LHC Beam Operation workshop - Evian 2011

12 Dec 2011, 10:00 → 14 Dec 2011, 13:00 Europe/Zurich

Royal Hotel

Mike LAMONT

 

The LHC Beam Operation workshop will be held on 12, 13 and 14 December 2011 in the Royal Hotel in EVIAN (74), France.

Attendance is by invitation only.

                                                                                                                                                                           

The principle aims of the workshop are to review 2011 LHC beam commissioning and beam operations experience, and to look forward to the operation of the LHC in 2012.

Issues addressed will cover: operation from injection to stable beams and possible improvements; analysis of availability and premature dump; problems encountered and possible improvements; and the performance of the machine protection system and other accelerator systems.

The operations plan for 2012 will be presented and discussions will address the strategies for luminosity delivery and machine development priorities.

                                                                                                                                                                            

Chairman	Mike LAMONT
Scientific Secretary	Malika MEDDAHI
Editors of the Proceedings	Brennan GODDARD, Sylvia DUBOURG
Informatics & infrastructure support	Pierre CHARRUE
Workshop Secretary	Sylvia DUBOURG

Monday, 12 December

10:15 → 10:45 Welcome Coffee

10:45 → 11:00 Opening remarks and setting the scene

Speaker: Mike Lamont

Paper Mike-introduction.pdf

Slides evian-kick-off-dec11-v2.pdf evian-kick-off-dec11-v2.pptx

11:00 → 12:50 Session 1: Review 2011

Minutes ses01min.ps

11:00 Introduction and review of the year including OP issues

Speaker: Mirko Pojer

Paper Introduction&review.pdf Introduction&review.docx

Slides Evian_MPojer.pdf Evian_MPojer.pptx

11:30 Premature dumps - analysis- number and cost, areas to target

Speaker: Markus Albert

Paper Premature_Beam_Dumps_in_2011.docx Premature_Beam_Dumps_in_2011.pdf

Slides Premature_Dumps_2011.pdf Premature_Dumps_2011.pptx

11:55 Availability and statistics - analysis, areas to target + SEUs, improvements in stats and faults collection

Speaker: Alick Macpherson

Paper Evian_Macpherson.pages Evian_Macpherson.pdf

Slides session1-Macpherson.pdf session1-Macpherson.ppt

12:20 Turnaround - analysis, Possible improvements, combined R&S, precycles, injection

Speaker: Walter Venturini Delsolaro

Paper Paper-WVD.docx Paper-WVD.pdf

Slides WVD-turnaround-2011.pptx

12:50 → 14:00 Buffet Lunch

14:00 → 15:40 Session 2 : Availability

14:00 QPS - analysis of main problems, areas to target, possible improvements

The fault statistics of the LHC Quench Protection System QPS for the LHC run 2011 will be presented and the various fault types explained. Starting with teething and EMC related problems, the tune feedback compatibility, hardware faults of the quench heater power supplies and spurious openings of electrical circuit breakers will be described in more details. Hereby as well the necessary and potential consolidation measures will be discussed. The role of the MPE standby service for the system availability will be addressed. Finally radiation induced faults and the respective mitigation and consolidation measures will be treated as separate subject.

Speaker: Reiner Denz

Abstract Session2-QPS.docx Session2-QPS.pdf

Paper evian_rd.docx evian_rd.pdf

Slides Evian_12-12-2011_rd.pdf Evian_12-12-2011_rd.pptx

14:25 Cryogenics - analysis, main problems, SEUs, beam related issues

After recalling the methodology in place, the statistics for LHC cryogenics will be presented for 2011, with analysis of the various origins and overall comparison with 2010. Beam parameters and their effects on operation will be described. Radiation induced effects will be described together with implemented or planned actions, as well as other major actions foreseen for the Xmas break. Perspectives for 2012 will be drawn, with suggestions for possible larger integration of the performance recording methodology.

