the bunch charge, the number of long-range beam-beam interactions, of β* and type of optics (flat or round), and possible compensation or additive effects between several low-β insertions in the ring depending on the orientation of the crossing plane at each interaction point. About 15 years ago, the use of current bearing wires was proposed at CERN in order to mitigate the long-range beam-beam effects [J. P. Koutchouk, CERN Report No. LHC-Project-Note 223, 2000], therefore offering the possibility to minimize the crossing angle with all the beneficial effects this might have: on the luminosity performance by reducing the need for crab-cavities or lowering their voltage, on the required aperture of the final focus magnets, on the strength of the orbit corrector involved in the crossing bumps, and finally on the heat load and radiation dose deposited in the final focus quadrupoles. In this paper, a semianalytical approach is developed for the compensation of the long-range beam-beam interactions with current wires. This reveals the possibility of achieving optimal correction through a careful adjustment of the aspect ratio of the β functions at the wire position. We consider the baseline luminosity upgrade plan of the Large Hadron Collider (HL-LHC project), and compare it to alternative scenarios, or so-called "configurations," where modifications are applied to optics, crossing angle, or orientation of the crossing plane in the two low-β insertions of the ring. For all these configurations, the beneficial impact of beam-beam compensation devices is then demonstrated on the tune footprint, the dynamical aperture, and/or the frequency map analysis of the nonlinear beam dynamics as the main figures of merit.

  13. Quench Protection Studies of 11T Nb$_3$Sn Dipole Models for LHC Upgrades

    SciTech Connect

    Zlobin, Alexander; Chlachidze, Guram; Nobrega, Alfred; Novitski, Igor; Karppinen, Mikko

    2014-07-01

    CERN and FNAL are developing 11 T Nb3Sn dipole magnets for the LHC collimation system upgrade. Due to the large stored energy, protection of these magnets during a quench is a challenging problem. This paper reports the results of experimental studies of key quench protection parameters including longitudinal and radial quench propagation in the coil, coil heating due to a quench, and energy extraction and quench-back effect. The studies were performed using a 1 m long 11 T Nb3Sn dipole coil tested in a magnetic mirror configuration.

  14. Construction and Bench Testing of a Rotatable Collimator for the LHC Collimation Upgrade

    SciTech Connect

    Smith, Jeffrey Claiborne; Keller, Lewis; Lundgren, Steven; Markiewicz, Thomas; /SLAC

    2010-08-26

    The Phase II upgrade to the LHC collimation system calls for complementing the 30 high robust Phase I graphite secondary collimators with 30 high Z Phase II collimators. The Phase II collimators must be robust in various operating conditions and accident scenarios. This paper reports on the final construction and testing of the prototype collimator to be installed in the SPS (Super Proton Synchrotron) at CERN. Bench-top measurements will demonstrate that the device is fully operational and has the mechanical and vacuum characteristics acceptable for installation in the SPS.

  15. COMPLETION OF SUPERCONDUCTING MAGNET PRODUCTION AT BNL FOR THE HERA LUMINOSITY UPGRADE

    SciTech Connect

    WANDERER,P.ANERELLA,M.ESCALLIER,J.GHOSH,A.JAIN,A.MARONE,A.MURATORE,J.PARKER,A.PRODELL,A.THOMPSON,P.WU,K.C.

    2001-09-24

    Brookhaven National Laboratory (BNL) has completed production of the superconducting multi-function magnets that are now installed as part of the HERA luminosity upgrade at DESY. The magnets, cryostats, and lead assemblies were designed and built at BNL. To fit inside the existing detectors, the coils plus cryostat structure had to meet a challenging radial budget (e.g., 39 mm horizontally). Two types of magnets were needed and three of each type were built. Each magnet contained normal and skew quadrupole, normal and skew dipole, and sextupole coils. The magnets operate in the {approx}1.5 T solenoid field of a detector. The quadrupole coils produce gradients up to 13 T/m. The dipole coils generate fields up to 0.3 T. Coils were wound under computer control using either seven-strand round cable or a single strand. To simultaneously avoid excessive synchrotron radiation background scattered from the beam pipe and yet have a small cryostat, one type of magnet used a tapered coil structure. The cryogenic system incorporates cooling with both 40 K helium and supercritical helium. All of the coils were tested in liquid helium in a vertical dewar. Quench test results have been excellent. The field quality of the magnets has met the stringent requirements imposed on interaction region magnets. One magnet of each type was tested at BNL as a completed assembly to verify the performance of the leads and cryostats. Two of each type were tested at DESY and then installed in the Zeus and H1 experiments. The remaining magnets are spares. Final results of quench testing, field quality measurements and cryogenic performance are reported.

  16. Triggering on electrons, jets and tau leptons with the CMS upgraded calorimeter trigger for the LHC RUN II

    NASA Astrophysics Data System (ADS)

    Zabi, A.; Beaudette, F.; Cadamuro, L.; Mastrolorenzo, L.; Romanteau, T.; Sauvan, J. B.; Strebler, T.; Marrouche, J.; Wardle, N.; Aggleton, R.; Ball, F.; Brooke, J.; Newbold, D.; Paramesvaran, S.; Smith, D.; Baber, M.; Bundock, A.; Citron, M.; Elwood, A.; Hall, G.; Iles, G.; Laner, C.; Penning, B.; Rose, A.; Tapper, A.; Durkin, T.; Harder, K.; Harper, S.; Shepherd-Themistocleous, C.; Thea, A.; Williams, T.

    2016-02-01

    The Compact Muon Solenoid (CMS) experiment has implemented a sophisticated two-level online selection system that achieves a rejection factor of nearly 105. During Run II, the LHC will increase its centre-of-mass energy up to 13 TeV and progressively reach an instantaneous luminosity of 2 × 1034 cm-2 s-1. In order to guarantee a successful and ambitious physics programme under this intense environment, the CMS Trigger and Data acquisition (DAQ) system has been upgraded. A novel concept for the L1 calorimeter trigger is introduced: the Time Multiplexed Trigger (TMT) . In this design, nine main processors receive each all of the calorimeter data from an entire event provided by 18 preprocessors. This design is not different from that of the CMS DAQ and HLT systems. The advantage of the TMT architecture is that a global view and full granularity of the calorimeters can be exploited by sophisticated algorithms. The goal is to maintain the current thresholds for calorimeter objects and improve the performance for their selection. The performance of these algorithms will be demonstrated, both in terms of efficiency and rate reduction. The callenging aspects of the pile-up mitigation and firmware design will be presented.

  17. Recent Progress on the Design of a Rotatable Copper Collimator for the LHC Collimation Upgrade

    SciTech Connect

    Smith, Jeffrey Claiborne; Keller, Lewis; Lundgren, Steven; Markiewicz, Thomas Walter; Lari, Luisella; /Cern /EPFL-ISIC

    2009-08-03

    The Phase II upgrade to the LHC collimation system calls for complementing the 30 high robust Phase I graphite collimators with 30 high Z Phase II collimators. One option is to use metallic rotatable collimators and this design will be discussed here. The Phase II collimators must be robust in various operating conditions and accident scenarios. Design issues include: (1) Collimator jaw deflection due to heating and sagitta must be small when operated in the steady state condition, (2) Collimator jaws must withstand transitory periods of high beam impaction with no permanent damage, (3) Jaws must recover from accident scenario where up to 8 full intensity beam pulses impact on the jaw surface and (4) The beam impedance contribution due to the collimators must be small to minimize coherent beam instabilities. This paper reports on recent updates to the design and testing.

  18. Trapped Mode Study For A Rotatable Collimator Design For The LHC Upgrade

    SciTech Connect

    Xiao, Liling; Ng, Cho-Kuen; Smith, Jeffery Claiborne; Caspers, Fritz; /SLAC /CERN

    2009-06-23

    A rotatable collimator is proposed for the LHC phase II collimation upgrade. When the beam crosses the collimator, it will excite trapped modes that can contribute to the beam energy loss and power dissipation on the vacuum chamber wall. Transverse trapped modes can also generate transverse kicks on the beam and may thus affect the beam quality. In this paper, the parallel eigensolver code Omega3P is used to search for all the trapped modes below 2 GHz in two collimator designs, one with rectangular and the other with circular vacuum chamber. It is found that the longitudinal trapped modes in the circular vacuum chamber design may cause excessive heating. Adding ferrite tiles on the circular vacuum chamber wall can strongly damp these trapped modes. We will present and discuss the simulation results.

  19. Longitudinal Wakefield Study in SLAC Rotatable Collimator Design for the LHC Phase II Upgrade

    SciTech Connect

    Xiao, Liling; Lundgren, Steven; Markiewicz, Thomas; Ng, Cho-Kuen; Smith, Jeffrey; /SLAC

    2010-08-25

    SLAC proposed a rotatable collimator design for the LHC Phase II collimation upgrade. There are 20 facet faces on each cylindrical jaw surface and two jaws are rotatable in order to introduce a clean surface in case of a beam hitting a jaw during operation. When the beam crosses the collimator, it will excite broad-band and narrow-band modes. The longitudinal modes can contribute to beam energy loss and power dissipation on the vacuum chamber wall. In this paper, the parallel finite element eigensolver Omega3P is used to search for all the longitudinal trapped modes in the SLAC collimator design. The power dissipation generated by the beam in collimators with different vacuum chamber and RF contact designs is discussed. It is found that a wider RF foil connecting the jaw and the vacuum flange can reduce efficiently the beam heating caused by the longitudinal modes.

  20. BPM Design and Impedance Considerations for a Rotatable Collimator for the LHC Collimation Upgrade

    SciTech Connect

    Smith, Jeffrey Claiborne; Keller, Lewis; Lundgren, Steven; Markiewicz, Thomas; Young, Andrew; /SLAC

    2010-08-26

    The Phase II upgrade to the LHC collimation system calls for complementing the 30 high robust Phase I graphite secondary collimators with 30 high Z Phase II collimators. This paper reports on BPM and impedance considerations and measurements of the integrated BPMs in the prototype rotatable collimator to be installed in the Super Proton Synchrotron (SPS) at CERN. The BPMs are necessary to align the jaws with the beam. Without careful design the beam impedance can result in unacceptable heating of the chamber wall or beam instabilities. The impedance measurements involve utilizing both a single displaced wire and two wires excited in opposite phase to disentangle the driving and detuning transverse impedances. Trapped mode resonances and longitudinal impedance are to also be measured and compared with simulations. These measurements, when completed, will demonstrate the device is fully operational and has the impedance characteristics and BPM performance acceptable for installation in the SPS.

  1. Measurements at TRIUMF on a 80 MHz Cavity Model for the CERN PS Upgrade for LHC.

    NASA Astrophysics Data System (ADS)

    Mitra, A. K.; Poirier, R. L.; Losito, R.

    1997-05-01

    The RF system of the CERN PS being upgraded to bunch a beam that can be captured by the SPS 200 MHz RF system for injection into LHC. Two identical 80 MHz cavities are part of this PS upgrade programme. At CERN, the cavity has been designed using SUPERFISH and MAFIA concerning its shape, tuning devices and amplifier coupling loop. TRIUMF has built a simplified full-scale, copper-lined, wooden model, designed such that the field patters of the fundamental accelerating mode and the longitudinal modes agree closely to CERN cavity ones. The aim of constructing the wooden model was primarily to check the design of the capacitive tuners, the power coupling loop and the HOM dampers for the longitudinal modes up to 1 GHz. The results of the measurements were used to define the parameters of the tuners and a reliable model to describe the interaction of the coupling look with the fundamental mode of the final CERN cavity. Five quarter-wave antennae are adequate to damp the first fifteen longitudinal modes. In order not to decrease the shunt impedance of the fundamental mode by more than 5%, a three-element filter has been used with the antenna which damps the first longitudinal mode at 256 MHz.

  2. Alignment of the ATLAS Inner Detector Upgraded for the LHC Run II

    NASA Astrophysics Data System (ADS)

    Jiménez Peña, J.

    2015-12-01

    ATLAS is equipped with a tracking system built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drift-tubes, all embedded in a 2T axial magnetic field. For the LHC Run II, the tracking system has been upgraded with the installation of a new pixel layer, the Insertable Barrel Layer (IBL). An outline of the track based alignment approach and its implementation within the ATLAS software will be presented. Special attention will be paid to integration in the alignment framework of the IBL, which plays a key role in precise reconstruction of the collider luminous region, interaction vertices and identification of long-lived heavy flavour states. In order to detect as soon as possible deformations and misalignments of the tracking system that may affect the data taking, a fast alignment chain was implemented at the Tier-0 at CERN. Latest upgrades and tests of this fast chain will be discussed, as well as the performance from the Cosmic Ray commissioning run.

  3. Upgrade of the CMS tracker

    NASA Astrophysics Data System (ADS)

    Tricomi, A.

    2014-03-01

    The LHC machine is planning an upgrade program which will smoothly bring the luminosity up to or above 5 × 1034 cm-2s-1 sometimes after 2020, to possibly reach an integrated luminosity of 3000 fb-1 at the end of that decade. The foreseen increases of both the instantaneous and the integrated luminosity by the LHC during the next ten years will necessitate a stepwise upgrade of the CMS tracking detector. During the extended end-of-year shutdown 2016-2017 the pixel detector will be exchanged with a new one. The so-called Phase1 Pixel foresees one additional barrel layer and one additional end-cap disk, a new readout chip, reduction of material, and the installation of more efficient cooling and powering systems. In the so-called Phase2, when LHC will reach the High Luminosity (HL-LHC) phase, CMS will need a completely new Tracker detector, in order to fully exploit the high-demanding operating conditions and the delivered luminosity. The new Tracker should have also trigger capabilities. To achieve such goals, R&D activities are ongoing to explore options and develop solutions that would allow including tracking information at Level-1. The design choices for the CMS pixel and outer tracker upgrades are discussed along with some highlights of the R&D activities.

  4. Energy deposited in the high luminosity inner triplets of the LHC by collision debris

    SciTech Connect

    Wildner, E.; Broggi, F.; Cerutti, F.; Ferrari, A.; Hoa, C.; Koutchouk, J.-P.; Mokhov, N.V.; /Fermilab

    2008-06-01

    The 14 TeV center of mass proton-proton collisions in the LHC produce not only debris interesting for physics but also showers of particles ending up in the accelerator equipment, in particular in the superconducting magnet coils. Evaluations of this contribution to the heat, that has to be transported by the cryogenic system, have been made to guarantee that the energy deposition in the superconducting magnets does not exceed limits for magnet quenching and the capacity of the cryogenic system. The models of the LHC base-line are detailed and include description of, for energy deposition, essential elements like beam-pipes and corrector magnets. The evaluations made using the Monte-Carlo code FLUKA are compared to previous studies using MARS. For the consolidation of the calculations, a dedicated comparative study of these two codes was performed for a reduced setup.

  5. Mitigation of effects of beam-induced energy deposition in the LHC high-luminosity interaction regions

    SciTech Connect

    Nikolai V. Mokhov et al.

    2003-05-28

    Beam-induced energy deposition in the LHC high luminosity interaction region components is one of the serious limits for the machine performance. The results of further optimization and comprehensive MARS14 calculations in the IP1 and IP5 inner and outer triplets are summarized for the updated lattice, calculation model, baseline pp-collision source term, and for realistic engineering constraints on the hardware design. It is shown that the optimized layout and absorbers would provide a sufficient reduction of peak power density and dynamic heat load in the superconducting components with an adequate safety margin. Accumulated dose and residual dose rates in and around the region components are also kept below the tolerable limits in the proposed design.

  6. Performance of the ATLAS Tile Hadronic Calorimeter at LHC in Run 1 and planned upgrades

    NASA Astrophysics Data System (ADS)

    Solovyanov, O.

    2014-10-01

    The Tile Calorimeter (TileCal) is the central section of the ATLAS hadronic calorimeter at the Large Hadron Collider, a key detector for the measurements of hadrons, jets, tau leptons and missing transverse energy. Scintillation light produced in the tiles is transmitted by wavelength shifting fibres to photomultiplier tubes (PMTs). The resulting electronic signals from approximately 10000 PMTs are digitized before being transferred to off-detector data-acquisition systems. The data quality procedures used during the LHC data-taking and the evolution of the detector status are explained in the presentation. The energy and the time reconstruction performance of the digitized signals is presented and the noise behaviour and its improvement during the detector consolidation in maintenance periods are shown. A set of calibration systems allow monitoring and equalization of the calorimeter channels responses via signal sources that act at every stage of the signal path, from scintillation light to digitized signal. These partially overlapping systems are described in detail, their individual performance is discussed as well as the comparative results from measurements of the evolution of the calorimeter response with time during the full LHC data-taking period. The TileCal upgrade aims at replacing the majority of the on- and off-detector electronics so that all calorimeter signals will be directly digitized and sent to the off-detector electronics in the counting room. To achieve the required reliability, redundancy has been introduced at different levels. For the off-detector electronics a special pre-processor board is being developed, which will take care of the initial trigger processing, while the main data are temporarily stored in the pipeline and de-randomiser memories.

  7. Design and Fabrication of a Single-Aperture 11T Nb3Sn Dipole Model for LHC Upgrades

    SciTech Connect

    Andreev, N.; Apollinari, G.; Barzi, E.; Bossert, R.; Nobrega, F.; Novitski, I.; Turrioni, D.; Yamada, R.; Zlobin, A.V.; Auchmann, B.; Karppinen, M.; /CERN

    2011-11-28

    The planned upgrade of the LHC collimation system includes additional collimators to be installed in the dispersion suppressor areas of points 2, 3 and 7. To provide the necessary longitudinal space for the collimators, a replacement of 8.33 T Nb-Ti LHC main dipoles with 11 T dipoles based on Nb{sub 3}Sn superconductor compatible with the LHC lattice and main systems is being considered. To demonstrate this possibility FNAL and CERN have started a joint program to develop a 2 m long single-aperture dipole magnet with the nominal field of 11 T at {approx}11.85 kA current and 60 mm bore. This paper describes the demonstrator magnet magnetic and mechanical designs and analysis, coil fabrication procedure. The Nb{sub 3}Sn strand and cable parameters and test results are also reported.

  8. LHC crab-cavity aspects and strategy

    SciTech Connect

    Calaga, R.; Tomas, R.; Zimmermann, F.

    2010-05-23

    The 3rd LHC Crab Cavity workshop (LHC-CC09) took place at CERN in October 2009. It reviewed the current status and identified a clear strategy towards a future crab-cavity implementation. Following the success of crab cavities in KEK-B and the strong potential for luminosity gain and leveling, CERN will pursue crab crossing for the LHC upgrade. We present a summary and outcome of the variousworkshop sessions which have led to the LHC crab-cavity strategy, covering topics like layout, cavity design, integration, machine protection, and a potential validation test in the SPS.

  9. POTENTIAL FOR HIGGS PHYSICS AT THE LHC AND SUPER-LHC.

    SciTech Connect

    CRANMER, K.S.

    2005-12-12

    The expected sensitivity of the LHC experiments to the discovery of the Higgs boson and the measurement of its properties is presented in the context of both the standard model and the its minimal supersymmetric extension. Prospects for a luminosity-upgraded ''Super-LHC'' are also presented. If it exists, the LHC should discover standard model Higgs boson, measure its mass accurately, and make various measurements of its couplings, spin and CP properties. In the context of the CP-conserving MSSM, the LHC should be able to discover one or more Higgs bosons over the entire m{sub A}-tan {beta} plane, with two or more observable in many cases. The large number of channels available insure a robust discovery and offer many opportunities for additional measurements. Observation of H {yields} {mu}{mu}, measurement of the tri-linear Higgs self-coupling, and various search channels are statistics-limited, and only possible with a luminosity upgrade. A luminosity upgrade would substantially improve some of the coupling measurements and generally extend the sensitivity in the MSSM Higgs plane. Efforts are ongoing to understand the upgrade of the LHC to the Super-LHC.

  10. Bench-Top Impedance Measurements for a Rotatable Copper Collimator for the LHC Phase II Collimation Upgrade

    SciTech Connect

    Smith, Jeffrey Claiborne; Bane, Karl; Doyle, Eric; Keller, Lew; Lundgren, Steve; Markiewicz, Tom; Ng, Cho-Kuen; Xiao, Liling; /SLAC

    2010-08-26

    Simulations have been performed in Omega3P to study both trapped modes and impedance contributions of a rotatable collimator for the LHC phase II collimation upgrade. Bench-top stretched coil probe impedance methods are also being implemented for measurements on prototype components to directly measure the low frequency impedance contributions. The collimator design also calls for a RF contact interface at both jaw ends with contact resistance much less than a milliohm in order to limit transverse impedance. DC resistance measurements in a custom built test chamber have been performed to test the performance of this interface.

  11. Pixel front-end with synchronous discriminator and fast charge measurement for the upgrades of HL-LHC experiments

    NASA Astrophysics Data System (ADS)

    Monteil, E.; Demaria, N.; Pacher, L.; Rivetti, A.; Da Rocha Rolo, M.; Rotondo, F.; Leng, C.

    2016-03-01

    The upgrade of the silicon pixel sensors for the HL-LHC experiments requires the development of new readout integrated circuits due to unprecedented radiation levels, very high hit rates and increased pixel granularity. The design of a very compact, low power, low threshold analog very front-end in CMOS 65 nm technology is described. It contains a synchronous comparator which uses an offset compensation technique based on storing the offset in output. The latch can be turned into a local oscillator using an asynchronous logic feedback loop to implement a fast time-over-threshold counting. This design has been submitted and the measurement results are presented.

  12. Thin n-in-p pixel sensors and the SLID-ICV vertical integration technology for the ATLAS upgrade at the HL-LHC

    NASA Astrophysics Data System (ADS)

    Macchiolo, A.; Andricek, L.; Ellenburg, M.; Moser, H. G.; Nisius, R.; Richter, R. H.; Terzo, S.; Weigell, P.

    2013-12-01

    This R&D activity is focused on the development of new modules for the upgrade of the ATLAS pixel system at the High Luminosity LHC (HL-LHC). The performance after irradiation of n-in-p pixel sensors of different active thicknesses is studied, together with an investigation of a novel interconnection technique offered by the Fraunhofer Institute EMFT in Munich, the Solid-Liquid-InterDiffusion (SLID), which is an alternative to the standard solder bump-bonding. The pixel modules are based on thin n-in-p sensors, with an active thickness of 75 μm or 150 μm, produced at the MPI Semiconductor Laboratory (MPI HLL) and on 100 μm thick sensors with active edges, fabricated at VTT, Finland. Hit efficiencies are derived from beam test data for thin devices irradiated up to a fluence of 4×1015 neq/cm2. For the active edge devices, the charge collection properties of the edge pixels before irradiation are discussed in detail, with respect to the inner ones, using measurements with radioactive sources. Beyond the active edge sensors, an additional ingredient needed to design four side buttable modules is the possibility of moving the wire bonding area from the chip surface facing the sensor to the backside, avoiding the implementation of the cantilever extruding beyond the sensor area. The feasibility of this process is under investigation with the FE-I3 SLID modules, where Inter Chip Vias are etched, employing an EMFT technology, with a cross section of 3 μm×10 μm, at the positions of the original wire bonding pads.

  13. Triple GEM detector sensitivity simulations with Geant4 for the CMS Forward Muon Upgrade at CERN LHC

    NASA Astrophysics Data System (ADS)

    Zenoni, Florian; CMS GEM Collaboration

    2015-04-01

    Triple Gas Electron Multiplier (GEM) detectors are being developed for the forward muon upgrade of the CMS experiment in Phase 2 of the CERN LHC. After the second long LHC shutdown, their implementation will take place for the GE1/1 system in the 1 . 5 < | η | < 2 . 2 region of the muon endcap. This upgrade aims at controlling muon level-1 trigger rates, thanks to their high performance in extreme particle rates (~ MHz/cm2). Moreover, the GEM technology can improve the muon track reconstruction and identification capabilities of the forward detector. The Triple GEMs will work in a hostile radiation background (several hundreds of Hz/cm2) mostly made of photons, neutrons, electrons and positrons. To understand how this background could affect the detectors' functionality it is important to know the sensitivity to these kinds of radiation. The goal of this work is to estimate the sensitivity of Triple GEMs to background particles in the CMS cavern environment, thanks to the latest updates of GEANT4, a toolkit for the simulation of the passage of particles through matter.

  14. Introduction to the HL-LHC Project

    NASA Astrophysics Data System (ADS)

    Rossi, L.; Brüning, O.

    The Large Hadron Collider (LHC) is one of largest scientific instruments ever built. It has been exploring the new energy frontier since 2010, gathering a global user community of 7,000 scientists. To extend its discovery potential, the LHC will need a major upgrade in the 2020s to increase its luminosity (rate of collisions) by a factor of five beyond its design value and the integrated luminosity by a factor of ten. As a highly complex and optimized machine, such an upgrade of the LHC must be carefully studied and requires about ten years to implement. The novel machine configuration, called High Luminosity LHC (HL-LHC), will rely on a number of key innovative technologies, representing exceptional technological challenges, such as cutting-edge 11-12 tesla superconducting magnets, very compact superconducting cavities for beam rotation with ultra-precise phase control, new technology for beam collimation and 300-meter-long high-power superconducting links with negligible energy dissipation. HL-LHC federates efforts and R&D of a large community in Europe, in the US and in Japan, which will facilitate the implementation of the construction phase as a global project.

  15. Results From the DAFNE High Luminosity Test

    SciTech Connect

    Milardi, C.; Alesini, D.; Biagini, M.E.; Boni, R.; Boscolo, M.; Bossi, F.; Buonomo, B.; Clozza, A.; Delle Monache, G.; Demma, T.; Di Pasquale, E.; Di Pirro, G.; Drago, A.; Gallo, A.; Ghigo, A.; Guiducci, S.; Ligi, C.; Marcellini, F.; Mazzitelli, G.; Murtas, F.; Pellegrino, L.; /Frascati /Novosibirsk, IYF /CERN /INFN, Cosenza /INFN, Rome /KEK, Tsukuba /Orsay, LAL /Rome U. /Pisa U. /INFN, Pisa /INFN, Rome3 /SLAC

    2012-04-11

    The DAPHNE collider, based on a new collision scheme including Large Piwinsky angle and Crab-Waist, has been successfully commissioned and is presently delivering luminosity to the SIDDHARTA detector. Large crossing angle and Crab-Waist scheme proved to be effective in: (1) Increasing luminosity, now a factor 2.7 higher than in the past; and (2) controlling transverse beam blow-up due to the beam-beam. Work is in progress to reach the ultimate design luminosity goal 5.0 {center_dot} 10{sup 32} cm{sup -2}s{sup -1}. The new collision scheme is the main design concept for a new project aimed at building a Super-B factory that is expected to achieve a luminosity of the order of 10{sup 36} cm{sup -2} s{sup -1} and it has been also taken into account to upgrade one of the LHC interaction regions.

  16. Status of the MSSM Higgs sector using global analysis and direct search bounds, and future prospects at the High Luminosity LHC

    NASA Astrophysics Data System (ADS)

    Bhattacherjee, Biplob; Chakraborty, Amit; Choudhury, Arghya

    2015-11-01

    In this paper, we search for the regions of the phenomenological minimal supersymmetric standard model (pMSSM) parameter space where one can expect to have moderate Higgs mixing angle (α ) with relatively light (up to 600 GeV) additional Higgses after satisfying the current LHC data. We perform a global fit analysis using most updated data (till December 2014) from the LHC and Tevatron experiments. The constraints coming from the precision measurements of the rare b-decays Bs→μ+μ- and b →s γ are also considered. We find that low MA(≲350 ) and high tan β (≳25 ) regions are disfavored by the combined effect of the global analysis and flavor data. However, regions with Higgs mixing angle α ˜0.1 - 0.8 are still allowed by the current data. We then study the existing direct search bounds on the heavy scalar/pseudoscalar (H /A ) and charged Higgs boson (H±) masses and branchings at the LHC. It has been found that regions with low to moderate values of tan β with light additional Higgses (mass ≤600 GeV ) are unconstrained by the data, while the regions with tan β >20 are excluded considering the direct search bounds by the LHC-8 data. The possibility to probe the region with tan β ≤20 at the high luminosity run of LHC are also discussed, giving special attention to the H →hh , H /A →t t ¯ and H /A →τ+τ- decay modes.

  17. The LHCb Upgrade

    NASA Astrophysics Data System (ADS)

    Jacobsson, Richard

    2013-11-01

    With the demonstration that LHCb can successfully perform forward precision measurements with event pileup, the operation and trigger strategy evolved significantly during the LHC Run 1 allowing LHCb to collect over 3fb-1 at centre-of-mass energies of 7TeV and 8TeV. Increased bandwidth opened the door for LHCb to extend the physics program. The additional statistics and well managed systematic effects together with the stable trigger and data taking conditions have led to a very large number of world-class measurements and dominance in heavy flavour physics [1], in addition to a reputation of an excellent forward general purpose detector at the LHC. Long Shutdown (LS) 1 (2013-2014) will allow LHCb to fully explore the large statistics collected and prepare LHCb for Run 2 (2015 - 2017). However, even after an additional expected integrated luminosity of 5-6 fb-1 in Run 2, many of the LHCb precision measurements will remain limited by statistics, and some exploratory physics modes will not even be accessible yet. With the need for reconstructing the event topology in order to efficiently trigger on the beauty and the charm hadrons decays, the current 1 MHz readout limit is the main bottle neck to run at higher luminosity and with higher trigger efficiencies. LHCb will therefore undergo a major upgrade in LS 2 ( 2018 - 2019) aimed at collecting an order of magnitude more data by 2028. The upgrade consists of a full readout at the LHC bunch crossing rate ( 40 MHz) with the ultimate flexibility of only a software trigger. In order to increase the instantaneous luminosity up to 2x1033cm-2s-1, several sub-detector upgrades are also underway to cope with the higher occupancies and radiation dose.

  18. Quench Performance of the First Twin-aperture 11 T Dipole for LHC upgrades

    SciTech Connect

    Zlobin, A. V.; Andreev, N.; Apollinari, G.; Barzi, E.; Chlachidze, G.; Nobrega, A.; Novitski, I.; Stoynev, S.; Turrioni, D.; Auchmann, B.; Izquierdo Bermudez, S.; Karppinen, M.; Rossi, L.; Savary, F.; Smekens, D.

    2015-06-01

    FNAL and CERN are developing a twin-aperture 11 T $Nb_{3}Sn$ dipole suitable for installation in the LHC. A single-aperture 2-m long dipole demonstrator and two 1-m long dipole models have been fabricated and tested at FNAL in 2012-2014. The two 1 m long collared coils were then assembled into the first twin-aperture $Nb_{3}Sn$ demonstrator dipole and tested. Test results of this twin-aperture $Nb_{3}Sn$ dipole model are reported and discussed.

  19. Cryogenics for HL-LHC

    NASA Astrophysics Data System (ADS)

    Tavian, L.; Brodzinski, K.; Claudet, S.; Ferlin, G.; Wagner, U.; van Weelderen, R.

    The discovery of a Higgs boson at CERN in 2012 is the start of a major program of work to measure this particle's properties with the highest possible precision for testing the validity of the Standard Model and to search for further new physics at the energy frontier. The LHC is in a unique position to pursue this program. Europe's top priority is the exploitation of the full potential of the LHC, including the high-luminosity upgrade of the machine and detectors with an objective to collect ten times more data than in the initial design, by around 2030. To reach this objective, the LHC cryogenic system must be upgraded to withstand higher beam current and higher luminosity at top energy while keeping the same operation availability by improving the collimation system and the protection of electronics sensitive to radiation. This chapter will present the conceptual design of the cryogenic system upgrade with recent updates in performance requirements, the corresponding layout and architecture of the system as well as the main technical challenges which have to be met in the coming years.

  20. Commissioning of the upgraded ATLAS Pixel Detector for Run2 at LHC

    NASA Astrophysics Data System (ADS)

    Dobos, Daniel

    2016-07-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long showdown, the detector was extracted from the experiment and brought to the surface, to equip it with new service quarter panels, to repair modules and to ease installation of the Insertable B-Layer, a fourth layer of pixel detectors, installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. An overview of the refurbishing of the Pixel Detector and of the IBL project as well as early performance tests using cosmic rays and beam data will be presented.

  1. Thin n-in-p planar pixel sensors and active edge sensors for the ATLAS upgrade at HL-LHC

    NASA Astrophysics Data System (ADS)

    Terzo, S.; Macchiolo, A.; Nisius, R.; Paschen, B.

    2014-12-01

    Silicon pixel modules employing n-in-p planar sensors with an active thickness of 200 μm, produced at CiS, and 100-200 μm thin active/slim edge sensor devices, produced at VTT in Finland have been interconnected to ATLAS FE-I3 and FE-I4 read-out chips. The thin sensors are designed for high energy physics collider experiments to ensure radiation hardness at high fluences. Moreover, the active edge technology of the VTT production maximizes the sensitive region of the assembly, allowing for a reduced overlap of the modules in the pixel layer close to the beam pipe. The CiS production includes also four chip sensors according to the module geometry planned for the outer layers of the upgraded ATLAS pixel detector to be operated at the HL-LHC. The modules have been characterized using radioactive sources in the laboratory and with high precision measurements at beam tests to investigate the hit efficiency and charge collection properties at different bias voltages and particle incidence angles. The performance of the different sensor thicknesses and edge designs are compared before and after irradiation up to a fluence of 1.4 × 1016 neq/cm2.

  2. Luminosity measurements at hadron colliders

    SciTech Connect

    Papadimitriou, Vaia; /Fermilab

    2008-04-01

    In this paper we discuss luminosity measurements at Tevatron and HERA as well as plans for luminosity measurements at LHC. We discuss luminosity measurements using the luminosity detectors of the experiments as well as measurements by the machine. We address uncertainties of the measurements, challenges and lessons learned.

  3. The ALICE high-level trigger read-out upgrade for LHC Run 2

    NASA Astrophysics Data System (ADS)

    Engel, H.; Alt, T.; Breitner, T.; Gomez Ramirez, A.; Kollegger, T.; Krzewicki, M.; Lehrbach, J.; Rohr, D.; Kebschull, U.

    2016-01-01

    The ALICE experiment uses an optical read-out protocol called Detector Data Link (DDL) to connect the detectors with the computing clusters of Data Acquisition (DAQ) and High-Level Trigger (HLT). The interfaces of the clusters to these optical links are realized with FPGA-based PCI-Express boards. The High-Level Trigger is a computing cluster dedicated to the online reconstruction and compression of experimental data. It uses a combination of CPU, GPU and FPGA processing. For Run 2, the HLT has replaced all of its previous interface boards with the Common Read-Out Receiver Card (C-RORC) to enable read-out of detectors at high link rates and to extend the pre-processing capabilities of the cluster. The new hardware also comes with an increased link density that reduces the number of boards required. A modular firmware approach allows different processing and transport tasks to be built from the same source tree. A hardware pre-processing core includes cluster finding already in the C-RORC firmware. State of the art interfaces and memory allocation schemes enable a transparent integration of the C-RORC into the existing HLT software infrastructure. Common cluster management and monitoring frameworks are used to also handle C-RORC metrics. The C-RORC is in use in the clusters of ALICE DAQ and HLT since the start of LHC Run 2.

  4. Performance of radiation-hard HV/HR CMOS sensors for the ATLAS inner detector upgrades

    NASA Astrophysics Data System (ADS)

    Liu, J.; Barbero, M.; Bilbao De Mendizabal, J.; Breugnon, P.; Godiot-Basolo, S.; Pangaud, P.; Rozanov, A.

    2016-03-01

    A major upgrade (Phase II Upgrade) to the Large Hadron Collider (LHC), scheduled for 2022, will be brought to the machine so as to extend its discovery potential. The upgraded LHC, called High-Luminosity LHC (HL-LHC), will run with a nominal leveled instantaneous luminosity of 5×1034 cm-2s-1, more than twice the expected luminosity. This unprecedented luminosity will result in higher occupancy and background radiations, which will request the design of a new Inner Tracker (ITk) which should have higher granularity, reduced material budget and improved radiation tolerance. A new pixel sensor concept based on High Voltage and High Resistivity CMOS (HV/HR CMOS) technology targeting the ATLAS inner detector upgrade is under exploration. With respect to the traditional hybrid pixel detector, the HV/HR CMOS sensor can potentially offer lower material budget, reduced pixel pitch and lower cost. Several prototypes have been designed and characterized within the ATLAS upgrade R&D effort, to investigate the detection and radiation hardness performance of various commercial technologies. An overview of the HV/HR CMOS sensor operation principle is described in this paper. The characterizations of three prototypes with X-ray, proton and neutron irradiation are also given.

  5. The upgraded LHCb RICH detector: Status and perspectives

    NASA Astrophysics Data System (ADS)

    Cardinale, R.

    2016-07-01

    The LHCb upgrade will take place during the second long shutdown of the LHC (LS2). The upgrade will enable the experiment to run at an instantaneous luminosity of 2 ×1033cm-2s-1 and will read out data at a rate of 40 MHz into a flexible software-based trigger. The two Ring Imaging Cherenkov detectors (RICH), installed in the LHCb experiment, will be re-designed to comply with these new operating conditions. The status and perspective of the RICH upgrade project will be presented.

  6. A Pattern Recognition Mezzanine based on Associative Memory and FPGA technology for Level 1 Track Triggers for the HL-LHC upgrade

    NASA Astrophysics Data System (ADS)

    Magalotti, D.; Alunni, L.; Biesuz, N.; Bilei, G. M.; Citraro, S.; Crescioli, F.; Fanò, L.; Fedi, G.; Magazzù, G.; Servoli, L.; Storchi, L.; Palla, F.; Placidi, P.; Rossi, E.; Spiezia, A.

    2016-02-01

    The increment of luminosity at HL-LHC will require the introduction of tracker information at Level-1 trigger system for the experiments in order to maintain an acceptable trigger rate for selecting interesting events despite the one order of increased magnitude in the minimum bias interactions. In order to extract the track information in the required latency (~ 5-10 μ s depending on the experiment), a dedicated hardware processor needs to be used. We here propose a prototype system (Pattern Recognition Mezzanine) as core of pattern recognition and track fitting for HL-LHC experiments, combining the power of both Associative Memory custom ASIC and modern Field Programmable Gate Array (FPGA) devices.

  7. Silicon strip tracking detector development and prototyping for the Phase-II upgrade of the ATLAS experiment

    NASA Astrophysics Data System (ADS)

    Kuehn, S.

    2016-07-01

    In about ten years from now, the Phase-II upgrade of the LHC will be carried out. Due to increased luminosity, a severe radiation dose and high particle rates will occur for the experiments. In consequence, several detector components will have to be upgraded. In the ATLAS experiment, the current inner detector will be replaced by an all-silicon tracking detector with the goal of at least delivering the present detector performance also in the harsh Phase-II LHC conditions. This report presents the current planning and results from first prototype measurements of the upgrade silicon strip tracking detector.

  8. From the LHC to Future Colliders

    SciTech Connect

    De Roeck, A.; Ellis, J.; Grojean, C.; Heinemeyer, S.; Jakobs, K.; Weiglein, G.; Azuelos, G.; Dawson, S.; Gripaios, B.; Han, T.; Hewett, J.; Lancaster, M.; Mariotti, C.; Moortgat, F.; Moortgat-Pick, G.; Polesello, G.; Riemann, S.; Assamagan, K.; Bechtle, P.; Carena, M.; Chachamis, G.; /more authors..

    2010-06-11

    Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300 fb{sup -1} of integrated luminosity, of the proposed sLHC luminosity upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10 fb{sup -1} of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, theWorking Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discovered by the LHC. Their reports provide the particle physics community with some tools for reviewing the scientific priorities for future colliders after the LHC produces its first harvest of new physics from multi-TeV collisions.

  9. Micromegas chambers for the experiment ATLAS at the LHC (A Brief Overview)

    NASA Astrophysics Data System (ADS)

    Gongadze, A. L.

    2016-03-01

    The increase in luminosity and energy of the Large hadron collider (LHC) in the next upgrade (Phase-1) in 2018-2019 will lead to a significant increase in radiation load on the ATLAS detector, primarily in the areas close to the interaction point of the LHC proton beams. One of these regions is the Small Wheel of the ATLAS Muon Spectrometer. It is planned to be replaced with the New Small Wheel that will have Micromegas chambers as main coordinate detectors. The paper gives an overview of all existing types of Micromegas detectors with special focus on the Micromegas chambers for the ATLAS detector upgrade.

  10. Characterization of irradiated detectors fabricated on p-type silicon substrates for super-LHC

    NASA Astrophysics Data System (ADS)

    Miñano, M.; Campabadal, F.; Escobar, C.; García, C.; González, S.; Lacasta, C.; Lozano, M.; Martí i García, S.; Pellegrini, G.; Rafí, J. M.; Ullán, M.

    2007-12-01

    An upgrade of the large hadron collider (LHC), the Super-LHC (SLHC), towards higher luminosities is currently being discussed as an extension of the LHC physics program. The goal of the SLHC is to operate at a luminosity of 10 35 cm -2 s -1 (10 times larger than that of the LHC one). Thus, the operation of the SLHC implies a need to upgrade the detectors of the LHC experiments. The current tracking system of ATLAS will not cope with that luminosity. New solutions must be investigated to improve the radiation tolerance of the semiconductor detector. p-Type bulk sensors are being considered for the ATLAS tracking system for the SLHC. Microstrip detectors fabricated by CNM-IMB on p-type high-resistivity float zone silicon have been irradiated with neutrons at the TRIGA Mark II reactor in Ljubljana up to a fluence of 10 16 cm -2 (as expected in the innermost region of the ATLAS upgrade) and have been characterized at IFIC Laboratory. The collected charge, after irradiation, has been measured by infrared laser illumination. The leakage current of those sensors is also reported.

  11. Novel module production methods for the CMS pixel detector, upgrade phase I

    NASA Astrophysics Data System (ADS)

    Blank, T.; Caselle, M.; Weber, M.; Kudella, S.; Colombo, F.; Hansen, K.; Arab, S.

    2015-02-01

    For the High-Luminosity upgrade of the LHC (HL-LHC), phase I, the CMS pixel detector needs to be replaced. In order to improve the tracking resolution even at high luminosity the pixel detector is upgraded by a fourth barrel layer. This paper describes the production process and results for the fourth barrel layer for the CMS silicon pixel detector, upgrade phase I. The additional barrel layer will be produced by KIT and DESY. Both research centers have commonly developed and investigated new production processes, including SAC solder bump jetting, gold stud bumping and "Precoat by Powder Processes" (PPS) to bump the sensor tiles and prepare them for the flip-chip process. First bare modules have been produced with the new digital ROC.

  12. The LHCb VELO upgrade

    NASA Astrophysics Data System (ADS)

    Rodríguez Pérez, Pablo

    2013-12-01

    LHCb is a forward spectrometer experiment dedicated to the study of new physics in the decays of beauty and charm hadrons produced in proton collisions at the Large Hadron Collider (LHC) at CERN. The VErtex LOcator (VELO) is the microstrip silicon detector surrounding the interaction point, providing tracking and vertexing measurements. The upgrade of the LHCb experiment, planned for 2018, will increase the luminosity up to 2×1033 cm-2 s-1 and will perform the readout as a trigger-less system with an event rate of 40 MHz. Extremely non-uniform radiation doses will reach up to 5×1015 1 MeV neq/cm2 in the innermost regions of the VELO sensors, and the output data bandwidth will be increased by a factor of 40. An upgraded detector is under development based in a pixel sensor of the Timepix/Medipix family, with 55 × 55 μm2 pixels. In addition a microstrip solution with finer pitch, higher granularity and thinner than the current detector is being developed in parallel. The current status of the VELO upgrade program will be described together with recent testbeam results.

  13. The upgraded ATLAS and CMS detectors and their physics capabilities.

    PubMed

    Wells, Pippa S

    2015-01-13

    The update of the European Strategy for Particle Physics from 2013 states that Europe's top priority should be the exploitation of the full potential of the LHC, including the high-luminosity upgrade of the machine and detectors with a view to collecting 10 times more data than in the initial design. The plans for upgrading the ATLAS and CMS detectors so as to maintain their performance and meet the challenges of increasing luminosity are presented here. A cornerstone of the physics programme is to measure the properties of the 125GeV Higgs boson with the highest possible precision, to test its consistency with the Standard Model. The high-luminosity data will allow precise measurements of the dominant production and decay modes, and offer the possibility of observing rare modes including Higgs boson pair production. Direct and indirect searches for additional Higgs bosons beyond the Standard Model will also continue. PMID:26949808

  14. The upgrade of the ATLAS first-level calorimeter trigger

    NASA Astrophysics Data System (ADS)

    Yamamoto, Shimpei

    2016-07-01

    The first-level calorimeter trigger (L1Calo) had operated successfully through the first data taking phase of the ATLAS experiment at the CERN Large Hadron Collider. Towards forthcoming LHC runs, a series of upgrades is planned for L1Calo to face new challenges posed by the upcoming increases of the beam energy and the luminosity. This paper reviews the ATLAS L1Calo trigger upgrade project that introduces new architectures for the liquid-argon calorimeter trigger readout and the L1Calo trigger processing system.

  15. Run 2 upgrades to the CMS Level-1 calorimeter trigger

    NASA Astrophysics Data System (ADS)

    Kreis, B.; Berryhill, J.; Cavanaugh, R.; Mishra, K.; Rivera, R.; Uplegger, L.; Apanasevich, L.; Zhang, J.; Marrouche, J.; Wardle, N.; Aggleton, R.; Ball, F.; Brooke, J.; Newbold, D.; Paramesvaran, S.; Smith, D.; Baber, M.; Bundock, A.; Citron, M.; Elwood, A.; Hall, G.; Iles, G.; Laner, C.; Penning, B.; Rose, A.; Tapper, A.; Foudas, C.; Beaudette, F.; Cadamuro, L.; Mastrolorenzo, L.; Romanteau, T.; Sauvan, J. B.; Strebler, T.; Zabi, A.; Barbieri, R.; Cali, I. A.; Innocenti, G. M.; Lee, Y.-J.; Roland, C.; Wyslouch, B.; Guilbaud, M.; Li, W.; Northup, M.; Tran, B.; Durkin, T.; Harder, K.; Harper, S.; Shepherd-Themistocleous, C.; Thea, A.; Williams, T.; Cepeda, M.; Dasu, S.; Dodd, L.; Forbes, R.; Gorski, T.; Klabbers, P.; Levine, A.; Ojalvo, I.; Ruggles, T.; Smith, N.; Smith, W.; Svetek, A.; Tikalsky, J.; Vicente, M.

    2016-01-01

    The CMS Level-1 calorimeter trigger is being upgraded in two stages to maintain performance as the LHC increases pile-up and instantaneous luminosity in its second run. In the first stage, improved algorithms including event-by-event pile-up corrections are used. New algorithms for heavy ion running have also been developed. In the second stage, higher granularity inputs and a time-multiplexed approach allow for improved position and energy resolution. Data processing in both stages of the upgrade is performed with new, Xilinx Virtex-7 based AMC cards.

  16. Upgrade of the ALICE Experiment: Letter Of Intent

    NASA Astrophysics Data System (ADS)

    ALICE collaboration; Abelev, B.; Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Masoodi, A. Ahmad; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Anderssen, E. C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Azmi, M. D.; Bach, M.; Badala, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bairathi, V.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Bán, J.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastian Van Beelen, J.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Battistin, M.; Batyunya, B.; Batzing, P. C.; Baudot, J.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Benettoni, M.; Benotto, F.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Berger, M. E.; Bertens, R. A.; Berzano, D.; Besson, A.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bhatti, A.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Boehmer, F. V.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bornschein, J.; Borshchov, V. N.; Bortolin, C.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Carena, F.; Carena, W.; Cariola, P.; Carminati, F.; Casanova Díaz, A.; Castillo Castellanos, J.; Casula, E. A. R.; Catanescu, V.; Caudron, T.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Claus, G.; Cleymans, J.; Colamaria, F.; Colella, D.; Coli, S.; Colledani, C.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Da Riva, E.; Das, D.; Das, I.; Das, K.; Das, S.; Dash, A.; Dash, S.; De, S.; Decosse, C.; DelagrangeI, H.; Deloff, A.; Déenes, E.; D'Erasmo, G.; de Barros, G. O. V.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Robertis, G.; De Roo, K.; de Rooij, R.; Diaz Corchero, M. A.; Dietel, T.; Divia, R.; Di Bari, D.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dorheim, S.; Dorokhov, A.; Doziere, G.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dulinski, W.; Dupieux, P.; Dutta Majumdar, A. K.; Ehlers, R. J., III; Elia, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernádez Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fiorenza, G.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Franco, M.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gajanana, D.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubilato, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez, R.; Gomez Marzoa, M.; Gonzáalez-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Graczykowski, L. K.

    2014-08-01

    ALICE (A Large Ion Collider Experiment) is studying the physics of strongly interacting matter, and in particular the properties of the Quark-Gluon Plasma (QGP), using proton-proton, proton-nucleus and nucleus-nucleus collisions at the CERN LHC (Large Hadron Collider). The ALICE Collaboration is preparing a major upgrade of the experimental apparatus, planned for installation in the second long LHC shutdown in the years 2018-2019. These plans are presented in the ALICE Upgrade Letter of Intent, submitted to the LHCC (LHC experiments Committee) in September 2012. In order to fully exploit the physics reach of the LHC in this field, high-precision measurements of the heavy-flavour production, quarkonia, direct real and virtual photons, and jets are necessary. This will be achieved by an increase of the LHC Pb-Pb instant luminosity up to 6×1027 cm-2s-1 and running the ALICE detector with the continuous readout at the 50 kHz event rate. The physics performance accessible with the upgraded detector, together with the main detector modifications, are presented.

  17. CMS Run-2 Instrumentation for beam radiation and luminosity measurement using novel detector technologies

    NASA Astrophysics Data System (ADS)

    Gomez Espinosa, Alejandro; CMS Collaboration Collaboration

    2016-03-01

    The higher energy and luminosity for Run 2 at the LHC initiated the development of dedicated technologies for beam radiation monitoring and luminosity measurement. A dedicated pixel luminosity detector measures coincidences in several three layer telescopes of silicon pixel detectors to arrive at a luminosity for each colliding LHC bunch pair. The full pixel data is also read out at a lower rate to reconstruct charged particle tracks for monitoring and beam spot determination. The upgraded fast beam conditions monitor measures the particle flux using 24 two pad single crystalline diamond sensors, equipped with a fast front-end ASIC, produced in 130 nm CMOS technology, for excellent time resolution. A new beam-halo monitor exploits Cerenkov light production in fused quartz crystals to provide direction sensitivity and excellent time resolution to separate incoming and outgoing particles. The back-end electronics of the beam monitoring systems include dedicated modules with high bandwidth digitizers developed in both VME and microTCA standards for per bunch beam measurements and gain monitoring. All sub-detectors have been taking data from the first day of LHC operation in April 2015. Detector performance results from the 2015 LHC Run II will be presented.

  18. Run II luminosity progress

    SciTech Connect

    Gollwitzer, K.; /Fermilab

    2007-06-01

    The Fermilab Tevatron Collider Run II program continues at the energy and luminosity frontier of high energy particle physics. To the collider experiments CDF and D0, over 3 fb{sup -1} of integrated luminosity has been delivered to each. Upgrades and improvements in the Antiproton Source of the production and collection of antiprotons have led to increased number of particles stored in the Recycler. Electron cooling and associated improvements have help make a brighter antiproton beam at collisions. Tevatron improvements to handle the increased number of particles and the beam lifetimes have resulted in an increase in luminosity.

  19. Silicon strip detectors for the ATLAS upgrade

    SciTech Connect

    Gonzalez-Sevilla, S.

    2011-07-01

    The Large Hadron Collider at CERN will extend its current physics program by increasing the peak luminosity by one order of magnitude. For ATLAS, one of the two general-purpose experiments of the LHC, an upgrade scenario will imply the complete replacement of its internal tracker due to the harsh conditions in terms of particle rates and radiation doses. New radiation-hard prototype n-in-p silicon sensors have been produced for the short-strip region of the future ATLAS tracker. The sensors have been irradiated up to the fluences expected in the high-luminous LHC collider. This paper summarizes recent results on the performance of the irradiated n-in-p detectors. (authors)

  20. Novel Geometries for the LHC Crab Cavity

    SciTech Connect

    B. Hall,G. Burt,C. Lingwood,Robert Rimmer,Haipeng Wang; Hall, B.; Burt, G.; Lingwood, C.; Rimmer, Robert; Wang, Haipeng

    2010-05-01

    The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the IP necessitates a more compact design than is possible with elliptical cavities such as those used at KEK. The reduction in size must be achieved without an increase in the operational frequency to maintain compatibility with the long bunch length of the LHC. This paper proposes a suitable superconducting variant of a four rod coaxial deflecting cavity (to be phased as a crab cavity), and presents analytical models and simulations of suitable designs.

  1. Novel Geometries for the LHC Crab Cavity

    SciTech Connect

    B. Hall, G. Burt, C. Lingwood, R. Rimmer, H. Wang

    2010-05-23

    The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the IP necessitates a more compact design than is possible with elliptical cavities such as those used at KEK. The reduction in size must be achieved without an increase in the operational frequency to maintain compatibility with the long bunch length of the LHC. This paper proposes a suitable superconducting variant of a four rod coaxial deflecting cavity (to be phased as a crab cavity), and presents analytical models and simulations of suitable designs.

  2. RHIC PLANS TOWARDS HIGHER LUMINOSITY

    SciTech Connect

    FEDOTOV,A.

    2007-06-25

    The Relativistic Heavy Ion Collider (RHIC) is designed to provide luminosity over a wide range of beam energies and species, including heavy ions, polarized protons, and tric beam collisions. In the first seven years of operation there has been a rapid increase in the achieved peak and average luminosity, substantially exceeding design values. Work is presently underway to achieve the Enhanced Design parameters. Planned major upgrades include the Electron Beam Ion Source (EBIS), RHIC-11, and construction of an electron-ion collider (eRHIC). We review the expected RHIC upgrade performance. Electron cooling and its impact on the luminosity both for heavy ions and protons are discussed in detail.

  3. LHCb Upgrade: Scintillating Fibre Tracker

    NASA Astrophysics Data System (ADS)

    Tobin, Mark

    2016-07-01

    The LHCb detector will be upgraded during the Long Shutdown 2 (LS2) of the LHC in order to cope with higher instantaneous luminosities and to read out the data at 40 MHz using a trigger-less read-out system. All front-end electronics will be replaced and several sub-detectors must be redesigned to cope with higher occupancy. The current tracking detectors downstream of the LHCb dipole magnet will be replaced by the Scintillating Fibre (SciFi) Tracker. The SciFi Tracker will use scintillating fibres read out by Silicon Photomultipliers (SiPMs). State-of-the-art multi-channel SiPM arrays are being developed to read out the fibres and a custom ASIC will be used to digitise the signals from the SiPMs. The evolution of the design since the Technical Design Report in 2014 and the latest R & D results are presented.

