1. R.Bailey, March 2008 Beam plans for Accelerator Systems R.Bailey, F.Zimmermann eLTC Summary March 2008

2. R.Bailey, March 2008 Overall commissioning strategy for protons (est d. 2005) Hardware commissioning Machine checkout Beam commissioning 43 bunch operation 75ns ops 25ns ops I Install Phase II and MKB 25ns ops II Stage A BC No beamBeam D A.Pilot physics run First collisions First collisions 43 bunches, no crossing angle, no squeeze, moderate intensities 43 bunches, no crossing angle, no squeeze, moderate intensities Push performance Push performance Performance limit 10 32 cm -2 s -1 (event pileup) Performance limit 10 32 cm -2 s -1 (event pileup) B.75ns operation Establish multi-bunch operation, moderate intensities Establish multi-bunch operation, moderate intensities Relaxed machine parameters (squeeze and crossing angle) Relaxed machine parameters (squeeze and crossing angle) Push squeeze and crossing angle Push squeeze and crossing angle Performance limit 10 33 cm -2 s -1 (event pileup) Performance limit 10 33 cm -2 s -1 (event pileup) C.25ns operation I Nominal crossing angle Nominal crossing angle Push squeeze Push squeeze Increase intensity to 50% nominal Increase intensity to 50% nominal Performance limit 2 10 33 cm -2 s -1 Performance limit 2 10 33 cm -2 s -1 D.25ns operation II Push towards nominal performance Push towards nominal performance

3. R.Bailey, March 2008 Stage A: Commissioning procedures (LHCCWG) Web based with EDMS approval http://lhccwg.web.cern.ch/lhccwg/overview_index.htm http://lhccwg.web.cern.ch/lhccwg/overview_index.htm

4. R.Bailey, March 2008 Stage A: Commissioning Phases Phase A.1First turnInjection commissioning and threading A.2Circulating pilotEstablish circulating beam, closed orbit, tunes, RF capture A.3450 GeV initial commissioningSystem commissioning (instrumentation, beam dump) A.4450 GeV opticsBeta beating, dispersion, coupling, non-linear field quality, aperture A.5450 GeV, increasing intensityPrepare the LHC for unsafe beam A.6450 GeV, two beam operationHandle 2 beams together A.7450 GeV, collisionsIf requested by experiments A.8Snap-back and rampSingle beam, 2 beams A.9Top energy checksSingle beam, 2 beams A.10Top energyCollisions A.11SqueezeCommissioning the Betatron squeeze in all IP’s A.12Experimental magnetsBeam commissioning with experimental magnets

5. R.Bailey, March 2008 Stage A: Phase 3 – Initial system commissioning Phase A.1 A.2 A.3 A.4 A.5 A.6 A.7 A.8 A.9 A.10 A.11 A.12 PhaseStepActivityWho (OP +) A.3 A3.1Final RF commissioning with Pilot IntensityRF A3.2BCTFR and BPM checks with Pilot IntensityBI A3.3First Commissioning of Beam Dumping System (pilot)BT BI ATB A3.4Commission systems with higher intensity (3 x 10 10 )BT BI RF A3.5Establish cycling machine (3 x 10 10 )OP A3.6Lifetime optimisation (3 x 10 10 )OP A3.7Further commissioning of beam instrumentation (3 x 10 10 )BI A3.8Basic optics checks in addition to LOCO Results (3 x 10 10 )AP BI RF A3.9Further commissioning of beam dumping system (3 x 10 10 )BT BI ATB A3.10Commission feedback systems (3 x 10 10 )RF BI A3.11Rough Setting up of the TDI (3 x 10 10 )BT ATB PhaseWill be working withMax beamWho (OP +) A.3 RF systems Beam dump with pilot TDI BCT Tune meter and PLL Wire scanners Synchrotron light Rest Gas Ionisation monitor Multi turn acquisition Feedback systems 3 10 10 RF ATB BI BT

6. R.Bailey, March 2008 Stage A: The view from the experts Phase A.1 A.2 A.3 A.4 A.5 A.6 A.7 A.8 A.9 A.10 A.11 A.12 BT RF Etc BI Etc