Speaker: Serge CLAUDET

Abstract Session2-Cryo.docx Session2-Cryo.pdf

Slides LHCCryo_Evian11.ppt

14:50 Technical stops: what were the issues in 2011, minimizing impact and improving recovery

As any other accelerator LHC has to undertake period of stop for maintenance. Five technical stops have been performed during 2011 run and a quite long recovery time has been sometimes experienced. An analysis of the reasons is presented with particular attention to the interventions carried out during the stop. An outlook on the future is also considered to try to increase the LHC availability, diminishing the downtime. The possibility of performing maintenance only once the machine undergoes a problem instead of during planned stops is also analyzed.

Speaker: Matteo Solfaroli Camillocci

Abstract Session2-Technical_Stops.docx Session2-Technical_Stops.pdf

Paper Technical_stops_2011_MSC.docx Technical_stops_2011_MSC.pdf

Slides Technical_stops_minimizing_impact_and_improving_recovery.pdf Technical_stops_minimizing_impact_and_improving_recovery.pptx

15:15 R2E – experience and outlook for 2012

2011 very successful LHC operation has provided valuable input for the detailed analysis of radiation levels and radiation induced equipment failures. Radiation levels around LHC critical areas and the LHC tunnel were studied in detail and compared to available simulation results, as well as put in perspective to LHC operation parameters. Observed radiation induced failures were not only analyzed in detail, but already addressed through early relocation measures and patch-solution on the equipment level. Both improvements will continue during this xMasBreak together with the installation of heavy shielding around the RBs and UJs in Point-1. Based on measured radiation levels, calculations for the shielding improvements and expected operational parameters this talk provides an update on the expected radiation levels around LHC critical areas. Briefly summarizing the already performed mitigation measures and equipment patches, an estimate is provided on expected equipment failure rates during 2012 operation. Required beam and measurement studies are highlighted in order to further improve the predictions of both radiation levels and expected equipment failures, the latter driving the chosen mitigation actions for LS1.

Speaker: Giovanni Spiezia

Abstract evian_r2e_abstract.docx evian_r2e_abstract.pdf

Paper SEUOverview_Proc_Evian_12_V2.docx SEUOverview_Proc_Evian_12_V2.pdf

Slides R2E_Status_Outlook_v4.pdf R2E_Status_Outlook_v4.pptx

15:40 → 16:15 Coffee Break - Room registration starts

16:15 → 18:00 Session 3: Injection

paper Evian2011_session3.doc Evian2011_session3.pdf

16:15 Transfer lines - stability and optimization

During the LHC proton run 2011 large drifts, shot-by-shot and even bunch-by-bunch trajectory variations were observed with the consequence of high losses at injection and frequent lengthy trajectory correction campaigns. The different effects will be quantified and an estimate for downtime caused by them in 2011 will be given. The sources of the instabilities, solutions for 2012 and achievable improvements will be discussed. Possible future upgrades (TCDI button BPMs,…) will also be mentioned.

Speaker: Lene Norderhaug Drosdal

Paper Evian-proceedings-transferlinestability.zip

Slides TransferLineStability-Evian-12Dec2011.pdf TransferLineStability-Evian-12Dec2011.pptx

16:40 Injection losses and protection, de-bunching, availability, sunglasses

Injection losses are compared for 2010 and 2011 operation. Mitigation techniques which were put in place in 2010 to reduce losses at injection are described. Issues in 2011 operation, their potential improvements, the experiments' view on beam quality at injection and the performance reach for 2012 are shown.

Speaker: Wolfgang Bartmann

Paper Bartmann_injection_losses.pdf

Slides Evian11_Injlosses.pdf Evian11_Injlosses.pptx

17:05 Beam preparation in injectors & beam characteristics through the injector complex

Beam parameters such as intensity, bunch intensity distribution, longitudinal emittances, satellite population, transverse emittances and beam tails, require frequent trimming in PSB, CPS and SPS. In 2011, operators on all three machines gained a lot of experience on the preparation of high quality LHC beams. From this experience we can present procedures and scenarios for the preparation of the LHC beams, and for the filling itself. An overview of the different beam parameters, and the tools to measure and control them, will be presented.