  4. Quality control and beam test of GEM detectors for future upgrades of the CMS muon high rate region at the LHC

    NASA Astrophysics Data System (ADS)

    Abbaneo, D.; Abbas, M.; Abbrescia, M.; Abdelalim, A. A.; Abi Akl, M.; Ahmed, W.; Ahmed, W.; Altieri, P.; Aly, R.; Armaingaud, C.; Asawatangtrakuldee, C.; Ashfaq, A.; Aspell, P.; Assran, Y.; Awan, I.; Bally, S.; Ban, Y.; Banerjee, S.; Barria, P.; Benussi, L.; Bhopatkar, V.; Bianco, S.; Bos, J.; Bouhali, O.; Braibant, S.; Buontempo, S.; Cai, J.; Calabria, C.; Caponero, M.; Caputo, C.; Cassese, F.; Castaneda, A.; Cauwenbergh, S.; Cavallo, F. R.; Celik, A.; Choi, M.; Choi, K.; Choi, S.; Christiansen, J.; Cimmino, A.; Colafranceschi, S.; Colaleo, A.; Conde Garcia, A.; Dabrowski, M. M.; De Lentdecker, G.; De Oliveira, R.; De Robertis, G.; Dildick, S.; Dildick, S.; Dorney, B.; Elmetenawee, W.; Fabrice, G.; Ferrini, M.; Ferry, S.; Flanagan, W.; Giacomelli, P.; Gilmore, J.; Guiducci, L.; Gutierrez, A.; Hadjiiska, R. M.; Hassan, A.; Hauser, J.; Hoepfner, K.; Hohlmann, M.; Hoorani, H.; Jeng, Y. G.; Kamon, T.; Karchin, P. E.; Kim, H. S.; Khotilovich, V.; Krutelyov, S.; Kumar, A.; Lee, J.; Lenzi, T.; Litov, L.; Loddo, F.; Maerschalk, T.; Magazzu, G.; Maggi, M.; Maghrbi, Y.; Magnani, A.; Majumdar, N.; Mal, P. K.; Mandal, K.; Marchioro, A.; Marinov, A.; Merlin, J. A.; Mohammed, N.; Mohanty, A. K.; Mohapatra, A.; Muhammad, S.; Mukhopadhyay, S.; Naimuddin, M.; Nuzzo, S.; Oliveri, E.; Pant, L. M.; Paolucci, P.; Park, I.; Passeggio, G.; Pavlov, B.; Philipps, B.; Phipps, M.; Piccolo, D.; Postema, H.; Pugliese, G.; Baranac, A. Puig; Radi, A.; Radogna, R.; Raffone, G.; Ramkrishna, S.; Ranieri, A.; Riccardi, C.; Rodrigues, A.; Ropelewski, L.; RoyChowdhury, S.; Ryu, M. S.; Ryu, G.; Safonov, A.; Sakharov, A.; Salva, S.; Saviano, G.; Sharma, A.; Swain, S. K.; Talvitie, J. P.; Talvitie, J. P.; Tamma, C.; Tatarinov, A.; Teng, H.; Turini, N.; Tuuva, T.; Twigger, J.; Tytgat, M.; Vai, I.; Van Stenis, M.; Venditi, R.; Verhagen, E.; Verwilligen, P.; Vitulo, P.; Wang, D.; Wang, M.; Yang, U.; Yang, Y.; Yonamine, R.; Zaganidis, N.; Zenoni, F.; Zhang, A.

    2015-03-01

    Gas Electron Multipliers (GEM) are a proven position sensitive gas detector technology which nowadays is becoming more widely used in High Energy Physics. GEMs offer an excellent spatial resolution and a high particle rate capability, with a close to 100% detection efficiency. In view of the high luminosity phase of the CERN Large Hadron Collider, these aforementioned features make GEMs suitable candidates for the future upgrades of the Compact Muon Solenoid (CMS) detector. In particular, the CMS GEM Collaboration proposes to cover the high-eta region of the muon system with large-area triple-GEM detectors, which have the ability to provide robust and redundant tracking and triggering functions. In this contribution, after a general introduction and overview of the project, the construction of full-size trapezoidal triple-GEM prototypes will be described in more detail. The procedures for the quality control of the GEM foils, including gain uniformity measurements with an x-ray source will be presented. In the past few years, several CMS triple-GEM prototype detectors were operated with test beams at the CERN SPS. The results of these test beam campaigns will be summarised.

  5. Measurements on HV-CMOS active sensors after irradiation to HL-LHC fluences

    NASA Astrophysics Data System (ADS)

    Ristic, B.

    2015-04-01

    During the long shutdown (LS) 3 beginning 2022 the LHC will be upgraded for higher luminosities pushing the limits especially for the inner tracking detectors of the LHC experiments. In order to cope with the increased particle rate and radiation levels the ATLAS Inner Detector will be completely replaced by a purely silicon based one. Novel sensors based on HV-CMOS processes prove to be good candidates in terms of spatial resolution and radiation hardness. In this paper measurements conducted on prototypes built in the AMS H18 HV-CMOS process and irradiated to fluences of up to 2·1016 neq cm-2 are presented.

  6. Design and performance of the upgrade of the CMS L1 muon trigger

    NASA Astrophysics Data System (ADS)

    Bortignon, P.

    2016-07-01

    After the Long Shutdown 1 (LS1) LHC will run at a center of mass energy of 13 TeV, providing CMS with proton collisions at an expected luminosity which is almost double the LHC design value of 1034cm-2s-1, and almost three times the peak luminosity reached during Run1 of 7.7 ·1033cm-2s-1. The higher luminosity and center of mass energy of the LHC will raise the Level 1 (L1) muon trigger rate by almost a factor six for a given muon transverse momentum pT threshold. It is therefore necessary to increase the muon (pT) threshold to keep the trigger rate below 100 kHz, the maximum sustainable rate for the CMS detectors. An increase of the L1 trigger thresholds implies a lowering of the efficiency in detecting signals from new physics. The CMS muon trigger is upgraded using custom designed AMC boards, with more powerful FPGAs and larger memories. The upgraded CMS muon trigger system implements pattern recognition and MVA (Boosted Decision Tree) regression techniques in the trigger boards for muon pT assignment, drastically reducing the trigger rate and improving the trigger efficiency. The upgraded system design exploits the redundancy of the CMS muon detectors at a very early stage merging different muon detector information already at L1. The pileup subtracted information from the upgraded calorimeter trigger allows to require isolated muons already in the L1 algorithms. The upgrade trigger is also designed to include inputs from GEM, the phase 2 muon detector upgrade in the very high pseudorapidity region.

  7. Luminosity determination at proton colliders

    NASA Astrophysics Data System (ADS)

    Grafström, P.; Kozanecki, W.

    2015-03-01

    Luminosity is a key parameter in any particle collider, and its precise determination has proven particularly challenging at hadron colliders. After introducing the concept of luminosity in its multiple incarnations and offering a brief survey of the pp and p p bar colliders built to date, this article outlines the various methods that have been developed for relative-luminosity monitoring, as well as the complementary approaches considered for establishing an absolute luminosity scale. This is followed by a survey, from both a historical and a technical perspective, of luminosity determination at the ISR, the S p p ¯ S, the Tevatron, RHIC and the LHC. For each of these, we first delineate the interplay between the experimental context, the specificities of the accelerator, and the precision targets suggested by the physics program. We then detail how the different methods were applied to specific experimental environments and how successfully they meet the precision goals.

  8. HIGHER LUMINOSITY B-FACTORIES

    SciTech Connect

    Seeman, John T

    2002-08-20

    The present B-factories PEP-II and KEKB have reached luminosities of 3-4 x 10{sup 33}/cm{sup 2}/s and delivered integrated luminosity at rates in excess of 4fb{sup -1} per month [1,2]. The recent turn on of these two B-Factories has shown that modern accelerator physics, design, and engineering can produce colliders that rapidly reach their design luminosities and deliver integrated luminosities capable of frontier particle physics discoveries. PEP-II and KEK-B with ongoing upgrade programs should reach luminosities of over 10{sup 34}/cm{sup 2}/s in a few years and with more aggressive improvements may reach luminosities of order 10{sup 35}/cm{sup 2}/s by the end of the decade. However, due to particle physics requirements, the next generation B-Factory may require significantly more luminosity. Initial parameters of a very high luminosity e{sup +}e{sup -} B-Factory or Super B-Factory (SBF) are being developed incorporating several new ideas from the successful operation of the present generation e{sup +}e{sup -} accelerators [3,4]. A luminosity approaching 10{sup 36}/cm{sup 2}/s{sup -1} appears possible. Furthermore, the ratio of average to peak luminosity may be increased by 30% due to continuous injection. The operation of this accelerator will be qualitatively different from present e{sup +}e{sup -} colliders due to this continuous injection.

  9. Fast beam condition monitor for CMS: Performance and upgrade

    NASA Astrophysics Data System (ADS)

    Leonard, Jessica L.; Bell, Alan; Burtowy, Piotr; Dabrowski, Anne; Hempel, Maria; Henschel, Hans; Lange, Wolfgang; Lohmann, Wolfgang; Odell, Nathaniel; Penno, Marek; Pollack, Brian; Przyborowski, Dominik; Ryjov, Vladimir; Stickland, David; Walsh, Roberval; Warzycha, Weronika; Zagozdzinska, Agnieszka

    2014-11-01

    The CMS beam and radiation monitoring subsystem BCM1F (Fast Beam Condition Monitor) consists of 8 individual diamond sensors situated around the beam pipe within the pixel detector volume, for the purpose of fast bunch-by-bunch monitoring of beam background and collision products. In addition, effort is ongoing to use BCM1F as an online luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. A report is given on the performance of BCM1F during LHC run I, including results of the van der Meer scan and on-line luminosity monitoring done in 2012. In order to match the requirements due to higher luminosity and 25 ns bunch spacing, several changes to the system must be implemented during the upcoming shutdown, including upgraded electronics and precise gain monitoring. First results from Run II preparation are shown.

  10. Implementation of FPGA-based level-1 tracking at CMS for the HL-LHC

    NASA Astrophysics Data System (ADS)

    Chaves, J.

    2014-10-01

    A new approach for track reconstruction is presented to be used in the all-hardware first level of the CMS trigger. The application of the approach is intended for the upgraded all-silicon tracker, which is to be installed for the High Luminosity era of the LHC (HL-LHC). The upgraded LHC machine is expected to deliver a luminosity on the order of 5 × 1034 cm-2s-1. This expected luminosity means there would be about 125 pileup events in each bunch crossing at a frequency of 40 MHz. To keep the CMS trigger rate at a manageable level under these conditions, it is necessary to make quick decisions on the events that will be processed. The timing estimates for the algorithm are expected to be below 5 μs, well within the requirements of the L1 trigger at CMS for track identification. The algorithm is integer-based, allowing it to be implemented on an FPGA. Currently we are working on a demonstrator hardware implementation using a Xilinx Virtex 6 FPGA. Results from simulations in C++ and Verilog are presented to show the algorithm performance in terms of data throughput and parameter resolution.

  11. Precision luminosity measurements at LHCb

    NASA Astrophysics Data System (ADS)

    The LHCb Collaboration

    2014-12-01

    Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy √s. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for √s = 2.76, 7 and 8 TeV (proton-proton collisions) and for √sNN = 5 TeV (proton-lead collisions). Both the "van der Meer scan" and "beam-gas imaging" luminosity calibration methods were employed. It is observed that the beam density profile cannot always be described by a function that is factorizable in the two transverse coordinates. The introduction of a two-dimensional description of the beams improves significantly the consistency of the results. For proton-proton interactions at √s = 8 TeV a relative precision of the luminosity calibration of 1.47% is obtained using van der Meer scans and 1.43% using beam-gas imaging, resulting in a combined precision of 1.12%. Applying the calibration to the full data set determines the luminosity with a precision of 1.16%. This represents the most precise luminosity measurement achieved so far at a bunched-beam hadron collider.

  12. The D0 Upgrade

    SciTech Connect

    Abachi, S.; D0 Collaboration

    1995-07-01

    In this paper we describe the approved DO Upgrade detector, and its physics capabilities. The DO Upgrade is under construction and will run during the next Fermilab collider running period in early 1999 (Run II). The upgrade is designed to work at the higher luminosities and shorter bunch spacings expected during this run. The major elements of t he upgrade are: a new tracking system with a silicon tracker, scintillating fiber tracker, a 2T solenoid, and a central preshower detector; new calorimeter electronics; new muon trigger and tracking detectors with new muon system electronics; a forward preshower detector; new trigger electronics and DAQ improvements to handle the higher rates.

  13. Novel Geometries for the LHC Crab Cavity

    SciTech Connect

    Hall, B.; Burt, G.; Smith, J. D.A.; Rimmer, R.; Wang, H.; Delayen, J.; Calaga, R.

    2009-05-01

    In 2017 the LHC is envisioned to increase its luminosity via an upgrade. This upgrade is likely to require a large crossing angle hence a crab cavity is required to align the bunches prior to collision. There are two possible schemes for crab cavity implementation, global and local. In a global crab cavity the crab cavity is far from the IP and the bunch rotates back and forward as it traverses around the accelerator in a closed orbit. For this scheme a two-cell elliptical squashed cavity at 800 MHz is preferred. To avoid any potential beam instabilities all the parasitic modes of the cavities must be damped strongly, however crab cavities have lower order and same order modes in addition to the usual higher order modes and hence a novel damping scheme must be used to provide sufficient damping of these modes. In the local scheme two crab cavities are placed at each side of the IP two start and stop rotation of the bunches. This would require crab cavities much smaller transversely than in the global scheme but the frequency cannot be increased any higher due to the long bunch length of the LHC beam. This will require a novel compact crab cavity design. A superconducting version of a two rod coaxial deflecting cavity as a suitable design is proposed in this paper.

  14. L1 track triggers for ATLAS in the HL-LHC

    DOE PAGESBeta

    Lipeles, E.

    2012-01-01

    The HL-LHC, the planned high luminosity upgrade for the LHC, will increase the collision rate in the ATLAS detector approximately a factor of 5 beyond the luminosity for which the detectors were designed, while also increasing the number of pile-up collisions in each event by a similar factor. This means that the level-1 trigger must achieve a higher rejection factor in a more difficult environment. This presentation discusses the challenges that arise in this environment and strategies being considered by ATLAS to include information from the tracking systems in the level-1 decision. The main challenges involve reducing the data volumemore » exported from the tracking system for which two options are under consideration: a region of interest based system and an intelligent sensor method which filters on hits likely to come from higher transverse momentum tracks.« less

  15. L1 track triggers for ATLAS in the HL-LHC

    SciTech Connect

    Lipeles, E.

    2012-01-01

    The HL-LHC, the planned high luminosity upgrade for the LHC, will increase the collision rate in the ATLAS detector approximately a factor of 5 beyond the luminosity for which the detectors were designed, while also increasing the number of pile-up collisions in each event by a similar factor. This means that the level-1 trigger must achieve a higher rejection factor in a more difficult environment. This presentation discusses the challenges that arise in this environment and strategies being considered by ATLAS to include information from the tracking systems in the level-1 decision. The main challenges involve reducing the data volume exported from the tracking system for which two options are under consideration: a region of interest based system and an intelligent sensor method which filters on hits likely to come from higher transverse momentum tracks.

  16. Summary of the Mini BNL/LARP/CARE-HHH Workshop on Crab Cavities for the LHC (LHC-CC08)

    SciTech Connect

    Ben-Zvi,I.; Calaga, R.; Zimmermann, F.

    2008-05-01

    The first mini-workshop on crab compensation for the LHC luminosity upgrade (LHC-CC08) was held February 24-25, 2008 at the Brookhaven National Laboratory. A total of 35 participants from 3 continents and 15 institutions from around the world participated to discuss the exciting prospect of a crab scheme for the LHC. If realized it will be the first demonstration in hadron colliders. The workshop is organized by joint collaboration of BNL, US-LARP and CARE-HHH. The enormous interest in the subject of crab cavities for the international linear collider and future light sources has resulted in a large international collaboration to exchange aspects of synergy and expertise. A central repository for this exchange of information documenting the latest design effort for LHC crab cavities is consolidated in a wiki page: https://twiki.cern.ch/twiki/bin/view/Main/LHCCrabCavities. The main goal of this workshop was to define a road-map for a prototype crab cavity to be installed in the LHC and to discuss the associated R&D and beam dynamics challenges. The diverse subject of implementing the crab scheme resulted in a scientific program with a wide range of subtopics which were divided into 8 sessions. Each session was given a list of fundamental questions to be addressed and used as a guideline to steer the discussions.

  17. Experimental status of supersymmetry after the LHC Run-I

    NASA Astrophysics Data System (ADS)

    Autermann, Christian

    2016-09-01

    The ATLAS and CMS experiments at the Large Hadron Collider (LHC) at CERN have searched for signals of new physics, in particular for supersymmetry. The data collected until 2012 at center-of-mass energies of 7 and 8 TeV and integrated luminosities of 5 fb-1 and 20 fb-1, respectively, agree with the expectation from standard model processes. Constraints on supersymmetry have been calculated and interpreted in different models. Limits on supersymmetry particle masses at the TeV scale have been derived and interpreted generally in the context of simplified model spectra. The constrained minimal supersymmetric standard model is disfavored by the experimental results. Natural supersymmetry scenarios with low supersymmetry particle masses remain possible in multiple regions, for example in those with compressed spectra, that are difficult to access experimentally. The upgraded LHC operating at √{ s } = 13 TeV is gaining sensitivity to the remaining unexplored SUSY parameter space.

  18. Bounding wide composite vector resonances at the LHC

    NASA Astrophysics Data System (ADS)

    Barducci, Daniele; Delaunay, Cédric

    2016-02-01

    In composite Higgs models (CHMs), electroweak precision data generically push colourless composite vector resonances to a regime where they dominantly decay into pairs of light top partners. This greatly attenuates their traces in canonical collider searches, tailored for narrow resonances promptly decaying into Standard Model final states. By reinterpreting the CMS same-sign dilepton (SS2 ℓ) analysis at the Large Hadron Collider (LHC), originally designed to search for top partners with electric charge 5/3, we demonstrate its significant coverage over this kinematical regime. We also show the reach of the 13 TeV run of the LHC, with various integrated luminosity options, for a possible upgrade of the SS2ℓ search. The top sector of CHMs is found to be more fine-tuned in the presence of colourless composite resonances in the few TeV range.

  19. Double-sided super-module R&D for the ATLAS tracker at HL-LHC - A summary

    NASA Astrophysics Data System (ADS)

    Clark, A.; Barbier, G.; Cadoux, F.; Endo, M.; Favre, Y.; Ferrere, D.; Gonzalez-Sevilla, S.; Hanagaki, K.; Hara, K.; Iacobucci, G.; Ikegami, Y.; Jinnouchi, O.; La Marra, D.; Nakamura, K.; Nishimura, R.; Perrin, E.; Seez, W.; Takubo, Y.; Takashima, R.; Terada, S.; Todome, K.; Unno, Y.; Weber, M.

    2014-11-01

    Following successive upgrades of the CERN Large Hadron Collider (LHC) until approximately 2025, the High Luminosity LHC (HL-LHC) is expected to deliver pp collisions of centre-of-mass energy √{ s } = 14 TeV with a levelled peak luminosity in excess of 5 ×1034cm-2s-1 and an integrated luminosity of order 300fb-1 per year. The ATLAS Collaboration intends to replace the existing Inner Tracking Detector by a new tracker, with readout electronics as well as silicon pixel and strip sensor technology capable of maintaining the excellent mechanical and electrical performance of the existing tracker in the severe radiation and high collision rate environment of the HL-LHC. The super-module integration concept extends the proven design of the existing barrel silicon strip tracker to the HL-LHC, with double-sided stereo silicon micro-strip modules assembled into a low mass local support structure. The first phase of the Super-Module R&D programme has been successfully completed, demonstrating the feasibility of the Super-Module concept. A summary is made up of the key prototype mechanical and electrical results of the R&D, as well as a short perspective of future developments.

  20. Upgrade to the Birmingham Irradiation Facility

    NASA Astrophysics Data System (ADS)

    Dervan, P.; French, R.; Hodgson, P.; Marin-Reyes, H.; Parker, K.; Wilson, J.; Baca, M.

    2015-10-01

    The Birmingham Irradiation Facility was developed in 2013 at the University of Birmingham using the Medical Physics MC40 cyclotron. It can achieve High Luminosity LHC (HL-LHC) fluences of 1015 (1 MeV neutron equivalent (neq)) cm-2 in 80 s with proton beam currents of 1 μA and so can evaluate effectively the performance and durability of detector technologies and new components to be used for the HL-LHC. Irradiations of silicon sensors and passive materials can be carried out in a temperature controlled cold box which moves continuously through the homogenous beamspot. This movement is provided by a pre-configured XY-axis Cartesian robot scanning system. In 2014 the cooling system and cold box were upgraded from a recirculating glycol chiller system to a liquid nitrogen evaporative system. The new cooling system achieves a stable temperature of -50 °C in 30 min and aims to maintain sub-0 °C temperatures on the sensors during irradiations. This paper reviews the design, development, commissioning and performance of the new cooling system.

  1. Status of Fast Interaction Trigger for ALICE Upgrade

    NASA Astrophysics Data System (ADS)

    Karavicheva, T. L.; Kurepin, A. B.; Trzaska, W. H.

    2015-06-01

    As a result of the LHC upgrade after the Long Shutdown 2, the expected luminosity and collision rate during the so called Run 3 will considerably exceed the design parameters for several of the key ALICE detectors systems including the forward trigger detectors. Furthermore, the introduction of a new Muon Forward Tracker significantly reduces the space envelope available for the upgraded Fast Interaction Trigger (FIT) detector on the muon spectrometer side. At the same time, FIT is expected to match and even exceed the functionality and performance currently secured by three ALICE sub-detectors: the time zero detector (T0), the VZERO system, and the Forward Multiplicity Detector (FMD). The harsh conditions of Run 3 would accelerate the ageing and radiation damage (detectable already during Run 1) of the FIT detector if we were to use standard PMTs. The solution came thanks to the latest developments in MCP-PMT technology providing compact photo sensors with excellent characteristics and stability.

  2. Luminosity monitoring in ATLAS with MPX detectors

    NASA Astrophysics Data System (ADS)

    Sopczak, A.

    2014-01-01

    The ATLAS-MPX detectors are based on the Medipix2 silicon devices designed by CERN for the detection of multiple types of radiation. Sixteen such detectors were successfully operated in the ATLAS detector at the LHC and collected data independently of the ATLAS data-recording chain from 2008 to 2013. Each ATLAS-MPX detector provides separate measurements of the bunch-integrated LHC luminosity. An internal consistency for luminosity monitoring of about 2% was demonstrated. In addition, the MPX devices close to the beam are sensitive enough to provide relative-luminosity measurements during van der Meer calibration scans, in a low-luminosity regime that lies below the sensitivity of the ATLAS calorimeter-based bunch-integrating luminometers. Preliminary results from these luminosity studies are presented for 2012 data taken at √s = 8 TeV proton-proton collisions.

  3. Luminosity Monitoring in ATLAS with MPX Detectors

    NASA Astrophysics Data System (ADS)

    Asbah, Nedaa

    2014-06-01

    The ATLAS-MPX detectors are based on the Medipix2 silicon devices designed by CERN for the detection of multiple types of radiation. Sixteen such detectors were successfully operated in the ATLAS detector at the LHC and collected data independently of the ATLAS data-recording chain from 2008 to 2013. Each ATLAS-MPX detector provides separate measurements of the bunch-integrated LHC luminosity. An internal consistency for luminosity monitoring of about 2% was demonstrated. In addition, the MPX devices close to the beam are sensitive enough to provide relative-luminosity measurements during van der Meer calibration scans, in a low-luminosity regime that lies below the sensitivity of the ATLAS calorimeter-based bunch-integrating luminometers. Preliminary results from these luminosity studies are presented for 2012 data taken at √ s = 8 TeV proton-proton collisions.

  4. Luminosity Lifetime

    SciTech Connect

    Zisman, M.S.

    1997-04-01

    In a symmetric or 'energy transparent' relativistic collider, the luminosity is given by L = N{sup 2}f{sub c}/4{pi}{sigma}*{sub x}{sigma}*{sub y} where N is the number of electrons or positrons per bunch, {sigma}*{sub x} ({sigma}*{sub y}) is the horizontal (vertical) rms beam size at the interaction point (IP), and f{sub c} is the collision frequency. If the beam sizes remain constant as the luminosity decreases, then the time dependence of luminosity is contained entirely in the time dependence of the beam currents, i.e., N O N(t), and we can rewrite the equation as L(t) = N{sup 2}(t)f{sub c}/4{pi}{sigma}*{sub x}{sigma}*{sub y}. There are two distinct categories for luminosity loss. In the first category are loss processes due to collisions between the two beams, that is, processes associated directly with the luminosity. In the second category (see below) are single-beam loss processes. The processes in the first category relevant to a high-energy collider are Bhabha scattering (e{sup +}e{sup -} O e{sup +}e{sup -}) and 'radiative' Bhabha scattering (e{sup +}e{sup -} O e{sup +}e{sup -}{gamma}). In the first process, a beam particle is lost if its angular deflection is beyond the ring's transverse acceptance; in the second process, loss occurs if the beam particle's momentum change is outside the longitudinal acceptance of the ring (typically determined by the RF bucket height).

  5. The versatile link, a common project for super-LHC

    SciTech Connect

    Amaral, Luis; Dris, Stefanos; Gerardin, Alexandre; Huffman, Todd; Issever, Cigdem; Pacheco, Alberto Jimenez; Jones, Mark; Kwan, Simon; Lee, Shih-Chang; Lian, Zhijun; Liu, Tiankuan; /CERN /Oxford U. /Fermilab /Taipei, Computing Ctr. /Southern Methodist U.

    2009-07-01

    Radiation tolerant, high speed optoelectronic data transmission links are fundamental building blocks in today's large scale High Energy Physics (HEP) detectors, as exemplified by the four experiments currently under commissioning at the Large Hadron Collider (LHC), see for example. New experiments or upgrades will impose even more stringent demands on these systems from the point of view of performance and radiation tolerance. This can already be seen from the developments underway for the Super Large Hadron Collider (SLHC) project, a proposed upgrade to the LHC aiming at increasing the luminosity of the machine by factor of 10 to 10{sup 35} cm{sup -2}s{sup -1}, and thus providing a better chance to see rare processes and improving statistically marginal measurements. In the past, specific data transmission links have been independently developed by each LHC experiment for data acquisition (DAQ), detector control as well as trigger and timing distribution (TTC). This was justified by the different types of applications being targeted as well as by technological limitations preventing one single solution from fitting all requirements. However with today's maturity of optoelectronic and CMOS technologies it is possible to envisage the development of a general purpose optical link which can cover most transmission applications: a Versatile Link. Such an approach has the clear advantage of concentrating the development effort on one single project targeting an optical link whose final functionality will only result from the topology and configuration settings adopted.

  6. Optimizing integrated luminosity of future hadron colliders

    NASA Astrophysics Data System (ADS)

    Benedikt, Michael; Schulte, Daniel; Zimmermann, Frank

    2015-10-01

    The integrated luminosity, a key figure of merit for any particle-physics collider, is closely linked to the peak luminosity and to the beam lifetime. The instantaneous peak luminosity of a collider is constrained by a number of boundary conditions, such as the available beam current, the maximum beam-beam tune shift with acceptable beam stability and reasonable luminosity lifetime (i.e., the empirical "beam-beam limit"), or the event pileup in the physics detectors. The beam lifetime at high-luminosity hadron colliders is largely determined by particle burn off in the collisions. In future highest-energy circular colliders synchrotron radiation provides a natural damping mechanism, which can be exploited for maximizing the integrated luminosity. In this article, we derive analytical expressions describing the optimized integrated luminosity, the corresponding optimum store length, and the time evolution of relevant beam parameters, without or with radiation damping, while respecting a fixed maximum value for the total beam-beam tune shift or for the event pileup in the detector. Our results are illustrated by examples for the proton-proton luminosity of the existing Large Hadron Collider (LHC) at its design parameters, of the High-Luminosity Large Hadron Collider (HL-LHC), and of the Future Circular Collider (FCC-hh).

  7. Progress on the upgrade of the CMS Hadron Calorimeter Front-End electronics

    SciTech Connect

    Anderson, Jake; Whitmore, Juliana; /Fermilab

    2011-11-01

    We present a scheme to upgrade the CMS HCAL front-end electronics in the second long shutdown to upgrade the LHC (LS2), which is expected to occur around 2018. The HCAL electronics upgrade is required to handle the major instantaneous luminosity increase (up to 5 * 10{sup 34} cm{sup -2} s{sup -1}) and an expected integrated luminosity of {approx}3000 fb{sup -1}. A key aspect of the HCAL upgrade is to read out longitudinal segmentation information to improve background rejection, energy resolution, and electron isolation at the L1 trigger. This paper focuses on the requirements for the new electronics and on the proposed solutions. The requirements include increased channel count, additional timing capabilities, and additional redundancy. The electronics are required to operate in a harsh environment and are constrained by the existing infrastructure. The proposed solutions span from chip level to system level. They include the development of a new ASIC ADC, the design and testing of higher speed transmitters to handle the increased data volume, the evaluation and use of circuits from other developments, evaluation of commercial FPGAs, better thermal design, and improvements in the overall readout architecture. We will report on the progress of the designs for these upgraded systems, along with performance requirements and initial design studies.

  8. Field Quality Study of a 1-m-Long Single-Aperture 11-T Nb$_3$Sn Dipole Model for LHC Upgrades

    SciTech Connect

    Chlachidze, G.; DiMarco, J.; Andreev, N.; Apollinari, G.; Auchmann, B.; Barzi, E.; Bossert, R.; Fiscarelli, L.; Karppinen, M.; Nobrega, F.; Novitski, I.; Rossi, L.; Smekens, D.; Turrioni, D.; Velev, G. V.; Zlobin, A. V.

    2014-01-01

    FNAL and CERN are carrying out a joint R&D program with the goal of building a 5.5-m-long twin-aperture 11-T Nb_3Sn dipole prototype that is suitable for installation in the LHC. An important part of the program is the development and test of a series of short single-aperture and twin-aperture dipole models with a nominal field of 11 T at the LHC operation current of 11.85 kA and 20% margin. This paper presents the results of magnetic measurements of a 1-m-long single-aperture Nb_3Sn dipole model fabricated and tested recently at FNAL, including geometrical field harmonics and effects of coil magnetization and iron yoke saturation.

  9. Online Luminosity Measurement at CMS for Energy Frontier Physics after LS1

    SciTech Connect

    Stickland, David P.

    2015-09-20

    This proposal was directed towards the measurement of Bunch-by-Bunch and Total Luminosity in the CMS experiment using Single-Crystal Diamond (sCVD) installed close to the Interaction Point - known as the Fast Beam Conditions Monitor, or BCM1F detector. The proposal was successfully carried out and in February 2015 CMS installed its upgraded BCM1F detector. At first collisions in June 2015 the BCM1F was used as the primary luminometer, then in August 2015 a Van De Meer scan has been carried out and the detailed luminometer calibration is under study. In all aspects of performance measurement the upgraded detector has satisfied its design parameters and as an overview of its performance in this report will show, we have high expectations that the detector will be a powerful addition to the luminosity measurement at CMS and LHC. The proposed upgrade of BCM1F was a collaboration of CMS Institutes in Germany (DESY-Zeuthen) and the USA (Princeton) and of CERN itself.

  10. The CMS pixel luminosity telescope

    NASA Astrophysics Data System (ADS)

    Kornmayer, A.

    2016-07-01

    The Pixel Luminosity Telescope (PLT) is a new complement to the CMS detector for the LHC Run II data taking period. It consists of eight 3-layer telescopes based on silicon pixel detectors that are placed around the beam pipe on each end of CMS viewing the interaction point at small angle. A fast 3-fold coincidence of the pixel planes in each telescope will provide a bunch-by-bunch measurement of the luminosity. Particle tracking allows collision products to be distinguished from beam background, provides a self-alignment of the detectors, and a continuous in-time monitoring of the efficiency of each telescope plane. The PLT is an independent luminometer, essential to enhance the robustness on the measurement of the delivered luminosity and to reduce its systematic uncertainties. This will allow to determine production cross-sections, and hence couplings, with high precision and to set more stringent limits on new particle production.

  11. Prototype Active Silicon Sensor in 150 nm HR-CMOS technology for ATLAS Inner Detector Upgrade

    NASA Astrophysics Data System (ADS)

    Rymaszewski, P.; Barbero, M.; Breugnon, P.; Godiot, S.; Gonella, L.; Hemperek, T.; Hirono, T.; Hügging, F.; Krüger, H.; Liu, J.; Pangaud, P.; Peric, I.; Rozanov, A.; Wang, A.; Wermes, N.

    2016-02-01

    The LHC Phase-II upgrade will lead to a significant increase in luminosity, which in turn will bring new challenges for the operation of inner tracking detectors. A possible solution is to use active silicon sensors, taking advantage of commercial CMOS technologies. Currently ATLAS R&D programme is qualifying a few commercial technologies in terms of suitability for this task. In this paper a prototype designed in one of them (LFoundry 150 nm process) will be discussed. The chip architecture will be described, including different pixel types incorporated into the design, followed by simulation and measurement results.

  12. Compact 400-Mhz Half-Wave Spoke Resonator Crab Cavitiy for the LHC Update

    SciTech Connect

    Li, Zenghai; Xiao, Liling; Ng, Cho; Markiewicz, Thomas; /SLAC

    2010-08-26

    Crab cavities are proposed for the LHC upgrade to improve the luminosity. There are two possible crab cavity installations for the LHC upgrade: the global scheme at Interaction Region (IR) 4 where the beam-beam separation is about 420-mm, and the local scheme at the IR5 where the beam-beam separation is only 194-mm. One of the design requirements as the result of a recent LHC-Crab cavity workshop is to develop a 400-MHz cavity design that can be utilized for either the global or local schemes at IR4 or IR5. Such a design would offer more flexibility for the final upgrade installation, as the final crabbing scheme is yet to be determined, and save R&D cost. The cavity size of such a design, however, is limited by the beam-beam separation at IR5 which can only accommodate a cavity with a horizontal size of about 145-mm, which is a design challenge for a 400-MHz cavity. To meet the new design requirements, we have developed a compact 400-MHz half-wave spoke resonator (HWSR) crab cavity that can fit into the tight spaces available at either IR4 or IR5. In this paper, we present the optimization of the HWSR cavity shape and the design of HOM, LOM, and SOM couplers for wakefield damping.

  13. Study of the Variation of Transverse Voltage in the 4 Rod Crab Cavity for LHC

    SciTech Connect

    B. Hall, G. Burt, C. Lingwood, R. Rimmer, H. Wang

    2011-04-01

    The planned high luminosity upgrade to LHC will utilise crab cavities to rotate the beam in order to increase the luminosity in the presence of a finite crossing angle. A compact design is required in order for the cavities to fit between opposing beam-lines. In this paper we discuss we discuss one option for the LHC crab cavity based on a 4 rod TEM deflecting cavity. Due to the large transverse size of the LHC beam the cavity is required to have a large aperture while maintaining a constant transverse voltage across the aperture. The cavity has been optimised to minimise the variation of the transverse voltage while keeping the peak surface electric and magnetic fields low for a given kick. This is achieved while fitting within the strict design space of the LHC. The variation of deflecting voltage across the aperture has been studied numerically and compared with numerical and analytical estimates of other deflecting cavity types. Performance measurements an aluminium prototype of this cavity are presented and compared to the simulated design.

  14. ATLAS LAr calorimeter performance and LHC Run-2 commissioning

    NASA Astrophysics Data System (ADS)

    Spettel, Fabian

    2016-07-01

    The ATLAS detector was built to study proton-proton collisions produced by the Large Hadron Collider (LHC) at a center of mass energy of up to 14 TeV. The Liquid Argon (LAr) calorimeters are used for all electromagnetic calorimetry as well as the hadronic calorimetry in the endcap and forward regions. They have shown excellent performance during the first LHC data taking campaign, from 2010 to 2012, so-called Run 1, at a peak luminosity of 8 ×1033cm-2s-1. During the next run, peak luminosities of 1.5 ×1034cm-2s-1 and even higher are expected at a 25 ns bunch spacing. Such a high collision rate may have an impact on the quality of the energy reconstruction which is attempted to be maintained at a high level using a calibration procedure described in this contribution. It also poses major challenges to the first level of the trigger system which is constrained to a maximal rate of 100 kHz. For Run-3, scheduled to start in 2019, instantaneous luminosity as high as 3 ×1034cm-2s-1 are foreseen imposing an upgrade of the LAr trigger system to maintain its performance. A demonstrator containing prototypes of the upgraded trigger electronic architecture has been installed on one of the barrel electromagnetic calorimeter readout front end crates to test it during the Run-2 campaign. The new architecture and its benefits for data taking will be discussed below as well as the results from first beam splash events.

  15. Upgrade of the LHCb Vertex Locator

    NASA Astrophysics Data System (ADS)

    Leflat, A.

    2014-08-01

    The upgrade of the LHCb experiment, planned for 2018, will transform the entire readout to a trigger-less system operating at 40 MHz. All data reduction algorithms will be executed in a high-level software farm, with access to all event information. This will enable the detector to run at luminosities of 1-2 × 1033/cm2/s and probe physics beyond the Standard Model in the heavy sector with unprecedented precision. The upgraded VELO must be low mass, radiation hard and vacuum compatible. It must be capable of fast pattern recognition and track reconstruction and will be required to drive data to the outside world at speeds of up to 2.5 Tbit/s. This challenge is being met with a new Vertex Locator (VELO) design based on hybrid pixel detectors positioned to within 5 mm of the LHC colliding beams. The sensors have 55 × 55 μm square pixels and the VELOPix ASIC which is being developed for the readout is based on the Timepix/Medipix family of chips. The hottest ASIC will have to cope with pixel hit rates of up to 900 MHz. The material budget will be optimised with the use of evaporative CO2 coolant circulating in microchannels within a thin silicon substrate. Microchannel cooling brings many advantages: very efficient heat transfer with almost no temperature gradients across the module, no CTE mismatch with silicon components, and low material contribution. This is a breakthrough technology being developed for LHCb. LHCb is also focussing effort on the construction of a lightweight foil to separate the primary and secondary LHC vacua, the development of high speed cables and radiation qualification of the module. The 40 MHz readout will also bring significant conceptual changes to the way in which the upgrade trigger is operated. Work is in progress to incorporate momentum and impact parameter information into the trigger at the earliest possible stage, using the fast pattern recognition capabilities of the upgraded detector. The current status of the VELO upgrade will

  16. Upgrade of the gas flow control system of the resistive current leads of the LHC inner triplet magnets: Simulation and experimental validation

    SciTech Connect

    Perin, A.; Casas-Cubillos, J.; Pezzetti, M.; Almeida, M.

    2014-01-29

    The 600 A and 120 A circuits of the inner triplet magnets of the Large Hadron Collider are powered by resistive gas cooled current leads. The current solution for controlling the gas flow of these leads has shown severe operability limitations. In order to allow a more precise and more reliable control of the cooling gas flow, new flowmeters will be installed during the first long shutdown of the LHC. Because of the high level of radiation in the area next to the current leads, the flowmeters will be installed in shielded areas located up to 50 m away from the current leads. The control valves being located next to the current leads, this configuration leads to long piping between the valves and the flowmeters. In order to determine its dynamic behaviour, the proposed system was simulated with a numerical model and validated with experimental measurements performed on a dedicated test bench.

  17. The upgrade of the Inner Tracking System of ALICE

    NASA Astrophysics Data System (ADS)

    Siddhanta, Sabyasachi

    2014-11-01

    ALICE has devised a comprehensive upgrade strategy to enhance its physics capabilities and to exploit the LHC running conditions after the second long shutdown of the LHC scheduled in 2018-2019. Within this upgrade programme, the upgrade of the Inner Tracking System (ITS) forms an important part. The upgraded ITS will have a barrel geometry consisting of seven layers of Monolithic Active Pixel Sensors (MAPS) with high granularity, which would fulfil the material budget, readout and radiation hardness requirements for the upgrade. In this contribution, an overview of the upgraded ITS, its technology and performance studies are presented.

  18. Future upgrade and physics perspectives of the ALICE TPC

    NASA Astrophysics Data System (ADS)

    Gunji, Taku

    2014-11-01

    The ALICE experiment at the Large Hadron Collider (LHC) proposes major detector upgrades to fully exploit the increase of the luminosity of the LHC in RUN 3 and to extend the physics reach for rare probes at low transverse momentum. The Time Projection Chamber (TPC) is one of the main tracking and PID devices in the central barrel of ALICE. The maximum trigger rate of the TPC is currently limited to about 3.5 kHz by the operation of a gating grid system. In order to make full use of the luminosity in RUN 3, the TPC is foreseen to be operated in an ungated mode with continuous readout. The existing MWPC readout will be replaced by a Micro-Pattern Gaseous Detector (MPGD) based readout, which provides intrinsic ion capture capability without gating. Extensive detector R&D employing Gas Electron Multiplier (GEM) and Micro-Mesh Gaseous detector (Micromegas) technologies, and simulation studies to advance the techniques for the corrections of space-charge distortions have been performed since 2012. In this paper, the expected detector performance and the status of the R&D program to achieve this ambitious goal are described.

  19. Small-strip Thin Gap Chambers for the muon spectrometer upgrade of the ATLAS experiment

    NASA Astrophysics Data System (ADS)

    Perez Codina, E.

    2016-07-01

    The ATLAS muon system upgrade to be installed during the LHC long shutdown in 2018/19, the so-called New Small Wheel (NSW), is designed to cope with the increased instantaneous luminosity in LHC Run 3. The small-strip Thin Gap Chambers (sTGC) will provide the NSW with a fast trigger and high precision tracking. The construction protocol has been validated by test beam experiments on a full-size prototype sTGC detector, showing the performance requirements are met. The intrinsic spatial resolution for a single layer has been found to be about 45 μm for a perpendicular incident angle, and the transition region between pads has been measured to be about 4 mm.

  20. Design optimization of pixel sensors using device simulations for the phase-II CMS tracker upgrade

    NASA Astrophysics Data System (ADS)

    Jain, G.; Bhardwaj, A.; Dalal, R.; Eber, R.; Eichorn, T.; Fernandez, M.; Lalwani, K.; Messineo, A.; Palomo, F. R.; Peltola, T.; Printz, M.; Ranjan, K.; Villa, I.; Hidalgo, S.

    2016-07-01

    In order to address the problems caused by the harsh radiation environment during the high luminosity phase of the LHC (HL-LHC), all silicon tracking detectors (pixels and strips) in the CMS experiment will undergo an upgrade. And so to develop radiation hard pixel sensors, simulations have been performed using the 2D TCAD device simulator, SILVACO, to obtain design parameters. The effect of various design parameters like pixel size, pixel depth, implant width, metal overhang, p-stop concentration, p-stop depth and bulk doping density on the leakage current and critical electric field are studied for both non-irradiated as well as irradiated pixel sensors. These 2D simulation results of planar pixels are useful for providing insight into the behaviour of non-irradiated and irradiated silicon pixel sensors and further work on 3D simulation is underway.

  1. The sROD module for the ATLAS Tile Calorimeter Phase-II Upgrade Demonstrator

    NASA Astrophysics Data System (ADS)

    Carrió, F.; Castillo, V.; Ferrer, A.; Fiorini, L.; Hernández, Y.; Higón, E.; Mellado, B.; March, L.; Moreno, P.; Reed, R.; Solans, C.; Valero, A.; Valls, J. A.

    2014-02-01

    TileCal is the central hadronic calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN. The main upgrade of the LHC to increase the instantaneous luminosity is scheduled for 2022. The High Luminosity LHC, also called upgrade Phase-II, will imply a complete redesign of the read-out electronics in TileCal. In the new read-out architecture, the front-end electronics aims to transmit full digitized information to the back-end system in the counting rooms. Thus, the back-end system will also provide digital calibrated information with enhanced precision and granularity to the first level trigger to improve the trigger efficiencies. The demonstrator project is envisaged to qualify this new proposed architecture. A reduced part of the detector, 1/256 of the total, will be equipped with the new electronics during 2014 to evaluate the proposed architecture in real conditions. The upgraded Read-Out Driver (sROD) will be the core element of the back-end electronics in Phase-II. The sROD module is designed on a double mid-size AMC format and will operate under an AdvancedTCA framework. The module includes two Xilinx Series 7 Field Programmable Gate Arrays (FPGAs) for data receiving and processing, as well as the implementation of embedded systems. Related to optical connectors, the sROD uses 4 QSFPs to receive and transmit data from the front-end electronics and 1 Avago MiniPOD to send preprocessed data to the first level trigger system. An SFP module maintains the compatibility with the existing hardware. A complete description of the sROD module for the demonstrator including the main functionalities, circuit design and the control software and firmware will be presented.

  2. Upgrade of the CMS muon system with triple-GEM detectors

    NASA Astrophysics Data System (ADS)

    Abbaneo, D.; Abbas, M.; Abbrescia, M.; Abdelalim, A. A.; Abi Akl, M.; Ahmed, W.; Ahmed, W.; Altieri, P.; Aly, R.; Ashfaq, A.; Aspell, P.; Assran, Y.; Awan, I.; Bally, S.; Ban, Y.; Banerjee, S.; Barria, P.; Benussi, L.; Bhopatkar, V.; Bianco, S.; Bos, J.; Bouhali, O.; Braibant, S.; Buontempo, S.; Cai, J.; Calabria, C.; Caputo, C.; Cassese, F.; Castaneda, A.; Cauwenbergh, S.; Cavallo, F. R.; Celik, A.; Choi, M.; Choi, K.; Choi, S.; Christiansen, J.; Cimmino, A.; Colafranceschi, S.; Colaleo, A.; Conde Garcia, A.; Dabrowski, M. M.; De Lentdecker, G.; De Oliveira, R.; de Robertis, G.; Dildick, S.; Dorney, B.; Elmetenawee, W.; Fabrice, G.; Ferry, S.; Giacomelli, P.; Gilmore, J.; Guiducci, L.; Gutierrez, A.; Hadjiiska, R. M.; Hassan, A.; Hauser, J.; Hoepfner, K.; Hohlmann, M.; Hoorani, H.; Jeng, Y. G.; Kamon, T.; Karchin, P. E.; Kim, H.; Krutelyov, S.; Kumar, A.; Lee, J.; Lee, J.; Lenzi, T.; Litov, L.; Loddo, F.; Maerschalk, T.; Magazzu, G.; Maggi, M.; Maghrbi, Y.; Magnani, A.; Majumdar, N.; Mal, P. K.; Mandal, K.; Marchioro, A.; Marinov, A.; Merlin, J. A.; Mohammed, N.; Mohanty, A. K.; Mohapatra, A.; Muhammad, S.; Mukhopadhyay, S.; Nuzzo, S.; Oliveri, E.; Pant, L. M.; Paolucci, P.; Park, I.; Passeggio, G.; Pavlov, B.; Philipps, B.; Phipps, M.; Piccolo, D.; Postema, H.; Pugliese, G.; Baranac, A. Puig; Radi, A.; Radogna, R.; Raffone, G.; Ramkrishna, S.; Ranieri, A.; Riccardi, C.; Rodrigues, A.; Ropelewski, L.; Roychoddhury, S.; Ryu, M. S.; Ryu, G.; Safonov, A.; Sakharov, A.; Salva, S.; Saviano, G.; Sharma, A.; Swain, S. K.; Talvitie, J. P.; Tamma, C.; Tatarinov, A.; Turini, N.; Tuuva, T.; Twigger, J.; Tytgat, M.; Vai, I.; van Stenis, M.; Venditi, R.; Verhagen, E.; Verwilligen, P.; Vitulo, P.; Yang, U.; Yang, Y.; Yonamine, R.; Zaganidis, N.; Zenoni, F.; Zhang, A.

    2014-10-01

    The CMS collaboration considers upgrading the muon forward region which is particularly affected by the high-luminosity conditions at the LHC. The proposal involves Gas Electron Multiplier (GEM) chambers, which are able to handle the extreme particle rates expected in this region along with a high spatial resolution. This allows to combine tracking and triggering capabilities, which will improve the CMS muon High Level Trigger, the muon identification and the track reconstruction. Intense R&D has been going on since 2009 and it has lead to the development of several GEM prototypes and associated detector electronics. These GEM prototypes have been subjected to extensive tests in the laboratory and in test beams at the CERN Super Proton Synchrotron (SPS). This contribution will review the status of the CMS upgrade project with GEMs and its impact on the CMS performance.

  3. Trigger algorithms and electronics for the ATLAS muon new small wheel upgrade

    NASA Astrophysics Data System (ADS)

    Guan, L.

    2016-01-01

    The New Small Wheel Upgrade for the ATLAS experiment will replace the innermost station of the Muon Spectrometer in the forward region in order to maintain its current performance during high luminosity data-taking after the LHC Phase-I upgrade. The New Small Wheel, comprising Micromegas and small Thin Gap Chambers, will reduce the rate of fake triggers coming from backgrounds in the forward region and significantly improve the Level-1 muon trigger selectivity by providing precise on-line segment measurements with ~ 1 mrad angular resolution. Such demanding precision, together with the short time (~ 1 μs) to prepare trigger data and perform on-line reconstruction, implies very stringent requirements on the design of trigger system and trigger electronics. This paper presents an overview of the design of the New Small Wheel trigger system, trigger algorithms and processor hardware.

  4. Development of radiation hard semiconductor sensors for charged particle tracking at very high luminosities

    NASA Astrophysics Data System (ADS)

    Betancourt, Christopher; Fadeyev, Vitaliy; Sadrozinski, Hartmut F.; Wright, John

    2010-09-01

    The RD50 collaboration (sponsored by the European Organization for Nuclear Research CERN) has been exploring the development of radiation hard semiconductor devices for very high-luminosity colliders since 2002. The target fluence to qualify detectors set by the anticipated dose for the innermost tracking layers of the future upgrade of the CERN large hadron collider (LHC) is 1016 1 MeV neutron equivalent (neq) cm-2. This is much larger than typical fluences in space, but is mainly limited to displacement and total dose damage, without the single-event effects typical for the space environment. RD50 investigates radiation hardening from many angles, including: Search for alternative semiconductor to replace silicon, improvement of the intrinsic tolerance of the substrate material (p- vs. n-type, initial doping concentration, oxygen concentration), optimization of the readout geometry (collection of holes or electrons, surface treatment), novel detector designs (3D, edge-less, interconnects).

  5. The D0 upgrade trigger

    SciTech Connect

    Eno, S.

    1994-09-01

    The current trigger system for the D0 detector at Fermilab`s Tevatron will need to be upgraded when the Min Injector is installed and the Tevatron can operate at luminosities exceeding 10{sup 32} cm{sup {minus}2}s{sup {minus}1} and with a crossing time of 132 ns. We report on preliminary designs for upgrades to the trigger system for the Main Injector era.

  6. High luminosity muon scattering at FNAL

    SciTech Connect

    Bazizi, K. ); Conrad, J.; Fang, G. ); Erdmann, M. ); Geesaman, D.; Jackson, H. ); Guyot, C.; Virchaux, M. ); Holmgren, H. ); Malensek, A.; Melanson, H.; Morfin

    1990-02-01

    The charge of this group was to evaluate the physics that can be done with a high luminosity {mu} scattering experiment at FNAL using the upgraded Tevatron muon beam, and consider the apparatus required. In this report, the physics that can be accomplished with a high luminosity {mu} scattering experiment is evaluated. The CERN and FNAL {mu} beams are compared in the context of such an experiment. The expected muon flux with the upgraded machine is estimated. Two possible detectors are compared: the air-core toroid experiment proposed by Guyot et al., and an upgraded version of the E665 double-diode apparatus now in place at FNAL. The relative costs of the detectors are considered. A list of detailed questions that need to be answered regarding the double-diode experiment has be compiled. 2 refs., 10 figs., 2 tabs.

  7. CERN LHC signals for warped electroweak neutral gauge bosons

    NASA Astrophysics Data System (ADS)

    Agashe, Kaustubh; Davoudiasl, Hooman; Gopalakrishna, Shrihari; Han, Tao; Huang, Gui-Yu; Perez, Gilad; Si, Zong-Guo; Soni, Amarjit

    2007-12-01

    We study signals at the Large Hadron Collider (LHC) for Kaluza-Klein (KK) excitations of the electroweak gauge bosons in the framework with the standard model (SM) gauge and fermion fields propagating in a warped extra dimension. Such a framework addresses both the Planck-weak and flavor hierarchy problems of the SM. Unlike the often studied Z' cases, in this framework, there are three neutral gauge bosons due to the underlying SU(2)L×SU(2)R×U(1)X gauge group in the bulk. Furthermore, couplings of these KK states to light quarks and leptons are suppressed, whereas those to top and bottom quarks are enhanced compared to the SM gauge couplings. Therefore, the production of light quark and lepton states is suppressed relative to other beyond the SM constructions, and the fermionic decays of these states are dominated by the top and bottom quarks, which are, though, overwhelmed by KK gluons dominantly decaying into them. However, as we emphasize in this paper, decays of these states to longitudinal W, Z and Higgs are also enhanced similarly to the case of top and bottom quarks. We show that the W, Z and Higgs final states can give significant sensitivity at the LHC to ˜2(3)TeV KK scale with an integrated luminosity of ˜100fb-1 (˜1ab-1). Since current theoretical framework(s) favor KK masses ≳3TeV, a luminosity upgrade of LHC is likely to be crucial in observing these states.

  8. Abort Gap Cleaning for LHC Run 2

    SciTech Connect

    Uythoven, Jan; Boccardi, Andrea; Bravin, Enrico; Goddard, Brennan; Hemelsoet, Georges-Henry; Höfle, Wolfgang; Jacquet, Delphine; Kain, Verena; Mazzoni, Stefano; Meddahi, Malika; Valuch, Daniel; Gianfelice-Wendt, Eliana

    2014-07-01

    To minimize the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.

  9. Design of a new front-end electronics test-bench for the upgraded ATLAS detector's Tile Calorimeter

    NASA Astrophysics Data System (ADS)

    Kureba, C. O.; Govender, M.; Hofsajer, I.; Ruan, X.; Sandrock, C.; Spoor, M.

    2015-10-01

    The year 2022 has been scheduled to see an upgrade of the Large Hadron Collider (LHC), in order to increase its instantaneous luminosity. The High Luminosity LHC, also referred to as the upgrade Phase-II, means an inevitable complete re-design of the read-out electronics in the Tile Calorimeter (TileCal) of the A Toroidal LHC Apparatus (ATLAS) detector. Here, the new read-out architecture is expected to have the front-end electronics transmit fully digitized information of the detector to the back-end electronics system. Fully digitized signals will allow more sophisticated reconstruction algorithms which will contribute to the required improved triggers at high pile-up. In Phase II, the current Mobile Drawer Integrity ChecKing (MobiDICK) test-bench will be replaced by the next generation test-bench for the TileCal superdrawers, the new Prometeo (A Portable ReadOut ModulE for Tilecal ElectrOnics). Prometeo is a portable, high-throughput electronic system for full certification of the front-end electronics of the ATLAS TileCal. It is designed to interface to the fast links and perform a series of tests on the data to assess the certification of the electronics. The Prometeo's prototype is being assembled by the University of the Witwatersrand and installed at CERN for further developing, tuning and tests. This article describes the overall design of the new Prometeo, and how it fits into the TileCal electronics upgrade.

  10. Performance of the Demonstrator System for the Phase-I Upgrade of the Trigger Readout Electronics of the ATLAS Liquid Argon Calorimeters

    NASA Astrophysics Data System (ADS)

    Dumont Dayot, N.

    2016-01-01

    For the Phase-I luminosity upgrade of the LHC a higher granularity trigger readout of the ATLAS LAr Calorimeters is foreseen to enhance the trigger feature extraction and background rejection. The new readout system digitizes the detector signals, which are grouped into 34000 so-called Super Cells, with 12 bit precision at 40 MHz and transfers the data on optical links to the digital processing system, which extracts the Super Cell energies. A demonstrator version of the complete system has now been installed and operated on the ATLAS detector. Results from the commissioning and performance measurements are reported.

