LHC Performance Workshop (Chamonix 2014)

Europe/Zurich
Chamonix - Les Aiglons

Chamonix - Les Aiglons

Frank (Scientific Secretary) Zimmermann (CERN) , Frédérick Bordry
Description

The LHC Performance Workshop (Chamonix 2014) will take place from 22 to 25 September 2014 in Hotel Les Aiglons in Chamonix.

Attendance is by invitation only.

A summing-up session will take place at CERN Globe on 8th October, 14:15.

Schedule-Summary
Timetable - PDF
    • 8:45 AM 9:00 AM
      Introduction 15m
      Speaker: Frederick Bordry
      Slides
    • 9:00 AM 1:00 PM
      Session 1 - LS1, HW Commissioning, Powering Tests - Coming out of LS1

      [Chair: Mirko Pojer; Scientific secretary: Laurette Ponce]

      Conveners: Laurette Ponce , Mirko Pojer
      summary
      • 9:00 AM
        Non-conformities (solved and pending) on the Superconducting Circuits 20m
        During LS1 all NC’s on the SC circuits limiting the operation to 4 TeV have been solved, so after LS1 the LHC can be run up to nominal design energy. However, still some NC’s remain, especially on the corrector circuits. In this talk an overview is given of the solved and remaining NC’s in the SC circuits.
        Speaker: Arjan Verweij
        Abstract
        Paper
        Slides
      • 9:20 AM
        Questions 10m
      • 9:30 AM
        Re-commissioning of the Superconducting Circuits 20m
        During LS1, the first planned LHC long shutdown, several modifications have been carried out on the technical systems, besides the superconducting circuits consolidation, with the goal of increasing the system performance and availability, while raising the energy to its design value. The plan and present status of the superconducting circuits re-commissioning is presented.
        Speaker: Matteo Solfaroli Camillocci
        Paper
        Slides
      • 9:50 AM
        Questions 10m
      • 10:00 AM
        Other Non-solved NC's across the LHC Ring and Potential Impact on Performance 20m
        During Run 1, several non conformities across the ring with impact on machine performances were identified and planned to be solved during the long shutdown 1. During this long shutdown, new non conformities were also produced and / or identified. In this talk, some of these non conformities are presented and discussed together with their impact on machine operation, technical stops and LS2.
        Speaker: Vincent Baglin
        Abstract
        Paper
        Slides
      • 10:20 AM
        Questions 10m
      • 10:30 AM
        Coffee break 30m
      • 11:00 AM
        Expected impact of hardware changes on impedance and beam induced heating during run 2 20m
        During LS1, many hardware changes affected the beam surrounding (consolidations, upgrades and new equipment). The expected consequences of these changes on the LHC beam coupling impedance will be reviewed in this talk, as well as their consequences on the related intensity limitations: beam instabilities and beam induced RF heating. These collective effects have affected the performance of the LHC before LS1, and this talk will provide a status of the expected issues that may come up as well as suggest mitigation strategies in case of problems.
        Speaker: Benoit Salvant
        abstract
        Paper
        Slides
      • 11:20 AM
        Questions 10m
      • 11:30 AM
        ADT and RF after LS1 20m
        During LS1a number of consolidations and upgrades have been undertaken in the LHC RF, including replacement of a cryomodule (four cavities, beam 2), upgrade of klystron collectors and new solid state crowbar systems. The RF parameters will be outlined in view of the consequences of the increased beam current and energy, and the exotic bunch spacing for the scrubbing beams. The LHC Transverse feedback system (ADT) is also undergoing a major upgrade during LS1, with double the total number of pickups to reduce the noise floor of the system, new beam position electronics and an upgraded digital signal processing system to accommodate all of the extra functionality that had been introduced during LHC run I, and more sophisticated signal processing algorithms to be deployed for run II. An external “observation box” to record transverse and longitudinal data from the RF and ADT systems is being implemented.
        Speaker: Andrew Butterworth (CERN)
        Paper
        Slides
      • 11:50 AM
        Questions 10m
      • 12:00 PM
        LBDS and Kickers after LS1 20m
        Modifications of the injection kickers(MKI) during LS1 will be reviewed together with the expected performance for the coming run with respect to heating and UFOs. The beam dump system has undergone several foreseen upgrades like a new link between the trigger synchronisation unit (TSU) to the beam interlock system, an additional retriggering line in case of TSU failure, a new dump protection absorber (TCDQ) and the installation of an additional vertical dilution kicker (MKBV) tank. Difficulties in holding off the voltage in the beam dump kickers (MKD) generators lead to an improved design of insulators and spacers. Results from the first week of reliability runs at 7 TeV will be shown. A set of new interlocks for the injection and dump systems has been introduced during LS1 and will be reviewed: transfer line collimators (TCDI) gap control via virtual beta* and injection dump (TDI) gap control, injection septum (MSI) current and TCDQ position linked to the beam energy tracking system (BETS). The strategy for deploying blindable beam loss monitors at injection will be presented.
        Speaker: Wolfgang Bartmann
        Paper
        Slides
      • 12:20 PM
        Questions 10m
    • 4:00 PM 7:00 PM
      Session 2 - Injector Status and Beams for LHC, Dry Runs, Sector Tests with Beam