Speaker: Karel Cornelis

Slides Beam_preparation.pdf Beam_preparation.pptx

17:35 Injection and Dump Systems

Performance and failures of the LHC injection and extraction system are presented. In particular, comparison with 2010 run, lessons learnt during operation with high intensity beams and foreseen upgrades are described. UFOs, vacuum and impedance problems related to the injection and extraction equipments are analysed together with possible improvements and solutions. New implemented features, diagnostic, acknowledgment, critical issues of XPOC and IQC application are addressed.

Speaker: Chiara Bracco

Paper CB_Evian.pdf

Slides

• Evian2011_injectionDump.pdf
• Evian2011_injectionDump.pdf
• Evian2011_injectionDump.pptx

19:30 → 21:00 Dinner

Tuesday, 13 December

08:30 → 10:10 Session 4: Operational performance

paper Summary.pdf

08:30 Aperture & optics – measurements and conclusions

In 2011, the LHC has delivered collisions with different optics configurations in the four interaction points. The performance has been pushed during the year until a final configuration with 3 IPs squeezed to 1 m was achieved. Correspondingly, the machine aperture has been measured in the different configurations, at injection and at top energy, to ensure a safe operation in all conditions of beta* and crossing angle configuration. In this paper, the 2011 commissioning experience of LHC optics is reviewed and the results of aperture measurements are presented and compared with the expectations. The measurement requirements for the 2012 operation and possible improvements are also discussed.

Speaker: Stefano Redaelli

Paper paper.pdf paper.ps

Slides SR_Aperture_2011-12-13.pdf SR_Aperture_2011-12-13.ppt

08:55 Emittance preservation in LHC: Present understanding, possible improvements/gains, required diagnostics

Emittance measurements during the LHC proton run 2011 indicated a blow-up of 20 % to 30 % from LHC injection to collisions. At the LHC design stage the total allowed emittance increase from SPS extraction to colliding beams was set to 7 %. This presentation will show the emittance preservation throughout the different parts of the LHC cycle and discuss the current limitations on emittance determination. Possible sources and cures for the observed blow-up will be presented. Possible improvements of emittance diagnostics and analysis tools together with a list of machine development tests in 2012 will also be shown.

Speaker: Verena Kain

Paper

• EmittancePreservation-WriteUp_2.docx
• EmittancePreservation-WriteUp_2.pdf
• EmittancePreservation-WriteUp_2.ps

Slides EmittancePreserv_evian.pdf EmittancePreserv_evian.ppt

09:20 Intensity ramp-up: 2011 experience - Limitations, mitigation, risks, strategy, pushing it in 2012, 1380 in 3 weeks?

The experience with ramping up the beam intensities in the early days of the 2011 run and after the subsequent technical stops will be summarized. Weak points and limitations will be identified and their possible mitigations evaluated. In view of the risks and drawbacks of a too aggressive approach, possible improvements of the applied strategy whilst maintaining the required validation points for the various equipment and machine protection system will be discussed.

Speaker: Markus Zerlauth

Paper Session_3_Ramp_Up.docx Session_3_Ramp_Up.pdf

Slides SESSION_3_Ramp_Up_1v0.pdf SESSION_3_Ramp_Up_1v0.pptx

09:45 Transverse feedback: high intensity operation, AGC, IGC, lessons for 2012

The transverse damper system (ADT) plays an important role in the preservation of the beam transverse emittance and for damping of oscillations driven by the coupled bunch instability. An overview of the ADT system will be presented with an emphasis on the important feedback loop parameters as they change from injection through the ramp into collision. The dedicated setting up procedure required for the different bunch intensities and bunch spacings will be explained. During the 2011 run the injection and abort gap cleaning became operational at injection energy. Preparations for cleaning at 3.5 TeV as well as batch selective transverse blow-up were completed and preliminarily tested. Plans for 2012 include study and potential improvement of the system impulse response to improve the 'selectivity' of the cleaning and blow up facility. The ADT also provides bunch- by-bunch observation which was extensively used during the run and MDs and will be further upgraded during the next year.