  11. Monotops at the LHC

    SciTech Connect

    Andrea, J.; Fuks, B.

    2011-10-01

    We explore scenarios where top quarks may be produced singly in association with missing energy, a very distinctive signature, which, in analogy with monojets, we dub monotops. We find that monotops can be produced in a variety of modes, typically characterized by baryon number-violating or flavorchanging neutral interactions. We build a simplified model that encompasses all the possible (tree-level) production mechanisms and study the LHC sensitiveness to a few representative scenarios by considering fully hadronic top decays. We find that constraints on such exotic models can already be set with 1 fb{sup -1} of integrated luminosity collected at {radical}(s)=7 TeV.

  12. Prototypes for components of a control system for the ATLAS pixel detector at the HL-LHC

    NASA Astrophysics Data System (ADS)

    Püllen, Lukas; Boek, Jennifer; Kersten, Susanne; Kind, Peter; Mättig, Peter; Zeitnitz, Christian

    2013-12-01

    In the years around 2020 an upgrade of the LHC to the HL-LHC is scheduled, which will increase the accelerator's instantaneous luminosity by a factor of 5 and the integrated luminosity by a factor of 10. In the context of this upgrade, the inner detector (including the pixel detector) of the ATLAS experiment will be replaced. This new pixel detector requires a specific control system which complies with strict requirements in terms of radiation hardness, material budget and space for the electronics in the ATLAS experiment. The University of Wuppertal is developing a concept for a DCS (Detector Control System) network consisting of two kinds of ASICs. The first ASIC is the DCS chip which is located on the pixel detector, very close to the interaction point. The second ASIC is the DCS Controller which is controlling 4×4 DCS chips from the outer regions of ATLAS via differential data lines. Both ASICs are manufactured in 130 nm deep sub-micron technology. We present results from reliability measurements under irradiation from new prototypes of components for the DCS network.

  13. Perspectives on Higher Luminosity B-Factories

    SciTech Connect

    Seeman, J

    2004-04-22

    The present B-factories PEP-II and KEKB have reached luminosities of 4-6 x 10{sup 33}/cm{sup 2}/s and delivered integrated luminosity at rates in excess of 6 fb{sup -1} per month [1,2]. The recent turn on of these two B-Factories has shown that modern accelerator physics, design, and engineering can produce colliders that rapidly reach their design luminosities and deliver integrated luminosities capable of frontier particle physics discoveries. PEP-II and KEK-B with ongoing upgrade programs should reach luminosities of over 10{sup 34}/cm{sup 2}/s in a few years and with more aggressive improvements may reach luminosities of order 4 x 10{sup 34}/cm{sup 2}/s by the end of the decade. However, due to particle physics requirements, the next generation B-Factory may require significantly more luminosity. Initial parameters of a very high luminosity e{sup +}e{sup -} B-Factory or Super B-Factory (SBF) are being developed incorporating several new ideas from the successful operation of the present generation e{sup +}e{sup -} accelerators [3,4]. A luminosity approaching 10{sup 36} cm{sup -2}s{sup -1} may be possible. Furthermore, the ratio of average to peak luminosity may be increased by 30% due to continuous injection. The operation of this new accelerator will be qualitatively different from present e{sup +}e{sup -} colliders due to this continuous injection.

  14. The D0 upgrade

    SciTech Connect

    Tuts, P.M. . Physics Dept.)

    1992-10-01

    The original D0 detector was proposed in 1983, with a focus on high P[sub T] physics using precision measurements of e's, [mu]'s, jets, and missing E[sub T]. This detector, as of the summer of 1992, has started data taking at the Fermilab Collider. However, by 1995/6 the luminosity will reach 10[sup 31] cm[sup [minus]2]sec[sup [minus]1], and the minimum bunch spacing will drop to 396ns from the present 3.5[mu]s (by the Main Injector era, luminosities will approach 10[sup 32] cm[sup [minus]2]sec[sup [minus]1] and minimum bunch spacings may reach 132ns). These changes in the accelerator conditions force us to upgrade or replace a number of detector subsystems in order to meet these new demands. In addition, the upgrade offers us the opportunity to expand the physics horizons to include not only the all important high P[sub T] physics menu, but also the low P[sub T] physics that has become increasingly important. In this paper we describe the D0 detector upgrade.

  15. The D0 upgrade

    SciTech Connect

    Tuts, P.M.; The D0 Collaboration

    1992-10-01

    The original D0 detector was proposed in 1983, with a focus on high P{sub T} physics using precision measurements of e`s, {mu}`s, jets, and missing E{sub T}. This detector, as of the summer of 1992, has started data taking at the Fermilab Collider. However, by 1995/6 the luminosity will reach 10{sup 31} cm{sup {minus}2}sec{sup {minus}1}, and the minimum bunch spacing will drop to 396ns from the present 3.5{mu}s (by the Main Injector era, luminosities will approach 10{sup 32} cm{sup {minus}2}sec{sup {minus}1} and minimum bunch spacings may reach 132ns). These changes in the accelerator conditions force us to upgrade or replace a number of detector subsystems in order to meet these new demands. In addition, the upgrade offers us the opportunity to expand the physics horizons to include not only the all important high P{sub T} physics menu, but also the low P{sub T} physics that has become increasingly important. In this paper we describe the D0 detector upgrade.

  16. Luminosity monitor at PEP

    SciTech Connect

    Fox, J.D.; Franklin, M.E.B.

    1981-02-01

    The luminosity monitor system utilized by the MKII Detector and by the PEP operators is described. This system processes information from 56 photomultipliers and calculates independent luminosities for each of the 3 colliding bunches in PEP. Design considerations, measurement techniques, and sources of error in the luminosity measurement are discussed.

  17. Commissioning of the upgraded CSC Endcap Muon Port Cards at CMS

    NASA Astrophysics Data System (ADS)

    Ecklund, K.; Liu, J.; Madorsky, A.; Matveev, M.; Michlin, B.; Padley, P.; Rorie, J.

    2016-01-01

    There are 180 1.6 Gbps optical links from 60 Muon Port Cards (MPC) to the Cathode Strip Chamber Track Finder (CSCTF) in the original system. Before the upgrade each MPC was able to provide up to three trigger primitives from a cluster of nine CSC chambers to the Level 1 CSCTF. With an LHC luminosity increase to 1035 cm-2s-1 at full energy of 7 TeV/beam, the simulation studies suggest that we can expect two or three times more trigger primitives per bunch crossing from the front-end electronics. To comply with this requirement, the MPC, CSCTF, and optical cables need to be upgraded. The upgraded MPC allows transmission of up to 18 trigger primitives from the peripheral crate. This feature would allow searches for physics signatures of muon jets that require more trigger primitives per trigger sector. At the same time, it is very desirable to preserve all the old optical links for compatibility with the older Track Finder during transition period at the beginning of Run 2. Installation of the upgraded MPC boards and the new optical cables has been completed at the CMS detector in the summer of 2014. We describe the final design of the new MPC mezzanine FPGA, its firmware, and results of tests in laboratory and in situ with the old and new CSCTF boards.

  18. LHC: The Large Hadron Collider

    SciTech Connect

    Lincoln, Don

    2015-03-04

    The Large Hadron Collider (or LHC) is the world’s most powerful particle accelerator. In 2012, scientists used data taken by it to discover the Higgs boson, before pausing operations for upgrades and improvements. In the spring of 2015, the LHC will return to operations with 163% the energy it had before and with three times as many collisions per second. It’s essentially a new and improved version of itself. In this video, Fermilab’s Dr. Don Lincoln explains both some of the absolutely amazing scientific and engineering properties of this modern scientific wonder.

  19. LHC signals for coset electroweak gauge bosons in warped/composite pseudo-Goldstone boson Higgs models

    NASA Astrophysics Data System (ADS)

    Agashe, Kaustubh; Azatov, Aleksandr; Han, Tao; Li, Yingchuan; Si, Zong-Guo; Zhu, Lijun

    2010-05-01

    The framework of a warped extra dimension with the standard model (SM) fields propagating in it is a very well-motivated extension of the SM since it can address both the Planck-weak and flavor hierarchy problems of the SM. Within this framework, solution to the little hierarchy problem motivates extending the SM electroweak (EW) 5D gauge symmetry in such a way that its breakdown to the SM delivers the SM Higgs boson. We study signals at the large hadron collider (LHC) for the extra EW (called coset) gauge bosons, a fundamental ingredient of this framework. The coset gauge bosons, due to their unique EW gauge quantum numbers [doublets of SU(2)L], do not couple at leading order to two SM particles. We find that, using the associated production of the charged coset gauge bosons via their coupling to bottom quark and a (light) Kaluza-Klein excitation of the top quark, the LHC can have a 3σ reach of ˜2(2.6)TeV for the coset gauge boson masses with ˜100(1000)fb-1 luminosity. Since current theoretical framework(s) suggest an indirect lower limit on coset gauge boson masses of ≳3TeV, luminosity or energy upgrade of LHC is likely to be crucial in observing these states.

  20. Future silicon sensors for the CMS Tracker Upgrade

    NASA Astrophysics Data System (ADS)

    Bernard-Schwarz, Maria; CMS Tracker Collaboration

    2013-01-01

    For the high-luminosity phase of LHC (Large Hadron Collider) at CERN a campaign was started in the CMS (Compact Muon Solenoid) experiment to investigate different radiation hard silicon detectors. Therefore 6 in. silicon wafers were ordered to answer various questions regarding for example the radiation tolerance and the annealing behavior of different sensor material. The testing variety includes sensor versions n-in-p and p-in-n in thicknesses from 50 μm to 300 μm. In terms of sensor material the difference between floating zone, magnetic Czochralski and epitaxial grown silicon is investigated. For the n-in-p sensors, the different isolation technologies, p-stop and p-spray, are tested. The design of the wafer contains test structures, diodes, mini-sensors, long and very short strip sensors, real pixel sensors and double metal routing variants. The irradiation is done with mixed fluences of protons and neutrons which represent the rates of integrated hadrons that are expected in the CMS tracker after the LHC upgrade. This paper presents an overview of results from measurements of non-irradiated test structures with different technologies and also the results after irradiation.

  1. Warped gravitons at the CERN LHC and beyond

    NASA Astrophysics Data System (ADS)

    Agashe, Kaustubh; Davoudiasl, Hooman; Perez, Gilad; Soni, Amarjit

    2007-08-01

    We study the production and decay of Kaluza-Klein (KK) gravitons at the CERN Large Hadron Collider (LHC), in the framework of a warped extra dimension in which the standard model (SM) fields propagate. Such a scenario can provide solutions to both the Planck-weak hierarchy problem and the flavor puzzle of the SM. In this scenario, the production via qq¯ annihilation and decays to the conventional photon and lepton channels are highly suppressed. However, we show that graviton production via gluon fusion followed by decay to longitudinal Z/W can be significant; vector boson fusion is found to be a subdominant production mode. In particular, the golden ZZ decay mode offers a distinctive 4-lepton signal that could lead to the observation at the LHC with 300fb-1 (SLHC with 3ab-1) of a KK graviton with a mass up to ˜2 (˜3) TeV for the ratio of the AdS5 curvature to the Planck scale modestly above unity. We argue that (contrary to the lore) such a size of the curvature scale can still be within the regime of validity of the framework. Upgrades beyond the SLHC luminosity are required to discover gravitons heavier than ˜4TeV, as favored by the electroweak and flavor precision tests in the simplest such models.

  2. Warped gravitons at the CERN LHC and beyond

    SciTech Connect

    Agashe, Kaustubh; Davoudiasl, Hooman; Soni, Amarjit; Perez, Gilad

    2007-08-01

    We study the production and decay of Kaluza-Klein (KK) gravitons at the CERN Large Hadron Collider (LHC), in the framework of a warped extra dimension in which the standard model (SM) fields propagate. Such a scenario can provide solutions to both the Planck-weak hierarchy problem and the flavor puzzle of the SM. In this scenario, the production via qq annihilation and decays to the conventional photon and lepton channels are highly suppressed. However, we show that graviton production via gluon fusion followed by decay to longitudinal Z/W can be significant; vector boson fusion is found to be a subdominant production mode. In particular, the golden ZZ decay mode offers a distinctive 4-lepton signal that could lead to the observation at the LHC with 300 fb{sup -1} (SLHC with 3 ab{sup -1}) of a KK graviton with a mass up to {approx}2 ({approx}3) TeV for the ratio of the AdS{sub 5} curvature to the Planck scale modestly above unity. We argue that (contrary to the lore) such a size of the curvature scale can still be within the regime of validity of the framework. Upgrades beyond the SLHC luminosity are required to discover gravitons heavier than {approx}4 TeV, as favored by the electroweak and flavor precision tests in the simplest such models.

  3. Scintillating Fibre Tracking at High Luminosity Colliders

    NASA Astrophysics Data System (ADS)

    Joram, C.; Haefeli, G.; Leverington, B.

    2015-08-01

    The combination of small diameter scintillating plastic fibres with arrays of SiPM photodetectors has led to a new class of SciFi trackers usable at high luminosity collider experiments. After a short review of the main principles and history of the scintillating fibre technology, we describe the challenges and developments of the large area Scintillating Fibre Tracker currently under development for the upgraded LHCb experiment.

  4. The sPHENIX Barrel Upgrade: Jet Physics and Beyond

    NASA Astrophysics Data System (ADS)

    Haggerty, John S.

    2013-05-01

    The past decade of heavy ion physics at RHIC has produced many surprising discoveries and puzzles. Currently the experiments at the LHC are providing a first look at things to come: a burgeoning program for studying the quark-gluon plasma with reconstructed jets. The PHENIX collaboration has developed a long term plan involving a series of upgrades designed to expand the physics capabilities and make use of the full enhanced luminosity at RHIC. With increased coverage and the addition of hadronic calorimetry, we demonstrate that the sPHENIX upgrade will be well positioned to provide a broad and exciting program of jet probe measurements. Sampling 50 billion Au + Au events annually, we will collect 10 million jets with transverse energy above 20 GeV and 100 thousand jets above 40 GeV. With the addition of new tracking layers and an EM preshower, a crucial program of upsilon measurements, as well as neutral pion measurements with a 40 GeV/c reach, can be made in a flexible accelerator facility capable of providing a diverse range of collision systems across many beam energies. And, ultimately, the sPHENIX detector will provide the base for staging a future electron-ion collider detector at eRHIC.

  5. A continuous read-out TPC for the ALICE upgrade

    NASA Astrophysics Data System (ADS)

    Lippmann, C.

    2016-07-01

    The largest gaseous Time Projection Chamber (TPC) in the world, the ALICE TPC, will be upgraded based on Micro Pattern Gas Detector technology during the second long shutdown of the CERN Large Hadron Collider in 2018/19. The upgraded detector will operate continuously without the use of a triggered gating grid. It will thus be able to read all minimum bias Pb-Pb events that the LHC will deliver at the anticipated peak interaction rate of 50 kHz for the high luminosity heavy-ion era. New read-out electronics will send the continuous data stream to a new online farm at rates up to 1 TByte/s. A fractional ion feedback of below 1% is required to keep distortions due to space charge in the TPC drift volume at a tolerable level. The new read-out chambers will consist of quadruple stacks of Gas Electron Multipliers (GEM), combining GEM foils with a different hole pitch. Other key requirements such as energy resolution and operational stability have to be met as well. A careful optimisation of the performance in terms of all these parameters was achieved during an extensive R&D program. A working point well within the design specifications was identified with an ion backflow of 0.63%, a local energy resolution of 11.3% (sigma) and a discharge probability comparable to that of standard triple GEM detectors.

  6. Tevatron operational status and possible lessons for the LHC

    SciTech Connect

    Lebedev, V.; /Fermilab

    2006-06-01

    This paper provides an overview of the Tevatron Run II luminosity progress and plans, including SC magnet measurements and modeling of field errors in view of the LHC operation. It also discusses antiproton production, stacking and cooling.

  7. Physics at the LHC: a short overview

    NASA Astrophysics Data System (ADS)

    d'Enterria, David

    2011-01-01

    The CERN Large Hadron Collider (LHC) started operation a few months ago. The machine will deliver proton-proton and nucleus-nucleus collisions at energies as high as = 14 TeV and luminosities up to ~ 1034 cm-2s-1 never reached before. The main open scientific questions that the seven LHC experiments - ATLAS, CMS, ALICE, LHCb, TOTEM, LHCf and MOEDAL - aim to solve in the coming years are succinctly reviewed.

  8. Continuing u.s. participation in the lhc accelerator program

    SciTech Connect

    Syphers, M.J.; /Fermilab

    2005-12-01

    The U.S. LHC Accelerator Research Program (LARP) was established to enable U.S. accelerator specialists to take on active and important roles in the LHC accelerator project during its commissioning and early operations, and to be a major collaborator in future LHC performance upgrades. It is hoped that this follow-on effort to the U.S. contributions to the LHC accelerator project will improve the capabilities of the U.S. accelerator community in accelerator science and technology in order to more effectively use, develop, and preserve unique U.S. resources and capabilities during the LHC era.

  9. Software for implementing trigger algorithms on the upgraded CMS Global Trigger System

    NASA Astrophysics Data System (ADS)

    Matsushita, Takashi; Arnold, Bernhard

    2015-12-01

    The Global Trigger is the final step of the CMS Level-1 Trigger and implements a trigger menu, a set of selection requirements applied to the final list of trigger objects. The conditions for trigger object selection, with possible topological requirements on multiobject triggers, are combined by simple combinatorial logic to form the algorithms. The LHC has resumed its operation in 2015, the collision-energy will be increased to 13 TeV with the luminosity expected to go up to 2x1034 cm-2s-1. The CMS Level-1 trigger system will be upgraded to improve its performance for selecting interesting physics events and to operate within the predefined data-acquisition rate in the challenging environment expected at LHC Run 2. The Global Trigger will be re-implemented on modern FPGAs on an Advanced Mezzanine Card in MicroTCA crate. The upgraded system will benefit from the ability to process complex algorithms with DSP slices and increased processing resources with optical links running at 10 Gbit/s, enabling more algorithms at a time than previously possible and allowing CMS to be more flexible in how it handles the trigger bandwidth. In order to handle the increased complexity of the trigger menu implemented on the upgraded Global Trigger, a set of new software has been developed. The software allows a physicist to define a menu with analysis-like triggers using intuitive user interface. The menu is then realised on FPGAs with further software processing, instantiating predefined firmware blocks. The design and implementation of the software for preparing a menu for the upgraded CMS Global Trigger system are presented.

  10. Operation of the Upgraded ATLAS Level-1 Central Trigger System

    NASA Astrophysics Data System (ADS)

    Glatzer, Julian

    2015-12-01

    The ATLAS Level-1 Central Trigger (L1CT) system is a central part of ATLAS data-taking and has undergone a major upgrade for Run 2 of the LHC, in order to cope with the expected increase of instantaneous luminosity of a factor of two with respect to Run 1. The upgraded hardware offers more flexibility in the trigger decisions due to the factor of two increase in the number of trigger inputs and usable trigger channels. It also provides an interface to the new topological trigger system. Operationally - particularly useful for commissioning, calibration and test runs - it allows concurrent running of up to three different subdetector combinations. An overview of the operational software framework of the L1CT system with particular emphasis on the configuration, controls and monitoring aspects is given. The software framework allows a consistent configuration with respect to the ATLAS experiment and the LHC machine, upstream and downstream trigger processors, and the data acquisition system. Trigger and dead-time rates are monitored coherently at all stages of processing and are logged by the online computing system for physics analysis, data quality assurance and operational debugging. In addition, the synchronisation of trigger inputs is watched based on bunch-by-bunch trigger information. Several software tools allow for efficient display of the relevant information in the control room in a way useful for shifters and experts. The design of the framework aims at reliability, flexibility, and robustness of the system and takes into account the operational experience gained during Run 1. The Level-1 Central Trigger was successfully operated with high efficiency during the cosmic-ray, beam-splash and first Run 2 data taking with the full ATLAS detector.

  11. Phase 1 Upgrade of the CMS Pixel Detector: Module Assembly and Testing

    NASA Astrophysics Data System (ADS)

    Kumar, Ashish

    2014-03-01

    The CMS pixel detector is the innermost component of the all-silicon tracking system located closest to the interaction point and thus operates in a high-occupancy/high-radiation environment created by particle collisions. The performance of the current pixel detector has been excellent during Run 1 of the LHC. However, the foreseen increases of the instantaneous and integrated luminosities at the LHC necessitate an upgrade of the pixel detector in order to maintain the excellent tracking and physics performance of the CMS detector. The new pixel detector is expected to be installed during the extended end-of-year shutdown in 2016/17. The main new features of the upgraded pixel detector would be ultra-light mechanical design with four barrel layers and three end-caps on either side of the interaction point, digital readout chip with higher rate capability and new cooling system. These and other design improvements, along with the current status on module assembly and testing, will be discussed.

  12. Development of edgeless n-on-p planar pixel sensors for future ATLAS upgrades

    NASA Astrophysics Data System (ADS)

    Bomben, Marco; Bagolini, Alvise; Boscardin, Maurizio; Bosisio, Luciano; Calderini, Giovanni; Chauveau, Jacques; Giacomini, Gabriele; La Rosa, Alessandro; Marchiori, Giovanni; Zorzi, Nicola

    2013-06-01

    The development of n-on-p "edgeless" planar pixel sensors being fabricated at FBK (Trento, Italy), aimed at the upgrade of the ATLAS Inner Detector for the High Luminosity phase of the Large Hadron Collider (HL-LHC), is reported. A characterizing feature of the devices is the reduced dead area at the edge, achieved by adopting the "active edge" technology, based on a deep etched trench, suitably doped to make an ohmic contact to the substrate. The project is presented, along with the active edge process, the sensor design for this first n-on-p production and a selection of simulation results, including the expected charge collection efficiency after radiation fluence of 1×1015 neq/cm2 comparable to those expected at HL-LHC (about ten years of running, with an integrated luminosity of 3000 fb-1) for the outer pixel layers. We show that, after irradiation and at a bias voltage of 500 V, more than 50% of the signal should be collected in the edge region; this confirms the validity of the active edge approach.

  13. A DC-DC conversion powering scheme for the CMS Phase-1 pixel upgrade

    NASA Astrophysics Data System (ADS)

    Feld, L.; Fleck, M.; Friedrichs, M.; Hensch, R.; Karpinski, W.; Klein, K.; Sammet, J.; Wlochal, M.

    2013-02-01

    The CMS pixel detector was designed for a nominal instantaneous LHC luminosity of 1ṡ1034 cm-2s-1. During Phase-1 of the LHC upgrade, the instantaneous luminosity will be increased to about twice this value. To preserve the excellent performance of the pixel detector despite the increase in particle rates and track densities, the CMS Collaboration foresees the exchange of its pixel detector in the shutdown 2016/2017. The new pixel detector will be improved in many respects, and will comprise twice the number of readout channels. A powering scheme based on DC-DC conversion will be adopted, which will enable the provision of the required power with the present cable plant. The powering scheme of the CMS pixel detector will be described, and the performance of prototype DC-DC buck converters will be presented, including power efficiency, system tests with DC-DC converters and pixel modules, thermal management, reliability at low temperature, and studies of potential frequency locking between DC-DC converters.

  14. Experimental Analysis of Gaseous Chambers for the ATLAS Muon sub-detector Upgrade R&D

    NASA Astrophysics Data System (ADS)

    Angulo, Emmanuel; Wotschack, Joerg

    2011-11-01

    CERN, the world's largest particle accelerator facility, has begun its ambitious Large Hadron Collider (LHC) program which is and will remain as the world energy frontier until at least 2030. ATLAS, one of the LHC experiments designed to search for new physics, has been taking data for two years. ATLAS has been investigating the necessary changes to its sub-detectors to withstand much higher instantaneous luminosity and to operate after 3000 fb-1 of integrated data. The goal is to achieve the same or better performance (spatial resolution, etc.) despite the large increase in event rate and final integrated dose. The current ATLAS Muon sub-detector will not be able to handle the increased luminosity of a factor of ten. This makes it necessary to replace the current muon sub-detector by possible new gaseous chambers that push their performance to limits never tested before. This talk will focus on the different lab experiments performed at CERN, including a test beam run, and the exciting results on two of the latest chamber prototypes (R19M and R19G) developed by the ATLAS Muon detector upgrade R&D team. This is the research project the author did at CERN during summer 2011.

  15. Experimental Analysis of Gaseous Chambers for the ATLAS Muon sub-detector Upgrade R&D

    NASA Astrophysics Data System (ADS)

    Angulo, Emmanuel

    2012-11-01

    CERN, the world's largest particle accelerator facility, has begun its ambitious Large Hadron Collider (LHC) program which is and will remain as the world energy frontier until at least 2030. ATLAS, one of the LHC experiments designed to search for new physics, has been taking data for two years. ATLAS has been investigating the necessary changes to its sub-detectors to withstand much higher instantaneous luminosity and to operate after 3000 fb-1 of integrated data. The goal is to achieve the same or better performance (spatial resolution, etc.) despite the large increase in event rate and final integrated dose. The current ATLAS Muon sub-detector will not be able to handle the increased luminosity of a factor of ten. This makes it necessary to replace the current muon sub-detector by possible new gaseous chambers that push their performance to limits never tested before. This talk will focus on the different lab experiments performed at CERN during the summers of 2011 and 2012, including functional uniformity results of a new ``T-series'' chamber design developed by the ATLAS Muon detector upgrade R&D team. As a result, a new visual mapping design was developed by the author that enabled an easier way to find anomalies in the chambers. This work has been presented to ATLAS Weekly Micromegas Meeting's 6 times during the summers of 2011 and 2012.

  16. Laboratory and testbeam results for thin and epitaxial planar sensors for HL-LHC

    NASA Astrophysics Data System (ADS)

    Bubna, M.; Bortoletto, D.; Bolla, G.; Shipsey, I.; Manfra, M. J.; Khan, K.; Arndt, K.; Hinton, N.; Godshalk, A.; Kumar, A.; Menasce, D.; Moroni, L.; Chramowicz, J.; Lei, C. M.; Prosser, A.; Rivera, R.; Uplegger, L.; Lo Vetere, M.; Robutti, E.; Ferro, F.; Ravera, F.; Costa, Marco

    2015-08-01

    The High-Luminosity LHC (HL-LHC) upgrade of the CMS pixel detector will require the development of novel pixel sensors which can withstand the increase in instantaneous luminosity to L=5×1034 cm-2s-1 and collect ~ 3000 fb-1 of data. The innermost layer of the pixel detector will be exposed to doses of about 1016 neq/ cm2. Hence, new pixel sensors with improved radiation hardness need to be investigated. A variety of silicon materials (Float-zone, Magnetic Czochralski and Epitaxially grown silicon), with thicknesses from 50 μm to 320 μm in p-type and n-type substrates have been fabricated using single-sided processing. The effect of reducing the sensor active thickness to improve radiation hardness by using various techniques (deep diffusion, wafer thinning, or growing epitaxial silicon on a handle wafer) has been studied. The results for electrical characterization, charge collection efficiency, and position resolution of various n-on-p pixel sensors with different substrates and different pixel geometries (different bias dot gaps and pixel implant sizes) will be presented.

  17. Laboratory and testbeam results for thin and epitaxial planar sensors for HL-LHC

    DOE PAGESBeta

    Bubna, M.; Bolla, G.; Bortoletto, D.; Shipsey, I.; Manfra, M.; Khan, K.; Arndt, K.; Hinton, N.; Godshalk, A.; Kumar, A.; et al

    2015-08-03

    The High-Luminosity LHC (HL-LHC) upgrade of the CMS pixel detector will require the development of novel pixel sensors which can withstand the increase in instantaneous luminosity to L = 5 × 1034 cm–2s–1 and collect ~ 3000fb–1 of data. The innermost layer of the pixel detector will be exposed to doses of about 1016 neq/ cm2. Hence, new pixel sensors with improved radiation hardness need to be investigated. A variety of silicon materials (Float-zone, Magnetic Czochralski and Epitaxially grown silicon), with thicknesses from 50 μm to 320 μm in p-type and n-type substrates have been fabricated using single-sided processing. The effect ofmore » reducing the sensor active thickness to improve radiation hardness by using various techniques (deep diffusion, wafer thinning, or growing epitaxial silicon on a handle wafer) has been studied. Furthermore, the results for electrical characterization, charge collection efficiency, and position resolution of various n-on-p pixel sensors with different substrates and different pixel geometries (different bias dot gaps and pixel implant sizes) will be presented.« less

  18. Laboratory and testbeam results for thin and epitaxial planar sensors for HL-LHC

    SciTech Connect

    Bubna, M.; Bolla, G.; Bortoletto, D.; Shipsey, I.; Manfra, M.; Khan, K.; Arndt, K.; Hinton, N.; Godshalk, A.; Kumar, A.; Menasce, D.; Moroni, L.; Chramowicz, J.; Lei, C. M.; Prosser, A.; Rivera, R.; Uplegger, L.; Vetere, Maurizio Lo; Robutti, Enrico; Ferro, Fabrizio; Ravera, Fabio; Costa, Marco

    2015-08-03

    The High-Luminosity LHC (HL-LHC) upgrade of the CMS pixel detector will require the development of novel pixel sensors which can withstand the increase in instantaneous luminosity to L = 5 × 1034 cm–2s–1 and collect ~ 3000fb–1 of data. The innermost layer of the pixel detector will be exposed to doses of about 1016 neq/ cm2. Hence, new pixel sensors with improved radiation hardness need to be investigated. A variety of silicon materials (Float-zone, Magnetic Czochralski and Epitaxially grown silicon), with thicknesses from 50 μm to 320 μm in p-type and n-type substrates have been fabricated using single-sided processing. The effect of reducing the sensor active thickness to improve radiation hardness by using various techniques (deep diffusion, wafer thinning, or growing epitaxial silicon on a handle wafer) has been studied. Furthermore, the results for electrical characterization, charge collection efficiency, and position resolution of various n-on-p pixel sensors with different substrates and different pixel geometries (different bias dot gaps and pixel implant sizes) will be presented.

  19. Status of LHC crab activity simulations and beam studies

    SciTech Connect

    Calaga,R.; Assman, R.; Barranco, J.; Barranco, J.; Calaga, R.; Caspers, F.; Ciapala, E.; De-Maria, R.; Koutchouk, J. P.; Linnecar, T.; Metral, E.; Morita, A.; Solyak, N.; Sun, Y.; Tomas, R.; Tuckmantel, J.; Weiler, T.; Zimmermann, F.

    2009-05-04

    The LHC crab cavity program is advancing rapidly towards a first prototype which is anticipated to be tested during the early stages of the LHC phase I upgrade and commissioning. The general project status and some aspects related to crab optics, collimation, aperture constraints, impedances, noise effects. beam transparency and machine protection critical for a safe and robust operation of LHC beams with crab cavities are addressed here.

  20. Progress with the Single-Sided Module Prototypes for the ATLAS Tracket Upgrade Stave

    SciTech Connect

    Allport, P.P.; Li, Z.; Affolder, A.A.; Anghinolfi, F.; Bates, R. et al.

    2010-06-04

    The ATLAS experiment is preparing for the planned luminosity upgrade of the LHC (the super-luminous LHC or sLHC) with a programme of development for tracking able to withstand an order of greater magnitude radiation fluence and much greater hit occupancy rates than the current detector. This has led to the concept of an all-silicon tracker with an enhanced performance pixel-based inner region and short-strips for much of the higher radii. Both sub-systems employ many common technologies, including the proposed 'stave' concept for integrated cooling and support. For the short-strip region, use of this integrated stave concept requires single-sided modules mounted on either side of a thin central lightweight support. Each sensor is divided into four rows of 23.82 mm length strips; within each row, there are 1280 strips of 74.5 {mu}m pitch. Well over a hundred prototype sensors are being delivered by Hamamatsu Photonics (HPK) to Japan, Europe and the US. We present results of the first 20 chip ABCN25 ASIC hybrids for these sensors, results of the first prototype 5120 strip module built with 40 ABCN25 read-out ASICs, and the status of the hybrids and modules being developed for the ATLAS tracker upgradestave programme.

  1. Developments in the ATLAS Tracking Software ahead of LHC Run 2

    NASA Astrophysics Data System (ADS)

    Styles, Nicholas; Bellomo, Massimiliano; Salzburger, Andreas; ATLAS Collaboration

    2015-05-01

    After a hugely successful first run, the Large Hadron Collider (LHC) is currently in a shut-down period, during which essential maintenance and upgrades are being performed on the accelerator. The ATLAS experiment, one of the four large LHC experiments has also used this period for consolidation and further developments of the detector and of its software framework, ahead of the new challenges that will be brought by the increased centre-of-mass energy and instantaneous luminosity in the next run period. This is of particular relevance for the ATLAS Tracking software, responsible for reconstructing the trajectory of charged particles through the detector, which faces a steep increase in CPU consumption due to the additional combinatorics of the high-multiplicity environment. The steps taken to mitigate this increase and stay within the available computing resources while maintaining the excellent performance of the tracking software in terms of the information provided to the physics analyses will be presented. Particular focus will be given to changes to the Event Data Model, replacement of the maths library, and adoption of a new persistent output format. The resulting CPU profiling results will be discussed, as well as the performance of the algorithms for physics processes under the expected conditions for the next LHC run.

  2. Design and prototyping of HL-LHC double quarter wave crab cavities for SPS test

    SciTech Connect

    Verdu-Andres, S.; Skaritka, J.; Wu, Q.; Xiao, B.; Belomestnykh, S.; Ben-Zvi, I.; Alberty, L.; Artoos, K.; Calaga, R.; Capatina, O.; Capelli, T.; Carra, F.; Leuxe, R.; Kuder, N.; Zanoni, C.; Li, Z.; Ratti, A.

    2015-05-03

    The LHC high luminosity project envisages the use of the crabbing technique for increasing and levelling the LHC luminosity. Double Quarter Wave (DQW) resonators are compact cavities especially designed to meet the technical and performance requirements for LHC beam crabbing. Two DQW crab cavities are under fabrication and will be tested with beam in the Super Proton Synchrotron (SPS) at CERN by 2017. This paper describes the design and prototyping of the DQW crab cavities for the SPS test.

  3. Hadron colliders (SSC/LHC)

    SciTech Connect

    Chao, A.W.; Palmer, R.B.; Evans, L.; Gareyte, J.; Siemann, R.H.

    1992-12-31

    The nominal SSC and LHC designs should operate conservatively at luminosities up to 10{sup 33} cm{sup {minus}2} s{sup {minus}1}. This luminosity is dictated by the event rates that can be handled by the detectors. However, this limit is event dependent (e.g. it does not take much of a detector to detect the event pp {yields} elephant; all one needs is extremely high luminosity). As such, it is useful to explore the possibility of going beyond the 10{sup 33} cm{sup {minus}2} s{sup {minus}1} level. Such exploration will also improve the accelerator physics understanding of pp collider designs. If the detector limitations are removed, the first accelerator limits occur when the luminosity is at the level of 10{sup 34} cm{sup {minus}2}s{sup {minus}1}. These accelerator limits will first be reviewed. The authors will then continue on to explore even higher luminosity as the ultimate limit of pp colliders. Accelerator technologies needed to achieve this ultimate luminosity as well as the R and D needed to reach it are discussed.

  4. Performance of a full-size small-strip thin gap chamber prototype for the ATLAS new small wheel muon upgrade

    NASA Astrophysics Data System (ADS)

    Abusleme, A.; Bélanger-Champagne, C.; Bellerive, A.; Benhammou, Y.; Botte, J.; Cohen, H.; Davies, M.; Du, Y.; Gauthier, L.; Koffas, T.; Kuleshov, S.; Lefebvre, B.; Li, C.; Lupu, N.; Mikenberg, G.; Mori, D.; Ochoa-Ricoux, J. P.; Codina, E. Perez; Rettie, S.; Robichaud-Véronneau, A.; Rojas, R.; Shoa, M.; Smakhtin, V.; Stelzer, B.; Stelzer-Chilton, O.; Toro, A.; Torres, H.; Ulloa, P.; Vachon, B.; Vasquez, G.; Vdovin, A.; Viel, S.; Walker, P.; Weber, S.; Zhu, C.

    2016-05-01

    The instantaneous luminosity of the Large Hadron Collider at CERN will be increased up to a factor of five with respect to the present design value by undergoing an extensive upgrade program over the coming decade. The most important upgrade project for the ATLAS Muon System is the replacement of the present first station in the forward regions with the so-called New Small Wheels (NSWs). The NSWs will be installed during the LHC long shutdown in 2019/2020. Small-Strip Thin Gap Chamber (sTGC) detectors are designed to provide fast trigger and high precision muon tracking under the high luminosity LHC conditions. To validate the design, a full-size prototype sTGC detector of approximately 1.2 × 1.0m2 consisting of four gaps has been constructed. Each gap provides pad, strip and wire readouts. The sTGC intrinsic spatial resolution has been measured in a 32 GeV pion beam test at Fermilab. At perpendicular incidence angle, single gap position resolutions of about 50 μm have been obtained, uniform along the sTGC strip and perpendicular wire directions, well within design requirements. Pad readout measurements have been performed in a 130 GeV muon beam test at CERN. The transition region between readout pads has been found to be 4 mm, and the pads have been found to be fully efficient.

  5. Tests of CMS Phase 1 Pixel Upgrade Back-End Electronics

    NASA Astrophysics Data System (ADS)

    Kilpatrick, Matthew

    2016-03-01

    The CMS detector will be upgraded so that it can handle the higher instantaneous luminosity of the 13-14 TeV collisions. The Phase 1 Pixel detector will experience a higher density of particle interactions requiring new front-end and read-out electronics. A front-end pixel data emulator was developed to validate the back-end readout electronics prior to installation and operation. A FPGA-based design emulates 400 Mbps data patterns from the front-end read-out chips and will be used to confirm that each Front End Driver (FED) can correctly decode and process the expected data patterns and error conditions. A FED test bench using the emulator can produce LHC-like conditions for stress testing FED hardware, firmware and online software. The design of the emulator and initial test results will be reported.

  6. The LHCb VELO upgrade

    NASA Astrophysics Data System (ADS)

    Dosil Suárez, Álvaro

    2016-07-01

    The upgrade of the LHCb experiment, planned for 2019, will transform the experiment to a trigger-less system reading out the full detector at 40 MHz event rate. All data reduction algorithms will be executed in a high-level software farm. The upgraded detector will run at luminosities of 2×1033 cm-2 s-1 and probe physics beyond the Standard Model in the heavy flavour sector with unprecedented precision. The Vertex Locator (VELO) is the silicon vertex detector surrounding the interaction region. The current detector will be replaced with a hybrid pixel system equipped with electronics capable of reading out at 40 MHz. The detector comprises silicon pixel sensors with 55×55 μm2 pitch, read out by the VeloPix ASIC, based on the TimePix/MediPix family. The hottest region will have pixel hit rates of 900 Mhits/s yielding a total data rate more than 3 Tbit/s for the upgraded VELO. The detector modules are located in a separate vacuum, separated from the beam vacuum by a thin custom made foil. The detector halves are retracted when the beams are injected and closed at stable beams, positioning the first sensitive pixel at 5.1 mm from the beams. The material budget will be minimised by the use of evaporative CO2 coolant circulating in microchannels within 400 μm thick silicon substrates.

  7. The ALICE Central Trigger Processor (CTP) upgrade

    NASA Astrophysics Data System (ADS)

    Krivda, M.; Alexandre, D.; Barnby, L. S.; Evans, D.; Jones, P. G.; Jusko, A.; Lietava, R.; Pospíšil, J.; Villalobos Baillie, O.

    2016-03-01

    The ALICE Central Trigger Processor (CTP) at the CERN LHC has been upgraded for LHC Run 2, to improve the Transition Radiation Detector (TRD) data-taking efficiency and to improve the physics performance of ALICE. There is a new additional CTP interaction record sent using a new second Detector Data Link (DDL), a 2 GB DDR3 memory and an extension of functionality for classes. The CTP switch has been incorporated directly onto the new LM0 board. A design proposal for an ALICE CTP upgrade for LHC Run 3 is also presented. Part of the development is a low latency high bandwidth interface whose purpose is to minimize an overall trigger latency.

  8. Diamond Pixel Luminosity Telescopes

    SciTech Connect

    Halyo, Valerie

    2014-12-23

    In this document, Halyo summaries her key contributions to CMS at the LHC and provide an explanation of their importance and her role in each project. At the end Halyo describes her recent research interest that includes GPU/MIC Acceleration of the High Level Trigger (HLT) to Extend the Physics Research at the LHC. A descriptionof her work the recent promising results that she accomplished and the deliverable are also elaborated. These contribution were only possible thanks to DOE support of junior faculty research and their clear goal to promote research and innovations. Princeton University i

  9. The D0 experiment's integrated luminosity for Tevatron Run IIa

    SciTech Connect

    Andeen, T.; Casey, B.C.K.; DeVaughan, K.; Enari, Y.; Gallas, E.; Krop, D.; Partridge, R.; Schellman, H.; Snow, G.R.; Yacoob, S.; Yoo, H.D.; /Brown U. /Fermilab /Indiana U. /Northwestern U. /Nebraska U.

    2007-04-01

    An essential ingredient in all cross section measurements is the luminosity used to normalize the data sample. In this note, we present the final assessment of the integrated luminosity recorded by the D0 experiment during Tevatron Run IIa. The luminosity measurement is derived from hit rates from the products of inelastic proton-antiproton collisions registered in two arrays of scintillation counters called the luminosity monitor (LM) detectors. Measured LM rates are converted to absolute luminosity using a normalization procedure that is based on previously measured inelastic cross sections and the geometric acceptance and efficiency of the LM detectors for registering inelastic events. During Run IIa, the LM detector performance was improved by a sequence of upgrades to the electronic readout system and other factors summarized in this note. The effects of these changes on the reported luminosity were tracked carefully during the run. Due to the changes, we partition the run into periods for which different conversions from measured LM rates to absolute luminosity apply. The primary upgrade to the readout system late in Run IIa facilitated a reevaluation of the overall normalization of the luminosity measurement for the full data sample. In this note, we first review the luminosity measurement technique employed by D0. We then summarize the changes to the LM system during Run IIa and the corresponding normalization adjustments. The effect of the adjustments is to increase D0's assessment of its recorded integrated luminosity compared to what was initially reported during Run IIa. The overall increase is 13.4% for data collected between April 20, 2002 (the beginning of Run IIa data used for physics analysis) and February 22, 2006 (the end of Run IIa).

  10. Prototypes for components of a control system for the ATLAS pixel detector at the HL-LHC

    NASA Astrophysics Data System (ADS)

    Boek, J.; Kersten, S.; Kind, P.; Mättig, P.; Püllen, L.; Zeitnitz, C.

    2013-03-01

    In the years around 2020 an upgrade of the LHC to the HL-LHC is scheduled, which will increase the accelerators luminosity by a factor of 10. In the context of this upgrade, the inner detector of the ATLAS experiment will be replaced entirely including the pixel detector. This new pixel detector requires a specific control system which complies with the strict requirements in terms of radiation hardness, material budget and space for the electronics in the ATLAS experiment. The University of Wuppertal is developing a concept for a DCS (Detector Control System) network consisting of two kinds of ASICs. The first ASIC is the DCS Chip which is located on the pixel detector, very close to the interaction point. The second ASIC is the DCS Controller which is controlling 4x4 DCS Chips from the outer regions of ATLAS via differential data lines. Both ASICs are manufactured in 130 nm deep sub micron technology. We present results from measurements from new prototypes of components for the DCS network.

  11. The LHCb trigger and its upgrade

    NASA Astrophysics Data System (ADS)

    Dziurda, A.

    2016-07-01

    The current LHCb trigger system consists of a hardware level, which reduces the LHC inelastic collision rate of 30 MHz, at which the entire detector is read out. In a second level, implemented in a farm of 20 k parallel-processing CPUs, the event rate is reduced to about 5 kHz. We review the performance of the LHCb trigger system during Run I of the LHC. Special attention is given to the use of multivariate analyses in the High Level Trigger. The major bottleneck for hadronic decays is the hardware trigger. LHCb plans a major upgrade of the detector and DAQ system in the LHC shutdown of 2018, enabling a purely software based trigger to process the full 30 MHz of inelastic collisions delivered by the LHC. We demonstrate that the planned architecture will be able to meet this challenge.

  12. QCD with LHC p-p and e-p Collisions

    NASA Astrophysics Data System (ADS)

    Ishitsuka, Masaki

    2014-09-01

    Recent results of quantum chromodynamics (QCD) studies using proton-proton collision data at the CERN Large Hadron Collider (LHC), as well as future prospects with a proton-electron collider project, the Large Hadron Electron Collider (LHeC), are presented. After the discovery of the Higgs boson, main physics subjects of the LHC are detailed studies of the Higgs properties and extensive exploration of new physics beyond the Standard Model at the energy frontier. The LHC is now in a shutdown period for the upgrade and will restart in 2015 first with the center-of-mass energy of 13 TeV and the energy will reach 14 TeV later on. The luminosity will also significantly increase with time. At a hadron collider, strong interaction takes critical roles. Therefore, comprehensive studies on QCD with theoretical and experimental aspects are essential in order to suppress the systematic uncertainties on the signal and background processes and improve the sensitivities to the new physics at the LHC. Measurements of the cross-sections and kinematics provide important tests of QCD predictions and modeling including higher order perturbative QCD calculations, proton structure encapsulated in parton distribution functions (PDFs) and parton shower and fragmentation processes. Various event topologies, such as productions of jets, electroweak bosons, heavy quarks and combination of these, have been investigated at the LHC to widely test the validity of QCD application. Among them, as an example, W production in association with charm quarks is sensitive to the PDF of strange quarks. In addition, the LHeC project proposes another approach to the QCD studies by a proton-electron collider, i.e. high resolution microscope, with a factor 4 higher center-of-mass energy with respect to the HERA collider, using a 7 TeV proton beam at the LHC with a new 60 GeV electron beam. Varieties of subjects are expected with the LHeC such as precise measurements of the PDF, distribution of partons at

  13. Unravelling strings at the CERN LHC

    SciTech Connect

    Kane, Gordon L.; Kumar, Piyush; Shao Jing

    2008-06-01

    We construct LHC signature footprints for four semirealistic string/M theory vacua with a minimal supersymmetric standard model visible sector. We find that they all give rise to limited regions in LHC signature space and are qualitatively different from each other for understandable reasons. We also propose a technique in which correlations of LHC signatures can be effectively used to distinguish among these string theory vacua. We expect the technique to be useful for more general string vacua. We argue that further systematic analysis with this approach will allow LHC data to disfavor or exclude major 'corners' of string/M theory and favor others. The technique can be used with limited integrated luminosity and improved.

  14. LHC Computing

    SciTech Connect

    Lincoln, Don

    2015-07-28

    The LHC is the world’s highest energy particle accelerator and scientists use it to record an unprecedented amount of data. This data is recorded in electronic format and it requires an enormous computational infrastructure to convert the raw data into conclusions about the fundamental rules that govern matter. In this video, Fermilab’s Dr. Don Lincoln gives us a sense of just how much data is involved and the incredible computer resources that makes it all possible.

  15. Upgrade and Operation of the DZero Central Track Trigger

    SciTech Connect

    Pangilinan, M.P.; Buehler, M.D.; /Virginia U.

    2007-04-01

    The D{O} experiment at the Fermilab p{bar p} Tevatron collider (Batavia, IL, USA) has undergone significant upgrades in anticipation of high luminosity running conditions. As part of the upgrade, the capabilities of the Central Track Trigger (CTT) to make trigger decisions based on hit patterns in the Central Fiber Tracker (CFT) have been much improved. We report on the implementation, commissioning and operation of the upgraded CTT system.

  16. Luminosity enhancements at SLAC

    SciTech Connect

    Coward, D.H.

    1984-04-01

    Several ideas are discussed that have been proposed to improve the luminosity at the SPEAR and PEP electron-positron storage rings and to insure good luminosity at the SLAC Linear Collider. There have been two proposals studied recently for SPEAR: a Microbeta insertion using Samarium Cobalt permanent magnets, and a Minibeta insertion using conventional quadrupole magnets. The notations Microbeta and minibeta used here are somewhat arbitrary since the front faces of the first quadrupole magnets for both insertions are at nearly the same distance from the interaction point.

  17. Level-2 Calorimeter Trigger Upgrade at CDF

    SciTech Connect

    Flanagan, G.U.; /Purdue U.

    2007-04-01

    The CDF Run II Level-2 calorimeter trigger is implemented in hardware and is based on an algorithm used in Run I. This system insured good performance at low luminosity obtained during the Tevatron Run II. However, as the Tevatron instantaneous luminosity increases, the limitations of the current system due to the algorithm start to become clear. In this paper, we will present an upgrade of the Level-2 calorimeter trigger system at CDF. The upgrade is based on the Pulsar board, a general purpose VME board developed at CDF and used for upgrading both the Level-2 tracking and the Level-2 global decision crate. This paper will describe the design, hardware and software implementation, as well as the advantages of this approach over the existing system.

  18. LARP Long Quadrupole: A "Long" Step Toward an LHC

    ScienceCinema

    Giorgio Ambrosio

    2010-01-08

    The beginning of the development of Nb3Sn magnets for particle accelerators goes back to the 1960?s. But only very recently has this development begun to face the challenges of fabricating Nb3Sn magnets which can meet the requirements of modern particle accelerators. LARP (the LHC Accelerator Research Program) is leading this effort focusing on long models of the Interaction Region quadrupoles for a possible luminosity upgrade of the Large Hadron Collider. A major milestone in this development is to test, by the end of 2009, 4m-long quadrupole models, which will be the first Nb3Sn accelerator-type magnets approaching the length of real accelerator magnets. The Long Quadrupoles (LQ) are ?Proof-of-Principle? magnets which are to demonstrate that Nb3Sn technology is sufficiently mature for use in high energy particle accelerators. Their design is based on the LARP Technological Quadrupole (TQ) models, under development at FNAL and LBNL, which have design gradients higher than 200 T/m and an aperture of 90 mm. Several challenges must be addressed for the successful fabrication of long Nb3Sn coils and magnets. These challenges and the solutions adopted will be presented together with the main features of the LQ magnets. Several R&D lines are participating to this effort and their contributions will be also presented.

  19. Preparing the ALICE DAQ upgrade

    NASA Astrophysics Data System (ADS)

    Carena, F.; Carena, W.; Chapeland, S.; Chibante Barroso, V.; Costa, F.; Dénes, E.; Divià, R.; Fuchs, U.; Grigore, A.; Kiss, T.; Rauch, W.; Rubin, G.; Simonetti, G.; Soós, C.; Telesca, A.; Vande Vyvre, P.; Von Haller, B.

    2012-12-01

    In November 2009, after 15 years of design and installation, the ALICE experiment started to detect and record the first collisions produced by the LHC. It has been collecting hundreds of millions of events ever since with both proton and heavy ion collisions. The future scientific programme of ALICE has been refined following the first year of data taking. The physics targeted beyond 2018 will be the study of rare signals. Several detectors will be upgraded, modified, or replaced to prepare ALICE for future physics challenges. An upgrade of the triggering and readout systems is also required to accommodate the needs of the upgraded ALICE and to better select the data of the rare physics channels. The ALICE upgrade will have major implications in the detector electronics and controls, data acquisition, event triggering and offline computing and storage systems. Moreover, the experience accumulated during more than two years of operation has also lead to new requirements for the control software. We will review all these new needs and the current R&D activities to address them. Several papers of the same conference present in more details some elements of the ALICE online system.

  20. Test Beam Results of 3D Silicon Pixel Sensors for the ATLAS upgrade

    SciTech Connect

    Grenier, P.; Alimonti, G.; Barbero, M.; Bates, R.; Bolle, E.; Borri, M.; Boscardin, M.; Buttar, C.; Capua, M.; Cavalli-Sforza, M.; Cobal, M.; Cristofoli, A.; Dalla Betta, G.F.; Darbo, G.; Da Via, C.; Devetak, E.; DeWilde, B.; Di Girolamo, B.; Dobos, D.; Einsweiler, K.; Esseni, D.; /Udine U. /INFN, Udine /Calabria U. /INFN, Cosenza /Barcelona, Inst. Microelectron. /Manchester U. /CERN /LBL, Berkeley /INFN, Genoa /INFN, Genoa /Udine U. /INFN, Udine /Oslo U. /ICREA, Barcelona /Barcelona, IFAE /SINTEF, Oslo /SINTEF, Oslo /SLAC /SLAC /Bergen U. /New Mexico U. /Bonn U. /SLAC /Freiburg U. /VTT Electronics, Espoo /Bonn U. /SLAC /Freiburg U. /SLAC /SINTEF, Oslo /Manchester U. /Barcelona, IFAE /Bonn U. /Bonn U. /CERN /Manchester U. /SINTEF, Oslo /Barcelona, Inst. Microelectron. /Calabria U. /INFN, Cosenza /Udine U. /INFN, Udine /Manchester U. /VTT Electronics, Espoo /Glasgow U. /Barcelona, IFAE /Udine U. /INFN, Udine /Hawaii U. /Freiburg U. /Manchester U. /Barcelona, Inst. Microelectron. /CERN /Fond. Bruno Kessler, Povo /Prague, Tech. U. /Trento U. /INFN, Trento /CERN /Oslo U. /Fond. Bruno Kessler, Povo /INFN, Genoa /INFN, Genoa /Bergen U. /New Mexico U. /Udine U. /INFN, Udine /SLAC /Oslo U. /Prague, Tech. U. /Oslo U. /Bergen U. /SUNY, Stony Brook /SLAC /Calabria U. /INFN, Cosenza /Manchester U. /Bonn U. /SUNY, Stony Brook /Manchester U. /Bonn U. /SLAC /Fond. Bruno Kessler, Povo

    2011-08-19

    Results on beam tests of 3D silicon pixel sensors aimed at the ATLAS Insertable-B-Layer and High Luminosity LHC (HL-LHC) upgrades are presented. Measurements include charge collection, tracking efficiency and charge sharing between pixel cells, as a function of track incident angle, and were performed with and without a 1.6 T magnetic field oriented as the ATLAS Inner Detector solenoid field. Sensors were bump bonded to the front-end chip currently used in the ATLAS pixel detector. Full 3D sensors, with electrodes penetrating through the entire wafer thickness and active edge, and double-sided 3D sensors with partially overlapping bias and read-out electrodes were tested and showed comparable performance. Full and partial 3D pixel detectors have been tested, with and without a 1.6T magnetic field, in high energy pion beams at the CERN SPS North Area in 2009. Sensors characteristics have been measured as a function of the beam incident angle and compared to a regular planar pixel device. Overall full and partial 3D devices have similar behavior. Magnetic field has no sizeable effect on 3D performances. Due to electrode inefficiency 3D devices exhibit some loss of tracking efficiency for normal incident tracks but recover full efficiency with tilted tracks. As expected due to the electric field configuration 3D sensors have little charge sharing between cells.

  1. Hipparcos luminosities and asteroseismology

    NASA Astrophysics Data System (ADS)

    Bedding, Timothy R.

    Asteroseismology involves using the resonant frequencies of a star to infer details about its internal structure and evolutionary state. Large efforts have been made and continue to be made to measure oscillation frequencies with both ground- and space-based telescopes, with typical precisions of one part in 103-104. However, oscillation frequencies are most useful when accompanied by accurate measurements of the more traditional stellar parameters such as luminosity and effective temperature. The Hipparcos catalogue provides luminosities with precisions of a few percent or better for many oscillating stars. I briefly discuss the importance of Hipparcos measurements for interpreting asteroseismic data on three types of oscillating stars: δ Scuti variables, rapidly oscillating Ap stars and solar-like stars.