7. R.Bailey, March 2008 Session 4 – Beam plans for accelerator systems Taking the Beam Commissioning Procedures as a basis, each presentation should elaborate the details of how the accelerator system in question is commissioned with beam through the various phases of the established plan. Taking the Beam Commissioning Procedures as a basis, each presentation should elaborate the details of how the accelerator system in question is commissioned with beam through the various phases of the established plan. Each presentation should cover Each presentation should cover what needs to be done at the various stages of commissioning what needs to be done at the various stages of commissioning how it will be done how it will be done who will do it who will do it how long it is expected to take how long it is expected to take As a minimum, each presentation should cover commissioning up to the performance levels attainable in phase A. A look forward into later stages is left to the discretion of the speaker As a minimum, each presentation should cover commissioning up to the performance levels attainable in phase A. A look forward into later stages is left to the discretion of the speaker

8. R.Bailey, March 2008 Session 4 – Beam plans for accelerator systems Accelerator systemSpeakerTime Beam Commissioning ProceduresR.Bailey20+10 Injection and associated protection devicesV.Kain30+10 Power converters (tracking between sectors)F.Bordry20+10 coffee RF acceleration systemsP.Baudrenghien30+10 Beam dump and associated protection devicesB.Goddard20+10 2h+1h lunch BI systemsR.Jones30+10 RADMONT.Wijnands20+10 Transverse damperW.Hofle20+10 coffee CollimatorsR.Assmann30+10 Machine protectionJ.Uythoven20+10 2h+1h

9. R.Bailey, March 2008 Power converters’ bible

10. R.Bailey, March 2008 Power converters Tracking between the 8 main dipole converters Tracking between the 8 main dipole converters 20ppm accuracy after calibration gives 0.7mmOK 20ppm accuracy after calibration gives 0.7mmOK Tracking between the dipole and quadrupole converters Tracking between the dipole and quadrupole converters 20ppm accuracy gives tune change 0.03OK 20ppm accuracy gives tune change 0.03OK Tracking between the quadrupole converters Tracking between the quadrupole converters 20ppm accuracy gives very small  beatingOK 20ppm accuracy gives very small  beatingOK Above reachable after calibration (automatic procedure) Above reachable after calibration (automatic procedure) Sector 45 tests show very good performance (no triplet) Sector 45 tests show very good performance (no triplet) LHC Power Converters performance will be measured and improved mainly without dedicated beam time Periodic calibration will be required PC experts should be very close to beam operation, for issues like Offsets between sectors Tracking measurement and correction Ramp

11. R.Bailey, March 2008 Injection and associated protection devices TDI MKI +90˚ TCDD TCLIB TCLIA Kicker MKI LEFT OF IP2 (H plane) RIGHT OF IP2 (H plane) TCLIM Septum MSI TCDI

12. R.Bailey, March 2008 Injection and associated protection devices Phase A1 (First turn) Phase A1 (First turn) First to TDI First to TDI Then beyond and into threading Then beyond and into threading Phase A2 and A3 (Circulating pilot++) Phase A2 and A3 (Circulating pilot++) Injection oscillations Injection oscillations Re-steer injection Re-steer injection Phase A4 (450GeV optics) Phase A4 (450GeV optics) Stability (1000 shots inject and dump) Stability (1000 shots inject and dump) Aperture in injection region Aperture in injection region MKI waveform MKI waveform Injection matching Injection matching Phase A5 (Increase intensity) Phase A5 (Increase intensity) Multi bunch injection and Protection devices Multi bunch injection and Protection devices 1-2 shifts/beam

13. 13 A function sets the RF frequency on the injection plateau and through the ramp Injection frequency, injection phase and stable phase will be adjusted by observing these two signals The VCXO generates the RF sent to the Cavity Controllers This synthesizer replaces the frequency program during physics Low level RF

14. R.Bailey, March 2008 RF acceleration systems Phase A1 (First turn) Phase A1 (First turn) RF OFF RF OFF Label buckets (Numerology and cogging) Label buckets (Numerology and cogging) Signal tuning Signal tuning Phase A2 (Circulating pilot++) Phase A2 (Circulating pilot++) RF ON RF ON Adjust RF frequency Adjust RF frequency Commission phase loop and synchro loop Commission phase loop and synchro loop Capture and check phasing of cavities with beam Capture and check phasing of cavities with beam Adjust positions of bunches for collisions in IRs Adjust positions of bunches for collisions in IRs Phases A3 onwards Phases A3 onwards As and when needed by commissioning program As and when needed by commissioning program Commission radial loop for the ramp Commission radial loop for the ramp Commission multi bunch injections Commission multi bunch injections Commission multi batch injections Commission multi batch injections Ramping Ramping Rephasing on the flat top Rephasing on the flat top 1 shift 8 shifts