      Session 2 [Chair: Rende Steerenberg; Scientific Secretary: Reyes Alemany Fernandez]

      Conveners: Rende Steerenberg , Reyes Alemany Fernandez
      summary
      • 4:00 PM
        LHC Injectors Complex Status 30m
        We will present the status of the LHC proton and ion injector chain as of September 2014. We will briefly recap the main modifications done during LS1, in particular those which influence the LHC beam quality. Then we will review the first months of beam operation of the PS complex machines and the status and plans for commissioning of the SPS. We will in particular focus on the re-start of the injectors after LS1, and highlight the lessons learned and possible improvements for the re-start after LS2. Finally we will have a first look at the first months of the 2015 injector schedule.
        Speaker: Klaus Hanke
        Paper
        Slides
      • 4:30 PM
        Questions 15m
      • 4:45 PM
        SPS Scrubbing 2014 20m
        Yearly machine scrubbing has been applied in the SPS since 2002 in order to reduce the amount of electron cloud in the machine and permit smooth operation with 25 ns beams. While a quick scrubbing is usually necessary to recover performance after any extended technical stop due to in vacuum deconditioning, a longer period needs to be envisaged when the machine stop is long and a large fraction of the machine is exposed to air. Therefore, the restart of the SPS after LS1 will offer a unique opportunity to qualify the machine degradation due to a long stop as well as quantify length and efficiency of a scrubbing run to recover the previous performance and possibly extend it to higher intensity beams. This information will be the key input to decide on the upgrade strategy for the SPS, as it will show whether the SPS can be operated with scrubbing also for future intensities or electron cloud needs to be actively suppressed through a-C coating. Goals, requirements (in terms of beam and instrumentation) and a possible planning of the SPS scrubbing run in 2014 will be covered by this presentation. In this context, we will also describe the doublet beam, which can be potentially used for enhancing the scrubbing efficiency.
        Speaker: Hannes Bartosik (CERN)
        Paper
        Slides
      • 5:05 PM
        Questions 10m
      • 5:15 PM
        Operational Beams for the LHC 30m
        The variety of beams, needed to set-up in the injectors as requested in the LHC, are reviewed, in terms of priority but also performance expectations and reach during 2015. This includes the single bunch beams for machine commissioning and measurements (pilot, probe, Indiv) but also the standard physics beams with 50 ns and 25 ns bunch spacing and their high brightness variants using the Bunch Compression Merging and Splitting (BCMS) scheme. The required parameters and target performance of special beams like the doublet for electron cloud enhancement and the more exotic 8b+4e beam, compatible with some post-scrubbing scenarios are also described. The progress and plans for the LHC ion production beams during 2014-2015 are detailed. Highlights on the current progress of the setting up of the various beams are finally presented with special emphasis on potential performance issues across the proton and ion injector chain.
        Speaker: Yannis Papaphilippou
        Paper
        Slides
      • 5:45 PM
        Questions 15m
      • 6:00 PM
        LHC Dry-Runs and Cold Check-out 20m
        During LS1 most of the equipment groups took the opportunity to upgrade, improve and refactor their hardware and software. A particular care is necessary for the operation team during the testing phase before beam commissioning. Some equipment and software tests from the control room have already started early in the year, including the communication with the experiments, RF frequency ramp, LBDS arming sequence etc… The results will be presented. In parallel, regular meetings between OP and the equipment’s group have started for the establishment of a working plan for the final machine check-out. The strategy for the machine preparation from now to the beam commissioning will explained.
        Speaker: Delphine Jacquet
        Paper
        Slides
      • 6:20 PM
        Questions 10m
      • 6:30 PM
        LHC Sector Test 20m
        Sector tests in the past were undoubtedly invaluable and fully met their goals. They resolved a long list of problems, debugged and tested the control system, the beam instrumentation, timing and synchronization, software, etc. Measurements with beam allowed detailed optics and apertures checks to be performed, discovering aperture bottlenecks and polarity issues that could be solved. Being sector tests an essential precursor and a high profile milestone in preparation for full beam commissioning, two sector tests (one for B1 and another one for B2) and two transfer line tests (TI2 and TI8) are proposed. This paper summarizes the proposed dates, the pre-requisites, how to stop the beam with collimators, the proposal for beam measurements, and gives a first detailed plan of the tests as a base for discussion.
        Speaker: Reyes Alemany Fernandez
        Paper
        Slides
      • 6:50 PM
        Questions 10m
    • 7:00 PM 8:30 PM
      Dinner 1h 30m
    • 9:00 AM 12:30 PM
      Session 3 - 2015 Commissioning with Beam

      Session 3 [Chair: Mike Lamont; Scientific secretary: Giulia Papotti]