Speaker: Daniel Valuch

Paper 4.4_DV.pdf

Slides

• ADT_evian2011.pdf
• ADT_evian2011.pptx
• slides

10:10 → 10:40 Coffee Break

10:40 → 12:20 Session 5: Beam loss and machine protection

paper session5.pdf

10:40 MPS response: issues, close shaves, holes, commissioning and validation procedures, rMPP role and response, change management (incl. SW releases)

The performance of the machine protection system during the 2011 run will be briefly summarized. Emphasis will be given to events which risked to exposed parts of the machine to damage. Further improvements and mitigations of potential holes in the protection systems as well as in the change management will be evaluated along with their impact on the 2012 run. The role of rMPP during the various operational phases (commissioning, intensity ramp up, MDs…) will be discussed.

Speaker: Markus Zerlauth

Paper Session_4_MPS.docx Session_4_MPS.pdf

Slides SESSION_4_MPS_1v0.pdf SESSION_4_MPS_1v0.pptx

11:05 UFOs: statistics, dependencies, MKI findings, hypotheses, models, FLUKA results, extrapolation to 7 TeV

UFOs are potentially the performance limitation for nominal LHC operation. Therefore, in 2011, the diagnostics for UFO events were significantly improved, dedicated experiments and measurements in the LHC and in the laboratory were made and complemented by FLUKA simulations and theoretical studies. In this talk, the state of knowledge is summarized and extrapolations for LHC operation in 2012 and beyond are presented. Mitigation strategies are proposed and related tests and measured for 2012 are specified.

Speaker: Tobias Baer

Paper T._Baer_-_UFOs_Observations,_Studies_and_Extrapolations_(Evian_2011).pdf T._Baer_-_UFOs_Observations,_Studies_and_Extrapolations_(Evian_2011).ps

Slides T._Baer_-_UFOs_in_the_LHC_-_Evian_Workshop_2011.pdf T._Baer_-_UFOs_in_the_LHC_-_Evian_Workshop_2011.pptx

11:30 Multi-turn losses and cleaning: collimator set-up, loss map methodology and frequency, use of on-line data to validate

LHC beam collimation is based on a hierarchical multi-stage cleaning system. Maintaining the correct hierarchy ensures maximal cleaning efficiency and machine protection. The operational collimator positions are established from the beam centres and sizes at each collimator measured in beam-based alignments. These are verified periodically during the year. The improvements made to the collimator alignment algorithm in 2011 are described. The time spent on setup and qualification by loss maps is summarized in detail. The stability of the collimator setup and cleaning efficiency is presented. An outlook to 2012 is given, including detailed considerations on improved setup speed, required frequency of setup and qualification and other possible improvements overall reducing beam time consumption for collimation.

Speaker: Gianluca Valentino

Paper Evian2011_Multi_turn_Losses_and_Cleaning_2011_2012.pdf Evian2011_Multi-turn_Losses_Cleaning_2011_2012.ps

Slides Evian2011_20111213_Multi-Turn_Losses_Cleaning_2011_2012.pdf Evian2011_20111213_Multi-Turn_Losses_Cleaning_2011_2012.pptx

11:55 Beta* reach: in depth analysis of 2011 – orbit, tolerances, aperture, feed-in to 2012, correction below 1 m, risk from asynch dump, hw limitations

The available aperture in the LHC imposes a lower limit on the achievable beta*. The aperture must be protected by the collimation system, and the collimator families have to be ordered in a strict hierarchy for optimal performance, with large enough margins that the hierarchy is not violated by machine imperfections such as closed orbit distortions or beta-beating. The achievable beta* is thus a function of both the aperture and the collimator settings. An overview of the run in 2011 is presented, as well as a review of the necessary margins between collimator families and the aperture. Finally an outlook towards possible scenarios for beta* in 2012 and at higher energies is given.