15. R.Bailey, March 2008 Beam dump and associated protection devices

16. R.Bailey, March 2008 Beam dump and associated protection devices Phase A3 (Circulating pilot++) Phase A3 (Circulating pilot++) First controlled extractions First controlled extractions Phase A4 (450GeV optics) Phase A4 (450GeV optics) IR6 aperture and TCDQ IR6 aperture and TCDQ Phase A5 (Increase intensity) Phase A5 (Increase intensity) Abort gap cleaning Abort gap cleaning Extraction trajectories Extraction trajectories Phase A8 (Ramp) Phase A8 (Ramp) Energy tracking Energy tracking Phase A9 (Top energy) Phase A9 (Top energy) IR6 aperture and TCDQ IR6 aperture and TCDQ Abort gap cleaning Abort gap cleaning Phase A11 (Squeeze) Phase A11 (Squeeze) Different optics Different optics TCDQ TCDQ 3-4 shifts 1-2 shifts 6-10 shifts 1-3 shifts 4-6 shifts 1 shift

17. R.Bailey, March 2008 Beam Instrumentation Phase A1 (First turn) Phase A1 (First turn) Screens, BPM in asynchronous mode, fast BCT, BLM Screens, BPM in asynchronous mode, fast BCT, BLM Check polarity errors while threading (stage the repairs) Check polarity errors while threading (stage the repairs) Phase A3 (Circulating pilot++) Phase A3 (Circulating pilot++) BPM in synchronous mode and systematic calibration (BPM, COD) BPM in synchronous mode and systematic calibration (BPM, COD) DC BCT & lifetime DC BCT & lifetime Tune meter with beam excitation Tune meter with beam excitation Via transverse damper easiest Via transverse damper easiest Via MKQ Via MKQ Head tail monitor for Chromaticity Head tail monitor for Chromaticity Wire scanner, SL (needs undulator), BGI (needs gas injection) Wire scanner, SL (needs undulator), BGI (needs gas injection) Abort gap monitor (needs undulator) Abort gap monitor (needs undulator) Phase A8 (Ramp) Phase A8 (Ramp) Continuous orbit, tune, coupling and chromaticity (+ feedbacks) Continuous orbit, tune, coupling and chromaticity (+ feedbacks) Continuous emittance monitoring (SL from D3 above 2TeV) Continuous emittance monitoring (SL from D3 above 2TeV) Phase A10 (Collisions) Phase A10 (Collisions) Luminosity (BRANA (ionisation) in 1&5, BRANB (CdTe in 2&8) Luminosity (BRANA (ionisation) in 1&5, BRANB (CdTe in 2&8) Schottky Schottky

18. R.Bailey, March 2008 Beam Instrumentation issues Chicken and Egg situation Chicken and Egg situation Good measurements needed to get good beam Good measurements needed to get good beam Good beam needed to get good measurements Good beam needed to get good measurements BTV images in LSS3 and LSS4 BTV images in LSS3 and LSS4 Single shot OK but not turn by turn Single shot OK but not turn by turn Need fast cameras Need fast cameras Not for 2008 (resource issues) Not for 2008 (resource issues) BPM in Intensity mode BPM in Intensity mode Requires intensity for precision better than 50% Requires intensity for precision better than 50% Complicated software mapping (B1 position ↔ B2 intensity) Complicated software mapping (B1 position ↔ B2 intensity) Have auto trigger anyway Have auto trigger anyway Fast BCT on single bunch Fast BCT on single bunch BGI BGI Needs gas injection for low intensities Needs gas injection for low intensities Considered risky by AT/VAC Considered risky by AT/VAC BRAN BRAN Ionisation monitors arrive just in time at best Ionisation monitors arrive just in time at best Hence iterative. Heavily interleaved with the commissioning program Time estimates difficult

19. R.Bailey, March 2008 Radiation monitoring systems Several systems, various groups, different objectives Several systems, various groups, different objectives RAMSES RAMSES BLM BLM RADMON RADMON BCM/BSC BCM/BSC Collaborative approach proposed to observations at key stages Collaborative approach proposed to observations at key stages Increase in beam intensity Increase in beam intensity Increase in energy Increase in energy Change of optics Change of optics Collisions Collisions Distinguish between Distinguish between Simulations, shielding and monitoring Simulations, shielding and monitoring Radiation damage effects Radiation damage effects Need to define a system commissioning team for these systems No dedicated beam time requested. In the shadow of other activities