      Conveners: Giulia Papotti , Mike Lamont
      summary
      • 9:00 AM
        Introduction 10m
        In motivating the session, the challenges of re-commissioning the LHC in 2015 are introduced.
        Speaker: Mike Lamont
        Paper
        Slides
      • 9:10 AM
        Experiments' Expectations for 2015 20m
        Expectations and constraints from the LHC experiments concerning the commissioning procedure and the running conditions for the 2015 data taking period are discussed, as well as the experiments views about the various beam parameters for the p-p period, like beam energy, maximum pileup, bunch spacing and luminosity limitation in IP2 and IP8. The goals and the constraints of the 2015 physics program are also presented, including the heavy ions period as well as special running conditions.
        Speaker: Emilio Meschi
        Paper
        Slides
      • 9:30 AM
        Questions 10m
      • 9:40 AM
        Baseline Machine Parameters and Configuration for 2015 20m
        This presentation shows the baseline machine parameters for the 2015 start-up, with focus on collimation and the reach in beta*. Since many machine systems have been upgraded during LS1, and the LHC will operate at a higher energy than before and with a tighter filling scheme, the commissioning phase risks to be less smooth than in 2012. Therefore, the proposed starting configuration of the LHC puts the focus on feasibility rather than peak performance and allows comfortable margins for operational uncertainties. Instead, once beam experience and a better machine knowledge has been obtained, a push in beta* and performance can be envisaged.
        Speaker: Roderik Bruce
        Paper
        Slides
      • 10:00 AM
        Questions 10m
      • 10:10 AM
        Coffee beak 30m
      • 10:40 AM
        Optics options for the 2015 LHC run 20m
        A review of the possible optics configurations for the 2015 LHC run will be made. The rationale behind the various scenarios will also be presented together with the latest results of the validation studies. Special runs, such as Van der Meer and high-beta, will be discussed too. Finally, the next steps and the related milestones will be discussed with the goal of achieving a consensual decision on the optics configuration to be used for the LHC in the coming weeks.
        Speaker: Massimo Giovannozzi
        Paper
        Slides
      • 11:00 AM
        Questions 10m
      • 11:10 AM
        Nominal Cycle and Options 20m
        During Run2 LHC operation will be based on the experience gained in Run1 while being operated at about its design energy. Longer time will be required by the main operational phases (e.g. precycle, ramp) and operational re-configurations are being considered to improve efficiency. The expected changes in the magnetic model and the impact of the data updates with the corrections calculated during LS1 are presented together with a general overview of the new operational cycle, including time, challenges and possible improvements of each phase.
        Speaker: Matteo Solfaroli Camillocci
        Paper
        Slides
      • 11:30 AM
        Questions 10m
      • 11:40 AM
        Scrubbing: Expectations and Strategy, Long Range Perspective 25m
        Electron cloud buildup simulations and machine experience during Run 1 showed that electron cloud effects could significantly limit the performance of the LHC when operating with 25 ns bunch spacing. Beam induced scrubbing will have to be used to lower the Secondary Electron Yield (SEY) of the beam chambers and therefore reduce electron cloud induced pressure rises, heat load and beam degradation. This contribution will review the experience accumulated on electron cloud effects during Run 1 and define a possible scrubbing strategy to allow operation with 25 ns beams in 2015. Several measures taken during LS1 should allow for an improved scrubbing efficiency compared with Run 1. Moreover, the potential of using a dedicated scrubbing scheme based on the “doublet” beam, following the promising SPS tests in 2012, will be described and analyzed. To conclude, possible alternatives of operation scenarios will be defined, which will depend on the degree of success of the scrubbing runs.
        Speaker: Giovanni Iadarola
      • 12:05 PM
        Questions 10m
    • 4:00 PM 7:05 PM
      Session 4 - LHC: Challenges and Strategy for Run2

      Session 4 [Chair: Markus Zerlauth; Scientific secretary: Belen Maria Salvachua Ferrando]