  2. Top quark physics at the LHC

    NASA Astrophysics Data System (ADS)

    Kim, Tae Jeong

    2014-04-01

    In 2011, an integrated luminosity of more than 5 fb-1 at 7 TeV has been delivered by the LHC. The measurement of the cross section in top quark pair production and in single top quark production, top quark mass, top quark properties and new physics searches in top quark decays have been performed at the CMS experiment with various integrated luminosities. An overview of the latest results of these measurements and searches by the time of ICFP 2012 conference will be presented.

  3. Interaction Region Upgrades of e+ e- B-Factories

    SciTech Connect

    Sullivan, M.; /SLAC

    2008-02-22

    Both the PEP-II and KEKB B-Factories have plans to upgrade their Interaction Regions (IRs) in order to improve luminosity performance. Last summer PEP-II added cooling to the IR beam pipe in order to increase beam currents thereby raising the luminosity. In addition, PEP-II is working on a design that modifies the permanent magnets near the Interaction Point (IP) for an even higher luminosity increase. KEKB is also planning an improvement to their IR that will decrease the detector beam pipe radius. In addition, KEK has a design to increase the luminosity of KEKB to 1 x 10{sup 35} cm{sup -2} sec{sup -1} which includes changes to the IR. PEP-II is also investigating the feasibility of a 1 x 10{sup 36} cm{sup -2} sec{sup -1} luminosity design. I summarize these various upgrades and concentrate on issues common to the different designs.

  4. The new front-end electronics for the ATLAS Tile Calorimeter Phase 2 Upgrade

    NASA Astrophysics Data System (ADS)

    Gomes, A.

    2016-02-01

    We present the plans, design, and performance results to date for the new front-end electronics being developed for the Phase 2 Upgrade of the ATLAS Tile Calorimeter. The front-end electronics will be replaced to address the increased luminosity at the HL-LHC around 2025, as well as to upgrade to faster, more modern components with higher radiation tolerance. The new electronics will operate dead-timelessly, pushing full data sets from each beam crossing to the data acquisition system that resides off-detector. The new on-detector electronics contains five main parts: the front-end boards that connect directly to the photomultiplier tubes; the Main Boards that digitize the data; the Daughter Boards that collect the data streams and contain the high speed optical communication links for writing data to the data acquisition system; a programmable high voltage control system; and a new low voltage power supply. There are different options for implementing these subcomponents, which will be described. The new system contains new features that in the current version include power system redundancy, data collection redundancy, data transmission redundancy with 2 QSFP optical transceivers and Kintex-7 FPGAs with firmware enhanced scheme for single event upset mitigation. To date, we have built a Demonstrator—a fully functional prototype of the new system. Performance results and plans are presented.

  5. SUSY searches at the LHC with the ATLAS experiment

    ScienceCinema

    None

    2011-04-25

    First ATLAS searches for signals of Supersymmetry in proton-proton collisions at the LHC are presented. These searches are performed in various channels containing different lepton and jet multiplicities in the final states; the full data sample recorded in the 2010 LHC run, corresponding to an integrated luminosity of 35 pb-1, has been analysed. Limits on squarks and gluins are the most stringent to date.

  6. Upgrade of the ATLAS Level-1 Trigger with event topology information

    NASA Astrophysics Data System (ADS)

    Simioni, E.; Artz, S.; Bauβ, B.; Büscher, V.; Jakobi, K.; Kaluza, A.; Kahra, C.; Palka, M.; Reiβ, A.; Schäffer, J.; Schäfer, U.; Schulte, A.; Simon, M.; Tapprogge, S.; Vogel, A.; Zinser, M.

    2015-12-01

    The Large Hadron Collider (LHC) in 2015 will collide proton beams with increased luminosity from 1034 up to 3 × 1034cm-2s-1. ATLAS is an LHC experiment designed to measure decay properties of high energetic particles produced in the protons collisions. The higher luminosity places stringent operational and physical requirements on the ATLAS Trigger in order to reduce the 40MHz collision rate to a manageable event storage rate of 1kHz while at the same time, selecting those events with valuable physics meaning. The Level-1 Trigger is the first rate-reducing step in the ATLAS Trigger, with an output rate of 100kHz and decision latency of less than 2.5µs. It is composed of the Calorimeter Trigger (L1Calo), the Muon Trigger (L1Muon) and the Central Trigger Processor (CTP). By 2015, there will be a new electronics element in the chain: the Topological Processor System (L1Topo system). The L1Topo system consist of a single AdvancedTCA shelf equipped with three L1Topo processor blades. It will make it possible to use detailed information from L1Calo and L1Muon processed in individual state-of-the-art FPGA processors. This allows the determination of angles between jets and/or leptons and calculates kinematic variables based on lists of selected/sorted objects. The system is designed to receive and process up to 6Tb/s of real time data. The paper reports the relevant upgrades of the Level-1 trigger with focus on the topological processor design and commissioning.

  7. Superconducting Magnet Technology for the Upgrade

    SciTech Connect

    Todesco, E.; Ambrosio, G.; Ferracin, P.; Rifflet, J. M.; Sabbi, G. L.; Segreti, M.; Nakamoto, T.; van Weelderen, R.; Xu, Q.

    2015-10-01

    In this section we present the magnet technology for the High Luminosity LHC. After a short review of the project targets and constraints, we discuss the main guidelines used to determine the technology, the field/gradients, the operational margins, and the choice of the current density for each type of magnet. Then we discuss the peculiar aspects of each class of magnet, with special emphasis on the triplet.

  8. Geometric beam coupling impedance of LHC secondary collimators

    NASA Astrophysics Data System (ADS)

    Frasciello, Oscar; Tomassini, Sandro; Zobov, Mikhail; Salvant, Benoit; Grudiev, Alexej; Mounet, Nicolas

    2016-02-01

    The High Luminosity LHC project is aimed at increasing the LHC luminosity by an order of magnitude. One of the key ingredients to achieve the luminosity goal is the beam intensity increase. In order to keep beam instabilities under control and to avoid excessive power losses a careful design of new vacuum chamber components and an improvement of the present LHC impedance model are required. Collimators are among the major impedance contributors. Measurements with beam have revealed that the betatron coherent tune shifts were higher by about a factor of 2 with respect to the theoretical predictions based on the LHC impedance model up to 2012. In that model the resistive wall impedance has been considered as the dominating impedance contribution for collimators. By carefully simulating also their geometric impedance we have contributed to the update of the LHC impedance model, reaching also a better agreement between the measured and simulated betatron tune shifts. During the just ended LHC Long Shutdown I (LSI), TCS/TCT collimators were replaced by new devices embedding BPMs and TT2-111R ferrite blocks. We present here preliminary estimations of their broad-band impedance, showing that an increase of about 20% is expected in the kick factors with respect to previous collimators without BPMs.

  9. Color Sextet Scalars in Early LHC Experiments

    SciTech Connect

    Berger, Edmond L.; Cao Qinghong; Chen, Chuan-Ren; Shaughnessy, Gabe; Zhang Hao

    2010-10-29

    We explore the potential for discovery of an exotic color sextet scalar in same-sign top quark pair production in early running at the LHC. We present the first phenomenological analysis at colliders of color sextet scalars with full top quark spin correlations included. We demonstrate that one can measure the scalar mass, the top quark polarization, and confirm the scalar resonance with 1 fb{sup -1} of integrated luminosity. The top quark polarization can distinguish gauge triplet and singlet scalars.

  10. hhjj production at the LHC

    DOE PAGESBeta

    Dolan, Matthew J.; Englert, Christoph; Greiner, Nicolas; Nordstrom, Karl; Spannowsky, Michael

    2015-08-25

    The search for di-Higgs production at the LHC in order to set limits on the Higgs trilinear coupling and constraints on new physics is one of the main motivations for the LHC high-luminosity phase. Recent experimental analyses suggest that such analyses will only be successful if information from a range of channels is included. We therefore investigate di-Higgs production in association with two hadronic jets and give a detailed discussion of both the gluon- and the weak boson-fusion (WBF) contributions, with a particular emphasis on the phenomenology with modified Higgs trilinear and quartic gauge couplings. We perform a detailed investigationmore » of the full hadronic final state and find that hhjj production should add sensitivity to a di-Higgs search combination at the HL-LHC with 3 ab-1. Since the WBF and GF contributions are sensitive to different sources of physics beyond the Standard Model, we devise search strategies to disentangle and isolate these production modes. In addition, while gluon fusion remains non-negligible in WBF-type selections, sizeable new physics contributions to the latter can still be constrained. As an example of the latter point we investigate the sensitivity that can be obtained for a measurement of the quartic Higgs–gauge boson couplings.« less

  11. The LUCID detector ATLAS luminosity monitor and its electronic system

    NASA Astrophysics Data System (ADS)

    Manghi, F. Lasagni

    2016-07-01

    In 2015 LHC is starting a new run, at higher center of mass energy (13 TeV) and with 25 ns bunch-spacing. The ATLAS luminosity monitor LUCID has been completely rebuilt, both the detector and the electronics, in order to cope with the new running conditions. The new detector electronics features a new read-out board (LUCROD) for signal acquisition and digitization, PMT-charge integration and single-side luminosity measurements, and a revisited LUMAT board for combination of signals from the two detectors. This note describes the new board design, the firmware and software developments, the implementation of luminosity algorithms, the optical communication between boards and the integration into the ATLAS TDAQ system.

  12. Machine optics studies for the LHC measurements

    NASA Astrophysics Data System (ADS)

    Trzebiński, Maciej

    2014-11-01

    In this work the properties of scattered protons in the vicinity of the ATLAS Interaction Point (IP1) for various LHC optics settings are discussed. Firstly, the beam elements installed around IP1 are presented. Then the ATLAS forward detector systems: Absolute Luminosity For ATLAS (ALFA) and ATLAS Forward Protons (AFP) are described and their similarities and differences are discussed. Next, the various optics used at Large Hadron Collider (LHC) are described and the beam divergence and width at the Interaction Point as well as at the ATLAS forward detectors locations are calculated. Finally, the geometric acceptance of the ATLAS forward detectors is shown and the impact of the LHC collimators on it is discussed.

  13. Higgs coupling measurements at the LHC

    NASA Astrophysics Data System (ADS)

    Englert, Christoph; Kogler, Roman; Schulz, Holger; Spannowsky, Michael

    2016-07-01

    Due to the absence of tantalising hints for new physics during the LHC's Run 1, the extension of the Higgs sector by dimension-six operators will provide the new phenomenological standard for searches of non-resonant extensions of the Standard Model. Using all dominant and subdominant Higgs production mechanisms at the LHC, we compute the constraints on Higgs physics-relevant dimension-six operators in a global and correlated fit. We show in how far these constraints can be improved by new Higgs channels becoming accessible at higher energy and luminosity, both through inclusive cross sections as well as through highly sensitive differential distributions. This allows us to discuss the sensitivity to new effects in the Higgs sector that can be reached at the LHC if direct hints for physics beyond the SM remain elusive. We discuss the impact of these constraints on well-motivated BSM scenarios.

  14. Prospects for Higgs and SM measurements at the HL-LHC

    NASA Astrophysics Data System (ADS)

    Savin, Alexander A.

    2015-05-01

    After a succesful startup of the LHC scientific program that has led to discovery of the Higgs boson it is time to make plans for the future. The high luminosity LHC (HLLHC) project is discussed, plans for possible Higgs and SM measurements are reviewed.

  15. Physics capabilities of the DO upgrade detector

    SciTech Connect

    Ellison, J.

    1994-11-01

    The D0 detector at Fermilab is being upgraded to meet the demands imposed by high luminosity Tevatron running planned to begin in 1998. The central tracking detectors will be replaced with silicon and scintillating fiber tracking systems inside a solenoidal magnetic field and a preshower detector will be added to aid in electron identification. The design and performance of these systems are described and detailed simulations of the physics capabilities of the upgraded detector are presented. In particular the authors focus on the study of electroweak boson properties and top quark physics and briefly describe the b-physics capabilities.

  16. Total dose dependence of oxide charge, interstrip capacitance and breakdown behavior of sLHC prototype silicon strip detectors and test structures of the SMART collaboration

    NASA Astrophysics Data System (ADS)

    Sadrozinski, H. F.-W.; Betancourt, C.; Heffern, R.; Henderson, I.; Pixley, J.; Polyakov, A.; Wilder, M.; Boscardin, M.; Piemonte, C.; Pozza, A.; Zorzi, N.; Dalla Betta, G.-F.; Resta, G.; Bruzzi, M.; Macchiolo, A.; Borrello, L.; Messineo, A.; Creanza, D.; Manna, N.

    2007-09-01

    Within the R&D Program for the luminosity upgrade proposed for the Large Hadron Collider (LHC), silicon strip detectors (SSD) and test structures (TS) were manufactured on several high-resistivity substrates: p-type Magnetic Czochralski (MCz) and Float Zone (FZ), and n-type FZ. To test total dose (TID) effects they were irradiated with 60Co gammas and the impact of surface radiation damage on the detector properties was studied. Selected results from the pre-rad and post-rad characterization of detectors and TS are presented, in particular interstrip capacitance and resistance, break-down voltage, flatband voltage and oxide charge. Surface damage effects show saturation after 150 krad and breakdown performance improves considerably after 210 krad. Annealing was performed both at room temperature and at 60 °C, and large effects on the surface parameters observed.

  17. Weak-strong Beam-beam Simulations for HL-LHC

    SciTech Connect

    Banfi, Danilo; Barranco, Javier; Pieloni, Tatiana; Valishev, Alexander

    2014-07-01

    In this paper we present dynamic aperture studies for possible High Luminosity LHC optics in the presence of beam-beam interactions, crab crossing schemes and magnets multipolar errors. Possible operational scenarios of luminosity leveling by transverse offset and betatron function are also studied and the impact on the beams stability is discussed.

  18. Upgrade of the Upstream Tracker at LHCb

    NASA Astrophysics Data System (ADS)

    Andrews, Jason; LHCb Collaboration

    2015-04-01

    The LHCb detector will be upgraded to allow it operate at higher collider luminosity without the need for a hardware trigger stage. Flavor enriched events will be selected in a software based, high level trigger, using fully reconstructed events. This presentation will describe the design, optimization and the expected performance of the Upstream Tracker (UT), which has a critical role in high level trigger scheme.

  19. The Design of an Upgrade to the Level-1 Trigger for the Endcap Muon System of the CMS Experiment

    NASA Astrophysics Data System (ADS)

    Carver, Matthew

    2014-03-01

    We present a description of a novel track finding algorithm and associated hardware to be implemented as an upgrade to the L1-Trigger of the endcap muon system of the CMS experiment at the LHC in Geneva, Switzerland. To handle the increased luminosity and pile-up expected from the LHC after the current shutdown, the algorithm uses predefined patterns to identify tracks left by muons in the detector at a rate of 40 MHz. If multiple tracks are found they are sorted on the quality of the muon, defined by the number of hit detectors and straightness of the pattern. The track finding logic is pipelined such that the trigger will operate with no deadtime and has an available latency on the order of 1 μs to make a decision. The electronics board housing this logic makes use of state-of-the-art field-programmable gate arrays and large memory lookup tables to accomplish its track finding purpose. Preliminary studies on simulated data show roughly 99.5% efficiency for both single and multiple muon tracks.

  20. Assembly Tests of the First Nb 3 Sn Low-Beta Quadrupole Short Model for the Hi-Lumi LHC

    DOE PAGESBeta

    Pan, H.; Felice, H.; Cheng, D. W.; Anderssen, E.; Ambrosio, G.; Perez, J. C.; Juchno, M.; Ferracin, P.; Prestemon, S. O.

    2016-01-18

    In preparation for the high-luminosity upgrade of the Large Hadron Collider (LHC), the LHC Accelerator Research Program (LARP) in collaboration with CERN is pursuing the development of MQXF: a 150-mm-aperture high-field Nb3Sn quadrupole magnet. Moreover, the development phase starts with the fabrication and test of several short models (1.2-m magnetic length) and will continue with the development of several long prototypes. All of them are mechanically supported using a shell-based support structure, which has been extensively demonstrated on several R&D models within LARP. The first short model MQXFS-AT has been assembled at LBNL with coils fabricated by LARP and CERN.more » In our paper, we summarize the assembly process and show how it relies strongly on experience acquired during the LARP 120-mm-aperture HQ magnet series. We also present comparison between strain gauges data and finite-element model analysis. Finally, we present the implication of the MQXFS-AT experience on the design of the long prototype support structure.« less

  1. STS atmospheric luminosities

    NASA Technical Reports Server (NTRS)

    Mende, S. B.

    1984-01-01

    During the STS-8 space shuttle mission special photographic and TV operations were carried out to record the properties of the spacecraft induced luminosities. One of these luminous phenomena is the quiescent vehicle glow which was photographed during the STS-8 mission with an image intensified photographic camera, with and without an objective grating. During the latter part of the mission the altitude of the shuttle was relatively low (120 n.m. = 222 km) and unprecedentedly high intensity of the glow was observed. The crew reported that the glow was easily visible to the naked eye. The proper orientation of the shuttle with respect to the velocity vector and the objective grating permitted the exposure of good objective spectrum of the glow in the visible region. From the results it is clear that the spectrum appears to be a continuum as observed by the image intensifier objective grating camera. Qualitative examination of the data shows that there is very tail little glow ion the wavelength range of 4300 to about 5000 angstroms. Above 5000 angstroms the glow becomes stronger towards the red and then it falls off towards higher wavelength and of the spectrum presumably because of the responsivity of the device.

  2. The operation of the LHC accelerator complex (1/2)

    ScienceCinema

    None

    2011-10-06

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  3. The operation of the LHC accelerator complex (2/2)

    ScienceCinema

    None

    2011-10-06

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  4. The operation of the LHC accelerator complex (1/2)

    SciTech Connect

    2010-04-07

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  5. The operation of the LHC accelerator complex (2/2)

    SciTech Connect

    2010-04-09

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  6. High luminosity muon collider design

    SciTech Connect

    Palmer, R.; Gallardo, J.

    1996-10-01

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

  7. High speed data transmission on small gauge cables for the ATLAS Phase-II Pixel detector upgrade

    NASA Astrophysics Data System (ADS)

    Shahinian, J.; Volk, J.; Fadeyev, V.; Grillo, A. A.; Meimban, B.; Nielsen, J.; Wilder, M.

    2016-03-01

    The High Luminosity LHC will present a number of challenges for the upgraded ATLAS detector. In particular, data transmission requirements for the upgrade of the ATLAS Pixel detector will be difficult to meet. The expected trigger rate and occupancy imply multi-gigabit per second transmission rates will be required but radiation levels at the smallest radius preclude completely optical solutions. Electrical transmission up to distances of 7m will be necessary to move optical components to an area with lower radiation levels. Here, we explore the use of small gauge electrical cables as a high-bandwidth, radiation hard solution with a sufficiently small radiation length. In particular, we present a characterization of various twisted wire pair (TWP) configurations of various material structures, including measurements of their bandwidth, crosstalk, and radiation hardness. We find that a custom ``hybrid'' cable consisting of 1m of a multi-stranded TWP with Poly-Ether-Ether-Ketone (PEEK) insulation and a thin Al shield followed by 6m of a thin twin-axial cable presents a low-mass solution that fulfills bandwidth requirements and is expected to be sufficiently radiation hard. Additionally, we discuss preliminary results of using measured S-parameters to produce a SPICE model for a 1m sample of the custom TWP to be used for the development of new pixel readout chips.

  8. Beam losses due to abrupt crab cavity failures in the LHC

    SciTech Connect

    Baer, T.; Barranco, J.; Calaga, R.; Tomas, R.; Wenninger, B.; Yee, B.; Zimmermann, F.

    2011-03-28

    A major concern for the implementation of crab crossing in a future High-Luminosity LHC (HL-LHC) is machine protection in an event of a fast crab-cavity failure. Certain types of abrupt crab-cavity amplitude and phase changes are simulated to characterize the effect of failures on the beam and the resulting particle-loss signatures. The time-dependent beam loss distributions around the ring and particle trajectories obtained from the simulations allow for a first assessment of the resulting beam impact on LHC collimators and on sensitive components around the ring. Results for the nominal LHC lattice is presented.

  9. The BaBar Level 1 Drift-Chamber Trigger Upgrade With 3D Tracking

    SciTech Connect

    Chai, X.D.; /Iowa U.

    2005-11-29

    At BABAR, the Level 1 Drift Chamber trigger is being upgraded to reduce increasing background rates while the PEP-II luminosity keeps improving. This upgrade uses the drift time information and stereo wires in the drift chamber to perform a 3D track reconstruction that effectively rejects background events spread out along the beam line.

  10. CDF level 2 trigger upgrade

    SciTech Connect

    Anikeev, K.; Bogdan, M.; DeMaat, R.; Fedorko, W.; Frisch, H.; Hahn, K.; Hakala, M.; Keener, P.; Kim, Y.; Kroll, J.; Kwang, S.; Lewis, J.; Lin, C.; Liu, T.; Marjamaa, F.; Mansikkala, T.; Neu, C.; Pitkanen, S.; Reisert, B.; Rusu, V.; Sanders, H.; /Fermilab /Chicago U. /Pennsylvania U.

    2006-01-01

    We describe the new CDF Level 2 Trigger, which was commissioned during Spring 2005. The upgrade was necessitated by several factors that included increased bandwidth requirements, in view of the growing instantaneous luminosity of the Tevatron, and the need for a more robust system, since the older system was reaching the limits of maintainability. The challenges in designing the new system were interfacing with many different upstream detector subsystems, processing larger volumes of data at higher speed, and minimizing the impact on running the CDF experiment during the system commissioning phase. To meet these challenges, the new system was designed around a general purpose motherboard, the PULSAR, which is instrumented with powerful FPGAs and modern SRAMs, and which uses mezzanine cards to interface with upstream detector components and an industry standard data link (S-LINK) within the system.

  11. Beam dynamics and expected RHIC performance with 56MHz RF upgrade

    SciTech Connect

    Fedotov,A.V.; Ben-Zvi, I.

    2009-05-04

    An upgrade of the RHIC storage RF system with a superconducting 56 MHz cavity was recently proposed. This upgrade will provide a significant increase in the acceptance of the RHIC 197 MHz storage RF bucket. This paper summarizes simulations of beam evolution due to intra-beam scattering (IBS) for beam parameters expected with the 56 MHz SRF cavity upgrade. Expected luminosity improvements are shown for Au ions at 100 GeV/nucleon and protons at 250 GeV.

  12. Cornering diphoton resonance models at the LHC

    NASA Astrophysics Data System (ADS)

    Backović, Mihailo; Kulkarni, Suchita; Mariotti, Alberto; Sessolo, Enrico Maria; Spannowsky, Michael

    2016-08-01

    We explore the ability of the high luminosity LHC to test models which can explain the 750 GeV diphoton excess. We focus on a wide class of models where a 750 GeV singlet scalar couples to Standard Model gauge bosons and quarks, as well as dark matter. Including both gluon and photon fusion production mechanisms, we show that LHC searches in channels correlated with the diphoton signal will be able to probe wide classes of diphoton models with L ˜ 3000 fb-1 of data. Furthermore, models in which the scalar is a portal to the dark sector can be cornered with as little as L ˜ 30 fb-1.

  13. Status and upgrade of the LHCb Vertex Locator

    NASA Astrophysics Data System (ADS)

    Gersabeck, M.

    2014-06-01

    The LHCb Vertex Locator (VELO) is the detector responsible for the detection of heavy hadrons through their flight distance. The performance of the VELO during its three years of operation during the LHC physics runs is presented, focussing on the latest studies. The primary results presented are the first observation of type-inversion at the LHC; a comparison of n-type and p-type silicon in operation; and the observation of a radiation-induced charge loss effect due to the presence of a second metal layer. The upgrade of the LHCb experiment, planned for 2018, will transform the entire readout to a trigger-less system operating at 40 MHz. The upgraded VELO must be light weight, radiation hard, and compatible with LHC vacuum requirements. The material budget will be optimised with the use of evaporative CO2 coolant circulating in micro-channels within a thin silicon substrate. The current status of the VELO upgrade will be described together with a presentation of recent test results, and a discussion of the R&D on alternative solutions which has been carried out within the LHCb VELO upgrade programme.

  14. Conceptual design of a 2 tesla superconducting solenoid for the Fermilab D{O} detector upgrade

    SciTech Connect

    Brzezniak, J.; Fast, R.W.; Krempetz, K.

    1994-05-01

    This paper presents a conceptual design of a superconducting solenoid to be part of a proposed upgrade for the D0 detector. This detector was completed in 1992, and has been taking data since then. The Fermilab Tevatron had scheduled a series of luminosity enhancements prior to the startup of this detector. In response to this accelerator upgrade, efforts have been underway to design upgrades for D0 to take advantage of the new luminosity, and improvements in detector technology. This magnet is conceived as part of the new central tracking system for D0, providing a radiation-hard high-precision magnetic tracking system with excellent electron identification.

  15. LHCb RICH Upgrade: an overview of the photon detector and electronic system

    NASA Astrophysics Data System (ADS)

    Cassina, L.

    2016-01-01

    The LHCb experiment is one of the four large detectors operating at the LHC at CERN and it is mainly devoted to CP violation measurements and to the search for new physics in rare decays of beauty and charm hadrons. The data from the two Ring Image Cherenkov (RICH-1 and RICH-2) detectors are essential to identify particles in a wide momentum range. From 2019 onwards 14 TeV collisions with luminosities reaching up to 2 × 1033 cm-2s-1 with 25 ns bunch spacing are planned, with the goal of collecting 5 fb-1 of data per year. In order to avoid degradation of the PID performance at such high rate (40 MHz), the RICH detector has to be upgraded. New photodetectors (Multi-anode photomultiplier tubes, MaPMTs) have been chosen and will be read out using an 8-channel chip, named CLARO, designed to sustain a photon counting rate up to 40 MHz, while minimizing the power consumption and the cross-talk. A 128-bit digital register allows selection of thresholds and attenuation values and provides features useful for testing and debugging. Photosensors and electronics are arranged in basic units, the first prototypes of which have been tested in charged particle beams in autumn 2014. An overview of the CLARO features and of the readout electronics is presented.

  16. R&D studies of the ATLAS LAr calorimeter readout electronics for super-LHC

    SciTech Connect

    Chen, H.

    2010-11-01

    The ATLAS Liquid Argon (LAr) calorimeters are high precision, high sensitivity and high granularity detectors. A total of 182,468 signals are digitized and processed real-time on detector, to provide energy and time deposited in each detector element at every occurrence of the L1-trigger. The current readout electronics will need to be upgraded to sustain the higher radiation levels expected with the increase of a factor 10 in luminosity at the LHC in the years {approx}2017. A completely innovative readout scheme is being developed. The front-end readout will send out data continuously at each bunch crossing through high speed radiation resistant optical links, the data will be processed real-time with the possibility of implementing trigger algorithms. This article is an overview of the R&D activities and architectural studies the ATLAS LAr Calorimeter Group is developing: front-end analog and mixed-signal ASIC design, radiation resistance optical-links in SOS, high-speed back-end processing units based on FPGA architectures and power supply distribution schemes.

  17. Upgrade of the ALICE Inner Tracking System

    NASA Astrophysics Data System (ADS)

    Kushpil, Svetlana; ALICE Collaboration

    2016-02-01

    ALICE detector was constructed to study the properties of hot and dense hadronic matter formed in relativistic nuclear collisions. During the second long LHC shutdown in 2019-2020, the collaboration plans to upgrade the current vertex detector, the Inner Tracking System (ITS), in order to increase the reconstruction accuracy of secondary vertices and to lower the threshold of particle transverse momentum measurement. The upgrade strategy of ITS is based on the application of new Monolithic Active Pixel Sensors (MAPS) designed in 0.18 μm CMOS technology. The 50 μm thick chip consists of a single silicon die incorporating a 0.18 μm high-resistivity silicon epitaxial layer (sensor active volume) and matrix of charge collection diodes (pixels) with readout electronics. Radiation hardness of the upgraded ITS is one of the crucial moments in the overall performance of the system. A wide set of MAPS structures with different read-out circuits was produced and is being studied by the ALICE collaboration to optimize the pixel sensor functionality. An overview of the ALICE ITS upgrade and the expected performance improvement will be presented together with selected results from a campaign that includes several irradiation and beam tests.

  18. ATLAS Tracking Detector Upgrade studies using the Fast Simulation Engine

    NASA Astrophysics Data System (ADS)

    Calace, Noemi; Salzburger, Andreas

    2015-12-01

    The successful physics program of the LHC Run-1 data taking period has put a strong emphasis on design studies for future upgrades of the existing LHC detectors. In ATLAS, testing alternative layouts through the full simulation and reconstruction chain is a work-intensive program, which can only be carried out for a few concept layouts. To facilitate layout prototyping, a novel technique based on the ATLAS reconstruction geometry and a fast simulation engine have been established that allow fast layout iterations and a realistic but fast Monte Carlo simulation. This approach is extended by a fast digitisation and reconstruction module.

  19. Top channel for early supersymmetry discovery at the LHC

    SciTech Connect

    Kane, Gordon L.; Kuflik, Eric; Lu, Ran; Wang, Lian-Tao

    2011-11-01

    Arguably the best-motivated channel for early LHC discovery is events including a high multiplicity of third generation quarks, such as four top quarks. For example generic string theories compactified to four dimensions with stabilized moduli typically have light gluinos with large branching ratios to t- and b-quarks. We analyze signals and background at 7 TeV LHC energy for 1 fb{sup -1} integrated luminosity, suggesting a reach for gluinos of about 650 GeV. A non-standard model signal from counting b-jets and leptons is robust, and provides information on the gluino mass, cross section, and spin.

  20. Study of Higgs boson production and its b-b(bar) decay in gamma-gamma processes in proton-nucleus collisions at the LHC

    SciTech Connect

    d'Enterria, David; Lansberg, Jean-Philippe; /Ecole Polytechnique, CPHT /SLAC

    2010-08-26

    We explore for the first time the possibilities to measure an intermediate-mass (m{sub H} = 115-140 GeV/c{sup 2}) Standard-Model Higgs boson in electromagnetic proton-lead (p Pb) interactions at the CERN Large Hadron Collider (LHC) via its b{bar b} decay. Using equivalent Weizsacker-Williams photon fluxes and Higgs effective field theory for the coupling {gamma}{gamma} {yields} H, we obtain a leading-order cross section of the order of 0.3 pb for exclusive Higgs production in elastic (p Pb {yields} {gamma}{gamma} p H Pb) and semielastic (p Pb {yields} {gamma}{gamma} X H Pb) processes at {radical}S{sub NN} = 8.8 TeV. After applying various kinematics cuts to remove the main backgrounds ({gamma}{gamma} {yields} b{bar b} and misidentified {gamma}{gamma} {yields} q{bar q} events), we find that a Higgs boson with m{sub H} = 120 GeV/c{sup 2} could be observed in the b{bar b} channel with a 3{sigma}-significance integrating 300 pb{sup -1} with an upgraded pA luminosity of 10{sup 31} cm{sup -2}s{sup -1}. We also provide for the first time semielastic Higgs cross sections, along with elastic t{bar t} cross sections, for electromagnetic pp, pA and AA collisions at the LHC.

  1. Evolutionary variations of solar luminosity

    NASA Technical Reports Server (NTRS)

    Endal, A. S.

    1982-01-01

    The Theoretical arguments for a 30% increase in the solar luminosity over the past 4.7 billion years are reviewed. A scaling argument shows that this increase can be predicted without detailed numerical calculations. The magnitude of the increase is independent of nuclear reaction rates, as long as conversion of hydrogen to helium provides the basic energy source of the Sun. The effect of the solar luminosity increase on the terrestrial climate is briefly considered. It appears unlikely that an enhanced greenhouse effect, due to reduced gases (NH3, CH4), can account for the long-term paleoclimatic trends.

  2. Constraints on anomalous top quark couplings at the LHC

    SciTech Connect

    Rizzo, T.G.

    1996-09-01

    Measurements of distributions associated with the pair production of top quarks at the LHC can be used to constrain (or observe) the anomalous chromomagnetic dipole moment(k) of the top. For example, using either the tt(bar) invariant mass or the Pt distribution of top we find that sensitivities to ; k; of order 0.05 are obtainable with 100 /fb of integrated luminosity. This is similar in magnitude to what can be obtained at a 500 GeV NLC with an integrated luminosity of 50 /fb through an examination of the e(+)e(-) right arrow tt(bar)g process.

  3. EPIC Computer Upgrade

    NASA Video Gallery

    Expedition 30 Commander Dan Burbank and Flight Engineer Don Pettit work on installing hardware for the Enhanced Processor and Integrated Communications (EPIC) upgrade of the International Space Sta...

  4. RHIC OPERATIONAL STATUS AND UPGRADE PLANS.

    SciTech Connect

    FISCHER, W.

    2006-06-23

    Since 2000 RHIC has collided, at 8 energies, 4 combinations of ion species, ranging from gold ions to polarized protons, and including the collisions of deuterons with gold ions. During that time the heavy ion and polarized proton peak luminosities increased by two orders and one order of magnitude respectively. The average proton polarization in store reached 65%. Planned upgrades include the evolution to the Enhanced Design parameters by about 2008, the construction of an Electron Beam Ion Source (EBIS) by 2009, the installation of electron cooling for RHIC II, and the implementation of the electron-ion collider eRHIC. We review the current performance, and the expected performance with these upgrades.

  5. The CDF L2 XFT Trigger Upgrade

    SciTech Connect

    Lister, Alison; /UC, Davis

    2008-10-01

    We briefly present the eXtremely Fast Tracker stereo track upgrade for the CDF Level 2 trigger system. This upgrade enabled full 3D track reconstruction at Level 2 of the 3-Level CDF online triggering system. Using information provided by the stereo layers of the Central Outer Tracker, we can decrease the trigger rate due to fake tracks by requiring the tracks to be consistent with a single vertex in all three dimensions but also by using the track information to 'point' to the various detector components. We will also discuss the effectiveness of the Level 2 stereo track algorithm at achieving reduced trigger rates with high efficiencies during high luminosity running.

  6. Alternative glues for the production of ATLAS silicon strip modules for the Phase-II upgrade of the ATLAS Inner Detector

    NASA Astrophysics Data System (ADS)

    Poley, L.; Bloch, I.; Edwards, S.; Friedrich, C.; Gregor, I.-M.; Jones, T.; Lacker, H.; Pyatt, S.; Rehnisch, L.; Sperlich, D.; Wilson, J.

    2016-05-01

    The Phase-II upgrade of the ATLAS detector for the High Luminosity Large Hadron Collider (HL-LHC) includes the replacement of the current Inner Detector with an all-silicon tracker consisting of pixel and strip detectors. The current Phase-II detector layout requires the construction of 20,000 strip detector modules consisting of sensor, circuit boards and readout chips, which are connected mechanically using adhesives. The adhesive used initially between readout chips and circuit board is a silver epoxy glue as was used in the current ATLAS SemiConductor Tracker (SCT). However, this glue has several disadvantages, which motivated the search for an alternative. This paper presents a study of six ultra-violet (UV) cure glues and a glue pad for possible use in the assembly of silicon strip detector modules for the ATLAS upgrade. Trials were carried out to determine the ease of use, thermal conduction and shear strength. Samples were thermally cycled, radiation hardness and corrosion resistance were also determined. These investigations led to the exclusion of three UV cure glues as well as the glue pad. Three UV cure glues were found to be possible better alternatives than silver loaded glue. Results from electrical tests of first prototype modules constructed using these glues are presented.

  7. Commissioning and Initial LHC Run-2 operation of the ATLAS minimum bias trigger scintillators

    NASA Astrophysics Data System (ADS)

    Hoffmann, M.

    2016-07-01

    The Minimum Bias Trigger Scintillators (MBTS) are sub-detectors in ATLAS delivering the primary trigger for selecting events from low luminosity proton-proton, lead-lead and lead-proton collisions with the smallest possible bias. The MBTS have undergone a complete replacement before LHC Run-2 and several improvements have been implemented in the layout. Since 2014 the MBTS have been commissioned with cosmic rays and first LHC Run-2 beam splash events. We summarise the outcome of the commissioning.

  8. Medical Imaging Inspired Vertex Reconstruction at LHC

    NASA Astrophysics Data System (ADS)

    Hageböck, S.; von Toerne, E.

    2012-12-01

    Three-dimensional image reconstruction in medical applications (PET or X-ray CT) utilizes sophisticated filter algorithms to linear trajectories of coincident photon pairs or x-rays. The goal is to reconstruct an image of an emitter density distribution. In a similar manner, tracks in particle physics originate from vertices that need to be distinguished from background track combinations. In this study it is investigated if vertex reconstruction in high energy proton collisions may benefit from medical imaging methods. A new method of vertex finding, the Medical Imaging Vertexer (MIV), is presented based on a three-dimensional filtered backprojection algorithm. It is compared to the open-source RAVE vertexing package. The performance of the vertex finding algorithms is evaluated as a function of instantaneous luminosity using simulated LHC collisions. Tracks in these collisions are described by a simplified detector model which is inspired by the tracking performance of the LHC experiments. At high luminosities (25 pileup vertices and more), the medical imaging approach finds vertices with a higher efficiency and purity than the RAVE “Adaptive Vertex Reconstructor” algorithm. It is also much faster if more than 25 vertices are to be reconstructed because the amount of CPU time rises linearly with the number of tracks whereas it rises quadratically for the adaptive vertex fitter AVR.

  9. Strongly coupled fourth generation at the LHC

    SciTech Connect

    Burdman, G.; Da Rold, L.; Eboli, O. J. P.; Matheus, R. D.

    2009-04-01

    We study extensions of the standard model with a strongly coupled fourth generation. This occurs in models where electroweak symmetry breaking is triggered by the condensation of at least some of the fourth-generation fermions. With focus on the phenomenology at the LHC, we study the pair production of fourth-generation down quarks, D{sub 4}. We consider the typical masses that could be associated with a strongly coupled fermion sector, in the range (300-600) GeV. We show that the production and successive decay of these heavy quarks into final states with same-sign dileptons, trileptons, and four leptons can be easily seen above background with relatively low luminosity. On the other hand, in order to confirm the presence of a new strong interaction responsible for fourth-generation condensation, we study its contribution to D{sub 4} pair production, and the potential to separate it from standard QCD-induced heavy quark production. We show that this separation might require large amounts of data. This is true even if it is assumed that the new interaction is mediated by a massive colored vector boson, since its strong coupling to the fourth generation renders its width of the order of its mass. We conclude that, although this class of models can be falsified at early stages of the LHC running, its confirmation would require high integrated luminosities.

  10. Calculation of integrated luminosity for beams stored in the Tevatron collider

    SciTech Connect

    Finley, D.A.

    1989-03-20

    A model for calculating the integrated luminosity of beams stored in the Tevatron collider will be presented. The model determines the instantaneous luminosity by calculating the overlap integral of bunched beams passing through the interaction region. The calculation accounts for the variation in beam size due to the beta functions and also for effects due to finite longitudinal emittance and non-zero dispersion in the interaction region. The integrated luminosity is calculated for the beams as they evolve due to processes including collisions and intrabeam scattering. The model has been applied to both the extant and upgraded Tevatron collider, but is not limited to them. The original motivation for developing the computer model was to determine the reduction in luminosity due to beams with non-zero longitudinal emittances. There are two effects: the transverse beam size is increased where the dispersion is non-zero; the finite length of the beam bunch combined with an increasing /beta/ function results in an increased transverse beam size at the ends of the bunch. The derivation of a sufficiently useful analytic expression for the luminosity proved to be intractable. Instead, a numerical integration computer program was developed to calculate the luminosity in the presence of a finite longitudinal emittance. The program was then expanded into a model which allows the luminosity to vary due to changes in emittances and reduction in bunch intensities. At that point, it was not difficult to calculate the integrated luminosity. 5 refs., 2 figs., 4 tabs.

  11. Run II of the LHC: The Accelerator Science

    NASA Astrophysics Data System (ADS)

    Redaelli, Stefano

    2015-04-01

    In 2015 the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) starts its Run II operation. After the successful Run I at 3.5 TeV and 4 TeV in the 2010-2013 period, a first long shutdown (LS1) was mainly dedicated to the consolidation of the LHC magnet interconnections, to allow the LHC to operate at its design beam energy of 7 TeV. Other key accelerator systems have also been improved to optimize the performance reach at higher beam energies. After a review of the LS1 activities, the status of the LHC start-up progress is reported, addressing in particular the status of the LHC hardware commissioning and of the training campaign of superconducting magnets that will determine the operation beam energy in 2015. Then, the plans for the Run II operation are reviewed in detail, covering choice of initial machine parameters and strategy to improve the Run II performance. Future prospects of the LHC and its upgrade plans are also presented.

  12. Supersymmetry At LHC

    SciTech Connect

    Khalil, Shaaban

    2008-04-21

    One of the main motivation of the experiments at the Large Hadron Collider (LHC), scheduled to start around 2006, is to search for supersymmetric particles. The region of the parameter space of the minimal supersymmetric standard model, where supersymmetry can be discovered is investigated. We show that if supersymmetry exists at electroweak scale, it would be easy to find signals for it at the LHC. If the LHC does find supersymmetry, this would be one of the greatest achievements in the history of theoretical physics.

  13. Performance of the prototype readout system for the CMS endcap hadron calorimeter upgrade

    NASA Astrophysics Data System (ADS)

    Pastika, N. J.

    2016-03-01

    The CMS experiment at the CERN Large Hadron Collider (LHC) will upgrade the photon detection and readout systems of its barrel and endcap hadron calorimeters (HCAL) through the second long shutdown of the LHC in 2018. The upgrade includes new silicon photomultipliers (SiPMs), SiPM control electronics, signal digitization via the Fermilab QIE11 ASIC, data formatting and serialization via a Microsemi FPGA, and data transmission via CERN Versatile Link technology. The first prototype system for the endcap HCAL has been assembled and characterized on the bench and in a test beam. The design of this new system and prototype performance are described.

  14. RHIC UPGRADES FOR HEAVY IONS AND POLARIZED PROTONS.

    SciTech Connect

    FISCHER, W.; ALESSI, J.; BEN-ZVI, I.; LITVINENKO, V.; ROSER, T.

    2005-10-24

    The Relativistic Heavy Ion Collider (RHIC), in operation since 2000, has exceeded its design parameters. The Enhanced Design parameters, expected to be reached in 2009, call for a 4-fold increase over the heavy ion design luminosity, and a 15-fold increase over the proton design luminosity, the latter with an average polarization of 70%. Also in 2009, it is planned to commission a new Electron Beam Ion Source, offering increased reliability and ion species that cannot be supplied currently. The upgrade to RHIC 11, based on electron cooling of the beams, aims to increase the average heavy ion luminosity by an order of magnitude, and the polarized proton luminosity by a factor 2-5. Plans for an electron-ion collider eRHIC is covered in another article in these proceedings.

  15. Commissioning and Alignment of the Pixel Luminosity Telescope of CMS

    NASA Astrophysics Data System (ADS)

    Riley, Grant; CMS Collaboration

    2015-04-01

    The Pixel Luminosity Telescope (PLT) is one of the newest additions to the CMS detector at the LHC. It consists of 16 3-layer telescopes of silicon pixel detectors pointing toward the interaction point at the center of CMS. The pixel detectors are based on the same technology as the silicon pixel detector of CMS. The chips have an additional output, called a fast-out. This fast-out is sent whenever a hit is detected, and will be used to measure the luminosity. The fast-out can also be used to self trigger the the PLT allowing for measurement of the systematics and beam backgrounds. The PLT is expected to significantly improve the precision of the luminosity measurement that is fundamental for particle searches and cross section measurements with the CMS detector. Furthermore, with reconstructed particle trajectories, measurements of beam backgrounds and the location of the interaction point centroid can be obtained. First experiences with the PLT detector before and after installation are presented and the track reconstruction is discussed.

  16. Spin and diffractive physics with a fixed-target experiment at the LHC (AFTER-LHC)

    SciTech Connect

    Lorce, C.; Chambert, V.; Didelez, J. P.; Genolini, B.; Hadjidakis, C.; Lansberg, J. P.; Rosier, P.; Brodsky, S. J.; Ferreiro, E. G.; Fleuret, F.

    2013-04-15

    We report on the spin and diffractive physics at a future multi-purpose f xed-target experiment with proton and lead LHC beams extracted by a bent crystal. The LHC multi-TeV beams allow for the most energetic f xed-target experiments ever performed, opening new domains of particle and nuclear physics and complementing that of collider physics, in particular that of RHIC and the EIC projects. The luminosity achievable with AFTER using typical targets would surpass that of RHIC by more than 3 orders of magnitude. The f xed-target mode has the advantage to allow for measurements of single-spin asymmetries with polarized target as well as of single-diffractive processes in the target region.

  17. Proposal to upgrade the MIPP data acquisition system

    SciTech Connect

    Baker, W.; Carey, D.; Johnstone, C.; Kostin, M.; Meyer, H.; Raja, R.; /Fermilab

    2005-03-01

    The MIPP TPC is the largest contributor to the MIPP event size by far. Its readout system and electronics were designed in the 1990's and limit it to a readout rate of 60 Hz in simple events and {approx} 20 Hz in complicated events. With the readout chips designed for the ALICE collaboration at the LHC, we propose a low cost effective scheme of upgrading the MIPP data acquisition speed to 3000 Hz.

  18. Readout chip for the CMS pixel detector upgrade

    NASA Astrophysics Data System (ADS)

    Rossini, Marco

    2014-11-01

    For the CMS experiment a new pixel detector is planned for installation during the extended shutdown in winter 2016/2017. Among the changes of the detector modified front end electronics will be used for higher efficiency at peak luminosity of the LHC and faster readout. The first prototype versions of the new readout chip have been designed and produced. The results of qualification and calibration for the new chip are presented in this paper.

  19. Hydrocarbonaceous material upgrading method

    SciTech Connect

    Brecher, Lee E.; Mones, Charles G.; Guffey, Frank D.

    2015-06-02

    A hydrocarbonaceous material upgrading method may involve a novel combination of heating, vaporizing and chemically reacting hydrocarbonaceous feedstock that is substantially unpumpable at pipeline conditions, and condensation of vapors yielded thereby, in order to upgrade that feedstock to a hydrocarbonaceous material condensate that meets crude oil pipeline specification.

  20. LHC and SPS Electron Cloud Studies

    SciTech Connect

    Jimenez, J.M.; Henrist, B.; Hilleret, N.; Laurent, J.-M.; Schulte, D.; Zimmermann, F.

    2005-06-08

    The additional heat load onto the LHC beam screens of the cold magnets in the bending sections ({approx}21 km) is still considered as one of the main possible limitations of the LHC performances. Since more than three years, the characteristics of the electron cloud are being studied in the SPS at ambient (RT) and cryogenic temperatures in both dipole and field free conditions. The results obtained in the SPS in 2003 showed a vacuum cleaning (or vacuum scrubbing) on both ambient and cryogenic surfaces. On the contrary, the heat load and the electron intensity (current collected at the detector) under both dipole and field free conditions at 4.5 or 30 K had shown only a limited decrease after 12 A.h of beam i.e. beam conditioning. Water contamination coming from the unbaked upstream and downstream parts of the SPS (non-baked machine) was suspected to be responsible for this behavior. The upgrade of the existing detectors as well as the design and results obtained with the new strip detector installed in a quadrupole are presented. Preliminary results on the electron cloud build up in the quadrupole will also be presented and compared to the predictions of the simulations. The effects of the gases physisorbed at cryogenic temperature in the SPS and in the laboratory are shown and the applicability to the LHC will be discussed.

  1. The LHC Experiments

    SciTech Connect

    Lincoln, Don

    2015-03-11

    The Large Hadron Collider or LHC is the world’s biggest particle accelerator, but it can only get particles moving very quickly. To make measurements, scientists must employ particle detectors. There are four big detectors at the LHC: ALICE, ATLAS, CMS, and LHCb. In this video, Fermilab’s Dr. Don Lincoln introduces us to these detectors and gives us an idea of each one’s capabilities.

  2. Improved bounds on the heavy neutrino productions at the LHC

    NASA Astrophysics Data System (ADS)

    Das, Arindam; Okada, Nobuchika

    2016-02-01

    The Majorana neutrino in the type-I seesaw and the pseudo-Dirac neutrinos in the inverse seesaw can have sizable mixings with the light neutrinos in the standard model, through which the heavy neutrinos can be produced at the LHC. In producing the heavy neutrinos, we study a variety of initial states such as quark-quark, quark-gluon and gluon-gluon as well as photon mediated processes. For the Majorana heavy neutrino production, we consider a same-sign dilepton plus dijet as the signal events. Using the recent ATLAS and CMS data at √{s }=8 TeV with 20.3 and 19.7 fb-1 luminosities, respectively, we obtain direct upper bounds on the light-heavy neutrino mixing angles. For the pseudo-Dirac heavy neutrino production we consider the final sate with a trilepton plus missing energy as the signal events. Using the recent anomalous multilepton search by CMS at √{s }=8 TeV with 19.5 fb-1 luminosity, we obtain upper bounds on the mixing angles. Taking the varieties of initial states into account, the previously obtained upper bounds on the mixing angles have been improved. We scale our results at the 8 TeV LHC to obtain a prospective search reach at the 14 TeV LHC with high luminosities.

  3. The luminosity function of quasars

    NASA Technical Reports Server (NTRS)

    Pei, Yichuan C.

    1995-01-01

    We propose a new evolutionary model for the optical luminosity function of quasars. Our analytical model is derived from fits to the empirical luminosity function estimated by Hartwick and Schade and Warren, Hewett, and Osmer on the basis of more than 1200 quasars over the range of redshifts 0 approximately less than z approximately less than 4.5. We find that the evolution of quasars over this entire redshift range can be well fitted by a Gaussian distribution, while the shape of the luminosity function can be well fitted by either a double power law or an exponential L(exp 1/4) law. The predicted number counts of quasars, as a function of either apparent magnitude or redshift, are fully consistent with the observed ones. Our model indicates that the evolution of quasars reaches its maximum at z approximately = 2.8 and declines at higher redshifts. An extrapolation of the evolution to z approximately greater than 4.5 implies that quasars may have started their cosmic fireworks at z(sub f) approximately = 5.2-5.5. Forthcoming surveys of quasars at these redshifts will be critical to constrain the epoch of quasar formation. All the results we derived are based on observed quasars and are therefore subject to the bias of obscuration by dust in damped Ly alpha systems. Future surveys of these absorption systems at z approximately greater than 3 will also be important if the formation epoch of quasars is to be known unambiguously.

  4. Plans for Deployment of Hollow Electron Lenses at the LHC for Enhanced Beam Collimation

    SciTech Connect

    Redaelli, S.; Bertarelli, A.; Bruce, R.; Perini, D.; Rossi, A.; Salvachua, B.; Stancari, G.; Valishev, A.

    2015-06-01

    Hollow electron lenses are considered as a possible means to improve the LHC beam collimation system, providing active control of halo diffusion rates and suppressing the population of transverse halos. After a very successful experience at the Tevatron, a conceptual design of a hollow e-lens optimized for the LHC was produced. Recent further studies have led to a mature preliminary technical design. In this paper, possible scenarios for the deployment of this technology at the LHC are elaborated in the context of the scheduled LHC long shutdowns until the full implementation of the HL-LHC upgrade in 2023. Possible setups of electron beam test stands at CERN and synergies with other relevant electron beam programmes are also discussed.

  5. Proposal to upgrade the MIPP experiment

    SciTech Connect

    Isenhower, D.; Sadler, M.; Towell, R.; Watson, S.; Peterson, R.J.; Baker, W.; Carey, D.; Christian, D.; Demarteau, M.; Jensen, D.; Johnstone, C.; Meyer, H.; Raja, R.; Ronzhin, A.; Solomey, N.; Wester, W.; Gutbrod, H.; Peters, K.; Feldman, G.; Torun, Y.; Messier, M.D.; /Indiana U. /Iowa U. /Dubna, JINR /Kent State U. /Groningen, KVI /Michigan U. /St. Petersburg, INP /Purdue U. /South Carolina U. /Virginia U. /Wisconsin U., Madison

    2006-09-01

    The upgraded MIPP physics results are needed for the support of NuMI projects, atmospheric cosmic ray and neutrino programs worldwide and will permit a systematic study of non-perturbative QCD interactions. The MIPP TPC is the largest contributor to the MIPP event size by far. Its readout system and electronics were designed in the 1990's and limit it to a readout rate of 60 Hz in simple events and {approx} 20 Hz in complicated events. With the readout chips designed for the ALICE collaboration at the LHC, we propose a low cost scheme of upgrading the MIPP data acquisition speed to 3000 Hz. This will also enable us to measure the medium energy numi target to be used for the NOvA/MINERvA experiments. We outline the capabilities of the upgraded MIPP detector to obtain high statistics particle production data on a number of nuclei that will help towards the understanding and simulation of hadronic showers in matter. Measurements of nitrogen cross sections will permit a better understanding of cosmic ray shower systematics in the atmosphere. In addition, we explore the possibilities of providing tagged neutral beams using the MIPP spectrometer that may be crucial for validating the Particle Flow Algorithm proposed for calorimeters for the International Linear Collider detectors. Lastly, we outline the physics potential of such a detector in understanding non-perturbative QCD processes.

  6. Distributed Russian Tier-2 - RDIG in Simulation and Analysis of Alice Data From LHC

    NASA Astrophysics Data System (ADS)

    Bogdanov, A.; Jancurova, L.; Kiryanov, A.; Kotlyar, V.; Mitsyn, V.; Lyublev, Y.; Ryabinkin, E.; Shabratova, G.; Smirnov, S.; Stepanova, L.; Urazmetov, W.; Zarochentsev, A.

    2011-12-01

    On the threshold of LHC data there were intensive test and upgrade of GRID application software for all LHC experiments at the top of the modern LCG middleware (gLite). The update of such software for ALICE experiment at LHC, AliEn[1] had provided stable and secure operation of sites developing LHC data. The activity of Russian RDIG (Russian Data Intensive GRID) computer federation which is the distributed Tier-2 centre are devoted to simulation and analysis of LHC data in accordance with the ALICE computing model [2]. Eight sites of this federation interesting in ALICE activity upgrade their middle ware in accordance with requirements of ALICE computing what ensured success of MC production and end-user analysis activity at all eight sites. The result of occupancy and efficiency of each site in the time of LHC operation will be presented in the report. The outline the results of CPU and disk space usage at RDIG sites for the data simulation and analysis of first LHC data from the exposition of ALICE detector [3] will be presented as well. There will be presented also the information about usage of parallel analysis facility based on PROOF [4].

  7. The 12 GeV JLab Upgrade Project

    SciTech Connect

    Smith, Elton

    2009-01-01

    The upgrade of the CEBAF Accelerator at Jefferson Lab to 12 GeV will deliver high luminosity and high quality beams, which will open unique opportunities for studies of the quark and gluon structure of hadrons in the valence region. Such physics will be made accessible by substantial additions to the experimental equipment in combination with the increased energy reach of the upgraded machine. The emphasis of the talk will be on the program in a new experimental Hall D designed to search for gluonic excitations.