20. R.Bailey, March 2008 Transverse damper Pick-up 1 Kicker Signal processing  beam  signal Pick-up 2  gain g Need real-time digital signal processing Match delays: t signal = t beam + MT 0 T0 : beam revolution time M=1: very common -> “One -Turn-Delay” feedback But M>1 also possible phase and delay adjustments feedback: curing transverse coupled bunch instabilities excitation: of transverse oscillations for beam measurements & other applications damping: of transverse injection oscillations

21. R.Bailey, March 2008 Transverse damper Damper essential to avoid increase of transverse emittance already in phase A (1-156 bunches) shot-to-shot reproducibility with single bunch, kicker ripple effect with 43 to 156 bunches Between now and first beam a lot of hardware commissioning, delay adjustments, calibrations in order to minimize time needed to get damper operational with beam Damper commissioning can start from phase A1 with observations Dedicated time required from phase A3 onwards (after RF capture) to set-up the system Injection damping available from phase A4 onwards Commissioning of abort gap cleaning from phase A5-A6 onwards Commissioning damper during ramp in A8 to prepare for higher intensity of phase B 1-2 shifts/beam MD: few ramps

22. R.Bailey, March 2008 Collimators Not needed until Phase A5 (Increase intensity) Not needed until Phase A5 (Increase intensity) Strategy proposed Strategy proposed Beam based setup to start Beam based setup to start Observable is beam loss signals Observable is beam loss signals Establish reference positions thereafter (reproducibility as issue) Establish reference positions thereafter (reproducibility as issue) Need orbit feedback to be working Need orbit feedback to be working Need to this for Need to this for 450GeV (phase A5) 450GeV (phase A5) Ramp (phases A8 A9) Ramp (phases A8 A9) Squeeze (phase A11) Squeeze (phase A11) 1. Start from end of ramp settings 2. Squeeze to 6m 3. Measure and correct tail population 4. Adjust dump protection TCDQ 5. Set collimators for next step (5m, 4m, 3.5m, 2.5m, 2m, …) 6. Squeeze to next step (5m, 4m, 3.5m, 2.5m, 2m, …) 7. Repeat steps 3 to 6 (target for this phase 2m) 4 shifts/beam

23. R.Bailey, March 2008 Machine protection system Beam Interlock System Beam Dumping System Injection Interlock Powering Interlocks sc magnets Powering Interlocks nc magnets QPS (several 1000) Power Converters ~1500 AUG UPS Power Converters Magnets Magnet Current Monitor Cryo OK RF System Movable Detectors LHC Experiments Beam Loss Monitors BCM Experimental Magnets Collimation System Collimator Positions Environmental parameters Transverse Feedback Beam Aperture Kickers Beam Lifetime FBCM Screens / Mirrors BTV Access System DoorsEIS Vacuum System Vacuum valves Access Safety Blocks RF Stoppers Beam loss monitors BLM Special BLMs Monitors aperture limits (some 100) Monitors in arcs (several 1000) Timing System (Post Mortem Trigger) Operator Buttons CCC Safe LHC Parameter Software Interlocks LHC Devices Sequencer LHC Devices LHC Devices Safe Beam Parameter Distribution Safe Beam Flag Little beam dependence Core Systems Protection elements

24. R.Bailey, March 2008 Machine protection system Commissioning of individual systems treated elsewhere Commissioning of individual systems treated elsewhere Documented by Machine Protection System Commissioning WG Documented by Machine Protection System Commissioning WG Now need to manage the overall system Now need to manage the overall system In all circumstances the state of the MPS should be known In all circumstances the state of the MPS should be known Inventory of ‘hardware’ which is not standard Inventory of ‘hardware’ which is not standard Settings Settings Interlock Levels Interlock Levels Masking Masking Disabling Disabling In all circumstances the operational limits and conditions of the machine should be clear In all circumstances the operational limits and conditions of the machine should be clear For the standard conditions For the standard conditions If one is allowed to only run under special conditions If one is allowed to only run under special conditions A body is needed to advise the EIC when significant changes to MPS systems and their settings need to be made to continue or optimise operation A body is needed to advise the EIC when significant changes to MPS systems and their settings need to be made to continue or optimise operation Tool(s) required for keeping track of MPS conditions Tool(s) required for keeping track of allowed machine conditions LHC Protection Panel