      Conveners: Belen Maria Salvachua Ferrando , Markus Zerlauth
      summary
      • 4:00 PM
        Strategy for First Two Months (commissioning to first stable beams) 20m
        The LHC schedule tentatively foresees two months of commissioning time between the start of beam commissioning and the establishment of first stable beams with a few nominal bunches at top energy. This phase will address the commissioning with beam of the various accelerator systems and take into account the changes occurred in LS1 and resulting new commissioning requirements. In presence of uncertainties with respect to the critical machine and beam parameters, a set of critical measurements to be performed early on in the commissioning are identified in order to establish a validation plan for the machine configuration for the subsequent intensity ramp up.
        Speaker: Stefano Redaelli
        Paper
        Slides
      • 4:20 PM
        Questions 10m
      • 4:30 PM
        Overall Strategy for Run 2 20m
        This presentation will focus on the strategy for the first year of Run 2. Global strategies and various scenarios for Run 2 were already discussed in details at the RLIUP workshop in October 2013. The top goal of LHC operation for 2015 is to establish reliable operation at 6.5 TeV with 25 ns bunch spacing, and with a competitive luminosity. The overall strategy for the year 2015 will be discussed; this includes scrubbing runs, intensity ramp ups, reaching out for lower beta* and higher luminosity. Besides high intensity proton operation, high beta* and ion runs will also be discussed.
        Speaker: Jorg Wenninger
        Paper
        Slides
      • 4:50 PM
        Questions 10m
      • 5:00 PM
        MPS Strategy for Commissioning and Operation 20m
        During Run 2, when operating at 6.5TeV and 25 ns bunch spacing, the LHC will accelerate and store beams with an energy of up to 372MJ. A very tiny fraction of this beam can cause severe damage to accelerator equipment if the energy is released in an uncontrolled way. The presentation addresses the machine protection considerations for the initial commissioning with and without beam and discusses the required (re-)qualifications for subsequent changes of beam/optics parameters during the run. The definition of the new setup beam intensity - impacting commissioning and later operation and machine developments - is recalled. The talk will conclude with an outlook on future challenges with respect to machine protection in view of the injector upgrade and HL-LHC.
        Speaker: Belen Maria Salvachua Ferrando
        Paper
        Slides
      • 5:20 PM
        Questions 10m
      • 5:30 PM
        Machine Development Priorities 20m
        The Machine Development requirements for Run 2 are largely determined by the overall commissioning plan of the LHC in 2015 and foreseen operational challenges related to optics, beta* squeeze, instabilities and equipment performance. Electron cloud scrubbing is not part of the MDs. The demands from the different groups involved, expressed during the "MD Day" on 2 September 2014, are presented and evaluated in the context of importance for the machine performance, the constraints imposed by the available beams (from the injectors and in the LHC) and the available MD time. Organisational aspects of the MDs, like procedures, contact persons and MD notes, will also be outlined.
        Speaker: Jan Uythoven
        Paper
        Slides
      • 5:50 PM
        Questions 10m
      • 6:00 PM
        BLM Threshold Strategy (vs UFOs and Quenches) 20m
        BLM thresholds around the ring need to be updated for 6.5 TeV operation during Run 2. This presentation focuses on the UFO beam-loss scenario: dedicated quench tests at the end of Run 1 have helped to update quench-level estimates; comprehensive FLUKA simulations were carried out to improve the predicted BLM signals and local energy-deposition; based on these simulations, one out of three BLMs in the arcs were re-located to improve the BLM sensitivity. We show the expected impact of all these changes. The discussion of the UFO scenario is followed by an overview of other beam-loss scenarios.
        Speaker: Bernhard Auchmann
        Paper
        Slides
      • 6:20 PM
        Questions 10m
      • 6:30 PM
        R2E and Availability 20m
        The talk will first provide a brief summary of LS1 and the performed R2E activities with particular focus on the expected improvements on the overall system failures. We will then focus on the strategy and goals for the post LS1 LHC operation era, identifying the requirements and potentials of further availability gain. This will be partly also put in the context of the general availability improvement options, especially for what concerns the fault tracking and respective future availability predictions. Finally, we will provide a brief outlook on the goals of the R2E/Availability workshop to be held in October.
        Speaker: Markus Brugger
        Paper
        Slides
      • 6:50 PM
        Questions 10m
    • 7:45 PM 9:15 PM
      Dinner 1h 30m
    • 9:00 AM 12:30 PM
      Session 5 - LIU

      Session 5 [Chairs: Malika Meddahi, Giovanni Rumolo)