  8. Status of the TOTEM experiment at LHC

    NASA Astrophysics Data System (ADS)

    Baechler, J.; Antchev, G.; Aspell, P.; Atanassov, I.; Avati, V.; Berardi, V.; Berretti, M.; Bossini, E.; Bozzo, M.; Brogi, P.; Brücken, E.; Buzzo, A.; Cafagna, F.; Calicchio, M.; Catanesi, M. G.; Covault, C.; Csörgő, T.; Deile, M.; Eggert, K.; Eremin, V.; Ferretti, R.; Ferro, F.; Fiergolski, A.; Garcia, F.; Giani, S.; Greco, V.; Grzanka, L.; Heino, J.; Hilden, T.; Intonti, M. R.; Kašpar, J.; Kopal, J.; Kundrát, V.; Kurvinen, K.; Lami, S.; Latino, G.; Lauhakangas, R.; Leszko, T.; Lippmaa, E.; Lokajíček, M.; Lo Vetere, M.; Lucas Rodríguez, F.; Macrí, M.; Magaletti, L.; Mercadante, A.; Minafra, N.; Minutoli, S.; Nemes, F.; Niewiadomski, H.; Oliveri, E.; Oljemark, F.; Orava, R.; Oriunno, M.; Österberg, K.; Palazzi, P.; Procházka, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Robutti, E.; Ropelewski, L.; Ruggiero, G.; Saarikko, H.; Sanguinetti, G.; Santroni, A.; Scribano, A.; Snoeys, W.; Sziklai, J.; Taylor, C.; Turini, N.; Vacek, V.; Vítek, M.; Welti, J.; Whitmore, J.

    2013-08-01

    The TOTEM experiment is dedicated to the measurement of the total proton-proton cross-section with the luminosity-independent method and the study of elastic and diffractive scattering processes. Two tracking telescopes, T1 and T2, integrated in the CMS detector, cover the pseudo-rapidity region between 3.1 and 6.5 on both sides of the interaction point IP5. The Roman Pot (RP) stations are located at distances of ±147 m and ±220 m with respect to the interaction point to measure the very forward scattered protons at very small angles. During the LHC technical stop in winter 2010/2011, the TOTEM experiment was completed with the installation of the T1 telescope and the RP stations at ±147 m. In 2011, the LHC machine provided special optics with the large ß*=90 m, allowing TOTEM to measure the elastic scattering differential cross-section, down to the four-momentum transfer squared |t|=2×10-2 GeV2. Using the optical theorem and extrapolation of the differential cross-section to t=0 (optical point), the total p-p cross-section at the LHC energy of √{ s} = 7 TeV could be computed for the first time. Furthermore we measured with standard LHC beam optics and the energy of √{ s} = 7 TeV the forward charged particle pseudorapidity density dn/dη in the range of 5.3<|η|<6.4. The status of the experiment, the performance of the detectors with emphasis on the RPs are described and the first physics results are presented.

  9. The ALICE experiment at the CERN LHC

    NASA Astrophysics Data System (ADS)

    ALICE Collaboration; Aamodt, K.; Abrahantes Quintana, A.; Achenbach, R.; Acounis, S.; Adamová, D.; Adler, C.; Aggarwal, M.; Agnese, F.; Aglieri Rinella, G.; Ahammed, Z.; Ahmad, A.; Ahmad, N.; Ahmad, S.; Akindinov, A.; Akishin, P.; Aleksandrov, D.; Alessandro, B.; Alfaro, R.; Alfarone, G.; Alici, A.; Alme, J.; Alt, T.; Altinpinar, S.; Amend, W.; Andrei, C.; Andres, Y.; Andronic, A.; Anelli, G.; Anfreville, M.; Angelov, V.; Anzo, A.; Anson, C.; Anticić, T.; Antonenko, V.; Antonczyk, D.; Antinori, F.; Antinori, S.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Aprodu, V.; Arba, M.; Arcelli, S.; Argentieri, A.; Armesto, N.; Arnaldi, R.; Arefiev, A.; Arsene, I.; Asryan, A.; Augustinus, A.; Awes, T. C.; Äysto, J.; Danish Azmi, M.; Bablock, S.; Badalà, A.; Badyal, S. K.; Baechler, J.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baldit, A.; Bán, J.; Barbera, R.; Barberis, P.-L.; Barbet, J. M.; Barnäfoldi, G.; Barret, V.; Bartke, J.; Bartos, D.; Basile, M.; Basmanov, V.; Bastid, N.; Batigne, G.; Batyunya, B.; Baudot, J.; Baumann, C.; Bearden, I.; Becker, B.; Belikov, J.; Bellwied, R.; Belmont-Moreno, E.; Belogianni, A.; Belyaev, S.; Benato, A.; Beney, J. L.; Benhabib, L.; Benotto, F.; Beolé, S.; Berceanu, I.; Bercuci, A.; Berdermann, E.; Berdnikov, Y.; Bernard, C.; Berny, R.; Berst, J. D.; Bertelsen, H.; Betev, L.; Bhasin, A.; Baskar, P.; Bhati, A.; Bianchi, N.; Bielčik, J.; Bielčiková, J.; Bimbot, L.; Blanchard, G.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Blyth, S.; Boccioli, M.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Bombonati, C.; Bondila, M.; Bonnet, D.; Bonvicini, V.; Borel, H.; Borotto, F.; Borshchov, V.; Bortoli, Y.; Borysov, O.; Bose, S.; Bosisio, L.; Botje, M.; Böttger, S.; Bourdaud, G.; Bourrion, O.; Bouvier, S.; Braem, A.; Braun, M.; Braun-Munzinger, P.; Bravina, L.; Bregant, M.; Bruckner, G.; Brun, R.; Bruna, E.; Brunasso, O.; Bruno, G. E.; Bucher, D.; Budilov, V.; Budnikov, D.; Buesching, H.; Buncic, P.; Burns, M.; Burachas, S.; Busch, O.; Bushop, J.; Cai, X.; Caines, H.; Calaon, F.; Caldogno, M.; Cali, I.; Camerini, P.; Campagnolo, R.; Campbell, M.; Cao, X.; Capitani, G. P.; Romeo, G. Cara; Cardenas-Montes, M.; Carduner, H.; Carena, F.; Carena, W.; Cariola, P.; Carminati, F.; Casado, J.; Casanova Diaz, A.; Caselle, M.; Castillo Castellanos, J.; Castor, J.; Catanescu, V.; Cattaruzza, E.; Cavazza, D.; Cerello, P.; Ceresa, S.; Černý, V.; Chambert, V.; Chapeland, S.; Charpy, A.; Charrier, D.; Chartoire, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chepurnov, V.; Chernenko, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chochula, P.; Chiavassa, E.; Chibante Barroso, V.; Choi, J.; Christakoglou, P.; Christiansen, P.; Christensen, C.; Chykalov, O. A.; Cicalo, C.; Cifarelli-Strolin, L.; Ciobanu, M.; Cindolo, F.; Cirstoiu, C.; Clausse, O.; Cleymans, J.; Cobanoglu, O.; Coffin, J.-P.; Coli, S.; Colla, A.; Colledani, C.; Combaret, C.; Combet, M.; Comets, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Contin, G.; Contreras, J.; Cormier, T.; Corsi, F.; Cortese, P.; Costa, F.; Crescio, E.; Crochet, P.; Cuautle, E.; Cussonneau, J.; Dahlinger, M.; Dainese, A.; Dalsgaard, H. H.; Daniel, L.; Das, I.; Das, T.; Dash, A.; Da Silva, R.; Davenport, M.; Daues, H.; DeCaro, A.; de Cataldo, G.; DeCuveland, J.; DeFalco, A.; de Gaspari, M.; de Girolamo, P.; de Groot, J.; DeGruttola, D.; DeHaas, A.; DeMarco, N.; DePasquale, S.; DeRemigis, P.; de Vaux, D.; Decock, G.; Delagrange, H.; DelFranco, M.; Dellacasa, G.; Dell'Olio, C.; Dell'Olio, D.; Deloff, A.; Demanov, V.; Dénes, E.; D'Erasmo, G.; Derkach, D.; Devaux, A.; Di Bari, D.; Di Bartelomen, A.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Dialinas, M.; Diaz, L.; Díaz Valdes, R.; Dietel, T.; Dima, R.; Ding, H.; Dinca, C.; Divià, R.; Dobretsov, V.; Dobrin, A.; Doenigus, B.; Dobrowolski, T.; Domínguez, I.; Dorn, M.; Drouet, S.; Dubey, A. E.; Ducroux, L.; Dumitrache, F.; Dumonteil, E.; Dupieux, P.; Duta, V.; Dutta Majumdar, A.; Dutta Majumdar, M.; Dyhre, Th; Efimov, L.; Efremov, A.; Elia, D.; Emschermann, D.; Engster, C.; Enokizono, A.; Espagnon, B.; Estienne, M.; Evangelista, A.; Evans, D.; Evrard, S.; Fabjan, C. W.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Farano, R.; Fearick, R.; Fedorov, O.; Fekete, V.; Felea, D.; Feofilov, G.; Férnandez Téllez, A.; Ferretti, A.; Fichera, F.; Filchagin, S.; Filoni, E.; Finck, C.; Fini, R.; Fiore, E. M.; Flierl, D.; Floris, M.; Fodor, Z.; Foka, Y.; Fokin, S.; Force, P.; Formenti, F.; Fragiacomo, E.; Fragkiadakis, M.; Fraissard, D.; Franco, A.; Franco, M.; Frankenfeld, U.; Fratino, U.; Fresneau, S.; Frolov, A.; Fuchs, U.; Fujita, J.; Furget, C.; Furini, M.; Fusco Girard, M.; Gaardhøje, J.-J.; Gabrielli, A.; Gadrat, S.; Gagliardi, M.; Gago, A.; Gaido, L.; Gallas Torreira, A.; Gallio, M.; Gandolfi, E.; Ganoti, P.; Ganti, M.; Garabatos, J.; Garcia Lopez, A.; Garizzo, L.; Gaudichet, L.; Gemme, R.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Giolu, G.; Giraudo, G.; Giubellino, P.; Glasow, R.; Glässel, P.; Ferreiro, E. G.; Gonzalez Gutierrez, C.; Gonzales-Trueba, L. H.; Gorbunov, S.; Gorbunov, Y.; Gos, H.; Gosset, J.; Gotovac, S.; Gottschlag, H.; Gottschalk, D.; Grabski, V.; Grassi, T.; Gray, H.; Grebenyuk, O.; Grebieszkow, K.; Gregory, C.; Grigoras, C.; Grion, N.; Grigoriev, V.; Grigoryan, A.; Grigoryan, C.; Grigoryan, S.; Grishuk, Y.; Gros, P.; Grosse-Oetringhaus, J.; Grossiord, J.-Y.; Grosso, R.; Grynyov, B.; Guarnaccia, C.; Guber, F.; Guerin, F.; Guernane, R.; Guerzoni, M.; Guichard, A.; Guida, M.; Guilloux, G.; Gulkanyan, H.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, V.; Gustafsson, H.-A.; Gutbrod, H.; Hadjidakis, C.; Haiduc, M.; Hamar, G.; Hamagaki, H.; Hamblen, J.; Hansen, J. C.; Hardy, P.; Hatzifotiadou, D.; Harris, J. W.; Hartig, M.; Harutyunyan, A.; Hayrapetyan, A.; Hasch, D.; Hasegan, D.; Hehner, J.; Heine, N.; Heinz, M.; Helstrup, H.; Herghelegiu, A.; Herlant, S.; Herrera Corral, G.; Herrmann, N.; Hetland, K.; Hille, P.; Hinke, H.; Hippolyte, B.; Hoch, M.; Hoebbel, H.; Hoedlmoser, H.; Horaguchi, T.; Horner, M.; Hristov, P.; Hřivnáčová, I.; Hu, S.; Guo, C. Hu; Humanic, T.; Hurtado, A.; Hwang, D. S.; Ianigro, J. C.; Idzik, M.; Igolkin, S.; Ilkaev, R.; Ilkiv, I.; Imhoff, M.; Innocenti, P. G.; Ionescu, E.; Ippolitov, M.; Irfan, M.; Insa, C.; Inuzuka, M.; Ivan, C.; Ivanov, A.; Ivanov, M.; Ivanov, V.; Jacobs, P.; Jacholkowski, A.; Jančurová, L.; Janik, R.; Jasper, M.; Jena, C.; Jirden, L.; Johnson, D. P.; Jones, G. T.; Jorgensen, C.; Jouve, F.; Jovanović, P.; Junique, A.; Jusko, A.; Jung, H.; Jung, W.; Kadija, K.; Kamal, A.; Kamermans, R.; Kapusta, S.; Kaidalov, A.; Kakoyan, V.; Kalcher, S.; Kang, E.; Kapitan, J.; Kaplin, V.; Karadzhev, K.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Karpio, K.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Mohsin Khan, M.; Khanzadeev, A.; Kharlov, Y.; Kikola, D.; Kileng, B.; Kim, D.; Kim, D. S.; Kim, D. W.; Kim, H. N.; Kim, J. S.; Kim, S.; Kinson, J. B.; Kiprich, S. K.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, T.; Kiworra, V.; Klay, J.; Klein Bösing, C.; Kliemant, M.; Klimov, A.; Klovning, A.; Kluge, A.; Kluit, R.; Kniege, S.; Kolevatov, R.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kornas, E.; Koshurnikov, E.; Kotov, I.; Kour, R.; Kowalski, M.; Kox, S.; Kozlov, K.; Králik, I.; Kramer, F.; Kraus, I.; Kravčáková, A.; Krawutschke, T.; Krivda, M.; Kryshen, E.; Kucheriaev, Y.; Kugler, A.; Kuhn, C.; Kuijer, P.; Kumar, L.; Kumar, N.; Kumpumaeki, P.; Kurepin, A.; Kurepin, A. N.; Kushpil, S.; Kushpil, V.; Kutovsky, M.; Kvaerno, H.; Kweon, M.; Labbé, J.-C.; Lackner, F.; Ladron de Guevara, P.; Lafage, V.; La Rocca, P.; Lamont, M.; Lara, C.; Larsen, D. T.; Laurenti, G.; Lazzeroni, C.; LeBornec, Y.; LeBris, N.; LeGailliard, C.; Lebedev, V.; Lecoq, J.; Lee, K. S.; Lee, S. C.; Lefévre, F.; Legrand, I.; Lehmann, T.; Leistam, L.; Lenoir, P.; Lenti, V.; Leon, H.; Monzon, I. Leon; Lévai, P.; Li, Q.; Li, X.; Librizzi, F.; Lietava, R.; Lindegaard, N.; Lindenstruth, V.; Lippmann, C.; Lisa, M.; Listratenko, O. M.; Littel, F.; Liu, Y.; Lo, J.; Lobanov, V.; Loginov, V.; López Noriega, M.; López-Ramírez, R.; López Torres, E.; Lorenzo, P. M.; Løvhøiden, G.; Lu, S.; Ludolphs, W.; Lunardon, M.; Luquin, L.; Lusso, S.; Lutz, J.-R.; Luvisetto, M.; Lyapin, V.; Maevskaya, A.; Magureanu, C.; Mahajan, A.; Majahan, S.; Mahmoud, T.; Mairani, A.; Mahapatra, D.; Makarov, A.; Makhlyueva, I.; Malek, M.; Malkiewicz, T.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manea, C.; Mangotra, L. K.; Maniero, D.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marcel, A.; Marchini, S.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marin, A.; Marin, J.-C.; Marras, D.; Martinengo, P.; Martínez, M. I.; Martinez-Davalos, A.; Martínez Garcia, G.; Martini, S.; Marzari Chiesa, A.; Marzocca, C.; Masciocchi, S.; Masera, M.; Masetti, M.; Maslov, N. I.; Masoni, A.; Massera, F.; Mast, M.; Mastroserio, A.; Matthews, Z. L.; Mayer, B.; Mazza, G.; Mazzaro, M. D.; Mazzoni, A.; Meddi, F.; Meleshko, E.; Menchaca-Rocha, A.; Meneghini, S.; Meoni, M.; Mercado Perez, J.; Mereu, P.; Meunier, O.; Miake, Y.; Michalon, A.; Michinelli, R.; Miftakhov, N.; Mignone, M.; Mikhailov, K.; Milosevic, J.; Minaev, Y.; Minafra, F.; Mischke, A.; Miśkowiec, D.; Mitsyn, V.; Mitu, C.; Mohanty, B.; Moisa, D.; Molnar, L.; Mondal, M.; Mondal, N.; Montaño Zetina, L.; Monteno, M.; Morando, M.; Morel, M.; Moretto, S.; Morhardt, Th; Morsch, A.; Moukhanova, T.; Mucchi, M.; Muccifora, V.; Mudnic, E.; Müller, H.; Müller, W.; Munoz, J.; Mura, D.; Musa, L.; Muraz, J. F.; Musso, A.; Nania, R.; Nandi, B.; Nappi, E.; Navach, F.; Navin, S.; Nayak, T.; Nazarenko, S.; Nazarov, G.; Nellen, L.; Nendaz, F.; Nianine, A.; Nicassio, M.; Nielsen, B. S.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B.; Nitti, M.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noto, F.; Nouais, D.; Nyiri, A.; Nystrand, J.; Odyniec, G.; Oeschler, H.; Oinonen, M.; Oldenburg, M.; Oleks, I.; Olsen, E. K.; Onuchin, V.; Oppedisano, C.; Orsini, F.; Ortiz-Velázquez, A.; Oskamp, C.; Oskarsson, A.; Osmic, F.; Österman, L.; Otterlund, I.; Ovrebekk, G.; Oyama, K.; Pachr, M.; Pagano, P.; Paić, G.; Pajares, C.; Pal, S.; Pal, S.; Pálla, G.; Palmeri, A.; Pancaldi, G.; Panse, R.; Pantaleo, A.; Pappalardo, G. S.; Pastirčák, B.; Pastore, C.; Patarakin, O.; Paticchio, V.; Patimo, G.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Pénichot, Y.; Pepato, A.; Pereira, H.; Peresunko, D.; Perez, C.; Perez Griffo, J.; Perini, D.; Perrino, D.; Peryt, W.; Pesci, A.; Peskov, V.; Pestov, Y.; Peters, A. J.; Petráček, V.; Petridis, A.; Petris, M.; Petrov, V.; Petrov, V.; Petrovici, M.; Peyré, J.; Piano, S.; Piccotti, A.; Pichot, P.; Piemonte, C.; Pikna, M.; Pilastrini, R.; Pillot, P.; Pinazza, O.; Pini, B.; Pinsky, L.; Pinto Morais, V.; Pismennaya, V.; Piuz, F.; Platt, R.; Ploskon, M.; Plumeri, S.; Pluta, J.; Pocheptsov, T.; Podesta, P.; Poggio, F.; Poghosyan, M.; Poghosyan, T.; Polák, K.; Polichtchouk, B.; Polozov, P.; Polyakov, V.; Pommeresch, B.; Pompei, F.; Pop, A.; Popescu, S.; Posa, F.; Pospíšil, V.; Potukuchi, B.; Pouthas, J.; Prasad, S.; Preghenella, R.; Prino, F.; Prodan, L.; Prono, G.; Protsenko, M. A.; Pruneau, C. A.; Przybyla, A.; Pshenichnov, I.; Puddu, G.; Pujahari, P.; Pulvirenti, A.; Punin, A.; Punin, V.; Putschke, J.; Quartieri, J.; Quercigh, E.; Rachevskaya, I.; Rachevski, A.; Rademakers, A.; Radomski, S.; Radu, A.; Rak, J.; Ramello, L.; Raniwala, R.; Raniwala, S.; Rasmussen, O. B.; Rasson, J.; Razin, V.; Read, K.; Real, J.; Redlich, K.; Reichling, C.; Renard, C.; Renault, G.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Revol, J.-P.; Reygers, K.; Ricaud, H.; Riccati, L.; Ricci, R. A.; Richter, M.; Riedler, P.; Rigalleau, L. M.; Riggi, F.; Riegler, W.; Rindel, E.; Riso, J.; Rivetti, A.; Rizzi, M.; Rizzi, V.; Rodriguez Cahuantzi, M.; Røed, K.; Röhrich, D.; Román-López, S.; Romanato, M.; Romita, R.; Ronchetti, F.; Rosinsky, P.; Rosnet, P.; Rossegger, S.; Rossi, A.; Rostchin, V.; Rotondo, F.; Roukoutakis, F.; Rousseau, S.; Roy, C.; Roy, D.; Roy, P.; Royer, L.; Rubin, G.; Rubio, A.; Rui, R.; Rusanov, I.; Russo, G.; Ruuskanen, V.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahoo, R.; Saini, J.; Saiz, P.; Salur, S.; Sambyal, S.; Samsonov, V.; Šándor, L.; Sandoval, A.; Sann, H.; Santiard, J.-C.; Santo, R.; Santoro, R.; Sargsyan, G.; Saturnini, P.; Scapparone, E.; Scarlassara, F.; Schackert, B.; Schiaua, C.; Schicker, R.; Schioler, T.; Schippers, J. D.; Schmidt, C.; Schmidt, H.; Schneider, R.; Schossmaier, K.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Schyns, E.; Scioli, G.; Scomparin, E.; Snow, H.; Sedykh, S.; Segato, G.; Sellitto, S.; Semeria, F.; Senyukov, S.; Seppänen, H.; Serci, S.; Serkin, L.; Serra, S.; Sesselmann, T.; Sevcenco, A.; Sgura, I.; Shabratova, G.; Shahoyan, R.; Sharkov, E.; Sharma, S.; Shigaki, K.; Shileev, K.; Shukla, P.; Shurygin, A.; Shurygina, M.; Sibiriak, Y.; Siddi, E.; Siemiarczuk, T.; Sigward, M. H.; Silenzi, A.; Silvermyr, D.; Silvestri, R.; Simili, E.; Simion, V.; Simon, R.; Simonetti, L.; Singaraju, R.; Singhal, V.; Sinha, B.; Sinha, T.; Siska, M.; Sitár, B.; Sitta, M.; Skaali, B.; Skowronski, P.; Slodkowski, M.; Smirnov, N.; Smykov, L.; Snellings, R.; Snoeys, W.; Soegaard, C.; Soerensen, J.; Sokolov, O.; Soldatov, A.; Soloviev, A.; Soltveit, H.; Soltz, R.; Sommer, W.; Soos, C.; Soramel, F.; Sorensen, S.; Soyk, D.; Spyropoulou-Stassinaki, M.; Stachel, J.; Staley, F.; Stan, I.; Stavinskiy, A.; Steckert, J.; Stefanini, G.; Stefanek, G.; Steinbeck, T.; Stelzer, H.; Stenlund, E.; Stocco, D.; Stockmeier, M.; Stoicea, G.; Stolpovsky, P.; Strmeň, P.; Stutzmann, J. S.; Su, G.; Sugitate, T.; Šumbera, M.; Suire, C.; Susa, T.; Sushil Kumar, K.; Swoboda, D.; Symons, J.; Szarka, I.; Szostak, A.; Szuba, M.; Szymanski, P.; Tadel, M.; Tagridis, C.; Tan, L.; Tapia Takaki, D.; Taureg, H.; Tauro, A.; Tavlet, M.; Tejeda Munoz, G.; Thäder, J.; Tieulent, R.; Timmer, P.; Tolyhy, T.; Topilskaya, N.; Torcato de Matos, C.; Torii, H.; Toscano, L.; Tosello, F.; Tournaire, A.; Traczyk, T.; Tröger, G.; Tromeur, W.; Truesdale, D.; Trzaska, W.; Tsiledakis, G.; Tsilis, E.; Tsvetkov, A.; Turcato, M.; Turrisi, R.; Tuveri, M.; Tveter, T.; Tydesjo, H.; Tykarski, L.; Tywoniuk, K.; Ugolini, E.; Ullaland, K.; Urbán, J.; Urciuoli, G. M.; Usai, G. L.; Usseglio, M.; Vacchi, A.; Vala, M.; Valiev, F.; Vande Vyvre, P.; Van Den Brink, A.; Van Eijndhoven, N.; Van Der Kolk, N.; van Leeuwen, M.; Vannucci, L.; Vanzetto, S.; Vanuxem, J.-P.; Vargas, M. A.; Varma, R.; Vascotto, A.; Vasiliev, A.; Vassiliou, M.; Vasta, P.; Vechernin, V.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Verhoeven, W.; Veronese, F.; Vetlitskiy, I.; Vernet, R.; Victorov, V.; Vidak, L.; Viesti, G.; Vikhlyantsev, O.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y.; Vodopianov, A.; Volpe, G.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Wabnitz, C.; Wagner, V.; Wallet, L.; Wan, R.; Wang, Y.; Wang, Y.; Wheadon, R.; Weis, R.; Wen, Q.; Wessels, J.; Westergaard, J.; Wiechula, J.; Wiesenaecker, A.; Wikne, J.; Wilk, A.; Wilk, G.; Williams, C.; Willis, N.; Windelband, B.; Witt, R.; Woehri, H.; Wyllie, K.; Xu, C.; Yang, C.; Yang, H.; Yermia, F.; Yin, Z.; Yin, Z.; Ky, B. Yun; Yushmanov, I.; Yuting, B.; Zabrodin, E.; Zagato, S.; Zagreev, B.; Zaharia, P.; Zalite, A.; Zampa, G.; Zampolli, C.; Zanevskiy, Y.; Zarochentsev, A.; Zaudtke, O.; Závada, P.; Zbroszczyk, H.; Zepeda, A.; Zeter, V.; Zgura, I.; Zhalov, M.; Zhou, D.; Zhou, S.; Zhu, G.; Zichichi, A.; Zinchenko, A.; Zinovjev, G.; Zoccarato, Y.; Zubarev, A.; Zucchini, A.; Zuffa, M.

    2008-08-01

    ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 16 × 16 × 26 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This

  10. Torsion discovery potential and its discrimination at CERN LHC

    SciTech Connect

    Almeida, F. M. L. Jr. de; Nepomuceno, A. A.; Vale, M. A. B. do

    2009-01-01

    Torsion models constitute a well-known class of extended quantum gravity models. In this paper we study some phenomenological consequences of a torsion field interacting with fermions at LHC. A torsion field could appear as a new heavy state characterized by its mass and couplings to fermions. These new states will form a resonance decaying into difermions, as occurs in many extensions of the standard model, such as models predicting the existence of additional neutral gauge bosons, usually named Z{sup '}. Using the dielectron channel we evaluate the integrated luminosity needed for a 5{sigma} discovery as a function of the torsion mass, for different coupling values. We also calculate the luminosity needed to discriminate, with 95% C.L., the two possible different torsion natures. Finally, we show that the observed signal coming from the torsion field could be distinguished from a signal coming from a new neutral gauge boson, provided there is enough luminosity.

  11. Tapping upgrade potential

    SciTech Connect

    Gill, H.S. )

    1993-01-01

    Modernizing aging hydropower stations presents plant owners with a unique opportunity for improving efficiency and plant output. But several factors should be considered before undertaking a turbine upgrade project.

  12. The D0 upgrade

    SciTech Connect

    Gruenendahl, S.; The D0 Collaboration

    1994-01-01

    In order to maximize the physics potential of the Fermilab Tevatron proton antiproton collider complex, both the accelerator system and the two large collider detectors are undergoing major upgrades during the remainder of this decade. For the D0 detector, the upgrade focuses on implementation of an integrated magnetic tracker in the central region of the detector, accompanied by those modifications to other parts of the apparatus necessary to cope with the increase in interaction rate provided by the collider.

  13. Optics upgrade for switchyard

    SciTech Connect

    Kobilarcik, Thomas R.; /Fermilab

    2005-08-01

    An upgrade of the Switchyard optics is proposed. This upgrade extends the P3 (old Main Ring) lattice through enclosure C. The septa for the 3-way Meson Area split is moved from enclosure F1 to enclosure M01. The functionality of the Meson Target Train is preserved. Finally, for the purpose of demonstrating that the resulting split can be transported, a straw-man lattice is proposed for enclosure M02 and beyond.

  14. Luminosity Functions for Globular Clusters

    NASA Astrophysics Data System (ADS)

    Silvestri, Fabio; Ventura, Paolo; D'Antona, Francesca; Mazzitelli, Italo

    1998-12-01

    We present theoretical mass-luminosity relations and luminosity functions (LFs) for globular cluster stars, from luminosities above the horizontal branch down to the minimum luminosity of hydrogen-burning stars. The LFs are available for metal mass fraction Z from Z = 10-4 to Z = 4 × 10-3, in the Johnson V band and in the Bessell-Cousins I band, and are based on tracks especially computed for this program, with the input physics of the models developed recently by D'Antona et al., Mazzitelli et al., and D'Antona & Mazzitelli. Two typical comparisons with observations are presented and discussed: (1) comparisons and statistical analysis with the LFs of the lower giant branch, turnoff region, and upper main sequence of several globular clusters from low to high metallicity, (2) derivation of the initial mass function (IMF) for the stars below the turnoff for several globular clusters for which Hubble Space Telescope data are available. In the first analysis we find that, for relatively large metallicities (Z >= 10-3) a good fit between theoretical and observed LFs can be found, although a simple χ2 statistical analysis shows that it is not possible to derive a strongly preferred age (or, equivalently, distance modulus) from the LF comparison. The fit with lower metallicity [Z ~ (1-2) × 10-4] LFs is less good but statistically acceptable. The main result is that the difference between observed and theoretical LFs of low-metallicity clusters reported by VandenBerg, Bolte, & Stetson appears to be much reduced in present models, and we give the possible reason why this happens and its consequences for the important parameter of the helium core mass at the flash. In the second application, we explore the effect of varying age and distance modulus on the mass function derived for a globular cluster. Distance moduli corresponding to the ``long'' distance scale (and relatively low ages) seem to be preferred based on these comparisons. The resulting index of the IMF is

  15. Sprite Luminosity and Radio Noise

    NASA Astrophysics Data System (ADS)

    Fullekrug, M.; Evans, A.; Mezentsev, A.; van der Velde, O.; Soula, S.

    2013-12-01

    Sprites are composed of individual streamer discharges (e.g., Pasko, 2010) which split into streamer tips (McHarg et al., 2010) with diameters 50-100 m at 60-80 km height (Kanmae et al., 2012). The sprite luminosity coincides in time and space with extremely low frequency electromagnetic radiation <3 kHz in excellent agreement with theory (Cummer and Fullekrug, 2001). This theory is based on current flowing in the body of sprites at 70-80 km height associated with large streamer densities (Pasko et al., 1998). A more detailed study shows specifically that the exponential growth and splitting of streamers at 70-80 km height results in an electron multiplication associated with the acceleration of electrons to a few eV. The accelerated electrons radiate a small amount of electromagnetic energy and the incoherent superposition of many streamers causes the observed electromagnetic radiation (Qin et al., 2012). It has been predicted that this newly recognized physical mechanism might also result in low frequency ( 30-300 kHz) electromagnetic radiation emanating from sprite streamers near 40 km height in the stratosphere, albeit with very small magnetic fields 10^{-17}-10^{-12} T from a single streamer (Qin et al., 2012). The presence of this predicted radiation was promptly confirmed by low frequency radio noise measurements during dancing sprites with a very sensitive radio receiver (Fullekrug et al., 2013). Specifically, it was found that the sprite luminosity coincides with sudden enhancements of the radio noise. These initial observations are extended here with a more detailed analysis to study the spatial coherence of the radio noise recorded with a novel network of sensitive radio receivers deployed during field work in the summer 2013. This network of radio receivers is used to study the relationship between the radio noise and the sprite luminosity observed with video cameras. The sprite luminosity is inferred from video recordings by use of sophisticated image

  16. Studies of RF Noise Induced Bunch Lengthening at the LHC

    SciTech Connect

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; /SLAC /CERN

    2011-08-17

    Radio Frequency (RF) noise induced bunch lengthening can strongly affect the Large Hadron Collider (LHC) performance through luminosity reduction, particle loss, and other effects. This work presents measurements from the LHC that better quantify the relationship between the RF noise and longitudinal emittance blowup and identify the performance limiting RF components. The experiments presented in this paper confirmed the predicted effects on the LHC bunch length growth. Dedicated measurements were conducted in the LHC to gain insight in the effect of RF noise to the longitudinal beam diffusion. It was evident that the growth rate of the bunch length is strongly related to the accelerating voltage phase noise power spectral density around f{sub s} + kf{sub rev}, as predicted in [4]. The noise threshold for 2.5 ps/hr growth was estimated to -101 dBc/Hz (SSB flat noise spectral density from f{sub s} to the edge of the closed loop bandwidth). A 9 dB margin is achieved with the current RF configuration and the BPL on. With this formalism it is now possible to estimate the effect of different operational and technical RF configurations on the LHC beam diffusion. This formalism could also be useful for the design of future RF systems and the budgeting of the allowed noise.

  17. Unidentified IRAS sources: Ultrahigh luminosity galaxies

    NASA Technical Reports Server (NTRS)

    Houck, J. R.; Schneider, D. P.; Danielson, G. E.; Beichman, C. A.; Lonsdale, C. J.; Neugebauer, G.; Soifer, B. T.

    1985-01-01

    Optical imaging and spectroscopy measurements were obtained for six of the high galactic latitude infrared sources reported by Houck, et al. (1984) from the IRAS survey to have no obvious optical counterparts on the POSS prints. All are identified with visually faint galaxies that have total luminosities in the range 5 x 10 to the 11th power stellar luminosity to 5 x 10 to the 12th power stellar luminosity. This luminosity emerges virtually entirely in the infrared. The origin of the luminosity, which is one to two orders of magnitude greater than that of normal galaxies, is not known at this time.

  18. DAQ Architecture for the LHCb Upgrade

    NASA Astrophysics Data System (ADS)

    Liu, Guoming; Neufeld, Niko

    2014-06-01

    LHCb will have an upgrade of its detector in 2018. After the upgrade, the LHCb experiment will run at a high luminosity of 2 × 1033 cm-2s-1. The upgraded detector will be read out at 40 MHz with a highly flexible software-based triggering strategy. The Data Acquisition (DAQ) system of LHCb reads out the data fragments from the Front-End Electronics and transports them to the High-Lever Trigger farm at an aggregate throughput of ~ 32 Tbit/s. The DAQ system will be based on high speed network technologies such as InfiniBand and/or 10/40/100 Gigabit Ethernet. Independent of the network technology, there are different possible architectures for the DAQ system. In this paper, we present our studies on the DAQ architecture, where we analyze size, complexity and relative cost. We evaluate and compare several data-flow schemes for a network-based DAQ: push, pull and push with barrel-shifter traffic shaping. We also discuss the requirements and overall implications of the data-flow schemes on the DAQ system.

  19. Performance of the new small-strip Thin Gap Chamber for the ATLAS Muon System at the LHC

    NASA Astrophysics Data System (ADS)

    Bellerive, Alain; Atlas Nsw Stgc Group Collaboration

    2016-03-01

    The instantaneous luminosity of the Large Hadron Collider (LHC) at CERN will be increased up to a factor of five with respect to the design value by undergoing an extensive upgrade program. The largest phase-1 upgrade project for the ATLAS Muon System is the replacement of the present first station in the forward region with the so-called New Small Wheel (NSW). The NSW consists of layers of Micromegas and small-strip Thin Gap Chambers (sTGC), both providing trigger and tracking capabilities. The precision reconstruction of tracks requires a spatial resolution of about 100 microns, and the trigger track segments have to be reconstructed with an angular resolution of approximately 1 mrad. The sTGC structure consists of a grid of gold-plated tungsten wires sandwiched between two resistive cathode planes. The precision cathode plane has strips with a 3.2mm pitch for precision readout and the cathode plane on the other side has pads for triggering. The pads are used to produce a 3-out-of-4 coincidence to identify muon tracks in an sTGC quadruplet. A full size sTGC quadruplet has been constructed and equipped with the first prototype of dedicated front-end electronics. The design of the sTGC will be described. The performance of the sTGC quadruplet has been characterized with data collected at the Fermilab and CERN test beam facilities. Spatial resolution and trigger efficiency results will be presented. An overview of the simulation and digitization model of the sTGC will also be summarized.

  20. Status report of the upgrade of the CMS muon system with Triple-GEM detectors

    NASA Astrophysics Data System (ADS)

    Abbaneo, D.; Abbas, M.; Abbrescia, M.; Abdelalim, A. A.; Abi Akl, M.; Aboamer, O.; Acosta, D.; Ahmad, A.; Ahmed, W.; Ahmed, W.; Aleksandrov, A.; Aly, R.; Altieri, P.; Asawatangtrakuldee, C.; Aspell, P.; Assran, Y.; Awan, I.; Bally, S.; Ban, Y.; Banerjee, S.; Barashko, V.; Barria, P.; Bencze, G.; Beni, N.; Benussi, L.; Bhopatkar, V.; Bianco, S.; Bos, J.; Bouhali, O.; Braghieri, A.; Braibant, S.; Buontempo, S.; Calabria, C.; Caponero, M.; Caputo, C.; Cassese, F.; Castaneda, A.; Cauwenbergh, S.; Cavallo, F. R.; Celik, A.; Choi, M.; Choi, S.; Christiansen, J.; Cimmino, A.; Colafranceschi, S.; Colaleo, A.; Conde Garcia, A.; Czellar, S.; Dabrowski, M. M.; De Lentdecker, G.; De Oliveira, R.; de Robertis, G.; Dildick, S.; Dorney, B.; Elmetenawee, W.; Endroczi, G.; Errico, F.; Fenyvesi, A.; Ferry, S.; Furic, I.; Giacomelli, P.; Gilmore, J.; Golovtsov, V.; Guiducci, L.; Guilloux, F.; Gutierrez, A.; Hadjiiska, R. M.; Hassan, A.; Hauser, J.; Hoepfner, K.; Hohlmann, M.; Hoorani, H.; Iaydjiev, P.; Jeng, Y. G.; Kamon, T.; Karchin, P.; Korytov, A.; Krutelyov, S.; Kumar, A.; Kim, H.; Lee, J.; Lenzi, T.; Litov, L.; Loddo, F.; Madorsky, A.; Maerschalk, T.; Maggi, M.; Magnani, A.; Mal, P. K.; Mandal, K.; Marchioro, A.; Marinov, A.; Masod, R.; Majumdar, N.; Merlin, J. A.; Mitselmakher, G.; Mohanty, A. K.; Mohamed, S.; Mohapatra, A.; Molnar, J.; Muhammad, S.; Mukhopadhyay, S.; Naimuddin, M.; Nuzzo, S.; Oliveri, E.; Pant, L. M.; Paolucci, P.; Park, I.; Passeggio, G.; Pavlov, B.; Philipps, B.; Piccolo, D.; Postema, H.; Puig Baranac, A.; Radi, A.; Radogna, R.; Raffone, G.; Ranieri, A.; Rashevski, G.; Riccardi, C.; Rodozov, M.; Rodrigues, A.; Ropelewski, L.; RoyChowdhury, S.; Ryu, G.; Ryu, M. S.; Safonov, A.; Salva, S.; Saviano, G.; Sharma, A.; Sharma, A.; Sharma, R.; Shah, A. H.; Shopova, M.; Sturdy, J.; Sultanov, G.; Swain, S. K.; Szillasi, Z.; Talvitie, J.; Tatarinov, A.; Tuuva, T.; Tytgat, M.; Vai, I.; Van Stenis, M.; Venditti, R.; Verhagen, E.; Verwilligen, P.; Vitulo, P.; Volkov, S.; Vorobyev, A.; Wang, D.; Wang, M.; Yang, U.; Yang, Y.; Yonamine, R.; Zaganidis, N.; Zenoni, F.; Zhang, A.

    2016-07-01

    For the High Luminosity LHC CMS is planning to install new large size Triple-GEM detectors, equipped with a new readout system in the forward region of its muon system (1.5 < | η | < 2.2). In this note we report on the status of the project, the main achievements regarding the detectors as well as the electronics and readout system.

  1. LHC and VLHC Based ep Colliders: e-Linac versus e-Ring

    NASA Astrophysics Data System (ADS)

    Gladilin, L.; Karadeniz, H.; Recepoglu, E.; Sultansoy, S.

    2007-06-01

    Linac-ring analogues of the LHC and VLHC based standard type ep collider proposals are discussed. It is shown that sufficiently high luminosities can be obtained with TESLA like linacs, whereas essential modifications are required for CLIC technology. The physics search potential of proposed ep colliders is demonstrated using pair production of heavy quarks as an example.

  2. eXtremely Fast Tracker trigger upgrade at CDF

    SciTech Connect

    Abulencia, A.; Azzurri, P.; Cochran, E.; Cox, C.; Cox, D.; Dittmann, J.; Donati, S.; Efron, J.; Erbacher, R.; Errede, D.; Fedorko, I.; /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore /Purdue U.

    2009-01-01

    The CDF II eXtremely Fast Tracker (XFT) is a trigger processor which reconstructs charged particle tracks in the transverse plane of the central tracking chamber. The XFT tracks are also extrapolated to the electromagnetic calorimeter and muon chambers to generate trigger electron and muon candidates. The XFT is crucial for the entire CDF II physics program: it detects high P{sub t} lepton from W/Z and heavy flavors decay and, in conjunction with the level 2 processor, it identifies secondary vertices from beauty decay. The XFT has thus been crucial for the recent measurement of the B{sub s}{sup 0} oscillation and {Sigma}{sub b}. The increase of the Tevatron instantaneous luminosity demanded an upgrade of the system to cope with the higher occupancy of the chamber. In the upgraded XFT, three-dimensional tracking reduces the level of fake tracks and measures the longitudinal track parameters, which strongly reinforce the trigger selection. This allows to maintain the trigger perfectly efficient at the record luminosities 2-3 x 10{sup 32} cm{sup -2} s{sup -1} and to maintain intact the CDF II high luminosity physics program, which includes the Higgs search. In this paper we review the architecture, the used technology, the performance and the impact of the upgraded XFT on the entire CDF II trigger strategy.

  3. LHC bounds on interactions of dark matter

    SciTech Connect

    Rajaraman, Arvind; Shepherd, William; Tait, Tim M. P.; Wijangco, Alexander M.

    2011-11-01

    We derive limits on the interactions of dark matter with quarks from ATLAS null searches for jets+missing energy based on {approx}1 fb{sup -1} of integrated luminosity, using a model-insensitive effective theory framework. We find that the new limits from the LHC significantly extend limits previously derived from CDF data at the Tevatron. Translated into the parameter space of direct searches, these limits are particularly effective for {approx} GeV mass weakly interacting massive particles. Our limits indicate tension with isospin-violating models satisfying minimal flavor violation which attempt to reconcile the purported CoGeNT excess with Xenon-100, indicating that either a light mediator or nontrivial flavor structure for the dark sector is necessary for a viable reconciliation of CoGeNT with Xenon.

  4. Upgrade of the ALICE Inner Tracking System

    NASA Astrophysics Data System (ADS)

    Keil, M.

    2015-03-01

    ALICE (A Large Ion Collider Experiment) is studying heavy-ion collisions at the CERN LHC, with the aim of forming, under extreme conditions of temperature and energy density, a Quark-Gluon Plasma (QGP) and studying its properties. The ALICE Collaboration is preparing a major upgrade of the experimental apparatus, planned for installation in the second long LHC shutdown in the years 2018-2019. A key element of the ALICE upgrade is the construction of a new, ultra-light, high-resolution Inner Tracking System (ITS) . The primary focus of the new ITS is on improving the performance for detection of heavy-flavour hadrons, and of thermal photons and low-mass di-electrons emitted by the QGP . With respect to the current detector, the new ITS will significantly enhance the determination of the distance of closest approach of a track to the primary vertex, the tracking efficiency at low transverse momenta, and the read-out rate capabilities. This will be achieved by seven concentric detector layers based on a 50 μm thick CMOS pixel sensor with a pixel pitch of about 30× 30 μm2. A key feature of the new ITS, which is optimized for high tracking accuracy at low transverse momenta, is the very low mass of the three innermost layers, which feature a material thickness of 0.3% X0 per layer. This contribution describes the design goals and layout of the new ALICE ITS, a summary of the R&D activities, with focus on the technical implementation of the main detector components, and the projected detector performance.

  5. Extreme luminosity imaging conical spectrograph

    SciTech Connect

    Pikuz, S. A.; Shelkovenko, T. A.; Mitchell, M. D.; Chandler, K. M.; Douglass, J. D.; McBride, R. D.; Jackson, D. P.; Hammer, D. A.

    2006-10-15

    A new configuration for a two-dimensional (2D) imaging x-ray spectrograph based on a conically bent crystal is introduced: extreme luminosity imaging conical spectrograph (ELICS). The ELICS configuration has important advantages over spectrographs that are based on cylindrically and spherically bent crystals. The main advantages are that a wide variety of large-aperture crystals can be used, and any desired magnification in the spatial direction (the direction orthogonal to spectral dispersion) can be achieved by the use of different experimental arrangements. The ELICS can be set up so that the detector plane is almost perpendicular to the incident rays, a good configuration for time-resolved spectroscopy. ELICSs with mica crystals of 45x90 mm{sup 2} aperture have been successfully used for imaging on the XP and COBRA pulsed power generators, yielding spectra with spatial resolution in 2D of Z pinches and X pinches.

  6. Cyclotron Institute Upgrade Project

    SciTech Connect

    Clark, Henry; Yennello, Sherry; Tribble, Robert

    2014-08-26

    The Cyclotron Institute at Texas A&M University has upgraded its accelerator facilities to extend research capabilities with both stable and radioactive beams. The upgrade is divided into three major tasks: (1) re-commission the K-150 (88”) cyclotron, couple it to existing beam lines to provide intense stable beams into the K-500 experimental areas and use it as a driver to produce radioactive beams; (2) develop light ion and heavy ion guides for stopping radioactive ions created with the K-150 beams; and (3) transport 1+ ions from the ion guides into a charge-breeding electron-cyclotron-resonance ion source (CB-ECR) to produce highly-charged radioactive ions for acceleration in the K-500 cyclotron. When completed, the upgraded facility will provide high-quality re-accelerated secondary beams in a unique energy range in the world.

  7. Antenna feedhorn software upgrade

    NASA Technical Reports Server (NTRS)

    Potter, P. D.

    1979-01-01

    The HYBRIDHORN computer program was developed to serve as an item of general purpose antenna feedhorn design and analysis software. The formulation contains a small flare angle approximation which is subject to question for designs such as the S- and X-band feedhorn. Additionally, the original formulation did not allow azimuthal variation indexes other than unity. The HYBRIDHORN program was upgraded to correct both of these deficiencies. A large flare angle formulation was found. In the upgrade, all of the major program elements were converted to Univac 1108 compatible structured FORTRAN (SFTRAN) for ease of software maintenance. The small and large angle formulations are described and sample numerical results are presented.

  8. MSSM Electroweak Baryogenesis and LHC Data

    SciTech Connect

    Carena, Marcela; Nardini, Germano; Quiros, Mariano; Wagner, Carlos E.M.

    2013-02-01

    Electroweak baryogenesis is an attractive scenario for the generation of the baryon asymmetry of the universe as its realization depends on the presence at the weak scale of new particles which may be searched for at high energy colliders. In the MSSM it may only be realized in the presence of light stops, and with moderate or small mixing between the left- and right-handed components. Consistency with the observed Higgs mass around 125 GeV demands the heavier stop mass to be much larger than the weak scale. Moreover the lighter stop leads to an increase of the gluon-gluon fusion Higgs production cross section which seems to be in contradiction with indications from current LHC data. We show that this tension may be considerably relaxed in the presence of a light neutralino with a mass lower than about 60 GeV, satisfying all present experimental constraints. In such a case the Higgs may have a significant invisible decay width and the stop decays through a three or four body decay channel, including a bottom quark and the lightest neutralino in the final state. All these properties make this scenario testable at a high luminosity LHC.

  9. PACIFIC: the readout ASIC for the SciFi Tracker of the upgraded LHCb detector

    NASA Astrophysics Data System (ADS)

    Mazorra, J.; Chanal, H.; Comerma, A.; Gascón, D.; Gómez, S.; Han, X.; Pillet, N.; Vandaele, R.

    2016-02-01

    The LHCb detector will be upgraded during the Long Shutdown 2 (LS2) of the LHC in order to cope with higher instantaneous luminosities and will switch to a 40 MHz readout rate using a trigger-less software based system. All front-end electronics will be replaced and several sub-detectors must be redesigned to cope with the higher detector occupancy and radiation damage. The current tracking detectors downstream of the LHCb dipole magnet will be replaced by the Scintillating Fibre (SciFi) Tracker. The SciFi Tracker will use scintillating fibres read out by Silicon Photomultipliers (SiPMs). State-of-the-art multi-channel SiPM arrays are being developed and a custom ASIC, called the low-Power ASIC for the sCIntillating FIbres traCker (PACIFIC), will be used to digitise the signals from the SiPMs. This article presents an overview of the R&D for the PACIFIC. It is a 64-channel ASIC implemented in 130 nm CMOS technology, aiming at a radiation tolerant design with a power consumption below 10 mW per channel. It interfaces directly with the SiPM anode through a current mode input, and provides a configurable non-linear 2-bit per channel digital output. The SiPM signal is acquired by a current conveyor and processed with a fast shaper and a gated integrator. The digitization is performed using a three threshold non-linear flash ADC operating at 40 MHz. Simulation and test results show the PACIFIC chip prototypes functioning well.

  10. Upgrade of the D0 detector: The Tevatron beyond 2 fb**(-1)

    SciTech Connect

    Quinn, Breese; /Mississippi U.

    2005-01-01

    Recent performance of Fermilab's Tevatron has exceeded this year's design goals and further accelerator upgrades are underway. The high-luminosity period which follows these improvements is known as Run IIb. The D0 experiment is in the midst of a comprehensive upgrade program designed to enable it to thrive with much higher data rate and occupancy. Extensive modifications of and additions to all levels of the trigger and the silicon tracker are in progress. All upgrade projects are on schedule for installation in the 2005 shutdown.

  11. MAPS development for the ALICE ITS upgrade

    NASA Astrophysics Data System (ADS)

    Yang, P.; Aglieri, G.; Cavicchioli, C.; Chalmet, P. L.; Chanlek, N.; Collu, A.; Gao, C.; Hillemanns, H.; Junique, A.; Kofarago, M.; Keil, M.; Kugathasan, T.; Kim, D.; Kim, J.; Lattuca, A.; Marin Tobon, C. A.; Marras, D.; Mager, M.; Martinengo, P.; Mazza, G.; Mugnier, H.; Musa, L.; Puggioni, C.; Rousset, J.; Reidt, F.; Riedler, P.; Snoeys, W.; Siddhanta, S.; Usai, G.; van Hoorne, J. W.; Yi, J.

    2015-03-01

    Monolithic Active Pixel Sensors (MAPS) offer the possibility to build pixel detectors and tracking layers with high spatial resolution and low material budget in commercial CMOS processes. Significant progress has been made in the field of MAPS in recent years, and they are now considered for the upgrades of the LHC experiments. This contribution will focus on MAPS detectors developed for the ALICE Inner Tracking System (ITS) upgrade and manufactured in the TowerJazz 180 nm CMOS imaging sensor process on wafers with a high resistivity epitaxial layer. Several sensor chip prototypes have been developed and produced to optimise both charge collection and readout circuitry. The chips have been characterised using electrical measurements, radioactive sources and particle beams. The tests indicate that the sensors satisfy the ALICE requirements and first prototypes with the final size of 1.5 × 3 cm2 have been produced in the first half of 2014. This contribution summarises the characterisation measurements and presents first results from the full-scale chips.

  12. Readout of the upgraded ALICE-ITS

    NASA Astrophysics Data System (ADS)

    Szczepankiewicz, A.

    2016-07-01

    The ALICE experiment will undergo a major upgrade during the second long shutdown of the CERN LHC. As part of this program, the present Inner Tracking System (ITS), which employs different layers of hybrid pixels, silicon drift and strip detectors, will be replaced by a completely new tracker composed of seven layers of monolithic active pixel sensors. The upgraded ITS will have more than twelve billion pixels in total, producing 300 Gbit/s of data when tracking 50 kHz Pb-Pb events. Two families of pixel chips realized with the TowerJazz CMOS imaging process have been developed as candidate sensors: the ALPIDE, which uses a proprietary readout and sparsification mechanism and the MISTRAL-O, based on a proven rolling shutter architecture. Both chips can operate in continuous mode, with the ALPIDE also supporting triggered operations. As the communication IP blocks are shared among the two chip families, it has been possible to develop a common Readout Electronics. All the sensor components (analog stages, state machines, buffers, FIFOs, etc.) have been modelled in a system level simulation, which has been extensively used to optimize both the sensor and the whole readout chain design in an iterative process. This contribution covers the progress of the R&D efforts and the overall expected performance of the ALICE-ITS readout system.

  13. LHC Nobel Symposium Proceedings

    NASA Astrophysics Data System (ADS)

    Ekelöf, Tord

    2013-12-01

    In the summer of 2012, a great discovery emerged at the Large Hadron Collider (LHC) at CERN in Geneva. A plethora of new precision data had already by then been collected by the ATLAS and CMS experiments at LHC, providing further extensive support for the validity of the Standard Model of particle physics. But what now appeared was the first evidence for what was not only the last unverified prediction of the Standard Model, but also perhaps the most decisive one: the prediction made already in 1964 of a unique scalar boson required by the theory of François Englert and Peter Higgs on how fundamental particles acquire mass. At that moment in 2012, it seemed particularly appropriate to start planning a gathering of world experts in particle physics to take stock of the situation and try to answer the challenging question: what next? By May 2013, when the LHC Nobel Symposium was held at the Krusenberg Mansion outside Uppsala in Sweden, the first signs of a great discovery had already turned into fully convincing experimental evidence for the existence of a scalar boson of mass about 125 GeV, having properties compatible with the 50-year-old prediction. And in October 2013, the evidence was deemed so convincing that the Swedish Royal Academy of Sciences awarded the Nobel Prize in Physics to Englert and Higgs for their pioneering work. At the same time the search at the LHC for other particles, beyond those predicted by the Standard Model, with heavier masses up to—and in some cases beyond—1 TeV, had provided no positive result. The triumph of the Standard Model seems resounding, in particular because the mass of the discovered scalar boson is such that, when identified with the Higgs boson, the Standard Model is able to provide predictions at energies as high as the Planck mass, although at the price of accepting that the vacuum would be metastable. However, even if there were some feelings of triumph, the ambience at the LHC Nobel Symposium was more one of

  14. Biochemical upgrading of oils

    DOEpatents

    Premuzic, Eugene T.; Lin, Mow S.

    1999-01-12

    A process for biochemical conversion of heavy crude oils is provided. The process includes contacting heavy crude oils with adapted biocatalysts. The resulting upgraded oil shows, a relative increase in saturated hydrocarbons, emulsions and oxygenates and a decrease in compounds containing in organic sulfur, organic nitrogen and trace metals. Adapted microorganisms which have been modified under challenged growth processes are also disclosed.

  15. Biochemical upgrading of oils

    DOEpatents

    Premuzic, E.T.; Lin, M.S.

    1999-01-12

    A process for biochemical conversion of heavy crude oils is provided. The process includes contacting heavy crude oils with adapted biocatalysts. The resulting upgraded oil shows, a relative increase in saturated hydrocarbons, emulsions and oxygenates and a decrease in compounds containing organic sulfur, organic nitrogen and trace metals. Adapted microorganisms which have been modified under challenged growth processes are also disclosed. 121 figs.