Speaker: Roderik Bruce

Paper betaStar2012.pdf

Slides 2011.12.13--Evian_betaStar--full--v3.pdf 2011.12.13--Evian_betaStar--full--v3.pptx

12:20 → 14:00 Buffet lunch

14:00 → 15:15 Session 6 : Systems operational performance

paper Evian-summary-S6-v3.pdf

14:00 Orbit and tune feedbacks/diagnostics – user perspective, performance, issues (ADT,QT trips)

Speaker: Laurette Ponce

Abstract Laurette.docx Laurette.pdf

Paper LP_6_01.pdf

Slides QFBAndOFBPerfomances.pdf QFBAndOFBPerfomances.ppt

14:25 Beam instrumentation - critical overview, beam size measurements – what happened to bunch by bunch, BPM (briefly)

Speaker: Mariusz Gracjan Sapinski

Abstract Mariusz.docx Mariusz.pdf

Paper Evian_BI_2011.pdf final2_tex.tar.gz

Slides

• Evian2011_BI.pdf
• Evian2011_BI.pptx
• Evian2011_BI.pptx

14:50 RF - matching, blow-up etc. system performance, intensity limits for 2012, de-bunching

Speaker: Philippe Baudrenghien

Abstract RF-Abstract.pdf

Paper Evian11v2.docx Evian11v2.pdf

Slides EvianShortv2Uploaded.pdf EvianShortv2Uploaded.pptx

15:15 → 15:45 Coffee Break

15:45 → 17:50 Session 7: Limitations

paper SESSION_7_summaryEvian.docx SESSION_7_summaryEvian.pdf

15:45 Impedance effects on beam stability

What was expected? What did we learn and what are the limitations from impedance? Effect of tight collimation settings, 25 ns vs 50 ns and 4 vs 3.5 TeV

Speaker: Nicolas Mounet

Paper Evian_2011_NMounet.pdf Evian_2011_NMounet.ps

Slides impedance_Evian_13122011.pdf

16:10 Beam induced heating

What were the expected heat loads? Review of the observations on temperature increases / outgassing for kickers, collimators, etc. Anything around the corner? Next limitations? What is the expected effect of bunch length (with the measured bunch spectrum)? Can we explain the observed heat loads by impedance effects? Mitigation measures 25 ns vs 50 ns and 4 vs 3.5 TeV

Speaker: Benoit Salvant

Paper beam_induced_heatingv5.docx beam_induced_heatingv5.pdf

Slides Draft_Evian5.pdf Draft_Evian5.pptx

16:35 E-cloud effects

What were the expected heat loads/stability limits? What did we learn and what are the limitations from e-cloud in terms of beam stability, heat load? Comparison with measurements: heat load vs. RF stable phase shift, SEY and reflectivity from heat load and pressure rise data. Effect of scrubbing run and requirements on SEY to operate the machine with 25 and 50 ns at 3.5 and at 4 TeV

Speaker: Giovanni Rumolo

Paper Evian-GR.pdf

Slides Evian-GR4pdf.pdf Evian-Rumolo.pptx

17:00 e-cloud & vacuum instabilities

Vacuum and cryogenics observations: 25 ns vs 50 ns. Can e-cloud explain everything? Effects observed at TDI, experiments, triplets, impact on background, Estimations for a scrubbing run for 25 ns operation, Shall we have a scrubbing period at 25 ns to operate at 50 ns? Shall we have a scrubbing fill after every technical stop? Interplay with cryogenics and potential solution or mitigation measures

Speaker: Giuseppe Bregliozzi

Paper EVIAN_Proceeding_Bregliozzi.pdf

Slides EVIAN_Bregliozzi.pdf EVIAN_Bregliozzi.pptx

17:25 Luminosity lifetime - protons

What did we learn and do we have a good model? What were the predictions (in particular LR)? Is beam-beam the only responsible for blow-up and luminosity lifetime? What did we learn and what are the limitations from beam-beam? Impact of separation (luminosity leveling), working point, crossing angle, 25 vs. 50 ns