      Conveners: Giovanni Rumolo , Malika Meddahi
      summary
      • 9:00 AM
        LINAC4: Progress on Hardware and Beam Commissioning 30m
        Linac4 has been commissioned with a temporary source until the energy of 12 MeV. The dynamics in the LEBT, in the RFQ and in the chopper line have been verified, as well as the acceleration to 12 MeV with the first DTL tank. Future plans foresee stages of commissioning at the energy of 50, 100 and finally 160 MeV interlaced with periods of installation and followed by a year-long reliability run. In this talk we will present the status of the linac4 beam commissioning, the status of readiness of the remaining accelerating structures as well as the path to the final source. The possibility of delivering to the PSB a 50 MeV proton beam from Linac4 will be discussed together with its impact on the overall schedule and the achievable beam characteristics.
        Speaker: Alessandra Lombardi
        Paper
        Slides
      • 9:30 AM
        Questions 10m
      • 9:40 AM
        Protons: Baseline and Alternatives, Studies Plan 30m
        This talk will focus on the injector improvements and upgrades foreseen within the LIU project as well as the expected benefits in terms of proton beam characteristics resulting from their implementation. The roadmap of the main upgrades will be illustrated, with special emphasis on the machine studies and milestones during Run 2 that will have an impact on it. In this framework, a strategy to choose between scrubbing and a--‐C coating of the SPS will be also presented and discussed. The performances of the full injector chain will be estimated for both Run 2 and operation after LS2. For this purpose, we will review not only the possible physics production beams, but also: 1) beams needed for electron cloud enhancement and efficient LHC scrubbing (doublets); 2) extra--‐ bright 25 ns beams produced with the pure batch compression scheme; 3) 8b+4e beams, which have the advantage of allowing for higher bunch current while potentially reducing the electron cloud build up.
        Speaker: Giovanni Rumolo
        Paper
        Slides
      • 10:10 AM
        Questions 10m
      • 10:20 AM
        Coffee break 30m
      • 10:50 AM
        Concerns with Low Emittance Beams Operation 20m
        New techniques for the production of 25 ns bunch trains in the LHC injector chain have been successfully tested in the last year of the LHC run 1. These new techniques can produce bunches with unprecedented brightness for similar bunch intensities like in the nominal scheme, but significantly reduced emittances. The material damage potential depends however roughly on the ratio intensity to emittance. The effect of the new beams in case of impact on protection devices and their attenuation therefore has to be carefully evaluated. This talk will summarize the result of material survival simulations for various possible beams after LS1 and LS2 for protection devices and dumps. Possible implications on operation with these beams and limitations of emittance measurement devices will be discussed as well. The talk will also highlight the necessity of beam based material tests in HiRadMat to fully understand material properties under the severe conditions of shock impact from high intensity beams.
        Speaker: Verena Kain
        Paper
        Slides
      • 11:10 AM
        Questions 10m
      • 11:20 AM
        Other Means to increase the SPS 25 ns Performance - Transverse Plane 10m
        The LHC Injectors Upgrade (LIU) project aims at extending the brightness and intensity reach of the injector complex. To go beyond the SPS RF and longitudinal limitations remaining after the implementation of all the LIU upgrades, further optimisation is proposed on the following aspects: 1) Alternative SPS optics configurations with intermediate transition energy between Q20 and Q26. Although the presently operational Q20 optics pushed the TMCI threshold from 1.6e11 p/b to 4e11 p/b, it might not be the optimal choice for maximizing the intensity of the 25 ns beam due to the RF power limitations. Possible optics configurations with intermediate transition energy could achieve a better balance between TMCI threshold and RF power requirements. 2) Increase of the number of colliding bunches in the LHC by transferring a larger number of bunches between the PS and the SPS. In this context, schemes for transferring 80 or more bunches per PS batch and their operational implications are discussed, together with possible advantages for mitigating other limits in the SPS and LHC. Finally, machine development studies during Run 2 for evaluating the feasibility and potential of these schemes are addressed.
        Speaker: Hannes Bartosik
        Paper
        Slides
      • 11:30 AM
        Questions 10m
      • 11:40 AM
        Other Means to Increase the SPS 25 ns Performance - Longitudinal Plane 15m
        At the end of the LHC run 2 in 2012 the 25 ns beam with an intensity of 1.3e11 p/b was successfully accelerated in the SPS. Further significant increase of bunch intensity in the SPS requires that all LIU baseline upgrades are in place (for 200 MHz and 800 MHz RF systems and e-­‐cloud mitigation), but even then the bunch intensity could be limited below the HL-­‐LHC value of 2.5E11 by beam-­‐loading and longitudinal beam instabilities. In this paper other means to increase the 25 ns beam performance are considered. In particular, we study the potential gain in stability for bunches with larger longitudinal emittance at the SPS extraction, possible in the scenario with a 200 MHz RF system in the LHC. The expected longitudinal limitations (coupled-­‐bunch instability, loss of Landau damping, microwave instability and RF power during the ramp) are analysed for a single and double RF operation and different optics (Q20, Q26 and intermediate one). Bunch rotation before extraction to the LHC is also addressed as a potential technique to decrease capture losses of long bunches in the LHC. Finally, the proposal for the related Machine Development sessions is also presented.
        Speaker: Theodoros Argyropoulos
        Paper
        Slides
      • 11:55 AM
        Questions 10m
      • 12:05 PM
        Ions: Baseline, Studies Plan and Strategy for Pending Options 15m
        We will review the performance of the ion injector chain of the LHC during LR1, and the baseline of the upgrades, which are planned in order to reach the performance required after LS2. After overviewing the open issues and a tentative list of planned machine developments, we present the beam characteristics expected during LR2 and beyond.
        Speaker: Michael Andreas Bodendorfer
        Paper
        Slides
      • 12:20 PM
        Questions 10m
    • 4:00 PM 7:00 PM
      Session 6 - HL-LHC

      Session 6 [Chair: Oliver Bruning; Scientific secretary: Paolo Ferracin]