  16. Upgrading Undergraduate Biology Education

    ERIC Educational Resources Information Center

    Musante, Susan

    2011-01-01

    On many campuses throughout the country, undergraduate biology education is in serious need of an upgrade. During the past few decades, the body of biological knowledge has grown exponentially, and as a research endeavor, the practice of biology has evolved. Education research has also made great strides, revealing many new insights into how…

  17. Prospects for Higgs searches at the Tevatron and LHC in the MSSM with explicit CP violation.

    SciTech Connect

    Draper, P.; Liu, T.; Wagner, C. E. M.; High Energy Physics; Univ. of Chicago

    2010-01-01

    We analyze the Tevatron and Large Hadron Collider (LHC) reach for the Higgs sector of the minimal supersymmetric standard model (MSSM) in the presence of explicit CP violation. Using the most recent studies from the Tevatron and LHC collaborations, we examine the CPX benchmark scenario for a range of CP-violating phases in the soft trilinear and gluino mass terms and compute the exclusion/discovery potentials for each collider on the (MH+,tan{beta}) plane. Projected results from standard model (SM)-like, nonstandard, and charged Higgs searches are combined to maximize the statistical significance. We exhibit complementarity between the SM-like Higgs searches at the LHC with low luminosity and the Tevatron, and estimate the combined reach of the two colliders in the early phase of LHC running.

  18. LHC forward physics

    SciTech Connect

    Cartiglia, N.; Royon, C.

    2015-10-02

    The goal of this report is to give a comprehensive overview of the rich field of forward physics, with a special attention to the topics that can be studied at the LHC. The report starts presenting a selection of the Monte Carlo simulation tools currently available, chapter 2, then enters the rich phenomenology of QCD at low, chapter 3, and high, chapter 4, momentum transfer, while the unique scattering conditions of central exclusive production are analyzed in chapter 5. The last two experimental topics, Cosmic Ray and Heavy Ion physics are presented in the chapter 6 and 7 respectively. Chapter 8 is dedicated to the BFKL dynamics, multiparton interactions, and saturation. The report ends with an overview of the forward detectors at LHC. Each chapter is correlated with a comprehensive bibliography, attempting to provide to the interested reader with a wide opportunity for further studies.

  19. Probing baryogenesis with displaced vertices at the LHC

    NASA Astrophysics Data System (ADS)

    Cui, Yanou; Shuve, Brian

    2015-02-01

    The generation of the asymmetric cosmic baryon abundance requires a departure from thermal equilibrium in the early universe. In a large class of baryogenesis models, the baryon asymmetry results from the out-of-equilibrium decay of a new, massive particle. We highlight that in the interesting scenario where this particle has a weak scale mass, this out-of-equilibrium condition requires a proper decay length larger than O(1) mm. Such new fields are within reach of the LHC, at which they can be pair produced leaving a distinctive, displaced-vertex signature. This scenario is realized in the recently proposed mechanism of baryogenesis where the baryon asymmetry is produced through the freeze-out and subsequent decay of a meta-stable weakly interacting massive particle ("WIMP baryogenesis"). In analogy to missing energy searches for WIMP dark matter, the LHC is an excellent probe of these new long-lived particles responsible for baryogenesis via the low-background displaced vertex channel. In our paper, we estimate the limits on simplified models inspired by WIMP baryogenesis from two of the most sensitive collider searches by CMS and ATLAS with 8 TeV LHC data. We also estimate the LHC reach at 13 TeV using current strategies, and demonstrate that up to a factor of 100 improvement in cross-section limits can be achieved by requiring two displaced vertices while lowering kinematic thresholds. For meta-stable WIMPs produced through electroweak interactions, the high luminosity LHC is sensitive to masses up to 2.5 TeV for lifetimes around 1 cm, while for singlets pair-produced through the off-shell-Higgs portal, the LHC is sensitive to production cross sections of O(10) ab for benchmark masses around 150 GeV. Our analysis and proposals also generally apply to displaced vertex signatures from other new physics such as hidden valley models, twin Higgs models and displaced supersymmetry.

  20. Synchro-betatron effects in the presence of large Piwinski angle and crab cavities at the HL-LHC

    SciTech Connect

    White S.; Calaga, R.; Miyamoto, R.

    2012-05-20

    The reduction of {beta}* at the collision points for the high luminosity LHC (HL-LHC) requires an increment in the crossing angle to maintain the normalized beam separation to suppress the effects of long-range beam-beam interactions. However, an increase in the crossing angle may give rise to synchro-betatron resonances which may negatively affect the beam emittance and lifetime. 6D weak-strong and strong-strong simulations were performed to study the effect of synchro-betatron resonances in the context of the HL-LHC layout and its suppression via crab crossing.

  1. D{O} upgrade muon electronics design

    SciTech Connect

    Baldin, B.; Green, D.; Haggerty, H.; Hansen, S.

    1994-11-01

    The planned luminosity for the upgrade is ten times higher than at present (L {approximately} 10{sup 32}cm{sup {minus}2}s{sup {minus}1}) and involves a time between collisions as small as 132 ns. To operate in this environment, completely new electronics is required for the 17,500 proportional drift tubes of the system. These electronics include a deadtimeless readout, a digital TDC with about 1 ns binning for the wire signals, fast charge integrators and pipelined ADCs for digitizing the pad electrode signals, a new wire signal triggering scheme and its associated trigger logic, and high level DSP processing. Some test results of measurements performed on prototype channels and a comparison with the existing electronics are presented.

  2. Tracking system of the upgraded LHCb

    NASA Astrophysics Data System (ADS)

    Obłąkowska-Mucha, A.; Szumlak, T.

    2016-07-01

    The upgrade of the LHCb experiment will run at an instantaneous luminosity up to 2 ×1033cm-2s-1 with a fully software based trigger, allowing us to read out the detector at a rate of 40 MHz. For this purpose, the full tracking system will be newly developed: the vertex locator (VELO) will be replaced by a pixel-based detector providing an excellent track reconstruction with an efficiency of above 99%. Upstream of the magnet, a silicon micro-strip detector with a high granularity and an improved acceptance, called the Upstream Tracker (UT) will be placed. The tracking system downstream of the magnet will be replaced by the Scintillating Fibre tracker (SciFi), which will consist of 12 layers using 2.5 m long scintillating fibres read out by silicon photo-multipliers.

  3. An LHCb general-purpose acquisition board for beam and background monitoring at the LHC

    NASA Astrophysics Data System (ADS)

    Alessio, F.; Guzik, Z.; Jacobsson, R.

    2011-01-01

    In this paper we will present an LHCb custom-made acquisition board which was developed for a continuous beam and background monitoring during LHC operations at CERN. The paper describes both the conceptual design and its performance, and concludes with results from the first period of beam operations at the LHC. The main purpose of the acquisition board is to process signals from a pair of beam pickups to continuously monitor the intensity of each bunch, and to monitor the phase of the arrival time of each proton bunch with respect to the LHC bunch clock. The extreme versatility of the board also allowed the LHCb experiment to build a high-speed and high-sensitivity readout system for a fast background monitor based on a pair of plastic scintillators. The board has demonstrated very good performance and proved to be conceptually valid during the first months of operations at the LHC. Connected to the beam pickups, it provides the LHCb experiment with a real-time measurement of the total intensity of each beam and of the arrival time of each beam at the LHCb Interaction Point. It also monitors the LHC filling scheme and the beam current per bunch at a continuous rate of 40 MHz, and assures a proper global timing of LHCb. The continuous readout of the scintillators at bunch clock speed provides the LHCb experiment with high-resolution information about the beam halo and fast losses during both injection and circulating beam. It has also provided valuable information to the LHC during machine commissioning with beam. Recent results also shows that it could contribute as a luminosity monitor independent from the LHCb experiment readout system. Beam, background and luminosity measurements are continuously fed back to the LHC in the data exchange framework between the experiments and the LHC machine aimed at improving efficiently the experimental conditions real-time.

  4. First results of the LHC longitudinal density monitor

    NASA Astrophysics Data System (ADS)

    Jeff, A.; Boccardi, A.; Bravin, E.; Fisher, A. S.; Lefevre, T.; Rabiller, A.; Roncarolo, F.; Welsch, C. P.

    2011-12-01

    The Large Hadron Collider (LHC) at CERN is the world's largest particle accelerator. It is designed to accelerate and collide protons or heavy ions up to the center-of-mass energies of 14 TeV. Knowledge of the longitudinal distribution of particles is important for various aspects of accelerator operation, in particular to check the injection quality and to measure the proportion of charge outside the nominally filled bunches during the physics periods. In order to study this so-called ghost charge at levels very much smaller than the main bunches, a longitudinal profile measurement with a very high dynamic range is needed. A new detector, the LHC Longitudinal Density Monitor (LDM) is a single-photon counting system measuring synchrotron light by means of an avalanche photodiode detector. The unprecedented energies reached in the LHC allow synchrotron light diagnostics to be used with both protons and heavy ions. A prototype was installed during the 2010 LHC run and was able to longitudinally profile the whole ring with a resolution close to the target of 50 ps. On-line correction for the effects of the detector deadtime, pile-up and afterpulsing allow a dynamic range of 105 to be achieved. First measurements with the LDM are presented here along with an analysis of its performance and an outlook for future upgrades.

  5. A PCIe Gen3 based readout for the LHCb upgrade

    NASA Astrophysics Data System (ADS)

    Bellato, M.; Collazuol, G.; D'Antone, I.; Durante, P.; Galli, D.; Jost, B.; Lax, I.; Liu, G.; Marconi, U.; Neufeld, N.; Schwemmer, R.; Vagnoni, V.

    2014-06-01

    The architecture of the data acquisition system foreseen for the LHCb upgrade, to be installed by 2018, is devised to readout events trigger-less, synchronously with the LHC bunch crossing rate at 40 MHz. Within this approach the readout boards act as a bridge between the front-end electronics and the High Level Trigger (HLT) computing farm. The baseline design for the LHCb readout is an ATCA board requiring dedicated crates. A local area standard network protocol is implemented in the on-board FPGAs to read out the data. The alternative solution proposed here consists in building the readout boards as PCIe peripherals of the event-builder servers. The main architectural advantage is that protocol and link-technology of the event-builder can be left open until very late, to profit from the most cost-effective industry technology available at the time of the LHC LS2.

  6. Depleted CMOS pixels for LHC proton-proton experiments

    NASA Astrophysics Data System (ADS)

    Wermes, N.

    2016-07-01

    While so far monolithic pixel detectors have remained in the realm of comparatively low rate and radiation applications outside LHC, new developments exploiting high resistivity substrates with three or four well CMOS process options allow reasonably large depletion depths and full CMOS circuitry in a monolithic structure. This opens up the possibility to target CMOS pixel detectors also for high radiation pp-experiments at the LHC upgrade, either in a hybrid-type fashion or even fully monolithic. Several pixel matrices have been prototyped with high ohmic substrates, high voltage options, and full CMOS electronics. They were characterized in the lab and in test beams. An overview of the necessary development steps and different approaches as well as prototype results are presented in this paper.

  7. LHC future prospects of the 750 GeV resonance

    NASA Astrophysics Data System (ADS)

    Sato, Ryosuke; Tobioka, Kohsaku

    2016-09-01

    A quantitative discussion on the future prospects of the 750 GeV resonance at the LHC experiment is given using a simple effective field theory analysis. The relative size of two effective operators relevant to diphoton decays can be probed by ratios of diboson signals in a robust way. We obtain the future sensitivities of Zγ, ZZ and WW resonance searches at the high luminosity LHC, rescaling from the current sensitivities at √{ s} = 13 TeV. Then, we show that a large fraction of parameter space in the effective field theory will be covered with 300 fb-1 and almost the whole parameter space will be tested with 3000 fb-1. This discussion is independent of production processes, other decay modes and total decay width.

  8. Single and Central Diffractive Higgs Production at the LHC

    SciTech Connect

    Ducati, M. B. Gay; Machado, M. M.; Silveira, G. G.

    2011-07-15

    The single and central diffractive production of the Standard Model Higgs boson is computed using the diffractive factorization formalism, taking into account a parametrization for the Pomeron structure function provided by the H1 Collaboration. We compute the cross sections at NLO accuracy for the gluon fusion process, since it is the leading mechanism for the Higgs boson production. The gap survival probability is also introduced to include the rescattering corrections due to spectator particles present in the interaction. The diffractive ratios are predicted for proton-proton collisions at the LHC, since the beam luminosity is favorable to the Higgs boson detection. These results provide updated estimations for the fraction of single and central diffractive events in the LHC kinematical regime.

  9. Performance of the Totem Detectors at the Lhc

    NASA Astrophysics Data System (ADS)

    Antchev, G.; Aspell, P.; Atanassov, I.; Avati, V.; Baechler, J.; Bagliesi, M. G.; Berardi, V.; Berretti, M.; Bossini, E.; Bottigli, U.; Bozzo, M.; Brücken, E.; Buzzo, A.; Cafagna, F. S.; Catanesi, M. G.; Cecchi, R.; Covault, C.; Csanád, M.; Csörgő, T.; Deile, M.; Doubek, M.; Eggert, K.; Eremin, V.; Ferro, F.; Fiergolski, A.; Garcia, F.; Giani, S.; Greco, V.; Grzanka, L.; Heino, J.; Hilden, T.; Karev, A.; Kašpar, J.; Kopal, J.; Kundrát, V.; Lami, S.; Latino, G.; Lauhakangas, R.; Leszko, T.; Lippmaa, E.; Lippmaa, J.; Lokajíček, M.; Losurdo, L.; Vetere, M. Lo; Rodríguez, F. Lucas; Macrí, M.; Mäki, T.; Mercadante, A.; Minafra, N.; Minutoli, S.; Nemes, F.; Niewiadomski, H.; Oliveri, E.; Oljemark, F.; Orava, R.; Oriunno, M.; Österberg, K.; Palazzi, P.; Pedreschi, E.; Procházka, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Robutti, E.; Ropelewski, L.; Ruggiero, G.; Saarikko, H.; Scribano, A.; Smajek, J.; Snoeys, W.; Spinella, F.; Sziklai, J.; Taylor, C.; Thys, A.; Turini, N.; Vacek, V.; Vítek, M.; Welti, J.; Whitmore, J.; Wyszkowski, P.

    2013-12-01

    The TOTEM Experiment is designed to measure the total proton-proton cross-section with the luminosity-independent method and to study elastic and diffractive pp scattering at the LHC. To achieve optimum forward coverage for charged particles emitted by the pp collisions in the interaction point IP5, two tracking telescopes, T1 and T2, are installed on each side of the IP in the pseudorapidity region 3.1≤|η|≤6.5, and special movable beam-pipe insertions — called Roman Pots (RP) — are placed at distances of ±147 m and ±220 m from IP5. This article describes in detail the working of the TOTEM detector to produce physics results in the first three years of operation and data taking at the LHC.

  10. Signals of Warped Extra Dimensions at the LHC

    SciTech Connect

    Osland, P.; Pankov, A. A.; Tsytrinov, A. V.; Paver, N.

    2010-12-22

    We discuss the signatures of the spin-2 graviton excitations predicted by the Randall-Sundrum model with one warped extra dimension, in dilepton and diphoton production at LHC. By using a specific angular analysis, we assess the ranges in mass and coupling constant where such gravitons can be discriminated against competitor spin-1 and spin-0 objects, that potentially could manifest themselves in these processes with the same mass and rate of events. Depending on the value of the coupling constant to quarks and leptons, the numerical results indicate graviton identification mass ranges up to 1.1-2.4 TeV and 1.6-3.2 TeV for LHC nominal energy of 14 TeV and time-integrated luminosity of 10 and 100fb{sup -1}, respectively.

  11. Gluino coannihilation and observability of gluinos at LHC run II

    NASA Astrophysics Data System (ADS)

    Nath, Pran; Spisak, Andrew B.

    2016-05-01

    The observability of a gluino at LHC run II is analyzed for the case where the gluino lies in the gluino-neutralino coannihilation region and the mass gap between the gluino and the neutralino is small. The analysis is carried out under the Higgs boson mass constraint and the constraint of dark matter relic density consistent with WMAP and Planck experiments. It is shown that in this case a gluino with mass much smaller than the current lower limit of ˜1500 GeV as given by LHC run II at 3.2 fb-1 of integrated luminosity would have escaped detection. The analysis is done using the signal regions used by the ATLAS Collaboration where an optimization of signal regions was carried out to determine the best regions for gluino discovery in the gluino-neutralino coannihilation region. It is shown that under the Higgs boson mass constraint and the relic density constraint, a gluino mass of ˜700 GeV would require 14 fb-1 of integrated luminosity for discovery and a gluino of mass ˜1250 GeV would require 3400 fb-1 of integrated luminosity for discovery at LHC run II. An analysis of dark matter for this case is also given. It is found that for the range of gluino masses considered, the neutralino mass lies within less than 100 GeV of the gluino mass. Thus a measurement of the gluino mass in the gluino-neutralino coannihilation region will provide a determination of the neutralino mass. In this region the neutralino is dominantly a gaugino and the spin-independent proton-neutralino cross section is small but much larger than the neutrino floor lying in the range ˜(1 - 10 )×10-47 cm2 . Thus a significant part of the parameter space of the model will lie within the reach of the next generation LUX-ZEPLIN dark matter experiment.

  12. A note on the fuzzy sphere area spectrum, black-hole luminosity and the quantum nature of spacetime

    NASA Astrophysics Data System (ADS)

    Santos, Victor; Silva, C. A. S.; Almeida, C. A. S.

    2015-05-01

    Noncommutative corrections to the classical expression for the fuzzy sphere area are found out through the asymptotic expansion for its heat kernel trace. As an important consequence, some quantum gravity deviations in the luminosity of black holes must appear. We calculate these deviations for a static, spherically symmetric, black hole with a horizon modeled by a fuzzy sphere. The results obtained could be verified through the radiation of black holes formed in the Large Hadron Collider (LHC).

  13. BNL upgrade plans

    SciTech Connect

    Foelsche, H.W.J.

    1987-01-01

    Brookhaven National Laboratory is proposing two major upgrade projects for a future experimental program with protons and heavy ions. The first is the construction of a Relativistic Heavy Ion Collider (RHIC) which will use the AGS complex as an injector. The second initiative is an upgrade of the AGS proton intensity and duty cycle. Both objectives require a Booster for the AGS which has recently been approved as a construction project. With the completion of the booster, and with certain modifications of the AGS, the facility will ultimately become capable of supporting average proton currents on the order of 25 to 50 microamperes. The RHIC will provide center-of-mass collision energies of 2 x 100 to 125 GeV/amu for ions up to the heaviest masses, and 2 x 250 GeV for protons.

  14. CRYOGENICS IN BEPCII UPGRADE.

    SciTech Connect

    JIA,L.; WANG,L.; LI,S.

    2002-07-22

    THIS PAPER PRESENTS A CRYOGENIC DESIGN FOR UPGRADING THE BEIJING ELECTRON POSITRON COLLIDER AT THE INSTITUTE OF HIGH ENERGY PHYSICS IN BEIJING. THE UPGRADE INVOLVES 3 NEW SUPERCONDUCTING FACILITIES, THE INTERACTION REGION QUADRUPOLE MAGNETS, THE DETECTOR SOLENOID MAGNETS AND THE SRF CAVITIES. FOR COOLING OF THESE DEVICES, A NEW CRYPLANT WITH A TOTAL CAPACITY OF 1.0KW AT 4.5K IS TO BE BUILT AT IHEP. AN INTEGRATED CRYOGENIC DESIGN TO FIT THE BEPCII CRYOGENIC LOADS WITH HIGH EFFICIENCY IS CARRIEDOUT USING COMPUTATIONAL PROCESS ANALYSIS SOFTWARE WITH THE EMPHASES ON ECONOMICS AND SAFETY IN BOTH CONSTRUCTION AND OPERATION OF THE PLANT. THIS PAPER DESCRIBES THE CRYOGENIC CHARACTERISTICS OF EACH SUPERCONDUCTING DEVICE, THEIR COOLING SCHEMES AND THE OVERALL CRYOPLANT.

  15. Commissioning of the read-out driver (ROD) card for the ATLAS IBL detector and upgrade studies for the pixel Layers 1 and 2

    NASA Astrophysics Data System (ADS)

    Balbi, G.; Bindi, M.; Falchieri, D.; Gabrielli, A.; Travaglini, R.; Chen, S.-P.; Hsu, S.-C.; Hauck, S.; Kugel, A.

    2014-11-01

    The higher luminosity that is expected for the LHC after future upgrades will require better performance by the data acquisition system, especially in terms of throughput. In particular, during the first shutdown of the LHC collider in 2013/14, the ATLAS Pixel Detector will be equipped with a fourth layer - the Insertable B-Layer or IBL - located at a radius smaller than the present three layers. Consequently, a new front end ASIC (FE-I4) was designed as well as a new off-detector chain. The latter is composed mainly of two 9U-VME cards called the Back-Of-Crate (BOC) and Read-Out Driver (ROD). The ROD is used for data and event formatting and for configuration and control of the overall read-out electronics. After some prototyping samples were completed, a pre-production batch of 5 ROD cards was delivered with the final layout. Actual production of another 15 ROD cards is ongoing in Fall 2013, and commissioning is scheduled in 2014. Altogether 14 cards are necessary for the 14 staves of the IBL detector, one additional card is required by the Diamond Beam Monitor (DBM), and additional spare ROD cards will be produced for a total of 20 boards. This paper describes some integration tests that were performed and our plan to test the production of the ROD cards. Slices of the IBL read-out chain have been instrumented, and ROD performance is verified on a test bench mimicking a small-sized final setup. This contribution will report also one view on the possible adoption of the IBL ROD for ATLAS Pixel Detector Layer 2 (firstly) and, possibly, in the future, for Layer 1.

  16. Diamond pad detector telescope for beam conditions and luminosity monitoring in ATLAS

    NASA Astrophysics Data System (ADS)

    Mikuž, M.; Cindro, V.; Dolenc, I.; Frais-Kölbl, H.; Gorišek, A.; Griesmayer, E.; Kagan, H.; Kramberger, G.; Mandić, I.; Niegl, M.; Pernegger, H.; Trischuk, W.; Weilhammer, P.; Zavrtanik, M.

    2007-09-01

    Beam conditions and the potential detector damage resulting from their anomalies have pushed the LHC experiments to plan their own monitoring devices in addition to those provided by the machine. ATLAS decided to build a telescope composed of two stations with four diamond pad detector modules each, placed symmetrically around the interaction point at z=±183.8cm and r˜55mm (η˜4.2). Equipped with fast electronics it allows time-of-flight separation of events resulting from beam anomalies from normally occurring p p interactions. In addition it will provide a coarse measurement of the LHC luminosity in ATLAS. Ten detector modules have been assembled and subjected to tests, from characterization of bare diamonds to source and beam tests. Preliminary results of beam test in the CERN PS indicate a signal-to-noise ratio of 14±2.

  17. Upgrade of the Belle Silicon Vertex Detector

    NASA Astrophysics Data System (ADS)

    Friedl, M.; Belle SVD Collaboration

    2010-11-01

    The Belle experiment at KEK (Tsukuba, Japan) was inaugurated in 1999 and has delivered excellent physics results since then, which were, for example, recognized in the Nobel Prize award 2008 to Kobayashi and Masukawa. An overall luminosity of 895 fb -1 has been recorded as of December 2008, and the present system will be running until 1 ab -1 is achieved. After that, a major upgrade is foreseen for both the KEK-B machine and the Belle detector. Already in 2004, the Letter of Intent for KEK Super B Factory was published. Intermediate steps of upgrade were considered for the Silicon Vertex Detector (SVD), which performs very well but already got close to its limit regarding the occupancy in the innermost layer and dead time. Eventually it was decided to keep the existing SVD2 system until 1 ab -1 and completely replace the silicon detector as well as its readout system for Super-Belle. The future SVD will be composed of double-sided silicon sensors as the present detector, but equipped with faster readout electronics, namely the APV25 chips originally made for CMS at CERN. Moreover, it will be enlarged by two additional layers and equipped with a double layer of DEPFET pixel detectors surrounding the beam pipe. The silicon sensors will be fabricated from 6 in. wafers (compared to the current 4 in. types) and the readout chain will be completely replaced, including front-end, repeaters and the back-end electronics in the counting house.

  18. Higgs Boson Search at LHC (and LHC/CMS status)

    SciTech Connect

    Korytov, Andrey

    2008-11-23

    Presented are the results of the most recent studies by the CMS and ATLAS collaborations on the expected sensitivity of their detectors to observing a Higgs boson at LHC. The overview is preceded with a brief summary of the LHC and the CMS Experiment status.

  19. LNV Higgses at LHC

    NASA Astrophysics Data System (ADS)

    Maiezza, Alessio; Nemevšek, Miha; Nesti, Fabrizio

    2016-06-01

    Lepton number is a fundamental symmetry that can be probed at the LHC. Here, we study the Higgs sector of theories responsible for neutrino mass generation. After a brief discussion of simple see-saw scenarios, we turn to theories where heavy Majorana neutrino mass is protected by a gauge symmetry and focus on the Left-Right symmetric theory. There, the SM-like Higgs boson can decay to a pair of heavy neutrinos and provide enough information to establish the origin of neutrino mass.

  20. LHC Nobel Symposium Proceedings

    NASA Astrophysics Data System (ADS)

    Ekelöf, Tord

    2013-12-01

    In the summer of 2012, a great discovery emerged at the Large Hadron Collider (LHC) at CERN in Geneva. A plethora of new precision data had already by then been collected by the ATLAS and CMS experiments at LHC, providing further extensive support for the validity of the Standard Model of particle physics. But what now appeared was the first evidence for what was not only the last unverified prediction of the Standard Model, but also perhaps the most decisive one: the prediction made already in 1964 of a unique scalar boson required by the theory of François Englert and Peter Higgs on how fundamental particles acquire mass. At that moment in 2012, it seemed particularly appropriate to start planning a gathering of world experts in particle physics to take stock of the situation and try to answer the challenging question: what next? By May 2013, when the LHC Nobel Symposium was held at the Krusenberg Mansion outside Uppsala in Sweden, the first signs of a great discovery had already turned into fully convincing experimental evidence for the existence of a scalar boson of mass about 125 GeV, having properties compatible with the 50-year-old prediction. And in October 2013, the evidence was deemed so convincing that the Swedish Royal Academy of Sciences awarded the Nobel Prize in Physics to Englert and Higgs for their pioneering work. At the same time the search at the LHC for other particles, beyond those predicted by the Standard Model, with heavier masses up to—and in some cases beyond—1 TeV, had provided no positive result. The triumph of the Standard Model seems resounding, in particular because the mass of the discovered scalar boson is such that, when identified with the Higgs boson, the Standard Model is able to provide predictions at energies as high as the Planck mass, although at the price of accepting that the vacuum would be metastable. However, even if there were some feelings of triumph, the ambience at the LHC Nobel Symposium was more one of

  1. 22nd RD50 Workshop on Radiation Hard Semiconductor Devices for High Luminosity Colliders

    SciTech Connect

    Seidel, Sally

    2013-05-06

    The 22nd RD50 Workshop on Radiation Hard Semiconductor Devices for High Luminosity Colliders was held on the campus of the University of New Mexico from June 3 to 5, 2013. This was the first North American meeting of the series going back to 2001. The sessions covered Material and Defect Characterization, Detector Characterization, Full Detector Systems, and New Structures. A half-day mini-workshop was allocated to radiation damage at LHC experiments. All talks are archived permanently available to the public at rd50.web.cern.ch. Financial support was used for room rental audiovisual equipment rental, and document preparation services.

  2. MicroTCA and AdvancedTCA equipment evaluation and developments for LHC experiments

    NASA Astrophysics Data System (ADS)

    Bobillier, V.; Haas, S.; Joos, M.; Mendez, J.; Mico, S.; Vasey, F.

    2016-02-01

    The MicroTCA (MTCA) and AdvancedTCA (ATCA) industry standards have been selected as the platform for many of the current and planned upgrades of the off-detector electronic systems of two of the LHC experiments at CERN. We present a status update from an ongoing project to evaluate commercial MTCA and ATCA components with particular emphasis on infrastructure equipment such as shelves and power-supplies. Shelves customized for use in the existing LHC rack infrastructure have been tested, and electrical and cooling measurements and simulations were performed. In-house developments for hardware platform management will also be shown.

  3. Simulations of Head-On Beam-Beam Compensation at RHIC and LHC

    SciTech Connect

    Valishev, A.; /Fermilab

    2010-05-19

    Electron lenses are proposed as a way to mitigate head-on beam-beam effects for RHIC and LHC upgrades. An extensive effort was put together within the US LARP in order to develop numerical simulations of beam-beam effects in the presence of electron lenses. In this report the results of numerical beam-beam simulations for RHIC and LHC are presented. The effect of electron lenses is demonstrated and sensitivity of beam-beam compensation to machine parameters is discussed.

  4. Prospects for jet measurements with sPHENIX and in the LHC Run 2

    NASA Astrophysics Data System (ADS)

    Perepelitsa, Dennis

    2015-10-01

    Measurements of fully reconstructed jets have become a sophisticated tool to probe the properties of the quark gluon plasma created in the collisions of ultrarelativistic heavy nuclei at RHIC and the LHC. This talk will discuss the prospects for what future jet measurements can reveal about the physics of jet quenching in the upcoming 5 TeV Pb+Pb collision data-taking at the LHC Run 2 and in 200 GeV Au+Au collisions at RHIC that are enabled by the sPHENIX detector upgrade.

  5. LER-LHC injector workshop summary and super-ferric fast cycling injector in the SPS tunnel

    SciTech Connect

    Ambrosio, Giorgio; Hays, Steven; Huang, Yuenian; Johnstone, John; Kashikhin, Vadim; MacLachlan, James; Mokhov, Nikolai; Piekarz, Henryk; Sen, Tanaji; Shiltsev, Vladimir; de Rijk, Gijsbert; /CERN

    2007-03-01

    A Workshop on Low Energy Ring (LER) in the LHC tunnel as main injector was convened at CERN on October 11-12, 2006. We present the outline of the LER based on the presentations, and respond to the raised questions and discussions including the post-workshop studies. We also outline the possibility of using the LER accelerator technologies for the fast cycling injector accelerator in the SPS tunnel (SF-SPS). A primary goal for the LER (Low Energy Ring) injector accelerator is to inject 1.5 TeV proton beams into the LHC, instead of the current injection scheme with 0.45 TeV beams from the SPS. At this new energy, the field harmonics [1] of the LHC magnets are sufficiently satisfactory to prevent the luminosity losses expected to appear when applying the transfer of the 0.45 TeV SPS beams. In addition, a feasibility study of batch slip stacking in the LER has been undertaken with a goal of increasing in this way the LHC luminosity by up to a factor of 4. A combined luminosity increase may, therefore, be in the range of an order of magnitude. In the long term, the LER injector accelerator would greatly facilitate the implementation of a machine, which doubles the LHC energy (DLHC).

  6. Supersymmetry at LHC

    SciTech Connect

    Bartl, A.; Soederqvist, J.; Paige, F.

    1996-11-22

    Supersymmetry (SUSY) is an appealing concept which provides a plausible solution to the fine tuning problem, while leaving the phenomenological success of the Standard Model (SM) unchanged. Moreover, some SUSY models allow for the unification of gauge couplings at a scale of M{sub GUT} {approx} 10{sup 16} GeV. A further attractive feature is the possibility of radiative breaking of the electro-weak symmetry group SU(2) {times} U(1). The masses of the SUSY partners of the SM particles are expected to be in the range 100 GeV to 1 TeV. One of the main goals of the Large Hadron Collider (LHC) will be either to discover weak-scale SUSY or to exclude it over the entire theoretically allowed parameter space. The authors have developed a strategy for the analysis of experimental data at LHC which will allow them to determine the scale for supersymmetry, to limit the model parameter space, and to make precision measurements of model parameters.

  7. The LHC Vacuum System

    NASA Astrophysics Data System (ADS)

    Gröbner, O.

    1997-05-01

    The Large Hadron Collider (LHC) at CERN, involves two proton storage rings with colliding beams of 7 TeV. The machine will be housed in the existing LEP tunnel and requires 16 m long superconducting bending magnets. The vacuum chamber will be the inner wall of the cryostat and hence at the temperature of the magnet cold bore, i.e. at 1.9 K and therefore a very good cryo-pump. To reduce the cryogenic power consumption, the heat load from synchrotron radiation and from the image currents in the vacuum chamber will be absorbed on a 'beam screen', which operates between 5 and 20 K, inserted in the magnet cold bore. The design pressure necessary for operation must provide a lifetime of many days and a stringent requirement comes from the power deposition in the superconducting magnet coils due to protons scattered on the residual gas which could lead to a magnet quench. Cryo-pumping of gas on the cold surfaces provides the necessary low gas densities but it must be ensured that the vapour pressure of cryo-sorbed molecules, of which H2 and He would be the most critical species, remains within acceptable limits. The room temperature sections of the LHC, specifically in the experiments, the vacuum must be stable against ion induced desorption and ISR-type 'pressure bumps'.

  8. LHC - a "Why" Facility

    ScienceCinema

    Gordon Kane

    2010-01-08

    The Standard Models of particle physics and cosmology describe the world we see, and how it works, very well. But we want to understand (not just accommodate) much more ? how does the Higgs mechanism work, what is the dark matter, why is the universe matter and not antimatter, why is parity violated, why are the particles (quarks and leptons) what they are, and why are the forces that act on them to make our world what they are, and more. Today is an exciting time to be doing particle physics ? on the experimental side we have data coming from LHC and dark matter experiments that will provide clues to these questions, and on the theoretical side we have a framework (string theory) that addresses all these ?why? questions. LHC data will not qualitatively improve our description ? rather, it may provide the data that will allow us to learn about the dark matter, the Higgs physics, the matter asymmetry, etc, to test underlying theories such as string theory, and begin to answer the ?why? questions. Supersymmetry is the best motivated discovery, and it would also open a window to the underlying theory near the Planck scale.

  9. Fitting the luminosity decay in the Tevatron

    SciTech Connect

    McCrory, E.; Shiltsev, V.; Slaughter, A.J.; Xiao, A.; /Fermilab

    2005-05-01

    This paper explores how to fit the decay of the luminosity in the Tevatron. The standard assumptions of a fixed-lifetime exponential decay are only appropriate for very short time intervals. A ''1/time'' functional form fits well, and is supported by analytical derivations. A more complex form, assuming a time-varying lifetime-like term, also produces good results. Changes in the luminosity can be factored into two phenomena: The luminosity burn-off rate, and the burn-off rate from non-luminosity effects. This is particularly relevant for the antiprotons in the Tevatron. The luminous and the non-luminous burn rate of the antiprotons are shown for Tevatron stores.

  10. Upgraded Coal Interest Group

    SciTech Connect

    Evan Hughes

    2009-01-08

    The Upgraded Coal Interest Group (UCIG) is an EPRI 'users group' that focuses on clean, low-cost options for coal-based power generation. The UCIG covers topics that involve (1) pre-combustion processes, (2) co-firing systems and fuels, and (3) reburn using coal-derived or biomass-derived fuels. The UCIG mission is to preserve and expand the economic use of coal for energy. By reducing the fuel costs and environmental impacts of coal-fired power generation, existing units become more cost effective and thus new units utilizing advanced combustion technologies are more likely to be coal-fired.

  11. Research ships upgraded

    NASA Astrophysics Data System (ADS)

    Two research vessels, operated by the Scripps Institution of Oceanography, University of California, San Diego, and Woods Hole Oceanographic Institution, Woods Hole, Mass., are undergoing scientific upgrading and engineering modifications costing $15 million each. The improvements will prepare them to take lead roles in major future ocean research efforts.Research vessel Knorr (operated by WHOI) entered the McDermott Shipyard in Amelia, LA., on February 15. It will receive new engines and a propulsion system, and its length will be increased from 245 to 279 feet. The R/V Melville (operated by SIO) is scheduled for the same 10-month remodeling to begin in mid-November.

  12. 'Upgrading' psoriasis responsibly.

    PubMed

    Boehncke, Sandra; Boehncke, Wolf-Henning

    2014-10-01

    Psoriasis is a 'pacemaker' in dermatology. Substantial progress has been made regarding our understanding of its pathophysiology and genetic background, fuelling developments in cutaneous biology in general. Besides, the clinical perspective on psoriasis is currently changing, taking into consideration comorbidity and the systemic dimensions of this seemingly organ-specific inflammation. The availability of drugs exhibiting fewer contraindications and improved long-term safety opened a discussion around replacing a relatively limited (regarding both objectives and duration) 'therapeutic' by a much broader 'management' approach when it comes to treating psoriasis as a systemic disease. The question arises whether this 'upgrade' is warranted. PMID:25040560

  13. The Bevalac Upgrade Project

    SciTech Connect

    Alonso, J.R.; Dwinell, R.D.; Feinberg, B.; Frias, R.; Gough, R.A.; Howard, D.R.; Hunt, D.B.; Krebs, G.F.; Krupnick, J.T.; Lewis, S.A.

    1987-03-01

    This paper describes a proposed upgrade of the Bevalac accelerator complex in which the present Bevatron is replaced with a modern, strong-focusing 17 T-m synchrotron. This new ring is designed to accelerate all ions throughout the periodic table with intensities 100 to 1000 times higher than the present Bevatron. It will also provide a substantially improved beam spill structure and will reduce operating costs. A fast extraction capability can be used to inject a future heavy ion storage ring. Pulse-to-pulse switching of energy and ion species is an important goal. The existing injectors, shielding, experimental facilities and utilities of the present Bevalac will remain substantially intact.

  14. The upgraded DØ detector

    NASA Astrophysics Data System (ADS)

    Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, D. L.; Adams, M.; Adams, T.; Agelou, M.; Agram, J.-L.; Ahmed, S. N.; Ahn, S. H.; Ahsan, M.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G. A.; Anastasoaie, M.; Andeen, T.; Anderson, J. T.; Anderson, S.; Andrieu, B.; Angstadt, R.; Anosov, V.; Arnoud, Y.; Arov, M.; Askew, A.; Åsman, B.; Assis Jesus, A. C. S.; Atramentov, O.; Autermann, C.; Avila, C.; Babukhadia, L.; Bacon, T. C.; Badaud, F.; Baden, A.; Baffioni, S.; Bagby, L.; Baldin, B.; Balm, P. W.; Banerjee, P.; Banerjee, S.; Barberis, E.; Bardon, O.; Barg, W.; Bargassa, P.; Baringer, P.; Barnes, C.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bhattacharjee, M.; Baturitsky, M. A.; Bauer, D.; Bean, A.; Baumbaugh, B.; Beauceron, S.; Begalli, M.; Beaudette, F.; Begel, M.; Bellavance, A.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Besson, A.; Beuselinck, R.; Beutel, D.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Binder, M.; Biscarat, C.; Bishoff, A.; Black, K. M.; Blackler, I.; Blazey, G.; Blekman, F.; Blessing, S.; Bloch, D.; Blumenschein, U.; Bockenthien, E.; Bodyagin, V.; Boehnlein, A.; Boeriu, O.; Bolton, T. A.; Bonamy, P.; Bonifas, D.; Borcherding, F.; Borissov, G.; Bos, K.; Bose, T.; Boswell, C.; Bowden, M.; Brandt, A.; Briskin, G.; Brock, R.; Brooijmans, G.; Bross, A.; Buchanan, N. J.; Buchholz, D.; Buehler, M.; Buescher, V.; Burdin, S.; Burke, S.; Burnett, T. H.; Busato, E.; Buszello, C. P.; Butler, D.; Butler, J. M.; Cammin, J.; Caron, S.; Bystricky, J.; Canal, L.; Canelli, F.; Carvalho, W.; Casey, B. C. K.; Casey, D.; Cason, N. M.; Castilla-Valdez, H.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapin, D.; Charles, F.; Cheu, E.; Chevalier, L.; Chi, E.; Chiche, R.; Cho, D. K.; Choate, R.; Choi, S.; Choudhary, B.; Chopra, S.; Christenson, J. H.; Christiansen, T.; Christofek, L.; Churin, I.; Cisko, G.; Claes, D.; Clark, A. R.; Clément, B.; Clément, C.; Coadou, Y.; Colling, D. J.; Coney, L.; Connolly, B.; Cooke, M.; Cooper, W. E.; Coppage, D.; Corcoran, M.; Coss, J.; Cothenet, A.; Cousinou, M.-C.; Cox, B.; Crépé-Renaudin, S.; Cristetiu, M.; Cummings, M. A. C.; Cutts, D.; da Motta, H.; Das, M.; Davies, B.; Davies, G.; Davis, G. A.; Davis, W.; De, K.; de Jong, P.; de Jong, S. J.; De La Cruz-Burelo, E.; De La Taille, C.; De Oliveira Martins, C.; Dean, S.; Degenhardt, J. D.; Déliot, F.; Delsart, P. A.; Del Signore, K.; DeMaat, R.; Demarteau, M.; Demina, R.; Demine, P.; Denisov, D.; Denisov, S. P.; Desai, S.; Diehl, H. T.; Diesburg, M.; Doets, M.; Doidge, M.; Dong, H.; Doulas, S.; Dudko, L. V.; Duflot, L.; Dugad, S. R.; Duperrin, A.; Dvornikov, O.; Dyer, J.; Dyshkant, A.; Eads, M.; Edmunds, D.; Edwards, T.; Ellison, J.; Elmsheuser, J.; Eltzroth, J. T.; Elvira, V. D.; Eno, S.; Ermolov, P.; Eroshin, O. V.; Estrada, J.; Evans, D.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Fagan, J.; Fast, J.; Fatakia, S. N.; Fein, D.; Feligioni, L.; Ferapontov, A. V.; Ferbel, T.; Ferreira, M. J.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fleck, I.; Fitzpatrick, T.; Flattum, E.; Fleuret, F.; Flores, R.; Foglesong, J.; Fortner, M.; Fox, H.; Franklin, C.; Freeman, W.; Fu, S.; Fuess, S.; Gadfort, T.; Galea, C. F.; Gallas, E.; Galyaev, E.; Gao, M.; Garcia, C.; Garcia-Bellido, A.; Gardner, J.; Gavrilov, V.; Gay, A.; Gay, P.; Gelé, D.; Gelhaus, R.; Genser, K.; Gerber, C. E.; Gershtein, Y.; Gillberg, D.; Geurkov, G.; Ginther, G.; Gobbi, B.; Goldmann, K.; Golling, T.; Gollub, N.; Golovtsov, V.; Gómez, B.; Gomez, G.; Gomez, R.; Goodwin, R.; Gornushkin, Y.; Gounder, K.; Goussiou, A.; Graham, D.; Graham, G.; Grannis, P. D.; Gray, K.; Greder, S.; Green, D. R.; Green, J.; Green, J. A.; Greenlee, H.; Greenwood, Z. D.; Gregores, E. M.; Grinstein, S.; Gris, Ph.; Grivaz, J.-F.; Groer, L.; Grünendahl, S.; Grünewald, M. W.; Gu, W.; Guglielmo, J.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hadley, N. J.; Haggard, E.; Haggerty, H.; Hagopian, S.; Hall, I.; Hall, R. E.; Han, C.; Han, L.; Hance, R.; Hanagaki, K.; Hanlet, P.; Hansen, S.; Harder, K.; Harel, A.; Harrington, R.; Hauptman, J. M.; Hauser, R.; Hays, C.; Hays, J.; Hazen, E.; Hebbeker, T.; Hebert, C.; Hedin, D.; Heinmiller, J. M.; Heinson, A. P.; Heintz, U.; Hensel, C.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Hong, S. J.; Hooper, R.; Hou, S.; Houben, P.; Hu, Y.; Huang, J.; Huang, Y.; Hynek, V.; Huffman, D.; Iashvili, I.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jacquier, Y.; Jaffré, M.; Jain, S.; Jain, V.; Jakobs, K.; Jayanti, R.; Jenkins, A.; Jesik, R.; Jiang, Y.; Johns, K.; Johnson, M.; Johnson, P.; Jonckheere, A.; Jonsson, P.; Jöstlein, H.; Jouravlev, N.; Juarez, M.; Juste, A.; Kaan, A. P.; Kado, M. M.; Käfer, D.; Kahl, W.; Kahn, S.; Kajfasz, E.

    2006-09-01

    The DØ experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to DØ.

  15. The luminosity of Population III star clusters

    NASA Astrophysics Data System (ADS)

    DeSouza, Alexander L.; Basu, Shantanu

    2015-06-01

    We analyse the time evolution of the luminosity of a cluster of Population III protostars formed in the early Universe. We argue from the Jeans criterion that primordial gas can collapse to form a cluster of first stars that evolve relatively independently of one another (i.e. with negligible gravitational interaction). We model the collapse of individual protostellar clumps using non-axisymmetric numerical hydrodynamics simulations. Each collapse produces a protostar surrounded by a massive disc (i.e. Mdisc /M* ≳ 0.1), whose evolution we follow for a further 30-40 kyr. Gravitational instabilities result in the fragmentation and the formation of gravitationally bound clumps within the disc. The accretion of these fragments by the host protostar produces accretion and luminosity bursts on the order of 106 L⊙. Within the cluster, we show that a simultaneity of such events across several protostellar cluster members can elevate the cluster luminosity to 5-10 times greater than expected, and that the cluster spends ˜15 per cent of its star-forming history at these levels. This enhanced luminosity effect is particularly enabled in clusters of modest size with ≃10-20 members. In one such instance, we identify a confluence of burst events that raise the luminosity to nearly 1000 times greater than the cluster mean luminosity, resulting in L > 108 L⊙. This phenomenon arises solely through the gravitational-instability-driven episodic fragmentation and accretion that characterizes this early stage of protostellar evolution.

  16. Upgraded demonstration vehicle task report

    NASA Technical Reports Server (NTRS)

    Bryant, J.; Hardy, K.; Livingston, R.; Sandberg, J.

    1981-01-01

    Vehicle/battery performance capabilities and interface problems that occurred when upgraded developmental batteries were integrated with upgraded versions of comercially available electric vehicles were investigated. Developmental batteries used included nickel zinc batteries, a nickel iron battery, and an improved lead acid battery. Testing of the electric vehicles and upgraded batteries was performed in the complete vehicle system environment to characterize performance and identify problems unique to the vehicle/battery system. Constant speed tests and driving schedule range tests were performed on a chassis dynamometer. The results from these tests of the upgraded batteries and vehicles were compared to performance capabilities for the same vehicles equipped with standard batteries.

  17. The X-ray luminosity function of very rich clusters and the luminosity-richness relation

    NASA Technical Reports Server (NTRS)

    Soltan, A.; Henry, J. P.

    1983-01-01

    For a sample of galactic clusters that includes richness class three, four, and five clusters, the significance of the luminosity-richness relation is estimated using nonparametric methods which are valid for any luminosity function. The Kolmogorov-Smirnov test is used to determine the significance at which the X-ray luminosities of clusters in one richness class are statistically equal to those in another. The a priori expectation that the high richness clusters are more luminous on average than lower richness objects is confirmed, but it is found that the luminosity function for clusters of richness class three or higher turns over for luminosities less than about 3 x 10 to the 44th ergs/s, while that for lower richness classes extends to at least an order of magnitude lower luminosity.

  18. Test Beam Results for ALICE TPC Upgrade Prototypes

    NASA Astrophysics Data System (ADS)

    Mulligan, James; Alice Tpc-Upgrade Collaboration

    2015-04-01

    The ALICE detector is one of four major experiments at the Large Hadron Collider (LHC), and its main purpose is to study the quark-gluon plasma created in relativistic heavy ion collisions. The Time Projection Chamber (TPC) is the main tracking detector within ALICE, and currently has an intrinsic rate limitation of 3 kHz. The LHC will be upgraded during Long Shutdown 2 in 2018 to have Pb-Pb collision rates up to 50 kHz, and so the TPC readout must be accordingly upgraded. This will be done by replacing the current Multi-Wire Proportional Chamber assembly, which uses a gating grid to prevent ion backflow, with Micro-Pattern Gas Detectors such as Gas Electron Multipliers (GEMs) and Micro-Mesh Gaseous Structures (MMGs), which allow for continuous rather than gated readout. A substantial R&D effort is underway for a 4-GEM design, as well as an alternate 2-GEM/MMG design. Prototypes of each design were tested in November-December 2014 at the PS and SPS beams at CERN; the results for the 2-GEM/MMG chambers will be presented.

  19. HP upgrade operational streamlining

    NASA Technical Reports Server (NTRS)

    Edge, David R.; Emenheiser, Kenneth S.; Hanrahan, William P., III; Mccollums, D.; Seery, Paul J.; Ricklefs, Randall L.

    1993-01-01

    New computer technology and resources must be successfully integrated into CDSLR station operations to manage new complex operational tracking requirements, support the on site production of new data products, support ongoing station performance improvements, and to support new station communication requirements. The NASA CDSLR Network is in the process of upgrading station computer resources with HP UNIX workstations, designed to automate a wide range of operational station requirements. The primary HP upgrade objective was to relocate computer intensive data system tasks from the controller computer to a new advanced computer environment designed to meet the new data system requirements. The HP UNIX environment supports fully automated real time data communications, data management, data processing, and data quality control. Automated data compression procedures are used to improve the efficiency of station data communications. In addition, the UNIX environment supports a number of semi-automated technical and administrative operational station tasks. The x window user interface generates multiple simultaneous color graphics displays, providing direct operator visibility and control over a wide range of operational station functions.

  20. SNO+ Readout Electronics Upgrades

    NASA Astrophysics Data System (ADS)

    Bonventre, Richard; Shokair, Timothy; Knapik, Robert

    2012-03-01

    The SNO+ experiment is designed to explore several topics in neutrino physics including neutrinoless double beta decay, reactor antineutrinos, and low energy solar neutrinos. SNO+ uses the existing Sudbury Neutrino Observatory (SNO) detector, with the heavy water target replaced with liquid scintillator. The new target requires an upgrade to the command and control electronics to handle the higher rates expected with scintillation light as compared to Cherenkov light. The readout electronics have been upgraded to autonomously push data to a central data acquisition computer over ethernet from each of the 19 front end crates. The autonomous readout is achieved with a field programmable gate array (FPGA) with an embedded processor. Inside the FPGA fabric a state machine is configured to pull data across the VME-like bus of each crate. A small C program, making use of the open source Light Weight IP (LWIP) libraries, is run directly on the hardware (with no operating system) to push the data via TCP/IP. The hybrid combination of `high-level' C code and a `low-level' VHDL state machine is a cost effective and flexible solution for reading out individual front end crates.

  1. Energy Efficiency Upgrades

    SciTech Connect

    Roby Williams

    2012-03-29

    The energy efficiency upgrades project at Hardin County General Hospital did not include research nor was it a demonstration project. The project enabled the hospital to replace outdated systems with modern efficient models. Hardin County General Hospital is a 501c3, nonprofit hospital and the sole community provider for Hardin and Pope Counties of Illinois. This project provided much needed equipment and facility upgrades that would not have been possible through locally generated funding. Task 1 was a reroofing of the hospital. The hospital architect designed the replacement to increase the energy efficiency of the hospital roof/ceiling structure. Task 2 was replacement and installation of a new more efficient CT scanner for the hospital. Included in the project was replacement of HVAC equipment for the entire radiological suite. Task 5 was a replacement and installation of a new higher capacity diesel-fueled emergency generator for the hospital replacing a 50+ year old gas-fired generator. Task 7 was the replacement of 50+ year-old walk-in cooler/freezer with a newer, energy efficient model. Task 8 was the replacement of 10+ year-old washing machines in the hospital laundry with higher capacity, energy efficient models. Task 9 was replacement of 50-year old single pane curtain window system with double-pane insulated windows. Additionally, insulation was added around ventilation systems and the curtain wall system.

  2. The pixel detector for the CMS phase-II upgrade

    NASA Astrophysics Data System (ADS)

    Dinardo, M. E.

    2015-04-01

    The high luminosity phase of the Large Hadron Collider (HL-LHC) requires a major pixel detector R&D effort to develop both readout chip and sensor that are capable to withstand unprecedented extremely high radiation. The target integrated luminosity of 3000 fb-1, that the HL-LHC is expected to deliver over about 10 years of operation, translates into a hadron fluence of 2×1016 1 MeV eq.n. / cm2, or equivalently 10 MGy of radiation dose in silicon, at about 3 cm from the interaction region where the first layer of the pixel detector could be located. The CMS collaboration has undertaken two baseline sensor R&D programs on thin n-on-p planar and 3D silicon sensor technologies. Together with the ATLAS collaboration it has also been established a common R&D effort for the development of the readout chip in the 65 nm CMOS technology. Status, progresses, and prospects of the CMS R&D effort are presented and discussed in this article.

  3. CDF Run IIb Silicon Vertex Detector DAQ Upgrade

    SciTech Connect

    S. Behari et al.

    2003-12-18

    The CDF particle detector operates in the beamline of the Tevatron proton-antiproton collider at Fermilab, Batavia, IL. The Tevatron is expected to undergo luminosity upgrades (Run IIb) in the future, resulting in a higher number of interactions per beam crossing. To operate in this dense radiation environment, an upgrade of CDF's silicon vertex detector (SVX) subsystem and a corresponding upgrade of its VME-based DAQ system has been explored. Prototypes of all the Run IIb SVX DAQ components have been constructed, assembled into a test stand and operated successfully using an adapted version of CDF's network-capable DAQ software. In addition, a PCI-based DAQ system has been developed as a fast and inexpensive tool for silicon detector and DAQ component testing in the production phase. In this paper they present an overview of the Run IIb silicon DAQ upgrade, emphasizing the new features and improvements incorporated into the constituent VME boards, and discuss a PCI-based DAQ system developed to facilitate production tests.

  4. The D0 level 3 DAQ system: operation and upgrades

    SciTech Connect

    Garcia-Bellido, Aran; Bose, Tulika; Brooijmans, Gustaaf; Chapin, Doug; Cutts, David; Fuess, Stuart; Gadfort, Thomas; Haas, Andrew; Lee, William; Rechenmacher, Ron; Snyder, Scott; /Washington U., Seattle /Brown U. /Columbia U. /Fermilab /Brookhaven

    2007-05-01

    The D{O} Level 3 data acquisition system for Run II of the Tevatron has been reliably operating since May 2002. Designed to handle average event sizes of 250 kilobytes at a rate of 1 kHz, the system has been upgraded to be able to process more events, doubling its typical output rate from 50 Hz to 100 Hz, while coping with higher event sizes at the beginning of high luminosity collider stores. The system routes and transfers event fragments from 63 VME crates to any of approximately 320 processing nodes. The addition of more farm nodes, the performance of the components, and the running experience are described here.

  5. Non-simplified SUSY: widetilde{τ }-coannihilation at LHC and ILC

    NASA Astrophysics Data System (ADS)

    Berggren, M.; Cakir, A.; Krücker, D.; List, J.; Melzer-Pellmann, I.-A.; Samani, B. Safarzadeh; Seitz, C.; Wayand, S.

    2016-04-01

    If new phenomena beyond the Standard Model will be discovered at the LHC, the properties of the new particles could be determined with data from the High-Luminosity LHC and from a future linear collider like the ILC. We discuss the possible interplay between measurements at the two accelerators in a concrete example, namely a full SUSY model which features a small widetilde{τ }_1-LSP mass difference. Various channels have been studied using the Snowmass 2013 combined LHC detector implementation in the Delphes simulation package, as well as simulations of the ILD detector concept from the Technical Design Report. We investigate both the LHC and the ILC capabilities for discovery, separation and identification of various parts of the spectrum. While some parts would be discovered at the LHC, there is substantial room for further discoveries at the ILC. We finally highlight examples where the precise knowledge about the lower part of the mass spectrum which could be acquired at the ILC would enable a more in-depth analysis of the LHC data with respect to the heavier states.