Speaker: Giulia Papotti

Paper Evian2011v1.pdf Evian2011v1.ps

Slides giulia20111213evian.pdf

17:50 → 18:05 Short Break

18:05 → 19:45 Talks from the experiments

18:05 TOTEM

Speaker: Simone Giani (CERN)

Slides Evian_TOTEM.pdf Evian_TOTEM.pptx

18:25 LHCb

Speaker: Pierluigi Campana (Laboratori Nazionali di Frascati (LNF))

Slides Evian_LHCb.pdf

18:45 ALICE

Speaker: Paolo Giubellino (Universita e INFN (IT))

Slides Evian_ALICE.pdf Evian_ALICE.pptx

19:05 ATLAS

Speaker: Dr Fabiola Gianotti (CERN)

Slides Evian_ATLAS.pdf Evian_ATLAS.pptx

19:25 CMS

Speaker: Guido Emilio Tonelli (CERN)

Slides Evian_CMS.pdf Evian_CMS.ppt

20:00 → 22:00 Cocktails and Dinner

Wednesday, 14 December

09:00 → 10:40 Session 8: 2012

Minutes

• Session2012DiscussionSummary.docx
• Session2012DiscussionSummary.pdf
• Session2012DiscussionSummary.ps

09:00 View from experiments including special physics run

Speaker: Benedetto Gorini

Abstract EvianAbstract2.rtf

Slides Evian.pdf Evian.pptx

09:25 Outlook for 2012

The approved 2012 schedule is shown. The possible options for the key parameters (energy, bunch spacing, beta*) to be used in 2012 are discussed. A limited number of scenarios are considered and estimates of their potential performance presented.

Speaker: Mike Lamont

Paper MIke-LHC2012.pdf

Slides evian-2012.pdf evian-2012.pptx

09:50 Implications of higher energy - summary of benefits, issues, commissioning cost, (SEUs? Cryo, QPS margins? Potential availability issues?)

Speaker: Reyes Alemany Fernandez

Abstract Session8-Implications_of_higher_energy.docx Session8-Implications_of_higher_energy.pdf

Paper Running-4TeV.pdf

Slides Running_in_2012_@_4_TeV_V4.pdf Running_in_2012_@_4_TeV_V4.pptx

10:15 First thoughts on MD priorities for 2012

Speaker: Frank Zimmermann

Abstract Session8-First_Thoughts_on_MD_Priorities.pdf

Slides

• Evian2011_MD-Priorities_FZ_RA_GP_v2.pdf
• Evian2011_MD-Priorities_FZ_RA_GP_v3.doc
• Evian2011_MD-Priorities_FZ_RA_GP_v3.pdf
• MD_Priorities_2012.pdf
• MD_Priorities_2012.pptx

10:40 → 11:00 Coffee break

11:00 → 11:40 Session 9: Summary of Sessions

11:00 Summary of Session 1

Speaker: Jorg Wenninger

Slides Summary-S1.v1.pdf Summary-S1.v1.pptx

11:05 Summary of Session 2

Speaker: Jan Uythoven

Minutes Evian_Summ_Sess2_Availability.docx Evian_Summ_Sess2_Availability.pdf

Slides Evian_ses2_summary_v2.pdf Evian_ses2_summary_v2.pptx

11:10 Summary of Session 3

Speaker: Malika Meddahi

Slides Session_3.pdf Session_3.pptx

11:15 Summary of Session 4

Speaker: Bernhard Holzer

Slides Evian_2011_Summary.pdf Evian_2011_Summary.ppt

11:20 Summary of Session 5

Speaker: Brennan Goddard

Slides Session_5.pdf Session_5.pptx

11:25 Summary of Session 6

Speaker: Eva Barbara Holzer

Slides session6_summary_v2.pdf session6_summary_v2.ppt

11:30 Summary of Session 7

Speaker: Gianluigi Arduini

Slides Evian_session7_summary.pdf Evian_session7_summary.pptx

11:40 → 12:10 Wrap-up