      Conveners: Oliver Bruning , Paolo Ferracin
      summary
      • 4:00 PM
        HL-LHC Parameter and Lay-out Baseline 20m
        The baseline parameters of the HL-LHC project will be reviewed and the new high-luminosity insertion region lay-out necessary to reach the project objectives will be described. The presentation will list other modifications that shall be carried out on the present LHC machine in order to reach the ambituous goal of 300 fb-1 delivered luminosity to the ATLAS and CMS experiments per year up to 2035. The main focus of the presentation will be the foreseen modifications carried out during LS3, while more details concerning the relevant changes planned during LS2 are dealt with in the following session "Long Shutdown 2 Strategy and Preparation"
        Speakers: Markus Zerlauth , Paolo Fessia
        Paper
        Slides
      • 4:20 PM
        Questions 10m
      • 4:30 PM
        HL-LHC Magnet Roadmap 20m
        We will first give an overview of the 11 T project, giving a summary of the main technical choices made at CERN and in FNAL, test results and future milestones. We then focus on the IR magnets in the HL-LHC. After a short description of the layout, and a catalogue of the numerous magnet types, we will give for each magnet family a summary of the main technical choices. We will then discuss how the magnets has been shared between collaborations, what are the main achievements until now and what are the future milestones. The critical points of the project will be reviewed, with a tentative schedule of the prototyping, production and installation phase.
        Speaker: Ezio Todesco
        Paper
        Slides
      • 4:50 PM
        Questions 10m
      • 5:00 PM
        HL-LHC RF Roadmap 20m
        In view of the HL-LHC parameters, the present and the foreseen RF systems are reviewed with the primary focus on technological aspects. This paper will describe the preparation and the test program of the SPS beam tests with crab cavities. Some aspects related to the integration of the crab cavity RF system in the LHC and the potential impact of the crab kissing scheme are addressed. The mode of operation for the 400 MHz accelerating RF system with HL-LHC beam currents and the associated issues are briefly outlined with possible improvements to the ACS system. Finally, the use of a harmonic system both at 200 MHz and 800 MHz for bunch profile manipulation and the associated technological challenges are described.
        Speaker: Rama Calaga
        Paper
        Slides
      • 5:20 PM
        Questions 10m
      • 5:30 PM
        HL-LHC alternative scenarios, parameters and lay-out 20m
        The HL-LHC parameters assume unexplored regimes for hadron colliders in various aspects of accelerator beam dynamics and technology. This paper reviews the possible alternatives that could potentially improve the HL-LHC baseline performance or lower the risks assumed by the project. The alternatives under consideration range between using flat beams at the IP, compensate the long-range beam-beam encounters with wires and adding new RF cavities with larger or lower frequencies with respect to the existing RF system.
        Speaker: Rogelio Tomas Garcia
        Paper
        Slides
      • 5:50 PM
        Questions 10m
      • 6:00 PM
        Collimation and MP Roadmap 20m
        The upgrade of the LHC collimation system represent is part of the HL-LHC baseline and represent an important element for the LHC upgrade. Depending of the performance limitations, we are preparing for a possible staged implementation starting already in the LHC long shutdown 2. In this paper, the main upgrade studies included in the HL baseline are presented. Additional studies for advanced collimation concepts are also introduced. The time line for collimation upgrade, synchronized with the LHC long shutdown planning, is discussed. Relevant machine protection aspects, including injection protection device upgrades in the LHC ring, are also discussed.
        Speaker: Stefano Redaelli
        Paper
        Slides
      • 6:20 PM
        Questions 10m
      • 6:30 PM
        Down Selection Criteria and MDs Prior to LS3 20m
        The operation of the LHC and the machine studies conducted during run I have provided important input for the validation of some of the choices that are at the base of the HL-LHC upgrade scenario but it has evidenced also some potential limitations, progress has been done in their understanding but some open points remain that need to be further studied to consolidate the operational scenario and performance (e.g. stability during the squeeze and collision process, electron cloud effects with 25 ns beams). Some of the solution proposed for the HL-LHC nominal scheme like the operation of crab cavities has not be tested in hadron machines so far and possible alternative solutions have been proposed (e.g. the implementation of long range wire compensators). The required validation studies and the possible criteria for the validation and down-selection of these options will be discussed.
        Speaker: Gianluigi Arduini
        Paper
        Slides
      • 6:50 PM
        Questions 10m
    • 7:00 PM 8:30 PM
      Aperitif 1h 30m
    • 8:30 PM 10:00 PM
      Dinner 1h 30m
    • 9:00 AM 12:40 PM
      Session 7 - Accelerators and non LHC Experiment Areas Consolidation up to LS3

      Session 7 [Chairs: Michael Benedikt, Florian Sonnemann]