  6. PDF4LHC recommendations for LHC Run II

    NASA Astrophysics Data System (ADS)

    Butterworth, Jon; Carrazza, Stefano; Cooper-Sarkar, Amanda; De Roeck, Albert; Feltesse, Joël; Forte, Stefano; Gao, Jun; Glazov, Sasha; Huston, Joey; Kassabov, Zahari; McNulty, Ronan; Morsch, Andreas; Nadolsky, Pavel; Radescu, Voica; Rojo, Juan; Thorne, Robert

    2016-02-01

    We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+{α }s uncertainties suitable for applications at the LHC Run II. We review developments since the previous PDF4LHC recommendation, and discuss and compare the new generation of PDFs, which include substantial information from experimental data from the Run I of the LHC. We then propose a new prescription for the combination of a suitable subset of the available PDF sets, which is presented in terms of a single combined PDF set. We finally discuss tools which allow for the delivery of this combined set in terms of optimized sets of Hessian eigenvectors or Monte Carlo replicas, and their usage, and provide some examples of their application to LHC phenomenology. This paper is dedicated to the memory of Guido Altarelli (1941-2015), whose seminal work made possible the quantitative study of PDFs.

  7. PDF4LHC recommendations for LHC Run II

    DOE PAGESBeta

    Butterworth, Jon; Carrazza, Stefano; Cooper-Sarkar, Amanda; Roeck, Albert De; Feltesse, Joel; Forte, Stefano; Gao, Jun; Glazov, Sasha; Huston, Joey; Kassabov, Zahari; et al

    2016-01-06

    We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+αs uncertainties suitable for applications at the LHC Run II. We review developments since the previous PDF4LHC recommendation, and discuss and compare the new generation of PDFs, which include substantial information from experimental data from the Run I of the LHC. We then propose a new prescription for the combination of a suitable subset of the available PDF sets, which is presented in terms of a single combined PDF set. Lastly, we finally discuss tools which allow for themore » delivery of this combined set in terms of optimized sets of Hessian eigenvectors or Monte Carlo replicas, and their usage, and provide some examples of their application to LHC phenomenology.« less

  8. TMX upgrade experimental operating plan

    SciTech Connect

    Coensgen, F.H.; Davis, J.C.; Simonen, T.C.

    1981-07-01

    This document describes the operating plan for the TMX Upgrade experiment. This plan covers the period from November 1981 to March 1983 and describes how the TMX will be brought into operation, our schedules and milestones, and how we will determine if the TMX Upgrade program milestones have been met.

  9. Skill Upgrading, Incorporated. Final Report.

    ERIC Educational Resources Information Center

    Skill Upgrading, Inc., Baltimore, MD.

    As in two other projects in Cleveland and Newark, New Jersey, this project was set up in Baltimore to provide technical assistance in designing ways to meet in-plant skills needs by upgrading job skills on entry workers through High Intensity Training (HIT). Skill Upgrading, Inc. was established in Maryland to provide training and manpower…

  10. hhjj production at the LHC

    SciTech Connect

    Dolan, Matthew J.; Englert, Christoph; Greiner, Nicolas; Nordstrom, Karl; Spannowsky, Michael

    2015-08-25

    The search for di-Higgs production at the LHC in order to set limits on the Higgs trilinear coupling and constraints on new physics is one of the main motivations for the LHC high-luminosity phase. Recent experimental analyses suggest that such analyses will only be successful if information from a range of channels is included. We therefore investigate di-Higgs production in association with two hadronic jets and give a detailed discussion of both the gluon- and the weak boson-fusion (WBF) contributions, with a particular emphasis on the phenomenology with modified Higgs trilinear and quartic gauge couplings. We perform a detailed investigation of the full hadronic final state and find that hhjj production should add sensitivity to a di-Higgs search combination at the HL-LHC with 3 ab-1. Since the WBF and GF contributions are sensitive to different sources of physics beyond the Standard Model, we devise search strategies to disentangle and isolate these production modes. In addition, while gluon fusion remains non-negligible in WBF-type selections, sizeable new physics contributions to the latter can still be constrained. As an example of the latter point we investigate the sensitivity that can be obtained for a measurement of the quartic Higgs–gauge boson couplings.

  11. A luminosity model of RHIC gold runs

    SciTech Connect

    Zhang, S.Y.

    2011-11-01

    In this note, we present a luminosity model for RHIC gold runs. The model is applied to the physics fills in 2007 run without cooling, and with the longitudinal cooling applied to one beam only. Having good comparison, the model is used to project a fill with the longitudinal cooling applied to both beams. Further development and possible applications of the model are discussed. To maximize the integrated luminosity, usually the higher beam intensity, smaller longitudinal and transverse emittance, and smaller {beta} are the directions to work on. In past 10 years, the RHIC gold runs have demonstrated a path toward this goal. Most recently, a successful commissioning of the bunched beam stochastic cooling, both longitudinal and transverse, has offered a chance of further RHIC luminosity improvement. With so many factors involved, a luminosity model would be useful to identify and project gains in the machine development. In this article, a preliminary model is proposed. In Section 2, several secondary factors, which are not yet included in the model, are identified based on the RHIC operation condition and experience in current runs. In Section 3, the RHIC beam store parameters used in the model are listed, and validated. In Section 4, the factors included in the model are discussed, and the luminosity model is presented. In Section 5, typical RHIC gold fills without cooling, and with partial cooling are used for comparison with the model. Then a projection of fills with more coolings is shown. In Section 6, further development of the model is discussed.

  12. Data Analysis Techniques at LHC

    SciTech Connect

    Boccali, Tommaso

    2005-10-12

    A review of the recent developments on data analysis techniques for the upcoming LHC experiments is presented, with the description of early tests ('Data Challenges'), which are being performed before the start-up, to validate the overall design.

  13. NIRSS Upgrades: Final Report

    NASA Technical Reports Server (NTRS)

    Politovich, Marcia K.

    2007-01-01

    This year we were able to further the NIRSS program by re-writing the data ingest and display code from LabVIEW to C++ and Java. This was leveraged by a University of Colorado Computer Science Department Senior Project. The upgrade made the display more portable and upgradeable. Comparisons with research aircraft flights conducted during AIRS-2 were also done and demonstrate reasonable skill in determining cloud altitudes and liquid water distribution. Improvements can still be made to the cloud and liquid logic. The icing hazard index was not evaluated here since that represents work in progress and needs to be made compatible with the new CIP-Severity algorithm. CIP is the Current Icing Potential product that uses a combination decision tree/fuzzy logic algorithm to combine numerical weather model output with operational sensor data (NEXRAD, GOES, METARs and voice pilot reports) to produce an hourly icing diagnosis across the CONUS. The new severity algorithm seeks to diagnose liquid water production through rising, cooling air, and depletion by ice processes. The information used by CIP is very different from that ingested by NIRSS but some common ground does exist. Additionally, the role of NIRSS and the information it both needs and provides needs to be determined in context of the Next Generation Air Traffic System (NGATS). The Weather Integrated Products Team has a plan for an Initial Operating Capability (IOC) to take place in 2012. NIRSS is not explicitly a part of that IOC but should be considered as a follow-on as part of the development path to a 2025 full capability.

  14. Novel silicon n-in-p pixel sensors for the future ATLAS upgrades

    NASA Astrophysics Data System (ADS)

    La Rosa, A.; Gallrapp, C.; Macchiolo, A.; Nisius, R.; Pernegger, H.; Richter, R. H.; Weigell, P.

    2013-08-01

    In view of the LHC upgrade phases towards HL-LHC the ATLAS experiment plans to upgrade the inner detector with an all silicon system. The n-in-p silicon technology is a promising candidate for the pixel upgrade thanks to its radiation hardness and cost effectiveness that allow for enlarging the area instrumented with pixel detectors. We present the characterization and performance of novel n-in-p planar pixel sensors produced by CiS (Germany) connected by bump bonding to the ATLAS readout chip FE-I3. These results are obtained before and after irradiation up to a fluence of 10161-MeV neq cm-2, and prove the operability of this kind of sensors in the harsh radiation environment foreseen for the pixel system at HL-LHC. We also present an overview of the new pixel production, which is on-going at CiS for sensors compatible with the new ATLAS readout chip FE-I4.

  15. Technical Design Report for the Upgrade of the ALICE Inner Tracking System

    NASA Astrophysics Data System (ADS)

    ALICE Collaboration; Abelev, B.; Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Masoodi, A. Ahmad; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Anderssen, E. C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Azmi, M. D.; Bach, M.; Badala, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bairathi, V.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Bán, J..; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastian Van Beelen, J.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Battistin, M.; Batyunya, B.; Batzing, P. C.; Baudot, J.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Benettoni, M.; Benotto, F.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Berger, M. E.; Bertens, R. A.; Berzano, D.; Besson, A.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bhatti, A.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Boehmer, F. V.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bornschein, J.; Borshchov, V. N.; Bortolin, C.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Carena, F.; Carena, W.; Cariola, P.; Carminati, F.; Casanova Díaz, A.; Castillo Castellanos, J.; Casula, E. A. R.; Catanescu, V.; Caudron, T.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Claus, G.; Cleymans, J.; Colamaria, F.; Colella, D.; Coli, S.; Colledani, C.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Da Riva, E.; Das, D.; Das, I.; Das, K.; Das, S.; Dash, A.; Dash, S.; De, S.; Decosse, C.; DelagrangeI, H.; Deloff, A.; Déenes, E.; D'Erasmo, G.; de Barros, G. O. V.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Robertis, G.; De Roo, K.; de Rooij, R.; Diaz Corchero, M. A.; Dietel, T.; Divia, R.; Di Bari, D.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dorheim, S.; Dorokhov, A.; Doziere, G.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dulinski, W.; Dupieux, P.; Dutta Majumdar, A. K.; Ehlers, R. J., III; Elia, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernádez Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fiorenza, G.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Franco, M.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gajanana, D.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubilato, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez, R.; Gomez Marzoa, M.; Gonzáalez-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.

    2014-08-01

    ALICE (A Large Ion Collider Experiment) is studying the physics of strongly interacting matter, and in particular the properties of the Quark-Gluon Plasma (QGP), using proton-proton, proton-nucleus and nucleus-nucleus collisions at the CERN LHC (Large Hadron Collider). The ALICE Collaboration is preparing a major upgrade of the experimental apparatus, planned for installation in the second long LHC shutdown in the years 2018-2019. A key element of the ALICE upgrade is the construction of a new, ultra-light, high-resolution Inner Tracking System (ITS) based on monolithic CMOS pixel detectors. The primary focus of the ITS upgrade is on improving the performance for detection of heavy-flavour hadrons, and of thermal photons and low-mass di-electrons emitted by the QGP. With respect to the current detector, the new Inner Tracking System will significantly enhance the determination of the distance of closest approach to the primary vertex, the tracking efficiency at low transverse momenta, and the read-out rate capabilities. This will be obtained by seven concentric detector layers based on a 50 μm thick CMOS pixel sensor with a pixel pitch of about 30×30 μm2. This document, submitted to the LHCC (LHC experiments Committee) in September 2013, presents the design goals, a summary of the R&D activities, with focus on the technical implementation of the main detector components, and the projected detector and physics performance.

  16. Measuring smuon-selectron mass splitting at the CERN LHC and patterns of supersymmetry breaking

    SciTech Connect

    Allanach, B. C.; Conlon, J. P.; Lester, C. G.

    2008-04-01

    With sufficient data, CERN LHC experiments can constrain the smuon-selectron mass splitting through differences in the dielectron and dimuon edges from supersymmetry (SUSY) cascade decays. We study the sensitivity of the LHC to this mass splitting, which within minimal supergravity may be constrained down to O(10{sup -4}) for 30 fb{sup -1} of integrated luminosity. Over substantial regions of SUSY breaking parameter space the fractional edge splitting can be significantly enhanced over the fractional mass splitting. Within models where the selectron and smuon are constrained to be universal at a high scale, edge splittings up to a few percent may be induced by renormalization group effects and may be significantly discriminated from zero. The edge splitting provides important information about high-scale SUSY breaking terms and should be included in any fit of LHC data to high-scale models.

  17. Cryogenic safety aspect of the low -$\\beta$ magnest systems at the Large Hadron Collider (LHC)

    SciTech Connect

    Darve, C.; /Fermilab

    2010-07-01

    The low-{beta} magnet systems are located in the LHC insertion regions around the four interaction points. They are the key elements in the beams focusing/defocusing process and will allow proton collisions at a luminosity of up to 10{sup 34}cm{sup -2}s{sup -1}. Large radiation dose deposited at the proximity of the beam collisions dictate stringent requirements for the design and operation of the systems. The hardware commissioning phase of the LHC was completed in the winter of 2010 and permitted to validate this system safe operation. This paper presents the analysis used to qualify and quantify the safe operation of the low-{beta} magnet systems in the Large Hadron Collider (LHC) for the first years of operation.

  18. TeV lepton number violation: From neutrinoless double-β decay to the LHC

    NASA Astrophysics Data System (ADS)

    Peng, Tao; Ramsey-Musolf, Michael J.; Winslow, Peter

    2016-05-01

    We analyze the sensitivity of next-generation tonne-scale neutrinoless double-β decay (0 ν β β ) experiments and searches for same-sign di-electrons plus jets at the Large Hadron Collider to TeV scale lepton number violating interactions. Taking into account previously unaccounted for physics and detector backgrounds at the LHC, renormalization group evolution, and long-range contributions to 0 ν β β nuclear matrix elements, we find that the reach of tonne-scale 0 ν β β generally exceeds that of the LHC for a class of simplified models. However, for a range of heavy particle masses near the TeV scale, the high luminosity LHC and tonne-scale 0 ν β β may provide complementary probes.

  19. Pixel module production and qualification for the phase I upgrade of CMS

    NASA Astrophysics Data System (ADS)

    Miñano Moya, M.

    2015-01-01

    The instantaneous luminosity of the Large Hadron Collider (LHC) is being increased in several steps over the next 10 years to maximize its discovery potential for new physics. However, at a luminosity of twice the design luminosity of the LHC of 1034 cm-2 s-1, the performance of the current CMS pixel detector is degraded by substantial deadtime caused by the readout chip (ROC). To make full use of the proton-proton collisions being provided by the LHC, CMS will replace its pixel detector during the extended winter shutdown in 2016-2017 with a new detector with four barrel layers and three disks in each endcap. Module production includes bump bonding, wire bonding, and gluing processes, as well as a series of functionality tests, calibrations and thermal cycling. One of the calibration steps is the X-ray calibration, which provides an absolute energy calibration of an internal calibration circuit. This circuit injects charge into the preamplifier to simulate a signal, and is used to define several parameters of the readout chip, including the threshold. Therefore, an absolute calibration is required in order to know the threshold in units of electrons. In this article, the barrel module assembly is explained, with a special focus on the X-ray calibration of the pixel detector.

  20. Prospects for Higgs boson searches at the Tevatron and LHC in the MSSM with explicit CP violation

    SciTech Connect

    Draper, Patrick; Liu Tao; Wagner, Carlos E. M.

    2010-01-01

    We analyze the Tevatron and Large Hadron Collider (LHC) reach for the Higgs sector of the minimal supersymmetric standard model (MSSM) in the presence of explicit CP violation. Using the most recent studies from the Tevatron and LHC collaborations, we examine the CPX benchmark scenario for a range of CP-violating phases in the soft trilinear and gluino mass terms and compute the exclusion/discovery potentials for each collider on the (M{sub H}{sup +},tan{beta}) plane. Projected results from standard model (SM)-like, nonstandard, and charged Higgs searches are combined to maximize the statistical significance. We exhibit complementarity between the SM-like Higgs searches at the LHC with low luminosity and the Tevatron, and estimate the combined reach of the two colliders in the early phase of LHC running.

  1. Radio luminosity function of brightest cluster galaxies

    NASA Astrophysics Data System (ADS)

    Yuan, Z. S.; Han, J. L.; Wen, Z. L.

    2016-08-01

    By cross-matching the currently largest optical catalogue of galaxy clusters and the NVSS radio survey data base, we obtain a large complete sample of brightest cluster galaxies (BCGs) in the redshift range of 0.05 < z ≤ 0.45, which have radio emission and redshift information. We confirm that more powerful radio BCGs tend to be these optically very bright galaxies located in more relaxed clusters. We derived the radio luminosity functions of the largest sample of radio BCGs, and find that the functions depend on the optical luminosity of BCGs and the dynamic state of galaxy clusters. However, the radio luminosity function does not show significant evolution with redshift.

  2. Stellar luminosity variations and global warming.

    PubMed

    Foukal, P

    1994-04-01

    Recent studies indicate that variation in the sun's luminosity is less than that observed in many other stars of similar magnetic activity. Current findings also indicate that in more active stars, the attenuation by faculae of sunspot luminosity modulation is less effective than in the sun at present. The sun could thus become photometrically more variable (and dimmer) if its magnetic activity exceeded present levels. But the levels of solar activity required for this to occur are not observed in carbon-14 and beryllium-10 records over the past several millennia, which indicates that such an increase in amplitude of surface magnetism-driven variations in solar luminosity is unlikely in the present epoch. PMID:17749020

  3. Light stops and observation of supersymmetry at LHC run II

    NASA Astrophysics Data System (ADS)

    Kaufman, Bryan; Nath, Pran; Nelson, Brent D.; Spisak, Andrew B.

    2015-11-01

    Light stops consistent with the Higgs boson mass of ˜126 GeV are investigated within the framework of minimal supergravity. It is shown that models with light stops which are also consistent with the thermal relic density constraints require stop coannihilation with the neutralino LSP. The analysis shows that the residual set of parameter points with light stops satisfying both the Higgs mass and the relic density constraints lie within a series of thin strips in the m0-m1 /2 plane for different values of A0/m0. Consequently, this region of minimal supergravity parameter space makes a number of very precise predictions. It is found that light stops of mass down to 400 GeV or lower can exist consistent with all constraints. A signal analysis for this class of models at LHC run II is carried out and the dominant signals for their detection identified. Also computed is the minimum integrated luminosity for 5 σ discovery of the models analyzed. If supersymmetry is realized in this manner, the stop masses can be as low as 400 GeV or lower, and the mass gap between the lightest neutralino and lightest stop will be approximately 30-40 GeV. We have optimized the ATLAS signal regions specifically for stop searches in the parameter space and find that a stop with mass ˜375 GeV can be discovered with as little as ˜60 fb-1 of integrated luminosity at run II of the LHC; the integrated luminosity needed for discovery could be further reduced with more efficient signature analyses. The direct detection of dark matter in this class of models is also discussed. It is found that dark matter cross sections lie close to, but above, coherent neutrino scattering and would require multiton detectors such as LZ to see a signal of dark matter for this class of models.

  4. Measurement of the Inclusive $Z \\to ee$ Production Cross Section in Proton-Proton Collisions at $\\sqrt{s}$ = 7TeV and $Z \\to ee$ Decays as Standard Candles for Luminosity at the Large Hadron Collider

    SciTech Connect

    Werner, Jeremy

    2011-01-01

    This thesis comprises a precision measurement of the inclusive \\Zee production cross section in proton-proton collisions provided by the Large Hadron Collider (LHC) at a center-of-mass energy of $\\sqrt{s}=7$~TeV and the absolute luminosity based on \\Zee decays. The data was collected by the Compact Muon Solenoid (CMS) detector near Geneva, Switzerland during the year of 2010 and corresponds to an integrated luminosity of $\\int\\mathcal{L}dt = 35.9\\pm 1.4$~pb$^{-1}$. Electronic decays of $Z$ bosons allow one of the first electroweak measurements at the LHC, making the cross section measurement a benchmark of physics performance after the first year of CMS detector and LHC machine operations. It is the first systematic uncertainty limited \\Zee cross section measurement performed at $\\sqrt{s}=7$~TeV. The measured cross section pertaining to the invariant mass window $M_{ee}\\in (60,120)$~GeV is reported as: $\\sigma(pp\\to Z+X) \\times \\mathcal{B}( Z\\to ee ) = 997 \\pm 11 \\mathrm{(sta t)} \\pm 19 \\mathrm{(syst)} \\pm 40 \\mathrm{(lumi)} \\textrm{ pb}$, which agrees with the theoretical prediction calculated to NNLO in QCD. Leveraging \\Zee decays as ``standard candles'' for measuring the absolute luminosity at the LHC is examined; they are produced copiously, are well understood, and have clean detector signatures. Thus the consistency of the inclusive \\Zee production cross section measurement with the theoretical prediction motivates inverting the measurement to instead use the \\Zee signal yield to measure the luminosity. The result, which agrees with the primary relative CMS luminosity measurement calibrated using Van der Meer separation scans, is not only the most precise absolute luminosity measurement performed to date at a hadron collider, but also the first one based on a physics signal at the LHC.

  5. The luminosity of galactic components and morphological segregation

    SciTech Connect

    Solanes, J. M.; Salvador-Sole, E.; Sanroma, M.; I.E.C., Barcelona )

    1989-09-01

    The luminosities of the bulge and disk components of disk galaxies are analyzed, and the possible correlation of these luminosities with morphological type and local density is explored. Galaxies of different types are found to be located in distinct bands in the bulge-to-disk luminosity ratio vs total luminosity diagram, allowing the determination of the typical bulge luminosity function of disk galaxies of different types from their respective total luminosity functions, along with a better characterization of morphological segregation among disk galaxies. No evidence for any bulge luminosity segregation is found, and disks appear to be less luminous with increasing local density. 33 refs.

  6. Characterization of irradiated test structures for the CMS tracker upgrade

    NASA Astrophysics Data System (ADS)

    Lutzer, Bernhard

    2013-12-01

    The CMS collaboration is currently conducting a campaign to identify radiation-hard materials for an upgrade of the CMS tracker. This upgrade is needed to be able to cope with the higher radiation background of the future HL-LHC; additionally the performance of the current tracker will be significantly degraded at the time of the upgrade, requiring a replacement. Several different test structures (TSs) and sensors have been designed for a 6 in. wafer layout. These wafers were produced by an industrial supplier (Hamamatsu Photonics K.K.) and differ by their bulk material (Float Zone, Magnetic Czochralski and CVD-Epi), thickness (from 50 μm to 320 μm) and N-P type doping. These TSs consist of different microelectronic devices including diodes, resistors or MOS structures. They enable the extraction of parameters which are not accessible in a silicon detector and allow the assessment of the quality of the sensors produced on the same wafer. The TSs have been irradiated with protons and neutrons to emulate the radiation damage caused by the particle fluence inside the future CMS tracker after 10 years of operation. This contribution will present measurements of non-irradiated and irradiated test structures at different fluences. The changes of the properties of the microelectronic devices will be discussed as well as the design of the TSs.

  7. NSLS control system upgrade status

    SciTech Connect

    Smith, J.; Ramamoorthy, S.; Tang, Y.; Flannigan, J.; Sathe, S.; Keane, J.; Krinsky, S.

    1993-07-01

    The NSLS control system initially installed in 1978 has undergone several modifications but the basic system architecture remained relatively unchanged. The need for faster response, increased reliability and better diagnostics made the control system upgrade a priority. Since the NSLS runs continuously, major changes to the control system are difficult. The upgrade plan had to allow continuous incremental changes to the control system without having any detrimental effect on operations. The plan had to provide for immediate improvement in a few key areas, such as data access rates, and be complete in a short time. At present, most accelerator operations utilize the upgraded control system.

  8. Summary of symposium: Low luminosity sources

    NASA Technical Reports Server (NTRS)

    Shu, Frank H.

    1987-01-01

    The author summarized certain aspects of the conference. He shares this task with another colleague thereby breaking the task into more manageable proportions. The author covers the low luminosity sources. He begins his review with a summary of some major themes of the conference and ends with a few speculations on possible theoretical mechanisms.

  9. RHIC Proton Luminosity and Polarization Improvement

    SciTech Connect

    Zhang, S. Y.

    2014-01-17

    The RHIC proton beam polarization can be improved by raising the Booster scraping, which also helps to reduce the RHIC transverse emittance, and therefore to improve the luminosity. By doing this, the beam-beam effect would be enhanced. Currently, the RHIC working point is constrained between 2/3 and 7/10, the 2/3 resonance would affect intensity and luminosity lifetime, and the working point close to 7/10 would enhance polarization decay in store. Run 2013 shows that average polarization decay is merely 1.8% in 8 hours, and most fills have the luminosity lifetime better than 14 hours, which is not a problem. Therefore, even without beam-beam correction, there is room to improve for RHIC polarization and luminosity. The key to push the Booster scraping is to raise the Booster input intensity; for that, two approaches can be used. The first is to extend the LINAC tank 9 pulse width, which has been successfully applied in run 2006. The second is to raise the source temperature, which has been successfully applied in run 2006 and run 2012.

  10. Tevatron Experimental Issues at High Luminosities

    SciTech Connect

    Kreps, Michal; CDF, for the; collaborations, D0

    2009-12-01

    In this paper we describe the detector components, triggers and analysis techniques for flavor physics at the Tevatron experiments CDF and D0. As Tevatron performs very well and runs at higher luminosities regularly we also touch issues related to it and efforts to improve detectors and triggers for such running.

  11. Fermilab Recycler Stochastic Cooling for Luminosity Production

    SciTech Connect

    Broemmelsiek, D.; Gattuso, C.

    2006-03-20

    The Fermilab Recycler began regularly delivering antiprotons for Tevatron luminosity operations in 2005. Methods for tuning the Recycler stochastic cooling system are presented. The unique conditions and resulting procedures for minimizing the longitudinal phase space density of the Recycler antiproton beam are outlined.

  12. LUMINOSITY EVOLUTION OF GAMMA-RAY PULSARS

    SciTech Connect

    Hirotani, Kouichi

    2013-04-01

    We investigate the electrodynamic structure of a pulsar outer-magnetospheric particle accelerator and the resulting gamma-ray emission. By considering the condition for the accelerator to be self-sustained, we derive how the trans-magnetic-field thickness of the accelerator evolves with the pulsar age. It is found that the thickness is small but increases steadily if the neutron-star envelope is contaminated by sufficient light elements. For such a light element envelope, the gamma-ray luminosity of the accelerator is kept approximately constant as a function of age in the initial 10,000 yr, forming the lower bound of the observed distribution of the gamma-ray luminosity of rotation-powered pulsars. If the envelope consists of only heavy elements, on the other hand, the thickness is greater, but it increases less rapidly than a light element envelope. For such a heavy element envelope, the gamma-ray luminosity decreases relatively rapidly, forming the upper bound of the observed distribution. The gamma-ray luminosity of a general pulsar resides between these two extreme cases, reflecting the envelope composition and the magnetic inclination angle with respect to the rotation axis. The cutoff energy of the primary curvature emission is regulated below several GeV even for young pulsars because the gap thickness, and hence the acceleration electric field, is suppressed by the polarization of the produced pairs.

  13. Luminosity enhancement in relativistic jets and altered luminosity functions for beamed objects

    NASA Technical Reports Server (NTRS)

    Urry, C. M.; Shafer, R. A.

    1983-01-01

    Due to relativistic effects, the observed emission from relativistic jets is quite different from the rest frame emission. Systematic differences between the observed and intrinsic intensities of sources in which jet phenomena are occurring are discussed. Assuming that jets have a power law luminosity function of a slope B, the observed luminosity distribution as a function of the velocity of the jet, the spectral index of the rest frame emission, and the range of angles of the jets relative to our line of sight are calculated. The results is well-approximated by two power laws, the higher luminosity end having the original power law index X and the lower luminosity end having a flattened exponent independent of B and only slightly greater than 1. A model consisting of beamed emission from a jet and unbeamed emission from a stationary central component is investigated. The luminosity functions for these two-component sources are calculated for two ranges of angles. For sources in which beaming is important, the luminosity function is much flatter. Because of this, the relative numbers of ""beamed'' and ""unbeamed'' sources detected on the sky depend strongly on the luminosity at which the comparison is made.

  14. The Luminosity Function of QSO Host Galaxies

    NASA Technical Reports Server (NTRS)

    Hamilton, Timothy S.; Casertano, Stefano; Turnshek, David A.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We present some results from our HST archival image study of 71 QSO host galaxies. The objects are selected to have z less than or equal to 0.46 and total absolute magnitude M(sub v) less than or equal to -23 in our adopted cosmology (H(sub 0) = 50 kilometers per second Mpc(sup-1), q(sub 0) = 0.5, lambda = 0)). The aim of this initial study is to investigate the composition of the sample with respect to host morphology and radio loudness, as well as derive the QSO host galaxy luminosity function. We have analyzed available WFPC2 images in R or I band (U in one case), using a uniform set of procedures. The host galaxies span a narrow range of luminosities and are exceptionally bright, much more so than normal galaxies, usually L greater than L*(sub v). The QSOs are almost equally divided among three subclasses: radio-loud QSOs with elliptical hosts, radio-quiet QSOs with elliptical hosts, and radio-quiet QSOs with spiral hosts. Radio-loud QSOs with spiral hosts are extremely rare. Using a weighting procedure, we derive the combined luminosity function of QSO host galaxies. We find that the luminosity function of QSO hosts differs in shape from that of normal galaxies but that they coincide at the highest luminosities. The ratio of the number of quasar hosts to the number of normal galaxies at a luminosity L*(sub v) is R = (Lv/11.48L*(sub v))(sup 2.46), where L*(sub v) corresponds to M*(sub v)= -22.35, and a QSO is defined to be an object with total nuclear plus host light M(sub v) less than or equal to -23. This ratio can be interpreted as the probability that a galaxy with luminosity L(sub V) will host a QSO at redshift z approximately equal to 0.26.

  15. Upgrading Diagnostic Diagrams

    NASA Astrophysics Data System (ADS)

    Proxauf, B.; Kimeswenger, S.; Öttl, S.

    2014-04-01

    Diagnostic diagrams of forbidden lines have been a useful tool for observers in astrophysics for many decades now. They are used to obtain information on the basic physical properties of thin gaseous nebulae. Moreover they are also the initial tool to derive thermodynamic properties of the plasma from observations to get ionization correction factors and thus to obtain proper abundances of the nebulae. Some diagnostic diagrams are in wavelengths domains which were difficult to take either due to missing wavelength coverage or low resolution of older spectrographs. Thus they were hardly used in the past. An upgrade of this useful tool is necessary because most of the diagrams were calculated using only the species involved as a single atom gas, although several are affected by well-known fluorescence mechanisms as well. Additionally the atomic data have improved up to the present time. The new diagnostic diagrams are calculated by using large grids of parameter space in the photoionization code CLOUDY. For a given basic parameter the input radiation field is varied to find the solutions with cooling-heating-equilibrium. Empirical numerical functions are fitted to provide formulas usable in e.g. data reduction pipelines. The resulting diagrams differ significantly from those used up to now and will improve the thermodynamic calculations.

  16. Naphtha upgrading process

    SciTech Connect

    Mc Guiness, M.P.; Mitchell, K.M.; Ware, R.A.

    1987-03-03

    A method is described for upgrading a paraffinic naphtha including major amounts of C/sub 5/ and C/sub 6/ components to produce gasoline boiling range products of improved octane number, which comprises (i) hydrocracking the naphtha over a hydrocracking catalyst comprising zeolite beta and a hydrogenation-dehydrogenation component under conditions of elevated temperature and pressure and in the presence of hydrogen and at a conversion of not more than 25 volume percent to C/sub 5-/ products. This is done to effect a partial, preferential hydrocracking of the paraffins of relatively longer chain length in the naphtha and a concurrent isomerization of n-paraffins, to form a hydrocracking effluent comprising isobutane and higher boiling materials; (ii) fractionating the hydrocracked effluent to form (i) an isobutane stream, (ii) a relatively low boiling stream having a boiling range of approximately C/sub 5/ to 200/sup 0/F. and comprising C/sub 5/ to C/sub 7/ iso-paraffins, and (iii) a relatively higher boiling stream having an initial boiling point of approximately 200/sup 0/F., and (iii) reforming the relatively high boiling point stream to form a gasoline boiling range product of improved octane rating.

  17. Luminosity of initial breakdown in lightning

    NASA Astrophysics Data System (ADS)

    Stolzenburg, M.; Marshall, T. C.; Karunarathne, S.; Karunarathna, N.; Vickers, L. E.; Warner, T. A.; Orville, R. E.; Betz, H.-D.

    2013-04-01

    Time correlated high-speed video and electromagnetic data for 15 cloud-to-ground and intracloud lightning flashes reveal bursts of light, bright enough to be seen through intervening cloud, during the initial breakdown (IB) stage and within the first 3 ms after flash initiation. Each sudden increase in luminosity is coincident with a CG type (12 cases) or an IC type (3 cases) IB pulse in fast electric field change records. The E-change data for 217 flashes indicate that all CG and IC flashes have IB pulses. The luminosity bursts of 14 negative CG flashes occur 11-340 ms before the first return stroke, at altitudes of 4-8 km, and at 4-41 km range from the camera. In seven cases, linear segments visibly advance away from the first light burst for 55-200 µs, then the entire length dims, then the luminosity sequence repeats along the same path. These visible initial leaders or streamers lengthen intermittently to about 300-1500 m. Their estimated 2-D speeds are 4-18 × 105 m s-1 over the first few hundred microseconds and decrease by about 50% over the first 2 ms. In other cases, only a bright spot or a broad area of diffuse light, presumably scattered by intervening cloud, is visible. The bright area grows larger over 20-60 µs before the luminosity fades in about 100 µs, then this sequence may repeat several times. In several flashes, a 1-2 ms period of little or no luminosity and small E-change is observed following the IB stage prior to stepped leader development.

  18. A Solar-luminosity Model and Climate

    NASA Technical Reports Server (NTRS)

    Perry, Charles A.

    1990-01-01

    Although the mechanisms of climatic change are not completely understood, the potential causes include changes in the Sun's luminosity. Solar activity in the form of sunspots, flares, proton events, and radiation fluctuations has displayed periodic tendencies. Two types of proxy climatic data that can be related to periodic solar activity are varved geologic formations and freshwater diatom deposits. A model for solar luminosity was developed by using the geometric progression of harmonic cycles that is evident in solar and geophysical data. The model assumes that variation in global energy input is a result of many periods of individual solar-luminosity variations. The 0.1-percent variation of the solar constant measured during the last sunspot cycle provided the basis for determining the amplitude of each luminosity cycle. Model output is a summation of the amplitudes of each cycle of a geometric progression of harmonic sine waves that are referenced to the 11-year average solar cycle. When the last eight cycles in Emiliani's oxygen-18 variations from deep-sea cores were standardized to the average length of glaciations during the Pleistocene (88,000 years), correlation coefficients with the model output ranged from 0.48 to 0.76. In order to calibrate the model to real time, model output was graphically compared to indirect records of glacial advances and retreats during the last 24,000 years and with sea-level rises during the Holocene. Carbon-14 production during the last millenium and elevations of the Great Salt Lake for the last 140 years demonstrate significant correlations with modeled luminosity. Major solar flares during the last 90 years match well with the time-calibrated model.

  19. Energy deposition studies for the high-luminosity Large Hadron Collider inner triplet magnets

    NASA Astrophysics Data System (ADS)

    Mokhov, N. V.; Rakhno, I. L.; Tropin, I. S.; Cerutti, F.; Esposito, L. S.; Lechner, A.

    2015-05-01

    A detailed model of the high-luminosity LHC inner triplet region with new large-aperture Nb3Sn magnets, field maps, corrector packages, and segmented tungsten inner absorbers was built and implemented into the fluka and mars15 codes. Detailed simulations have been performed coherently with the codes on the impact of particle debris from the 14-TeV center-of-mass pp-collisions on the short- and long-term stability of the inner triplet magnets. After optimizing the absorber configuration, the peak power density averaged over the magnet inner cable width is found to be safely below the quench limit at the luminosity of 5 ×1034 cm-2 s-1 . For the anticipated lifetime integrated luminosity of 3000 fb-1 , the peak dose calculated for the innermost magnet insulator ranges from 20 to 35 MGy, a figure close to the commonly accepted limit. Dynamic heat loads to the triplet magnet cold mass are calculated to evaluate the cryogenic capability. fluka and mars results on energy deposition are in very good agreement.

  20. Upgrading in an Industrial Setting. Final Report.

    ERIC Educational Resources Information Center

    Russell, Wendell

    The project objectives were: (1) to assess existing industrial upgrading practices in an Atomic Energy Commission contractor organization, (2) to design new alternative upgrading methods, (3) to experiment with new upgrading methods, (4) to plan for utilization of proven upgrading programs, and (5) to document and disseminate activities. A twelve…

  1. Upgrade of the trigger system of CMS

    NASA Astrophysics Data System (ADS)

    Jeitler, Manfred; CMS Collaboration

    2013-08-01

    Various parts of the CMS trigger and in particular the Level-1 hardware trigger will be upgraded to cope with increasing luminosity, using more selective trigger conditions at Level 1 and improving the reliability of the system. Many trigger subsystems use FPGAs (Field Programmable Gate Arrays) in the electronics and will benefit from developments in this technology, allowing us to place much more logic into a single FPGA chip, thus reducing the number of chips, electronic boards and interconnections and in this way improving reliability. A number of subsystems plan to switch from the old VME bus to the new microTCA crate standard. Using similar approaches, identical modules and common software wherever possible will reduce costs and manpower requirements and improve the serviceability of the whole trigger system. The computer-farm based High-Level Trigger will not only be extended by using increasing numbers of more powerful PCs but there are also concepts for making it more robust and the software easier to maintain, which will result in better efficiency of the whole system.

  2. Setting priorities for safeguards upgrades

    SciTech Connect

    Al-Ayat, R.A.; Judd, B.R.; Patenaude, C.J.; Sicherman, A.

    1987-07-10

    This paper describes an analytic approach and a computer program for setting priorities among safeguards upgrades. The approach provides safeguards decision makers with a systematic method for allocating their limited upgrade resources. The priorities are set based on the upgrades cost and their contribution to safeguards effectiveness. Safeguards effectiveness is measured by the probability of defeat for a spectrum of potential insider and outsider adversaries. The computer program, MI$ER, can be used alone or as a companion to ET and SAVI, programs designed to evaluate safeguards effectiveness against insider and outsider threats, respectively. Setting the priority requires judgments about the relative importance (threat likelihoods and consequences) of insider and outsider threats. Although these judgments are inherently subjective, MI$ER can analyze the sensitivity of the upgrade priorities to these weights and determine whether or not they are critical to the priority ranking. MI$ER produces tabular and graphical results for comparing benefits and identifying the most cost-effective upgrades for a given expenditure. This framework provides decision makers with an explicit and consistent analysis to support their upgrades decisions and to allocate the safeguards resources in a cost-effective manner.

  3. Setting priorities for safeguards upgrades

    SciTech Connect

    Al-Ayat, R.A.; Judd, B.R.; Patenaude, C.J.; Sicherman, A.

    1987-07-01

    This paper describes an analytic approach and a computer program for setting priorities among safeguards upgrades. The approach provides safeguards decision makers with a systematic method for allocating their limited upgrade resources. The priorities are set based on the upgrades cost and their contribution to safeguards effectiveness. Safeguards effectiveness is measured by the probability of defeat for a spectrum of potential insider and outsider adversaries. The computer program, MI$ER, can be used alone or as a companion to ET and SAVI, programs designed to evaluate safeguards effectiveness against insider and outsider threats, respectively. Setting the priority required judgments about the relative importance (threat likelihoods and consequences) of insider and outsider threats. Although these judgments are inherently subjective, MI$ER can analyze the sensitivity of the upgrade priorities to these weights and determine whether or not they are critical to the priority ranking. MI$ER produces tabular and graphical results for comparing benefits and identifying the most cost-effective upgrades for a given expenditure. This framework provides decision makers with an explicit and consistent analysis to support their upgrades decisions and to allocate the safeguards resources in a cost-effective manner.

  4. From hybrid to CMOS pixels ... a possibility for LHC's pixel future?

    NASA Astrophysics Data System (ADS)

    Wermes, N.

    2015-12-01

    Hybrid pixel detectors have been invented for the LHC to make tracking and vertexing possible at all in LHC's radiation intense environment. The LHC pixel detectors have meanwhile very successfully fulfilled their promises and R&D for the planned HL-LHC upgrade is in full swing, targeting even higher ionising doses and non-ionising fluences. In terms of rate and radiation tolerance hybrid pixels are unrivaled. But they have disadvantages as well, most notably material thickness, production complexity, and cost. Meanwhile also active pixel sensors (DEPFET, MAPS) have become real pixel detectors but they would by far not stand the rates and radiation faced from HL-LHC. New MAPS developments, so-called DMAPS (depleted MAPS) which are full CMOS-pixel structures with charge collection in a depleted region have come in the R&D focus for pixels at high rate/radiation levels. This goal can perhaps be realised exploiting HV technologies, high ohmic substrates and/or SOI based technologies. The paper covers the main ideas and some encouraging results from prototyping R&D, not hiding the difficulties.

  5. Probe of extra dimensions in lepton pair production at the LHC: An update

    NASA Astrophysics Data System (ADS)

    Pankov, A. A.; Serenkova, I. A.; Tsytrinov, A. V.

    2014-07-01

    Arkani-Hamed, Dimopoulous, and Dvali have proposed a model (ADD) of low-scale quantum gravity featuring large extra dimensions. In this model, the exchange of Kaluza-Klein towers of gravitons can enhance the production rate of lepton pairs at high invariant mass in proton-proton collisions at the LHC. By considering the present and future LHC energy regimes, we reanalyse the potential of the LHC to discover the effects of large extra dimensions and to discriminate between various theoretical models. Specifically, in latter case we explore the capability of the LHC to distinguish spin-2 Kaluza-Klein towers of gravitons exchange from other new physics effects which might be conveniently parametrized by the four-fermion contact interactions. We find that the LHC with planned energy 14 TeV and luminosity 100 fb-1 will be capable of discovering (and identifying) graviton exchange effects in the large extra dimensions with the cutoff parameter of order MS = 6.2 TeV (4.8 TeV) for d = 6 and MS = 8.8 TeV (6.8 TeV) for d = 3.

  6. Probe of extra dimensions in lepton pair production at the LHC: An update

    SciTech Connect

    Pankov, A. A.; Serenkova, I. A.; Tsytrinov, A. V.

    2009-01-01

    Arkani-Hamed, Dimopoulous, and Dvali have proposed a model (ADD) of low-scale quantum gravity featuring large extra dimensions. In this model, the exchange of Kaluza-Klein towers of gravitons can enhance the production rate of lepton pairs at high invariant mass in proton-proton collisions at the LHC. By considering the present and future LHC energy regimes, we reanalyse the potential of the LHC to discover the effects of large extra dimensions and to discriminate between various theoretical models. Specifically, in latter case we explore the capability of the LHC to distinguish spin-2 Kaluza-Klein towers of gravitons exchange from other new physics effects which might be conveniently parametrized by the four-fermion contact interactions. We find that the LHC with planned energy 14 TeV and luminosity 100 fb⁻¹ will be capable of discovering (and identifying) graviton exchange effects in the large extra dimensions with the cutoff parameter of order M{sub S} = 6.2 TeV (4.8 TeV) for d = 6 and M{sub S} = 8.8 TeV (6.8 TeV) for d = 3.

  7. The quasar mass-luminosity plane

    NASA Astrophysics Data System (ADS)

    Steinhardt, Charles Louis

    2010-11-01

    This thesis investigates the quasar mass-luminosity plane, as a new tool to explore the relationship between black hole mass and quasar luminosity over time. Previous techniques used quasar luminosity function and mass functions, which are one-dimensional projections of the mass-luminosity plane. The M --- L plane contains information that cannot be seen in these projections. We use 62,185 quasars from the Sloan Digital Sky Survey DR5 sample to develop several new constraints on quasar accretion. Black hole masses, based on the widths of their Hbeta, Mg II, and C IV lines and adjacent continuum luminosities, were used assuming using standard virial mass estimate scaling laws. In each redshift interval over the range 0.2 < z < 4.0, low-mass quasars reach at their Eddington luminosity, but high-mass quasars fall short, even by a factor of ten or more at 0.2 < z < 0.6. We examine several potential sources of measurement uncertainty or bias and show that none of them can account for this effect. We also show the statistical uncertainty in virial mass estimation to have an upper bound of ˜ 0.2 dex, smaller than the 0.4 dex previously reported. The maximum mass of quasars at each redshift is sharp and evolving. High-mass black holes turn off their luminous accretion at higher redshift than lower-mass black holes. Further, turnoff for quasars at any given mass is synchronized to within 0.7--3 Gyr, tighter than would be expected given the dynamics of their host galaxies. We find potential signatures of the quasar turnoff mechanism, including a dearth of high-mass quasars at low Eddington ratio, low CIV/MgII emission line ratio, and a red spectral tilt. Finally, we use these new constraints to analyze models for the evolution of individual quasars over time. We find a restricted family of tracks that lie within the M --- L plane at all redshifts, suggesting that a single, constant feedback mechanism between all supermassive black holes and their host galaxies might apply

  8. Study of new FNAL-NICADD extruded scintillator as active media of large EMCal of ALICE at LHC

    SciTech Connect

    Oleg A. Grachov et al.

    2004-05-04

    The current conceptual design of proposed Large EMCal of ALICE at LHC is based largely on the scintillating mega-tile/fiber technology implemented in CDF Endplug upgrade project and in both barrel and endcap electromagnetic calorimeters of the STAR. The cost of scintillating material leads us to the choice of extruded polystyrene based scintillator, which is available in new FNAL-NICADD facility. Result of optical measurements, such as light yield and light yield variation, show that it is possible to use this material as active media of Large EMCal of ALICE at LHC.

  9. A pattern recognition mezzanine based on associative memory and FPGA technology for L1 track triggering at HL-LHC

    NASA Astrophysics Data System (ADS)

    Alunni, L.; Biesuz, N.; Bilei, G. M.; Citraro, S.; Crescioli, F.; Fanò, L.; Fedi, G.; Magalotti, D.; Magazzù, G.; Servoli, L.; Storchi, L.; Palla, F.; Placidi, P.; Papi, A.; Piadyk, Y.; Rossi, E.; Spiezia, A.

    2016-07-01

    The increase of luminosity at HL-LHC will require the introduction of tracker information at Level-1 trigger system for the experiments to maintain an acceptable trigger rate to select interesting events despite the one order of magnitude increase in the minimum bias interactions. To extract in the required latency the track information a dedicated hardware has to be used. We present the tests of a prototype system (Pattern Recognition Mezzanine) as core of pattern recognition and track fitting for HL-LHC ATLAS and CMS experiments, combining the power of both Associative Memory custom ASIC and modern Field Programmable Gate Array (FPGA) devices.

  10. Le LHC, un tunnel cosmique

    ScienceCinema

    None

    2011-10-06

    Et si la lumière au bout du tunnel du LHC était cosmique ? En d?autres termes, qu?est-ce que le LHC peut nous apporter dans la connaissance de l?Univers ? Car la montée en énergie des accélérateurs de particules nous permet de mieux appréhender l?univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l?Univers ? La matière noire est-elle détectable au LHC ? L?énergie noire ? Pourquoi l?antimatière accumulée au CERN est-elle si rare dans l?Univers ? Et si le CERN a bâti sa réputation sur l?exploration des forces faibles et fortes qui opèrent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l?évolution cosmique ? Depuis une trentaine d?années, notre compréhension de l?univers dans ses plus grandes dimensions et l?appréhension de son comportement aux plus petites distances sont intimement liées : en quoi le LHC va-t-il tester expérimentalement cette vision unifiée ? Tout public, entrée libre / Réservations au +41 (0)22 767 76 76

  11. Performance measurement of the upgraded D0 central track trigger

    SciTech Connect

    Mommsen, Remigius, K.; /Manchester U. /Fermilab

    2006-12-01

    The D0 experiment was upgraded in spring 2006 to harvest the full physics potential of the Tevatron accelerator at Fermi National Accelerator Laboratory, Batavia, Illinois, USA. It is expected that the peak luminosity delivered by the accelerator will increase to over 300 x 10{sup 30} cm{sup -2} s{sup -1}. One of the upgraded systems is the Central Track Trigger (CTT). The CTT uses the Central Fiber Tracker (CFT) and Preshower detectors to identify central tracks with p{sub T} > 1.5GeV at the first trigger level. Track candidates are formed by comparing fiber hits to predefined track equations. In order to minimize latency, this operation is performed in parallel using combinatorial logic implemented in FPGAs. Limited hardware resources prevented the use of the full granularity of the CFT. This leads to a high fake track rate as the occupancy increases. In order to mitigate the problem, new track-finding hardware was designed and commissioned. We report on the upgrade and the improved performance of the CTT system.

  12. User and Performance Impacts from Franklin Upgrades

    SciTech Connect

    He, Yun

    2009-05-10

    The NERSC flagship computer Cray XT4 system"Franklin" has gone through three major upgrades: quad core upgrade, CLE 2.1 upgrade, and IO upgrade, during the past year. In this paper, we will discuss the various aspects of the user impacts such as user access, user environment, and user issues etc from these upgrades. The performance impacts on the kernel benchmarks and selected application benchmarks will also be presented.

  13. Experimental demonstration of beam-beam compensation by Tevatron electron lenses and prospects for the LHC

    SciTech Connect

    Shiltsev, V.; Alexahin, Y.; Kamerdzhiev, V.; Kuznetsov, G.; Zhang, X.L.; Bishofberger, K.; /Los Alamos

    2007-06-01

    Electromagnetic long-range and head-on interactions of high intensity proton and antiproton beams are significant sources of beam loss and lifetime limitations in the Tevatron Collider Run II (2001-present). We present observations of the beam-beam phenomena in the Tevatron and results of relevant beam studies. We analyze the data and various methods employed in high energy physics (HEP) operation, predict the performance for planned luminosity upgrades and discuss ways to improve it.

  14. Diffraction dissociation at the LHC

    NASA Astrophysics Data System (ADS)

    Jenkovszky, László; Orava, Risto; Salii, Andrii

    2013-04-01

    We report on recent calculations of low missing mass single (SD) and double (DD) diffractive dissociation at LHC energies. The calculations are based on a dual-Regge model, dominated by a single Pomeron exchange. The diffractively excited states lie on the nucleon trajectory N*, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single-and double diffraction dissociation in the kinematical range of present and future LHC measurements are given.

  15. LHC Symposium 2003: Summary Talk

    SciTech Connect

    Jeffrey A. Appel

    2003-08-12

    This summary talk reviews the LHC 2003 Symposium, focusing on expectations as we prepare to leap over the current energy frontier into new territory. We may learn from what happened in the two most recent examples of leaping into new energy territory. Quite different scenarios appeared in those two cases. In addition, they review the status of the machine and experiments as reported at the Symposium. Finally, I suggest an attitude which may be most appropriate as they look forward to the opportunities anticipated for the first data from the LHC.

  16. L'Aventure du LHC

    ScienceCinema

    None

    2011-10-06

    Cette présentation s?adressera principalement aux personnes qui ont construit le LHC. La construction du LHC fut longue et difficile. De nombreux problèmes sont apparus en cours de route. Tous ont été résolus grâce au dévouement et à l?engagement du personnel et des collaborateurs. Je reviendrai sur les coups durs et les réussites qui ont marqués ces 15 dernières années et je vous montrerai combien cette machine, le fruit de vos efforts, est extraordinaire.

  17. Diffraction dissociation at the LHC

    SciTech Connect

    Jenkovszky, Laszlo; Orava, Risto; Salii, Andrii

    2013-04-15

    We report on recent calculations of low missing mass single (SD) and double (DD) diffractive dissociation at LHC energies. The calculations are based on a dual-Regge model, dominated by a single Pomeron exchange. The diffractively excited states lie on the nucleon trajectory N*, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single-and double diffraction dissociation in the kinematical range of present and future LHC measurements are given.

  18. B Physics at the LHC

    SciTech Connect

    Gersabeck, Marco

    2010-02-10

    The LHC is scheduled to start its first physics data taking period later in 2009. Primarily LHCb but also ATLAS and CMS will start a rich B physics programme with the potential of revealing New Physics in the heavy flavour sector. This contribution will cover the prospects for B physics at the LHC with particular emphasis to early measurements. This includes CP violation measurements in B{sub d}{sup 0} and B{sub s}{sup 0} decays, searches for rare decays such as B{sub s}{sup 0}->{mu}{mu}, as well as semileptonic and radiative channels.

  19. Experimental Methods at the LHC

    NASA Astrophysics Data System (ADS)

    Korytov, Andrey

    The lectures presented below cover the basics of proton-proton collisions at the LHC, the principles of particle detection, the methodologies employed for reconstruction of individual collision events, general strategies for signal event selection, data-driven techniques for evaluating signal efficiencies and background rates, as well as the main statistical concepts used for physics inference from selected data. The described principles and concepts are then illustrated on an example of a search for a Higgs boson and measurement of its properties in the H → ZZ → 4ℓ decay mode. The discussion is largely based on CMS, taken as a representative LHC experiment.

  20. L'Aventure du LHC

    SciTech Connect

    2010-06-11

    Cette présentation s’adressera principalement aux personnes qui ont construit le LHC. La construction du LHC fut longue et difficile. De nombreux problèmes sont apparus en cours de route. Tous ont été résolus grâce au dévouement et à l’engagement du personnel et des collaborateurs. Je reviendrai sur les coups durs et les réussites qui ont marqués ces 15 dernières années et je vous montrerai combien cette machine, le fruit de vos efforts, est extraordinaire.

  1. Measurement of reference cross sections in pp and Pb-Pb collisions at the LHC in van der Meer scans with the ALICE detector

    NASA Astrophysics Data System (ADS)

    Gagliardi, M.; Alice Collaboration

    2012-03-01

    Reference cross sections have been measured with the ALICE detector in both pp and Pb-Pb collisions, in dedicated luminosity calibration experiments (van der Meer scans) at the LHC. The results and their uncertainties are discussed, together with a few selected applications.

  2. Measurement of Electromagnetic Cross Sections in Heavy Ion Interations and Its Consequences for Luminosity Lifetimes in Ion Colliders

    SciTech Connect

    Datz, S.; Grafstroem, P.; Knudsen, H.; Krause, H.F.; Mikkelsen, U.; Scheidenberger, C.; Schuch, R.H.; Vane, C.R.; Vilakazi, Z.

    1999-03-29

    The limitation of the luminosity lifetime in high energy heavy ion colliders like RHIC or LHC operating in ion mode is set by the very large cross section of beam - beam interactions. One of the dominant processes at relativistic energies is electron capture from pair production in the strong electromagnetic field provided by the high Z of the ions. The capture cross sections for Pb82+ interacting with a number targets have been measured using one of the high energy resolution 158 GeV/nucleon beams at CERN. The results, together with results on electromagnetic dissociation, are discussed in terms of beam lifetimes for RHIC and LHC using extrapolations of the measurements to the corresponding collider energies.

  3. RF TECHNIQUES FOR IMPROVED LUMINOSITY IN RHIC.

    SciTech Connect

    BRENNAN,J.M.BLASKIEWICZ,J.BUTLER,J.DELONG,J.FISCHER,W.HAYES,T.

    2004-07-05

    The luminosity of the Relativistic Heavy Ion Collider has improved significantly [1] over the first three physics runs. A number of special rf techniques have been developed to facilitate higher luminosity. The techniques described herein include: an ultra low-noise rf source for the 197 MHz storage rf system, a frequency shift switch-on technique for transferring bunches from the acceleration to the storage system, synchronizing the rings during the energy ramp (including crossing the transition energy) to avoid incidental collisions, installation of dedicated 200 MHZ cavities to provide longitudinal Landau damping on the ramp, and the development of a bunch merging scheme in the Booster to increase the available bunch intensity from the injectors.