25. R.Bailey, March 2008 Selected points from the discussions experiments: initial pile-up ~ 2 events/Xing; turning on experimental solenoids & dipoles; injection inhibits from experiment experiments: initial pile-up ~ 2 events/Xing; turning on experimental solenoids & dipoles; injection inhibits from experiment injection: optics study prior to aperture checks; TCDI/TLCIs retracted during commissioning; stability studies – dump can fire every 20 s injection: optics study prior to aperture checks; TCDI/TLCIs retracted during commissioning; stability studies – dump can fire every 20 s power converters: excellent performance, but two systematic spikes on the ramp caused by high precision ADCs ; important time saving from “recatching” the magnet current after failure; inner triplet = still terra incognita; tools for ramping 8 sectors in parallel & dipole- quadrupole synchronism; ; commissioning of energy meter power converters: excellent performance, but two systematic spikes on the ramp caused by high precision ADCs ; important time saving from “recatching” the magnet current after failure; inner triplet = still terra incognita; tools for ramping 8 sectors in parallel & dipole- quadrupole synchronism; ; commissioning of energy meter RF: effect of RF phase noise on the beam; path length difference between the two beams; phase drifts between CCC and IR4; alternative techniques to correct injection phase errors RF: effect of RF phase noise on the beam; path length difference between the two beams; phase drifts between CCC and IR4; alternative techniques to correct injection phase errors radiation levels: 1 week CNGS ~ 1 year LHC; move out of UJ with sensitive electronics; week-21 calibration experiment on TED for point 2 and point 8; sensitivity to single-event failures 100 times worse than assumed previously; new AB-AT-TS working group radiation levels: 1 week CNGS ~ 1 year LHC; move out of UJ with sensitive electronics; week-21 calibration experiment on TED for point 2 and point 8; sensitivity to single-event failures 100 times worse than assumed previously; new AB-AT-TS working group

26. R.Bailey, March 2008 Selected Selected points from the discussions instrumentation: BPM polarity checks possible only with beam; BPM intensity mode has huge error (50% variation) for single bunch – so it may not be useful; two monitors of beam size in store (wire scanner & SLM); multi-turn acquisitions on the ramp for optics validation; BLMs and common BPMs are only instruments sensitive to both beams; matching monitor available only for 1 beam 1 plane study only in 2008 - no fallback solution; resolution of screens in the dump line instrumentation: BPM polarity checks possible only with beam; BPM intensity mode has huge error (50% variation) for single bunch – so it may not be useful; two monitors of beam size in store (wire scanner & SLM); multi-turn acquisitions on the ramp for optics validation; BLMs and common BPMs are only instruments sensitive to both beams; matching monitor available only for 1 beam 1 plane study only in 2008 - no fallback solution; resolution of screens in the dump line damper: abort gap cleaning before ramp; injection kicker ripple damper: abort gap cleaning before ramp; injection kicker ripple collimation: periodic verification of protection hierarchy; relative cross calibration; monitoring of beta beating; test of cleaning efficiency with transverse blow up? ; how to go through the squeeze without making circles with quenches and beam loss? collimation: periodic verification of protection hierarchy; relative cross calibration; monitoring of beta beating; test of cleaning efficiency with transverse blow up? ; how to go through the squeeze without making circles with quenches and beam loss? machine protection: “LHC Protection Panel” will make decisions; interlock on optics? concept of “safe” beam; damage level uncertainty machine protection: “LHC Protection Panel” will make decisions; interlock on optics? concept of “safe” beam; damage level uncertainty

27. R.Bailey, March 2008 Concluding remarks Now need to cross check information given with the existing chronological procedures Now need to cross check information given with the existing chronological procedures Time estimates shown are for system commissioning needs by the relevant specialists and have been given in many cases in some detail Time estimates shown are for system commissioning needs by the relevant specialists and have been given in many cases in some detail Overall time estimates need to include other activities (ramp, measurement and correction of machine parameters, machine protection) Overall time estimates need to include other activities (ramp, measurement and correction of machine parameters, machine protection) Parallelism of certain activities to be explored, either by working in parallel on one beam or by working with 2 beams quasi-independently Parallelism of certain activities to be explored, either by working in parallel on one beam or by working with 2 beams quasi-independently Several discussion points also to be followed up Several discussion points also to be followed up 75 shifts