      Conveners: Florian Sonnemann , Michael Benedikt
      • 9:00 AM
        Linacs 15m
        The consolidation requests for Linacs 2 and 3 will be summarised and prioritised, as well as the requests for the transfer line between Linac2 and the PSB which will be reused for Linac4 beams in the future.
        Speaker: Richard Scrivens
        Paper
        Slides
      • 9:15 AM
        Questions 5m
      • 9:20 AM
        PSB and PS Consolidation for LS2 and Beyond 30m
        The consolidation activities proposed for the PSB and PS until the end of LS2 will be revised. Particular attention is given to the activities with direct impact on machine operation and machine performances. The analysis on the interventions and priorities proposed will be done by system (e.g. injection, extraction, RF, beam instrumentation, etc..) , with the goal of verifying that the consolidation activities of a specific item is consistently taken into account by the different groups.
        Speaker: Simone Gilardoni
      • 9:50 AM
        Questions 10m
      • 10:00 AM
        SPS Consolidation for LS2 and Beyond 30m
        As a major part of the LHC injector chain and with its own dedicated physics program it is essential that the SPS remains capable of reliably providing high quality beams. This presentation will give an overview of the consolidation plans concerning the SPS and its transfer lines as provided by each of the equipment groups to the IEFC committee. The overview will be presented from a perspective of machine operation. These consolidation plans will be reviewed focusing principally on the impact on operation with beam and will endeavor to highlight any of the works which are of particular interest or represent a particular concern for operations. This presentation will not focus on LIU or other project work unless there is a direct consequence of one upon the other.
        Speaker: James Ridewood
        Paper
        Slides
      • 10:30 AM
        Questions 10m
      • 10:40 AM
        Coffee break 30m
      • 11:10 AM
        AD + LEIR 20m
        As the AD programme now faces a renewed lease of life following the start of the ELENA project, it is essential to ensure best possible reliability and performance for the next 20 years or so. The AD machine, which was started in 1999, is based on the Antiproton Collector (AC) ring of the Antiproton Accumulator Complex (AAC) which in turn was constructed in the mid-80:ies. Since most of the major AD components were retained from the AC, we now have a significant amount of 30-year old equipment to deal with. LEIR is in a similar situation having started life in the 80-ies, supplying antiproton beams at various energies for the PS physics programme. After having been transformed into a heavy ion accumulator in 2004 and subsequently used in operation, some consolidation needs have become apparent. LEIR is expected to keep delivering heavy ions to the North Area and to the LHC until 2035, and possibly light ions to a new biology research facility in the South Hall. A consolidation programme is underway for both machines and here we will discuss the main aspects of ongoing and planned activities from an operational point of view.
        Speaker: Tommy Eriksson
        Paper
        Slides
      • 11:30 AM
        Questions 10m
      • 11:40 AM
        NA + EA 20m
        The PS East Area (EA) and the SPS North Area (NA) are world-wide unique facilities of CERN that provide secondary beams to NUMEROUS different EXPERIMENTS every year, doing reserach covering fundamental particle physics, detector prototype testing for LHC, space experiments and medical applications. They represent a core activity of the laboratory and besides LHC, the purpose of the continuous operation of the injector complex to high energies. The amplitude of installations is large, in terms of km of tunnels, installed equipment, infrastructure needs, comparable to that of SPS. The relevant consolidation items identified by the groups as presented in the IEFC sessions will be summarised.
        Speaker: Adrian Fabich
        Slides
      • 12:00 PM
        Questions 10m
      • 12:10 PM
        Isolde and n_TOF Consolidation 20m
        The ISOLDE Facility resumed operation in July 2014 providing low energy radioactive ion beams (RIB) to a physics community of over 500 collaborators. While progress continues on the upgrade of the REX-ISOLDE post-accelerator within the HIE-ISOLDE project, assuring the production of RIB for an approved and demanding physics program will require extensive maintenance of the existing facility. The consolidation requests driven by operation include; the replacement of the ISOLDE target stations, more commonly known as Frontends, renovation of the Resonant Laser Ionization (RILIS) equipment and operation of the REXEBIS and REXTRAP - the low energy systems of the REX-ISOLDE post-accelerator. However, the radiation protection issues associated with the present performance of ISOLDE and the potential consequences associated with a possible increase in p-beam power should be considered. Consequently, consolidation of the overall shielding of the ISOLDE target area is presented along with the need to replace the ISOLDE beam dumps, both crucial to the exploitation of ISOLDE after the commissioning of Linac 4. The n_TOF Facility also successfully started its physics program in July 2014 making more efficient use of the neutron flux following the commissioning of EAR2, the second experimental area above the n_TOF target. However, installed in 2008 and with a projected lifetime of approximately 10 years, the present n_TOF neutron spallation target is already showing initial signs of surface corrosion. The monolithic Pb block along with its cooling system cannot be repaired due to both its design and expected dose rate after removal and will therefore have to be replaced during the LS2 period to ensure reliable physics after LS2. Further consolidation requirements include the dismantling of the first n_TOF target cooling station and the replacement of the power converter and controls of the sweeping magnet in EAR1. Finally, common to both facilities is the radioactive environment of each target area and the need to intervene within a given time window to benefit from a maximum of radioactive cooling. This implies that all preparation and construction of replacement equipment be completed before the start of the LS2 period.
        Speaker: Richard Catherall
        Paper
        Slides
      • 12:30 PM
        Questions 10m
    • 2:00 PM 5:35 PM
      Session 8 - Long Shutdown 2 Strategy and Preparation

      Session 8 [Chair: José Miguel Jiménez; Scientific secretary: Jean-Philippe Tock]