  4. Optimization of integrated luminosity in the Tevatron

    SciTech Connect

    Gattuso, C.; Convery, M.; Syphers, M.; /Fermilab

    2009-04-01

    We present the strategy which has been used recently to optimize the performance of the Fermilab Tevatron proton-antiproton collider. We use a relatively simple heuristic model based on the antiproton production rate, which optimizes the number of antiprotons in a store in order to maximize the integrated luminosity. A store is terminated as soon as the target number of antiprotons is reached and the Tevatron quickly resets to load another store. Since this procedure was implemented, the integrated luminosity has improved by {approx} 35%. Other recent operational improvements include decreasing the shot setup time, and reducing beam-beam effects by making the proton and antiproton brightness more compatible, for example by scraping protons to smaller emittances.

  5. A deep luminosity function for 47 Tucanae.

    NASA Astrophysics Data System (ADS)

    Harris, W. E.; Hesser, J. E.

    CCD photometry in B and V reaching B(lim) ≅ 25 has been employed to obtain the luminosity function and color-magnitude diagram for the main sequence of 47 Tuc. For 5 < Mv < 10 the authors find that its LF is essentially flat (Δlog n/Δm ≡ 0). The CMD is successfully matched by isochrones with [Fe/H] = -0.5 and t ≅ 15×109y.

  6. Readout control for high luminosity accelerators

    NASA Astrophysics Data System (ADS)

    Belusevic, R.; Nixon, G.

    1991-09-01

    In this article we discuss some aspects of data acquisition at high luminosities and offer a set of design principles concerning readout control electronics and related software. As an example we include a brief description of a data transfer and processing system for future hadron colliders, featuring a transputer-based crate controller and a set of readout cards. This is a simplified and more efficient version of our design recently published in Nuclear Instruments and Methods. [A295 (1991) 391].

  7. New Evidence for a Substellar Luminosity Problem

    NASA Astrophysics Data System (ADS)

    Dupuy, Trent J.; Liu, M. C.; Ireland, M.

    2014-01-01

    HD 130948BC was the first field brown dwarf system to have both a dynamically measured mass and precise age constraint, from its solar-type host star, and it was unexpectedly ≈2× more luminous than predicted by substellar evolutionary models. However, because of the difficulty in determining accurate stellar ages, even in this nearly ideal case of a young star where numerous age indicators agree, it has been unclear if the apparent over-luminosity could be due to an erroneous age for this unique system. If such large systematic errors actually exist in substellar evolutionary models it could have wide-ranging implications, from determinations of the initial mass function to the masses estimated for directly imaged planets. We present here a new dynamical mass for a pair of brown dwarfs that also have a well-determined age from their young, solar-type star. This first check on the substellar "luminosity problem" reveals a nearly identical systematic error as was previously observed. We compare predictions from commonly used evolutionary models and present possible explanations for this problem. There are little appreciated, large differences (≈0.2 dex) in the predicted luminosity evolution of substellar objects which, along with the discrepancies of models compared to observations, currently limit our ability to characterize the fundamental properties of both brown dwarfs and directly imaged exoplanets.

  8. EVOLUTION OF THE Halpha LUMINOSITY FUNCTION

    SciTech Connect

    Westra, Eduard; Geller, Margaret J.; Kurtz, Michael J.; Fabricant, Daniel G.; Dell'Antonio, Ian

    2010-01-01

    The Smithsonian Hectospec Lensing Survey (SHELS) is a window on the star formation history over the last 4 Gyr. SHELS is a spectroscopically complete survey for R{sub tot} < 20.3 over 4 square{sup 0}. We use the 10k spectra to select a sample of pure star-forming galaxies based on their Halpha emission line. We use the spectroscopy to determine extinction corrections for individual galaxies and to remove active galaxies in order to reduce systematic uncertainties. We use the large volume of SHELS with the depth of a narrowband survey for Halpha galaxies at z approx 0.24 to make a combined determination of the Halpha luminosity function at z approx 0.24. The large area covered by SHELS yields a survey volume big enough to determine the bright end of the Halpha luminosity function from redshift 0.100 to 0.377 for an assumed fixed faint-end slope alpha = -1.20. The bright end evolves: the characteristic luminosity L* increases by 0.84 dex over this redshift range. Similarly, the star formation density increases by 0.11 dex. The fraction of galaxies with a close neighbor increases by a factor of 2-5 for L{sub Ha}lpha approx> L* in each of the redshift bins. We conclude that triggered star formation is an important influence for star-forming galaxies with Halpha emission.

  9. A new readout control system for the LHCb upgrade at CERN

    NASA Astrophysics Data System (ADS)

    Alessio, F.; Jacobsson, R.

    2012-11-01

    The LHCb experiment has proposed an upgrade towards a full 40 MHz readout system in order to run between five and ten times its initial design luminosity. The entire readout architecture will be upgraded in order to cope with higher sub-detector occupancies, higher rate and higher network load. In this paper, we describe the architecture, functionalities and a first hardware implementation of a new fast Readout Control system for the LHCb upgrade, which will be entirely based on FPGAs and bi-directional links. We also outline the real-time implementations of the new Readout Control system, together with solutions on how to handle the synchronous distribution of timing and synchronous information to the complex upgraded LHCb readout architecture. One section will also be dedicated to the control and usage of the newly developed CERN GBT chipset to transmit fast and slow control commands to the upgraded LHCb Front-End electronics. At the end, we outline the plans for the deployment of the system in the global LHCb upgrade readout architecture.

  10. Studies of Transverse-Momentum-Dependent Distributions with a Fixed-Target ExpeRiment Using the LHC Beams (AFTER@LHC)

    NASA Astrophysics Data System (ADS)

    Massacrier, L.; Anselmino, M.; Arnaldi, R.; Brodsky, S. J.; Chambert, V.; den Dunnen, W.; Didelez, J. P.; Genolini, B.; Ferreiro, E. G.; Fleuret, F.; Gao, Y.; Hadjidakis, C.; Hřivnáčová, I.; Lansberg, J. P.; Lorcé, C.; Mikkelsen, R.; Pisano, C.; Rakotozafindrabe, A.; Rosier, P.; Schienbein, I.; Schlegel, M.; Scomparin, E.; Trzeciak, B.; Uggerhøj, U. I.; Ulrich, R.; Yang, Z.

    2016-02-01

    We report on the studies of Transverse-Momentum-Dependent distributions (TMDs) at a future fixed-target experiment -AFTER@LHC- using the p+ or Pb ion LHC beams, which would be the most energetic fixed-target experiment ever performed. AFTER@LHC opens new domains of particle and nuclear physics by complementing collider-mode experiments, in particular those of RHIC and the EIC projects. Both with an extracted beam by a bent crystal or with an internal gas target, the luminosity achieved by AFTER@LHC surpasses that of RHIC by up to 3 orders of magnitude. With an unpolarised target, it allows for measurements of TMDs such as the Boer-Mulders quark distributions and the distribution of unpolarised and linearly polarised gluons in unpolarised protons. Using polarised targets, one can access the quark and gluon Sivers TMDs through single transverse-spin asymmetries in Drell-Yan and quarkonium production. In terms of kinematics, the fixed-target mode combined with a detector covering ηlab ∈ [1, 5] allows one to measure these asymmetries at large x↑ in the polarised nucleon.

  11. The physics program of a high-luminosity asymmetric B Factory at SLAC

    SciTech Connect

    Not Available

    1989-10-01

    A high-luminosity asymmetric energy B Factory, proposed as an upgrade to the PEP storage ring at SLAC, provides the best opportunity to study CP violation as a means of testing the consistency of the Standard Model. If the phenomenon of CP violation is explained by the Standard Model simply through the non-zero angles and phase of the Kobayashi-Maskawa matrix, then there are precise relations between the K-M parameters and the various measurable CP-violating asymmetries in B meson decay. Should these consistency relations fail, the origin of CP violation must lie outside the Standard Model framework. Our measurements would then lead to the first experiment-driven extensions of the Standard Model. The B Factory will also carry out a varied, high-quality program of studies of other aspects of the physics of b quarks, as well as high-precision measurements in {tau} and charm physics. We describe a detailed series of measurements to be carried out in the first few years at a peak luminosity of 3 {times} 10{sup 33} cm{sup -2}sec{sup -1}, the initial luminosity goal of the B Factory, as well as the program accessible to a larger data sample.

  12. The Physics Program of a High-Luminosity Asymmetric B Factory at SLAC

    SciTech Connect

    Eisner, A.; Mandelkern, M.; Morrison, R.; Witherell, M.; Burchat, P.; Kent, J.; Erbacher, R.; Vernon, W.; Eigen, G.; Hitlin, D.; Porter, F.; Weinstein, A.; Wisniewski, W.; Wagner, S.; Franzini, P.; Tuts, M.; Averill, D.; Snyder, A.; Goldhaber, G.; Oddone, P.; Roe, N.; Ronan, M.; Spahn, M.; MacFarlane, D.; Bartelt, J.; Bloom, E.; Bulos, F.; Cords, D.; Dib, C.; Dorfan, J.; Dunietz, I.; Gilman, F.; Godfrey, G.; Hyer, T.; Jensen, G.; Leith, D.; Marsiske, H.; Nir, Y.; Lee-Franzini, J.

    1989-10-01

    A high-luminosity asymmetric energy B Factory, proposed as an upgrade to the PEP storage ring at SLAC, provides the best opportunity to study CP violation as a means of testing the consistency of the Standard Model. If the phenomenon of CP violation is xplained by the Standard Model simply through the non-zero angles and phase of the Kobayashi-Maskawa matrix, then there are precise relations between the K-M parameters and the various measurable CP-violating asymmetries in B meson decay. Should these onsistency relations fail, the origin of CP violation must lie outside the Standard Model framework. Our measurements would then lead to the first experiment-driven extensions of the Standard Model. The B Factory will also carry out a varied, high-quality program of studies f other aspects of the physics of b quarks, as well as high-precision measurements in r and charm physics. We describe a detailed series of measurements to be carried out in the first few years at a peak luminosity of 3 x 10{sup 33} cm{sup -2}sec{sup -1}, the initial luminosity goal of the B Factory, as well as the program accessible to a larger data sample.

  13. Upgrade of the cryogenic CERN RF test facility

    SciTech Connect

    Pirotte, O.; Benda, V.; Brunner, O.; Inglese, V.; Maesen, P.; Vullierme, B.; Koettig, T.

    2014-01-29

    With the large number of superconducting radiofrequency (RF) cryomodules to be tested for the former LEP and the present LHC accelerator a RF test facility was erected early in the 1990’s in the largest cryogenic test facility at CERN located at Point 18. This facility consisted of four vertical test stands for single cavities and originally one and then two horizontal test benches for RF cryomodules operating at 4.5 K in saturated helium. CERN is presently working on the upgrade of its accelerator infrastructure, which requires new superconducting cavities operating below 2 K in saturated superfluid helium. Consequently, the RF test facility has been renewed in order to allow efficient cavity and cryomodule tests in superfluid helium and to improve its thermal performances. The new RF test facility is described and its performances are presented.

  14. Performance simulation studies for the ALICE TPC GEM upgrade

    NASA Astrophysics Data System (ADS)

    Ljunggren, M.

    2016-07-01

    To be able to exploit the anticipated interaction rate of 50 kHz in Pb-Pb collisions during run 3 of the LHC (beyond 2019), the ALICE TPC will be upgraded to allow continuous readout. As this is not possible with the current Multi Wire Proportional Chamber (MWPC) based amplification, the readout will be replaced with Gas Electron Multiplier (GEM) readout chambers that can suppress ~ 99% of the ion back flow. The space charge of the remaining 1% ion back flow, however, will cause significant distortions to the measured tracks of order cm. Simulation studies to characterize the distortions and test correction strategies have been performed, which show that the intrinsic momentum resolution, without these distortions, can be recovered.

  15. Upgrade of the cryogenic CERN RF test facility

    NASA Astrophysics Data System (ADS)

    Pirotte, O.; Benda, V.; Brunner, O.; Inglese, V.; Koettig, T.; Maesen, P.; Vullierme, B.

    2014-01-01

    With the large number of superconducting radiofrequency (RF) cryomodules to be tested for the former LEP and the present LHC accelerator a RF test facility was erected early in the 1990's in the largest cryogenic test facility at CERN located at Point 18. This facility consisted of four vertical test stands for single cavities and originally one and then two horizontal test benches for RF cryomodules operating at 4.5 K in saturated helium. CERN is presently working on the upgrade of its accelerator infrastructure, which requires new superconducting cavities operating below 2 K in saturated superfluid helium. Consequently, the RF test facility has been renewed in order to allow efficient cavity and cryomodule tests in superfluid helium and to improve its thermal performances. The new RF test facility is described and its performances are presented.

  16. String Physics at the LHC

    SciTech Connect

    Anchordoqui, Luis A.

    2008-11-23

    The LHC program will include the identification of events with single high-k{sub T} photons as probes of new physics. We show that this channel is uniquely suited to search for experimental evidence of TeV-scale open string theory.

  17. Event generator for the LHC

    NASA Astrophysics Data System (ADS)

    Gleisberg, T.; Höche, S.; Krauss, F.; Schälicke, A.; Schumann, S.; Winter, J.

    2006-04-01

    In this contribution the new event generation framework S HERPA will be presented. It aims at the full simulation of events at current and future high-energy experiments, in particular the LHC. Some results related to the production of jets at the Tevatron will be discussed.

  18. The history of the LHC

    SciTech Connect

    2010-05-11

    Abstract: From the civil engineering, to the manufacturing of the various magnet types, each building block of this extraordinary machine required ambitious leaps in innovation. This lecture will review the history of the LHC project, focusing on the many challenges -- scientific, technological, managerial -- that had to be met during the various phases of R&D;, industrialization, construction, installation and commissioning.

  19. PHOBOS in the LHC era

    SciTech Connect

    Steinberg, Peter

    2015-01-15

    The PHOBOS experiment ran at the RHIC collider from 2000 to 2005, under the leadership of Wit Busza. These proceedings summarize selected PHOBOS results, highlighting their continuing relevance amidst the wealth of new results from the lead–lead program at the Large Hadron Collider (LHC)

  20. Post-LHC accelerator magnets

    SciTech Connect

    Gourlay, Stephen A.

    2001-06-10

    The design and practicality of future accelerators, such as hadron colliders and neutrino factories being considered to supercede the LHC, will depend greatly on the choice of superconducting magnets. Various possibilities will be reviewed and discussed, taking into account recent progress and projected improvements in magnet design and conductor development along with the recommendations from the 2001 Snowmass workshop.

  1. The history of the LHC

    ScienceCinema

    None

    2011-10-06

    Abstract: From the civil engineering, to the manufacturing of the various magnet types, each building block of this extraordinary machine required ambitious leaps in innovation. This lecture will review the history of the LHC project, focusing on the many challenges -- scientific, technological, managerial -- that had to be met during the various phases of R&D;, industrialization, construction, installation and commissioning.

  2. First Beam Measurements with the LHC Synchrotron Light Monitors

    SciTech Connect

    Lefevre, Thibaut; Bravin, Enrico; Burtin, Gerard; Guerrero, Ana; Jeff, Adam; Rabiller, Aurelie; Roncarolo, Federico; Fisher, Alan; /SLAC

    2012-07-13

    The continuous monitoring of the transverse sizes of the beams in the Large Hadron Collider (LHC) relies on the use of synchrotron radiation and intensified video cameras. Depending on the beam energy, different synchrotron light sources must be used. A dedicated superconducting undulator has been built for low beam energies (450 GeV to 1.5 TeV), while edge and centre radiation from a beam-separation dipole magnet are used respectively for intermediate and high energies (up to 7 TeV). The emitted visible photons are collected using a retractable mirror, which sends the light into an optical system adapted for acquisition using intensified CCD cameras. This paper presents the design of the imaging system, and compares the expected light intensity with measurements and the calculated spatial resolution with a cross calibration performed with the wire scanners. Upgrades and future plans are also discussed.

  3. Mechanical Design of a Second Generation LHC IR Quadrupole

    SciTech Connect

    Caspi, S.; Bartlett, S.E.; Dietderich, D.R.; Ferracin, P.; Gourlay, S.A.; Hafalia, R.R.; Hannaford, C.R.; Lietzke, A.F.; McInturff,A.D.; Sabbi, G.; Scanlan, R.M.

    2003-11-10

    One of the proposed options to increase the LHC luminosity is the replacement of the existing inner triplets at the Interaction Regions with new low-beta larger aperture quadrupoles operating at the same gradient. Lawrence Berkeley National Laboratory (LBNL) is carrying out preliminary studies of a large-bore Nb{sub 3}Sn quadrupole. The mechanical design presents a support structure based on the use of keys and bladders without self-supporting collars. This technology has been proven effective in several successful common coil Nb{sub 3}Sn dipoles built at LBNL, and it is for the first time applied to a cos(2{var_theta}) design. In this paper we present a detailed analysis of the quadrupole mechanical behavior, demonstrating the possibility of delivering, through this method, well-controlled coil precompression during assembly, cool-down and excitation. The study has been performed with the finite element program ANSYS.

  4. The TOTEM experiment at the LHC and its physics results

    NASA Astrophysics Data System (ADS)

    Nemes, F.

    2013-12-01

    The TOTEM experiment at the LHC has measured proton-proton elastic scattering in dedicated runs at s=7and8TeV. The proton-proton total, elastic and inelastic cross-sections were derived with different methods by either using the optical theorem or a luminosity independent method, where the directly measured inelastic and elastic rates are applied. The TOTEM experiment presented its first preliminary cross-sections for soft single and double diffraction at s=7 TeV. The central diffraction analysis is ongoing, including a common TOTEM-CMS analysis. The charged particle pseudorapidity density distribution, dN/dη, was determined at 7 and 8 TeV.

  5. Hardware Testing of the BaBar Drift Chamber Electronics Upgrade (SULI paper)

    SciTech Connect

    Littlejohn, Bryce; Chu, Yiwen; Wiik, Liv; /SLAC

    2006-01-04

    The BaBar drift chamber provides position, timing, and dE/dx measurements for charged decay products of the {Upsilon}(4S) resonance at 10.58 GeV. Increasing data collection rates stemming from higher PEP II luminosities and background have highlighted dead time problems in the drift chamber's data acquisition system. A proposed upgrade, called Phase II, aims to solve the problem with the introduction of rewritable, higher-memory firmware in the DAQ front-end electronics that lowers dataflow through the system. After fabrication, the new electronics components were tested to ensure proper function and reliability before installation in the detector. Some tests checked for successful operation of individual components, while others operated entire sections of the upgraded system in a mockup drift chamber environment. This paper explains the testing process and presents results regarding performance of the upgrade electronics.

  6. Luminosity-independent measurement of the proton-proton total cross section at √s=8 TeV.

    PubMed

    Antchev, G; Aspell, P; Atanassov, I; Avati, V; Baechler, J; Berardi, V; Berretti, M; Bossini, E; Bottigli, U; Bozzo, M; Brücken, E; Buzzo, A; Cafagna, F S; Calicchio, M; Catanesi, M G; Covault, C; Csanád, M; Csörgő, T; Deile, M; Doubek, M; Eggert, K; Eremin, V; Ferretti, R; Ferro, F; Fiergolski, A; Garcia, F; Giani, S; Greco, V; Grzanka, L; Heino, J; Hilden, T; Intonti, R A; Kašpar, J; Kopal, J; Kundrát, V; Kurvinen, K; Lami, S; Latino, G; Lauhakangas, R; Leszko, T; Lippmaa, E; Lokajíček, M; Lo Vetere, M; Lucas Rodríguez, F; Macrí, M; Mäki, T; Mercadante, A; Minafra, N; Minutoli, S; Nemes, F; Niewiadomski, H; Oliveri, E; Oljemark, F; Orava, R; Oriunno, M; Österberg, K; Palazzi, P; Procházka, J; Quinto, M; Radermacher, E; Radicioni, E; Ravotti, F; Robutti, E; Ropelewski, L; Ruggiero, G; Saarikko, H; Santroni, A; Scribano, A; Smajek, J; Snoeys, W; Sziklai, J; Taylor, C; Turini, N; Vacek, V; Vítek, M; Welti, J; Whitmore, J; Wyszkowski, P

    2013-07-01

    The TOTEM collaboration has measured the proton-proton total cross section at √s=8 TeV using a luminosity-independent method. In LHC fills with dedicated beam optics, the Roman pots have been inserted very close to the beam allowing the detection of ~90% of the nuclear elastic scattering events. Simultaneously the inelastic scattering rate has been measured by the T1 and T2 telescopes. By applying the optical theorem, the total proton-proton cross section of (101.7±2.9) mb has been determined, well in agreement with the extrapolation from lower energies. This method also allows one to derive the luminosity-independent elastic and inelastic cross sections: σ(el)=(27.1±1.4) mb; σ(inel)=(74.7±1.7) mb. PMID:23862993

  7. Luminosity-Independent Measurement of the Proton-Proton Total Cross Section at s=8TeV

    NASA Astrophysics Data System (ADS)

    Antchev, G.; Aspell, P.; Atanassov, I.; Avati, V.; Baechler, J.; Berardi, V.; Berretti, M.; Bossini, E.; Bottigli, U.; Bozzo, M.; Brücken, E.; Buzzo, A.; Cafagna, F. S.; Calicchio, M.; Catanesi, M. G.; Covault, C.; Csanád, M.; Csörgő, T.; Deile, M.; Doubek, M.; Eggert, K.; Eremin, V.; Ferretti, R.; Ferro, F.; Fiergolski, A.; Garcia, F.; Giani, S.; Greco, V.; Grzanka, L.; Heino, J.; Hilden, T.; Intonti, R. A.; Kašpar, J.; Kopal, J.; Kundrát, V.; Kurvinen, K.; Lami, S.; Latino, G.; Lauhakangas, R.; Leszko, T.; Lippmaa, E.; Lokajíček, M.; Lo Vetere, M.; Lucas Rodríguez, F.; Macrí, M.; Mäki, T.; Mercadante, A.; Minafra, N.; Minutoli, S.; Nemes, F.; Niewiadomski, H.; Oliveri, E.; Oljemark, F.; Orava, R.; Oriunno, M.; Österberg, K.; Palazzi, P.; Procházka, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Robutti, E.; Ropelewski, L.; Ruggiero, G.; Saarikko, H.; Santroni, A.; Scribano, A.; Smajek, J.; Snoeys, W.; Sziklai, J.; Taylor, C.; Turini, N.; Vacek, V.; Vítek, M.; Welti, J.; Whitmore, J.; Wyszkowski, P.

    2013-07-01

    The TOTEM collaboration has measured the proton-proton total cross section at s=8TeV using a luminosity-independent method. In LHC fills with dedicated beam optics, the Roman pots have been inserted very close to the beam allowing the detection of ˜90% of the nuclear elastic scattering events. Simultaneously the inelastic scattering rate has been measured by the T1 and T2 telescopes. By applying the optical theorem, the total proton-proton cross section of (101.7±2.9)mb has been determined, well in agreement with the extrapolation from lower energies. This method also allows one to derive the luminosity-independent elastic and inelastic cross sections: σel=(27.1±1.4)mb; σinel=(74.7±1.7)mb.

  8. Supersymmetry Without Prejudice at the 7 TeV LHC

    SciTech Connect

    Conley, John A.; Gainer, James S.; Hewett, JoAnne L.; Le, My Phuong; Rizzo, Thomas G.; /SLAC

    2011-08-12

    We investigate the model independent nature of the Supersymmetry search strategies at the 7 TeV LHC. To this end, we study the missing-transverse-energy-based searches developed by the ATLAS Collaboration that were essentially designed for mSUGRA. We simulate the signals for {approx} 71k models in the 19-dimensional parameter space of the pMSSM. These models have been found to satisfy existing experimental and theoretical constraints and provide insight into general features of the MSSM without reference to a particular SUSY breaking scenario or any other assumptions at the GUT scale. Using backgrounds generated by ATLAS, we find that imprecise knowledge of these estimated backgrounds is a limiting factor in the potential discovery of these models and that some channels become systematics-limited at larger luminosities. As this systematic error is varied between 20-100%, roughly half to 90% of this model sample is observable with significance S {ge} 5 for 1 fb{sup -1} of integrated luminosity. We then examine the model characteristics for the cases which cannot be discovered and find several contributing factors. We find that a blanket statement that squarks and gluinos are excluded with masses below a specific value cannot be made. We next explore possible modifications to the kinematic cuts in these analyses that may improve the pMSSM model coverage. Lastly, we examine the implications of a null search at the 7 TeV LHC in terms of the degree of fine-tuning that would be present in this model set and for sparticle production at the 500 GeV and 1 TeV Linear Collider.

  9. Physical protection upgrades in Ukraine.

    SciTech Connect

    Djakov, A.

    1998-08-06

    The U.S. DOE is providing nuclear material safeguards assistance in both material control and accountability and in physical protection to several facilities in Ukraine. This paper summarizes the types of physical protection upgrades that have been or are presently being implemented at these facilities. These facilities include the Kiev Institute for Nuclear Research, Kharkov Institute of Physics and Technology, Sevastopol Institute of Nuclear Energy and Industry, and the South Ukraine Nuclear Power Plant. Typical upgrades include: hardening of storage areas; improvements in access control, intrusion detection, and CCTV assessment; central alarm station improvements; and implementation of new voice communication systems. Methods used to implement these upgrades and problems encountered are discussed. Training issues are also discussed.

  10. A Level-1 Tracking Trigger for the CMS upgrade using stacked silicon strip detectors and advanced pattern technologies

    NASA Astrophysics Data System (ADS)

    Boudoul, G.

    2013-01-01

    Experience at high luminosity hadrons collider experiments shows that tracking information enhances the trigger rejection capabilities while retaining high efficiency for interesting physics events. The design of a tracking based trigger for the High Luminosity LHC (HL-LHC) is an extremely challenging task, and requires the identification of high-momentum particle tracks as a part of the Level 1 Trigger. Simulation studies show that this can be achieved by correlating hits on two closely spaced silicon strip sensors, and reconstructing tracks at L1 by employing an Associative Memory approach. The progresses on the design and development of this micro-strip stacked prototype modules and the performance of few prototype detectors will be presented. Preliminary results of a simulated tracker layout equipped with stacked modules are discussed in terms of pT resolution and triggering capabilities. Finally, a discussion on the L1 architecture will be given.

  11. Status of TMX upgrade diagnostics construction

    SciTech Connect

    Hornady, R.S.; Davis, J.C.; Simonen, T.C.

    1981-07-20

    This report describes the status of the initial TMX Upgrade diagnostics and the state of development of additional diagnostics being prepared for later TMX Upgrade experiments. The initial diagnostic instrument set has been described in the TMX Upgrade Proposal. This set is required to get TMX Upgrade operational and to evaluate its initial performance. Additional diagnostic instruments are needed to then carry out the more detailed experiments outlined by the TMX Upgrade program milestones. The relation of these new measurements to the physics program is described in The TMX Upgrade Program Plan.

  12. Exploring the Standard Model with the High Luminosity, Polarized Electron-Ion Collider

    SciTech Connect

    Milner, Richard G.

    2009-08-04

    The Standard Model is only a few decades old and has been successfully confirmed by experiment, particularly at the high energy frontier. This will continue with renewed vigor at the LHC. However, many important elements of the Standard Model remain poorly understood. In particular, the exploration of the strong interaction theory Quantum Chromodynamics is in its infancy. How does the spin-1/2 of the proton arise from the fundamental quark and gluon constituents? Can we understand the new QCD world of virtual quarks and gluons in the nucleon? Using precision measurements can we test the limits of the Standard Model and look for new physics? To address these and other important questions, physicists have developed a concept for a new type of accelerator, namely a high luminosity, polarized electron-ion collider. Here the scientific motivation is summarized and the accelerator concepts are outlined.

  13. Searching for New Physics with Top Quarks and Upgrade to the Muon Spectrometer at ATLAS

    SciTech Connect

    Schwarz, Thomas Andrew

    2015-06-29

    Over the funding period of this award, my research has focused on searching for new physics with top quarks and in the Higgs sector. The highly energetic top quark events at the LHC are an excellent venue to search for new physics, as well as make standard model measurements. Further, the recent discovery of the Higgs boson motivates searching for new physics that could be associated with it. This one-year award has facilitated the beginning of my research program, which has resulted in four publications, several conference talks, and multiple leadership positions within physics groups. Additionally, we are contributing to ATLAS upgrades and operations. As part of the Phase I upgrade, I have taken on the responsibility of the design, prototyping, and quality control of a signal packet router for the trigger electronics of the New Small Wheel. This is a critical component of the upgrade, as the router is the main switchboard for all trigger signals to track finding processors. I am also leading the Phase II upgrade of the readout electronics of the muon spectrometer, and have been selected as the USATLAS Level-2 manager of the Phase II upgrade of the muon spectrometer. The award has been critical in these contributions to the experiment.

  14. Event Plane Resolution Simulations for The Fast Interaction Trigger Detector of ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Sulaimon, Isiaka; Harton, Austin; Garcia, Edmundo; Alice-Fit Collaboration

    2016-03-01

    CERN (European Center for Nuclear Research) is a global laboratory that studies proton and heavy ion collisions at the Large Hadron Collider (LHC). ALICE (A Large Ion Collider Experiment) is one of four large experiments of the LHC. ALICE is dedicated to the study of the transition of matter to Quark Gluon Plasma in heavy ion collisions. In the present ALICE detector there are two sub-detectors, (the T0 and V0), that provide minimum bias trigger, multiplicity trigger, beam-gas event rejection, collision time for other sub detectors, on line multiplicity and event plane determination. In order to adapt these functionalities to the collision rates expected for the LHC upgrade after 2020, it is planned to replace these systems by a single detector system, called the Fast Interaction Trigger (FIT). In this presentation we describe the performance parameters of the FIT upgrade; show the proposed characteristics of the T0-Plus and the simulations that support the conceptual design of this detector. In particular we describe the performance simulations of the event plane resolution. This material is based upon work supported by the National Science Foundation under Grants NSF-PHY-0968903 and NSF-PHY-1305280.

  15. THE LUMINOSITY PROFILES OF BRIGHTEST CLUSTER GALAXIES

    SciTech Connect

    Donzelli, C. J.; Muriel, H.; Madrid, J. P.

    2011-08-01

    We have derived detailed R-band luminosity profiles and structural parameters for a total of 430 brightest cluster galaxies (BCGs), down to a limiting surface brightness of 24.5 mag arcsec{sup -2}. Light profiles were initially fitted with a Sersic's R {sup 1/n} model, but we found that 205 ({approx}48%) BCGs require a double component model to accurately match their light profiles. The best fit for these 205 galaxies is an inner Sersic model, with indices n {approx} 1-7, plus an outer exponential component. Thus, we establish the existence of two categories of the BCG luminosity profiles: single and double component profiles. We found that double profile BCGs are brighter ({approx}0.2 mag) than single profile BCGs. In fact, the Kolmogorov-Smirnov test applied to these subsamples indicates that they have different total magnitude distributions, with mean values M{sub R} = -23.8 {+-} 0.6 mag for single profile BCGs and M{sub R} = -24.0 {+-} 0.5 mag for double profile BCGs. We find that partial luminosities for both subsamples are indistinguishable up to r = 15 kpc, while for r > 20 kpc the luminosities we obtain are on average 0.2 mag brighter for double profile BCGs. This result indicates that extra-light for double profile BCGs does not come from the inner region but from the outer regions of these galaxies. The best-fit slope of the Kormendy relation for the whole sample is a = 3.13 {+-} 0.04. However, when fitted separately, single and double profile BCGs show different slopes: a{sub single} = 3.29 {+-} 0.06 and a{sub double} = 2.79 {+-} 0.08. Also, the logarithmic slope of the metric luminosity {alpha} is higher in double profile BCGs ({alpha}{sub double} = 0.65 {+-} 0.12) than in single profile BCGs ({alpha}{sub single} = 0.59 {+-} 0.14). The mean isophote outer ellipticity (calculated at {mu} {approx} 24 mag arcsec{sup -2}) is higher in double profile BCGs (e{sub double} = 0.30 {+-} 0.10) than in single profile BCGs (e{sub single} = 0.26 {+-} 0.11). Similarly

  16. Testing the minimal direct gauge mediation at the LHC

    NASA Astrophysics Data System (ADS)

    Hamaguchi, Koichi; Ibe, Masahiro; Yanagida, Tsutomu T.; Yokozaki, Norimi

    2014-07-01

    We reexamine the models with gauge mediation in view of the minimality and the Higgs boson mass. As a result, we arrive at a very simple model of direct gauge mediation which does not suffer from the flavor problems nor the CP problems. The minimal supersymmetric Standard Model spectrum is determined by only three parameters, the size of the effective supersymmetry breaking, the messenger scale, and the messenger number. Surprisingly, such a very simple model is not only consistent with all the current constraints but also is testable at the upgraded LHC experiments. In particular, we show that the parameter space which is consistent with the Higgs boson mass at around 126 GeV can be tested through the stable stau searches at the 14 TeV run of the LHC. The gravitino is a viable candidate for a dark matter. We also give a short discussion on a possible connection of our model to the recently discovered x-ray line signal at 3.5 keV in the X-ray Multi-Mirror Mission Newton x-ray observatory data.

  17. Forward shower counters for diffractive physics at the LHC

    NASA Astrophysics Data System (ADS)

    Albrow, Michael; Collins, Paula; Penzo, Aldo

    2014-11-01

    The LHC detectors have incomplete angular coverage in the forward direction, for example in the region 6 ≲ |η| ≲ 8, which can be improved with the addition of simple scintillation counters around the beam pipes about 50 m to 120 m from the intersection point. These counters detect showers created by particles hitting the beam pipes and nearby material. The absence of signals in these counters in low pileup conditions is an indication of a forward rapidity gap as a signature of diffraction. In addition, they can be used to detect hadrons from low mass diffractive excitations of the proton, not accompanied by a leading proton but adjacent to a rapidity gap over (e.g.) 3 ≲ |η| ≲ 6. Such a set of forward shower counters, originally used at CDF, was used in CMS (FSC) for high-β* running with TOTEM during LHC Run-1. During LS1 the CMS FSC system is being upgraded for future low pileup runs. A similar system, called HERSCHEL is being installed in LHCb. ALICE is implementing scintillation counters, ADA and ADC, with 4.5 ≲ |η| ≲ 6.4.

  18. Searching for the layered structure of space at the LHC.

    SciTech Connect

    Anchordoqui, L. A.; Dai, D. C.; Goldberg, H.; Landsberg, G.; Shaughnessy, G.; Stojkovic, D.; Weiler, T. J.

    2011-06-23

    Alignment of the main energy fluxes along a straight line in a target plane has been observed in families of cosmic ray particles detected in the Pamir mountains. The fraction of events with alignment is statistically significant for families with superhigh energies and large numbers of hadrons. This can be interpreted as evidence for coplanar hard scattering of secondary hadrons produced in the early stages of the atmospheric cascade development. This phenomenon can be described within the recently proposed 'crystal world,' with latticized and anisotropic spatial dimensions. Planar events are expected to dominate particle collisions at a hard-scattering energy exceeding the scale {Lambda}{sub 3} at which space transitions from 3D{r_equilibrium}2D. We study specific collider signatures that will test this hypothesis. We show that the energy spectrum of Drell-Yan (DY) scattering is significantly modified in this framework. At the LHC, two jet and three jet events are necessarily planar, but four jet events can test the hypothesis. Accordingly, we study in a model-independent way the 5{sigma} discovery reach of the ATLAS and CMS experiments for identifying four jets coplanarities. For the extreme scenario in which all pp {yields} 4 jet scattering processes become coplanar above {Lambda}{sub 3}, we show that with an integrated luminosity of 10(100) fb{sup -1} the LHC experiments have the potential to discover correlations between jets if {Lambda}{sub 3} {approx}< 1.25(1.6) TeV.

  19. Distinguishing Dirac/Majorana sterile neutrinos at the LHC

    NASA Astrophysics Data System (ADS)

    Dib, Claudio O.; Kim, C. S.; Wang, Kechen; Zhang, Jue

    2016-07-01

    We study the purely leptonic decays of W±→e±e±μ∓ν and μ±μ±e∓ν produced at the LHC, induced by sterile neutrinos with mass mN below MW in the intermediate state. Since the final state neutrino escapes detection, one cannot tell whether this process violates lepton number, which would indicate a Majorana character for the intermediate sterile neutrino. Our study shows that when the sterile neutrino mixings with electrons and muons are different enough, one can still discriminate between the Dirac and Majorana character of this intermediate neutrino by simply counting and comparing the above decay rates. After performing collider simulations and statistical analysis, we find that at the 14 TeV LHC with an integrated luminosity of 3000 fb-1, for two benchmark scenarios mN=20 and 50 GeV, at least a 3 σ level of exclusion on the Dirac case can be achieved for disparities as mild as, e.g., |UN e|2<0.7 |UN μ|2 or |UN μ|2<0.7 |UN e|2 , provided that |UN e|2 and |UN μ|2 are both above ˜2 ×10-6.

  20. CLOC: Cluster Luminosity Order-Statistic Code

    NASA Astrophysics Data System (ADS)

    Da Silva, Robert L.; Krumholz, Mark R.; Fumagalli, Michele; Fall, S. Michael

    2016-02-01

    CLOC computes cluster order statistics, i.e. the luminosity distribution of the Nth most luminous cluster in a population. It is flexible and requires few assumptions, allowing for parametrized variations in the initial cluster mass function and its upper and lower cutoffs, variations in the cluster age distribution, stellar evolution and dust extinction, as well as observational uncertainties in both the properties of star clusters and their underlying host galaxies. It uses Markov chain Monte Carlo methods to search parameter space to find best-fitting values for the parameters describing cluster formation and disruption, and to obtain rigorous confidence intervals on the inferred values.

  1. Oxygen-rich Mira variables: Near-infrared luminosity calibrations. Populations and period-luminosity relations

    NASA Technical Reports Server (NTRS)

    Alvarez, R.; Mennessier, M.-O.; Barthes, D.; Luri, X.; Mattei, J. A.

    1997-01-01

    Hipparcos astrometric and kinematical data of oxygen-rich Mira variables are used to calibrate absolute near-infrared magnitudes and kinematic parameters. Three distinct classes of stars with different kinematics and scale heights were identified. The two most significant groups present characteristics close to those usually assigned to extended/thick disk-halo populations and old disk populations, respectively, and thus they may differ by their metallicity abundance. Two parallel period-luminosity relations are found, one for each population. The shift between these relations is interpreted as the consequence of the effects of metallicity abundance on the luminosity.

  2. LUMINOSITY INCREASES IN GOLD-GOLD OPERATION IN RHIC.

    SciTech Connect

    FISCHER,W.AHERNS,L.BAI,M.ET AL.

    2004-07-05

    After an exploratory phase, during which a number of beam parameters were varied, the RHIC experiments now demand higher luminosity to study heavy ion collisions in detail. In gold-gold, operation, RHIC delivers now twice the design luminosity. During the last gold-gold operating period (Run-4) the machine delivered 15 times more luminosity than during the previous gold-gold operating period (Run-2), two years ago. We give an overview of the changes that increased the instantaneous luminosity and luminosity lifetime, raised the reliability, and improved the operational efficiency.

  3. CORRELATION BETWEEN GROUP LOCAL DENSITY AND GROUP LUMINOSITY

    SciTech Connect

    Deng Xinfa; Yu Guisheng

    2012-11-10

    In this study, we investigate the correlation between group local number density and total luminosity of groups. In four volume-limited group catalogs, we can conclude that groups with high luminosity exist preferentially in high-density regions, while groups with low luminosity are located preferentially in low-density regions, and that in a volume-limited group sample with absolute magnitude limit M{sub r} = -18, the correlation between group local number density and total luminosity of groups is the weakest. These results basically are consistent with the environmental dependence of galaxy luminosity.

  4. Long-Range And Head-On Beam-Beam Compensation Studies in RHIC With Lessons for the LHC

    SciTech Connect

    Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; Dorda, U.; Koutchouk, J.P.; Sterbini, G.; Zimmermann, F.; Kim, H.J.; Sen, T.; Shiltsev, V.; Valishev, A.; Qiang, J.; Kabel, A.; /SLAC

    2011-11-28

    Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are are also important consideration for the LHC upgrades. To mitigate long-range effects, current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. Electron lenses were proposed for both RHIC and the LHC to reduce the head-on beam-beam effect. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.

  5. Long-range and head-on beam-beam compensation studies in RHIC with lessons for the LHC

    SciTech Connect

    Fischer,W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; Dorda, U.; Koutchouk, J. -P.; Sterbini, G.; Zimmermann, F.; Kim, H. -J.; Sen, T.; Shiltsev, V.; Valishev, A.; Qiang, J.; Kabel, A.

    2008-11-24

    Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are also important consideration for the LHC upgrades. To mitigate long-range effects current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. To reduce the head-on beam-beam effect electron lenses were proposed for both RIDC and the LHC. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.

  6. Old PCs: Upgrade or Abandon?

    ERIC Educational Resources Information Center

    Perez, Ernest

    1997-01-01

    Examines the practical realities of upgrading Intel personal computers in libraries, considering budgets and technical personnel availability. Highlights include adding RAM; putting in faster processor chips, including clock multipliers; new hard disks; CD-ROM speed; motherboards and interface cards; cost limits and economic factors; and…

  7. Design approach for the development of a cryomodule for compact crab cavities for Hi-Lumi LHC

    SciTech Connect

    Pattalwar, Shrikant; Goudket, Philippe; McIntosh, Peter; Wheelhouse, Alan; Jones, Thomas; Templeton, Niklas; Burt, Graeme; Hall, Ben; Wright, Loren; Peterson, Tom

    2014-01-29

    A prototype Superconducting RF (SRF) cryomodule, comprising multiple compact crab cavities is foreseen to realise a local crab crossing scheme for the “Hi-Lumi LHC”, a project launched by CERN to increase the luminosity performance of LHC. A cryomodule with two cavities will be initially installed and tested on the SPS drive accelerator at CERN to evaluate performance with high-intensity proton beams. A series of boundary conditions influence the design of the cryomodule prototype, arising from; the complexity of the cavity design, the requirement for multiple RF couplers, the close proximity to the second LHC beam pipe and the tight space constraints in the SPS and LHC tunnels. As a result, the design of the helium vessel and the cryomodule has become extremely challenging. This paper assesses some of the critical cryogenic and engineering design requirements and describes an optimised cryomodule solution for the evaluation tests on SPS.

  8. Solar luminosity variations in solar cycle 21

    NASA Technical Reports Server (NTRS)

    Willson, Richard C.; Hudson, H. S.

    1988-01-01

    Long-term variations in the solar total irradiance found in the ACRIM I experiment on the SMM satellite have revealed a downward trend during the declining phase of solar cycle 21 of the sunspot cycle, a flat period between mid-1095 and mid-1987, and an upturn in late 1987 which suggests a direct correlation of luminosity and solar active region population. If the upturn continues into the activity maximum of solar cycle 22, a relation between solar activity and luminosity of possible climatological significance could be ascertained. The best-fit relationship for the variation of total irradiance S with sunspot number Rz and 10-cm flux F(10) are S = 1366.82 + 7.71 x 10 to the -3rd Rz and S = 1366.27 + 8.98 x 10 to the -3rd F(10)(W/sq m). These findings could be used to approximate total irradiance variations over the periods for which these indices have been compiled.

  9. Luminosity Function Evolution of Young Star Clusters

    NASA Astrophysics Data System (ADS)

    Chen, W. P.; Kao, K. C.; Hu, J. Y.

    The luminosity function of a star cluster evolves markedly during the pre-main sequence phase. With an assumed initial mass function (Miller & Scalo, 1979) and pre-main sequence tracks (D'Antona & Mazzitelli, 1994), we calculate a set of monochromatic luminosity functions which, when compared with observations, can be used to infer the age and star formation history (coeval versus intermittent) of a star cluster. Applied to the Trapezium cluster (2.2 micron imaging data by Zinncker et al 1993), our model suggests an age close to 10^6 years, whereas in IC 348 (2 micron data from Lada & Lada, 1995) the age estimate yields 4--6 times 10^6 years and continual bursts of star formation seem to have occurred in this cluster. CCD imaging observations at optical-infrared I band are presented for NGC 663, for which an age of 1--3 times 10^7 years is inferred. The initial mass function for NGC 663 in the range 2--7.1 {Modot} has a slope of -0.77 plus or minus 0.20, much shallower than that for the solar neighborhood field stars. We interpret this being due to the mass segregation in the cluster.

  10. Probing the Luminosity Function of Young Quasars

    NASA Astrophysics Data System (ADS)

    Urrutia, Tanya; Glikman, E.; Lacy, M.

    2010-01-01

    In the last year, we have been using the Triple Spec Near-Infrared spectrograph on the Palomar Observatory to identify candidate dust-reddened quasars using the FIRST radio survey, the UKIDSS near-infrared survey and the SDSS optical survey. A previous campaign using the shallow near-infrared 2MASS survey, was very successful in finding dust obscured quasars by finding very red (R-K > 4, J-K > 1.7) radio sources (Glikman et al. 2007). Among them are many young, interacting galaxies (Urrutia, Lacy & Becker 2008) and a large fraction of Low Ionization Broad Absorption Line Quasars (Urrutia et al. 2009), implying that the red quasar population probes a young phase in the lifetime of an AGN. By using the same color criteria on the deeper UKIDSS survey, we are able to probe into higher redshifts and lower luminosity red quasars. This is a first step to build a luminosity function for dust-obscured quasars. We then will be able to answer the question if young quasars are more generally more luminous as their older counterparts, perhaps because of higher accretion efficiency.

  11. Low luminosity AGNs in the local universe

    NASA Astrophysics Data System (ADS)

    Ikiz, Tuba; Peletier, Reynier F.; Yesilyaprak, Cahit

    2016-04-01

    Galaxies are known to contain black holes (e.g. Ferrarese & Merritt 2000), whose mass correlates with the mass of their bulge. A fraction of them also has an Active Galactic Nucleus (AGN), showing excess emission thought to be due to accretion of mass by the supermassive black hole at the center of the galaxy. It is thought that AGNs play a very important role during the formation of galaxies by creating large outflows that stop star formation in the galaxy (see e.g. Kormendy & Ho 2013). The aim is to detect the fraction of Low Luminosity Active Galactic Nucleus (LLAGN) in the nearby Universe. At present, they are typically found using optical spectroscopy (e.g. Kauffmann, Heckman et al. 2003), who discuss the influence of the AGN on the host galaxy and vice versa. However, optical spectra are seriously affected by extinction in these generally very dusty objects, and therefore can only give us partial information about the AGN. I used a newly-found method, and apply it to the S4G sample, a large, complete, sample of nearby galaxies, which I am studying in detail with a large collaboration, to detect the fraction of low luminosity AGNs, and to better understand the relation between AGNs and their host galaxy which is thought to be crucial for their formation.

  12. Thermodynamics and luminosities of rainbow black holes

    NASA Astrophysics Data System (ADS)

    Mu, Benrong; Wang, Peng; Yang, Haitang

    2015-11-01

    Doubly special relativity (DSR) is an effective model for encoding quantum gravity in flat spacetime. As result of the nonlinearity of the Lorentz transformation, the energy-momentum dispersion relation is modified. One simple way to import DSR to curved spacetime is ``Gravity's rainbow'', where the spacetime background felt by a test particle would depend on its energy. Focusing on the ``Amelino-Camelia dispersion relation'' which is E2 = m2+p2[1-η(E/mp)n] with n > 0, we investigate the thermodynamical properties of a Schwarzschild black hole and a static uncharged black string for all possible values of η and n in the framework of rainbow gravity. It shows that there are non-vanishing minimum masses for these two black holes in the cases with η < 0 and n >= 2. Considering effects of rainbow gravity on both the Hawking temperature and radius of the event horizon, we use the geometric optics approximation to compute luminosities of a 2D black hole, a Schwarzschild one and a static uncharged black string. It is found that the luminosities can be significantly suppressed or boosted depending on the values of η and n.

  13. Development of MQXF: The Nb3Sn low-β quadrupole for the HiLumi LHC

    DOE PAGESBeta

    Ferracin, P.; G. Ambrosio; Anerella, M.; Ballarino, A.; Bajas, H.; Bajko, M.; Bordini, B.; Bossert, R.; Cheng, D. W.; Dietderich, D. R.; et al

    2015-12-18

    The High Luminosity (HiLumi) Large Hadron Collider (LHC) project has, as the main objective, to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new interaction region layout, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the interaction points by a factor of two, which requires doubling the aperture of the low-β (or inner triplet) quadrupole magnets. The use of Nb3Sn superconducting material and, as a result, the possibility of operating atmore » magnetic field levels in the windings higher than 11 T will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the U.S. LHC Accelerator Research Program and the Conseil Europeen pour la Recherche Nucleaire (CERN), has now entered the construction and test phase of the short models. Concurrently, the preparation for the development of the full-length prototypes has been initiated. Lastly, this paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.« less

  14. Simplified SIMPs and the LHC

    NASA Astrophysics Data System (ADS)

    Daci, N.; De Bruyn, I.; Lowette, S.; Tytgat, M. H. G.; Zaldivar, B.

    2015-11-01

    The existence of Dark Matter (DM) in the form of Strongly Interacting Massive Particles (SIMPs) may be motivated by astrophysical observations that challenge the classical Cold DM scenario. Other observations greatly constrain, but do not completely exclude, the SIMP alternative. The signature of SIMPs at the LHC may consist of neutral, hadron-like, trackless jets produced in pairs. We show that the absence of charged content can provide a very efficient tool to suppress dijet backgrounds at the LHC, thus enhancing the sensitivity to a potential SIMP signal. We illustrate this using a simplified SIMP model and present a detailed feasibility study based on simulations, including a dedicated detector response parametrization. We evaluate the expected sensitivity to various signal scenarios and tentatively consider the exclusion limits on the SIMP elastic cross section with nucleons.

  15. A highly selective first-level muon trigger with MDT chamber data for ATLAS at HL-LHC

    NASA Astrophysics Data System (ADS)

    Nowak, S.; Kroha, H.

    2016-07-01

    Highly selective triggers are essential for the physics programme of the ATLAS experiment at HL-LHC where the instantaneous luminosity will be about an order of magnitude larger than the LHC instantaneous luminosity in Run 1. The first level muon trigger rate is dominated by low momentum muons below the nominal trigger threshold due to the moderate momentum resolution of the Resistive Plate and Thin Gap trigger chambers. The resulting high trigger rates at HL-LHC can be sufficiently reduced by using the data of the precision Muon Drift Tube chambers for the trigger decision. This requires the implementation of a fast MDT read-out chain and of a fast MDT track reconstruction algorithm with a latency of at most 6 μs. A hardware demonstrator of the fast read-out chain has been successfully tested at the HL-LHC operating conditions at the CERN Gamma Irradiation Facility. The fast track reconstruction algorithm has been implemented on a fast trigger processor.

  16. Catching Collisions in the LHC

    SciTech Connect

    Fruguiele, Claudia; Hirschauer, Jim

    2015-06-16

    Now that the Large Hadron Collider has officially turned back on for its second run, within every proton collision could emerge the next new discovery in particle physics. Learn how the detectors on the Compact Muon Solenoid, or CMS, experiment capture and track particles as they are expelled from a collision. Talking us through these collisions are Claudia Fruguiele and Jim Hirschauer of Fermi National Accelerator Laboratory, the largest U.S. institution collaborating on the LHC.

  17. LHC magnet quench protection system

    NASA Astrophysics Data System (ADS)

    Coull, L.; Hagedorn, D.; Remondino, V.; Rodriguez-Mateos, F.

    1994-07-01

    The quench protection system for the superconducting magnets of the CERN Large Hadron Collider (LHC) is described. The system is based on the so called 'cold diode' concept. In a group of series connected magnets if one magnet quenches then the magnetic energy of all the magnets will be dissipated in the quenched magnet so destroying it. This is avoided by by-passing the quenched magnet and then rapidly de-exciting the unquenched magnets. For the LHC machine it is foreseen to use silicon diodes situated inside the cryostat as by-pass elements - so called 'cold diodes'. The diodes are exposed to some 50 kGray of radiation during a 10 year operation life-time. The high energy density of the LHC magnets (500 kJ/m) coupled with the relatively slow propagation speed of a 'natural' quench (10 to 20 m/s) can lead to excessive heating of the zone where the quench started and to high internal voltages. It is therefore necessary to detect quickly the incipient quench and fire strip heaters which spread the quench out more quickly over a large volume of the magnet. After a quench the magnet chain must be de-excited rapidly to avoid spreading the quench to other magnets and over-heating the by-pass diode. This is done by switching high-power energy-dump resistors in series with the magnets. The LHC main ring magnet will be divided into 16 electrically separated units which has important advantages.

  18. Design, performance, and upgrade of the D0 calorimeter

    SciTech Connect

    Kotcher, J.

    1995-01-01

    The D0 detector, located at the Fermi National Accelerator Laboratory in Batavia, Illinois, USA, is a large hermetic detector designed for the study of proton-antiproton collisions at a center-of-mass energy of 2 TeV. The calorimeter is a sampling device that employs uranium absorber and liquid argon as the active material. It has been designed for the high-precision energy measurement of electrons and jets over the full solid angle, and excellent missing transverse energy resolution for enhanced neutrino {open_quotes}detection{close_quotes}. The authors report on some fundamental aspects of the D0 calorimeter`s design and performance (the latter having been measured in both test beams and during recent data taking at the Fermilab collider), and their plan for the upgrade, which has been designed to accomodate the higher luminosities anticipated after completion of the Fermilab Main Injector.

  19. Operation of the Run IIB D0 Luminosity System and Determination of the Run IIB Luminosity Constant

    SciTech Connect

    Prewitt, Michelle Victoria; /Rice U.

    2010-04-01

    The luminosity system is an integral part of the D0 detector that must be properly maintained to provide accurate luminosity measurements for physics analysis. After the addition of a readout layer to the silicon vertex detector in 2006, it was necessary to re-calculate the effective inelastic cross section to which the luminosity monitor is sensitive. The preliminary analysis showed that the luminosity constant did not change with the addition of the extra layer of silicon. A full study of the revised luminosity constant including a complete analysis of systematic uncertainties has been completed. The luminosity constant was determined to be {sigma}{sub eff} = 48.3 {+-} 1.9 {+-} 0.6 mb, which reduces the D0 contribution to the luminosity measurement uncertainty by almost 3%.

  20. Single top squark production as a probe of natural supersymmetry at the LHC

    NASA Astrophysics Data System (ADS)

    Hikasa, Ken-ichi; Li, Jinmian; Wu, Lei; Yang, Jin Min

    2016-02-01

    Light top squarks (stops) and light higgsinos are the key features of natural supersymmetry (SUSY), where the higgsinos χ˜1± and χ˜1,2 0 are nearly degenerate and act as the missing transverse energy (ET) at the LHC. Besides the pair production via strong interaction, the stop can be produced via the electroweak interaction. The determination of the electroweak properties of the stop is an essential task for the LHC and future colliders. So, in this paper, we investigate the single stop (t˜1) production p p →t˜1+ ET via the electroweak interaction in natural SUSY at the LHC, which gives the monotop signature t + ET from t˜1→t χ˜1,2 0 or the monobottom signature b + ET from t˜1→b χ˜1+. We perform Monte Carlo simulations for these signatures and obtain the observations: (1) The signal b + ET has a better sensitivity than t + ET for probing natural SUSY; (2) the parameter region with a higgsino mass 100 GeV ≲μ ≲225 GeV and stop mass mt˜1≲620 GeV can be probed through such single stop production with S /√{B }>3 and 4 %≲S /B ≲19 % at the 14 TeV LHC with an integrated luminosity of 3000 fb-1 .