      Conveners: Jean-Philippe Tock , José Miguel Jiménez
      summary
      • 2:05 PM
        Scope of the Long Shutdown 2 (optimisation of the period 2015-2018) 10m
        Speaker: José Miguel Jiménez
        Paper
        Slides
      • 2:15 PM
        Questions 5m
      • 2:20 PM
        What has been learnt from LS1 20m
        The Long Shutdown 1, which started in February 2013, is almost finished. A huge number of activities have been performed, and the machine is now being cooled-down and power tested. As part of the preparation for Long Shutdown 2, the talk will review the process of the coordination of LS1 from the preparatory phase to the testing phase. The preparatory phase is a very important process: an accurate view of what is to be done, and what can be done is essential. But reality is always different, the differences between what was planned and what was done will be presented. Daily coordination is essential for the good progress of the works. The talk will recall the coordination and reporting processes, highlighting points of success and points to be improved in matter of general coordination, in-situ coordination, safety coordination (including safety rules), logistics…
        Speaker: Katy Foraz
        Paper
        Transparents
      • 2:40 PM
        Questions 10m
      • 2:50 PM
        Safety & Radiation Aspects 15m
        CERN’s Radiation Protection Rules and Regulations are based on European Directives and Basic Safety Standards, as well as on the national radiation protection legislations of the two Host States France and Switzerland. These reference rules and best practices continuously develop, with a tendency towards increasing restrictions whilst activities in radiation areas at CERN strongly intensify in particular during long shut-downs like the LS1. The LS1 has been a particular challenge for radiation protection due to the large amount of tasks to be accomplished, ranging from works in slightly radioactive areas such as the LHC arcs (e.g. SMACC) to major consolidation projects in controlled radiation areas such as the target areas TDC2/TCC2 or ISOLDE. At the same time, radiation protection continued to implement European radiation protection rules and best practices leading to some significant changes coinciding with the beginning of LS1. Examples are the new training scheme for radiation protection, the individual and operational dosimetry system and an enhanced system for the tracing of radioactive material (TREC). Due to a common effort, CERN succeeded in meeting its objective of keeping individual doses below 3 mSv over 12 months during LS1. Only a very few experts out of around 8500 monitored persons received slightly higher doses, but still well below the legal limit. Furthermore, there was no significant radiation protection incident. This excellent result demonstrates that CERN’s procedures and tools put into place to keep the dose to workers as low as reasonable achievable (ALARA) are effective and adapted to the needs of a High Energy Physics laboratory. Today, the ALARA principle has become an important part of CERN’s culture. Progress made and experience gained from LS1 will be an important asset for LS2. With respect to LS2, the radiological risk in the injectors and related facilities will be more or less similar to LS1. However, radiation levels in the LHC and its experiments will increase and the radiological classification of some areas will change from Supervised Radiation Area to Controlled Radiation Area. This will have consequences for the future training of radiation workers, job and dose planning and dosimetry. There will also be further developments with regard to applicable radiation protection rules, in particular with respect to the inter-site transport of radioactive material, where international transport rules apply, and with respect to exemption limits for radioactive material that will decrease by about a factor of ten for the radionuclides which are most common at CERN (e.g. 22Na, 60Co). To verify such low values for such large quantities of material within a very short delay will represent a challenge to the Radiation Protection Group. LS2 will profit from the experience gained in LS1, but adjustments will be necessary and the next years will be used to efficiently prepare radiation protection for LS2.
        Speaker: Doris Forkel-Wirth
        Paper
        Slides
      • 3:05 PM
        Questions 10m
      • 3:15 PM
        LIU Planned Activities 20m
        The baseline LIU installation activities corresponding to both ion and proton upgrades will be described for the whole injector chain. The additional possible installation activities linked to the pending options on which decision will be made during 2015 will also be reviewed. It will be examined whether any of these activities can be anticipated to earlier shutdowns or postponed beyond LS2, emphasising the consequences on beam operation and the preparation and performance reach of the LIU beams for HL-LHC. The corresponding support needed from the various CERN groups together with the required technical expertise will be estimated. Finally, a preliminary LIU installation master schedule will be presented.
        Speaker: Julie Coupard
        Paper
        Transparents
      • 3:35 PM
        Questions 10m
      • 3:45 PM
        Coffee break 30m
      • 4:15 PM
        HL-LHC Planned Activities - Accelerator 20m
        This presentation will be focused on the activities planned by HL-LHC during the period pre LS2 and during LS2 with their milestones, deliverables and key constrains. It will also give an overview of the construction and test facilities that will have to be upgraded or built to allow the construction and test of the future components of HL-LHC.
        Speaker: Isabel Bejar Alonso
        Paper
        Slides
      • 4:35 PM
        Questions 10m
      • 4:45 PM
        LHC Experiments Upgrade and Maintenance 20m
        The LHC experiments have planned significant maintenance and upgrade efforts for LS2. ALICE and LHCb will implement major upgrades with important changes to the entire apparatus, while ATLAS and CMS will perform their major detector upgrades only during LS3. However, the overall scale of the LS2 operations is quite similar for all experiments. The presentation will review the LS2 plans of the experiments and focus on aspects related to support needed from the technical sector.
        Speaker: Werner Riegler
        Paper
        Slides
      • 5:05 PM
        Questions 10m
      • 5:15 PM
        LHC @ LS2 20m
        After a second period of operation of more than 3 years, the accelerator complex will be stopped for about 18 months. The main purpose of the Long Shutdown 2 (LS2) is the LHC injectors upgrade (LIU). Nevertheless LHC will profit from this period to perform the full maintenance of all the equipment, to consolidate part of the machine and to anticipate activities, where possible, of the LHC High Luminosity (HL-LHC) project. This talk will review all the major LS2 activities (maintenance, consolidation and HL-LHC), identifying those which can be anticipated during end of year technical stops, and those which will have to be postponed to Long Shutdown3. The support needed from infrastructure services and logistics will be highlighted, as well those requiring technical expertise from the Accelerator and Technology sector. A preliminary LS2 schedule will be proposed, including the driving activities and the critical path.
        Speaker: Marzia Bernardini
        Paper
        Slides
      • 5:25 PM
        Questions 5m