LHC Sector TestMike Lamont

LHC sector test - MAC June 07

OutlineOverviewMotivationPre-requisites/preparationTests with beamOrganisationConclusions

LHC sector test - MAC June 07

OverviewTI8 injection L8 LHCb - arc 7-8 IR72 weeks with beamClose sectors 8-1, 7-8 and 6-7Beam Pilot Beam for the most part: single bunch of 5 - 10 x 109 protons Total intensity: 3 x 1013 protons - comparable with one nominal intensity LHC extraction from the SPS

LHC sector test - MAC June 07

Injection

LHC sector test - MAC June 07

Triplets & LHCbAiming for minimal losses in LHCb

LHC sector test - MAC June 07

Sector 7-8X 23

LHC sector test - MAC June 07

IR7 layout Intercept the beam with the three TCPs and with the TCSGs Invert the polarity of D3 Switch OFF all the quadrupolesStefano RaedelliRalph Assmann

LHC sector test - MAC June 07

Intercepting the beam with the TCPs

LHC sector test - MAC June 07

IR7Three TCPs closed smartly, D3 in opposite polarity, quadrupoles offAll beam particles interact with >1m of C (typical=1.8m; max=3m)Additional protection from the next secondary collimators

EM showers are expected to be absorbed by MBW and MQW yokes (no issues for magnet). Detailed estimates should confirm that.

Minimum impact on the machine: - D3 polarity change (cable). - Lock collimators in position - Local activation - simulations to be performed.

LHC sector test - MAC June 07

Motivation

LHC sector test - MAC June 07

IntegrationFull test of a majority of subsystems over more than one eighth of the ring

Allows staged approach to the full problem space

Time to fully resolve problems before the real thingAnalysis, improvements, resolution, adjustment

The lessons learnt will reduce the time needed for full commissioningBuys breathing space if there are any serious problems

LHC sector test - MAC June 07

Integration & commission with beam:Full-blown system wide integration test

LHC sector test - MAC June 07

Beam the ultimate diagnostic

Polarity of magnetic elementsAperture in the cold machineResponse of key beam instrumentationMagnet field quality

"What like a bullet can undeceive?" Herman Melville

LHC sector test - MAC June 07

MilestoneMachine ProtectionControls++Magnets (model etc.)Beam InstrumentationBT: Kickers, Septa, TDICollimationRadiation ProtectionAccessOperationsHardware Commissioning

LHC sector test - MAC June 07

Required circuits

LHC sector test - MAC June 07

IR8Plus dipole correctors

LHC sector test - MAC June 07

DS left IP8Plus dipole correctors Item: Two lips, indifferent red Item: Two grey eyes with lids to them Item: One neck, one chin, and so forth.

LHC sector test - MAC June 07

Arc 7-8

CircuitsNumber of circuitsPriorityMain bendsMBRB.A7811Main quadsMQRQF, RQD21Skew quadsMQSRQS [B2]11Trim quadsMQTRQTF,RQTD [B2]21Orbit correctorsMCBRCB [B2]23 H & 24 V1Lattice sextupolesMSRSF,RSD [B2]42Lattice octupolesMOROD, ROF [B2]13Skew sextupolesMSSRSS [B2]13b3 spoolMCSRCS [B2]13b4 spoolMCORCO [B2]13b5 spoolMCDRCD [B2]13

LHC sector test - MAC June 07

DS/LSS - right of 7Q7,Q8,Q10,Q11: one MQTL alongside the MQ quadrupole

Q9: two MQTLsPlus dipole correctors

LHC sector test - MAC June 07

Required circuitsTo get beam through sector 78, the main circuits listed above are required to be commissioned to 450 GeV.

For limited recycling, it would be preferable for listed circuits to be available to, say, the equivalent 1 TeV level.

Beam 2 Circuits only Circuits commissioned to 450 GeV+ only

LHC sector test - MAC June 07

Other systemsInjection elements: septa, kickersCollimatorsMachine ProtectionBeam Instrumentation: BPMs, BLMs, BTV, BCT, BSTMagnet Model:Transfer functions, harmonicsControlsSoftware/toolsAccess systemRadiation ProtectionRadiation MonitoringOptics, aperture modelSector Test is another progressive milestone to be used for testing key functionalityWork in progress but most of this is in good shape.Effort in these areas is essentially orthogonal to HWC.

LHC sector test - MAC June 07

AccessSector 6-7.Interlocked gate right of IP 6Point 7 (PM76)Access system operational.Point 8 (PM85) Access point fully operational. PZ85Interlocked door in shielding wallSector 1-8: Interlocked gate left of IP 1Final Configuration

LHC sector test - MAC June 07

Radiation ProtectionAll major installation will have finished and access to the zones affected after the test will be limited. Dose maps for collimators in IR7 to be carefully evaluated.Given analysis, and measurements during and after the test, it is envisaged that:Certain areas might be declared controlled areas for the first few days after the test;Thereafter these areas would join the rest of the sectors involved as supervised areasLHCb remains an undesignated area

Traceability restrictions come into force Need for additional RP instrumentation to be evaluated.

Work in progress. NB amount of beam is minimal.

LHC sector test - MAC June 07

Beam

LHC sector test - MAC June 07

1. Commission injection regionSteer into ring, onto TDICheck instrumentation, septa, kickers, apertureJan Uythoven

LHC sector test - MAC June 07

2. Thread to IR7Commission trajectory acquisition and correctionThread beam

Jorg Wenninger

LHC sector test - MAC June 07

3. Linear optics measurementsTrajectory response using correctors and BPMsBPM + corrector polarity and calibration errorsPhase, couplingDispersion measurement with dp and BPMsBetatron matching measurement with BTVs

LHC sector test - MAC June 07

4. BLM system testsGet the system up and running, recording lossesPrior calibration with source: expect reasonable numbersAcquisition & display of beam lossesSome crosstalk studies possible (in principle beam 1 monitors available)Bernd Dehning

LHC sector test - MAC June 07

5. Aperture measurementFirst iteration : oscillation from 2 correctors at 90 to probe all phasesSecond iteration if needed/time : p bumps (local anomalies, specific regions)

Brennan Goddard

LHC sector test - MAC June 07

6. Momentum ApertureTransmission vs momentum offset by changing SPS RF frequencyRe-scale TI 8 to new momentum

dp/p = 0.004 (1mm en)

LHC sector test - MAC June 07

7. Field quality checksKick-response and trajectory analysis LOCO might be able to get a handle on average a2, b2 and b3 field errors of MBs, b2 of MQs Possibly extend method to check multipole corrector polarities (possibly via strong excitation))

Jorg Wenninger

LHC sector test - MAC June 07

8. Effects of magnetic cycle Machine reproducibility and persistent current effects at injection for reduced pre-cycle

LHC sector test - MAC June 07

Quenches with beam motivation:- safe and efficient operation- avoid quenches and damageControlled, well defined tests to establish:Absolute quench limitsBLM threshold values Model and understanding of correlation of loss pattern, quench level, BLM signalsTest important for efficient commissioning of BLM system with circulating beam9. Quench limits and BLM response

LHC sector test - MAC June 07

Other possibilities10. Energy offset versus time on flat bottom11. Transfer line collimation studies12. Injection projection studies13. Separation and crossing angle bumpsInjecting onto vertical separation bumpBump closure, induced dispersion, aperture14. Commission multi-bunch injection

LHC sector test - MAC June 07

Beam tests - summary

LHC sector test - MAC June 07

Sheet1

PriorityDurationIntensity# shotsComments

hp+p+

1End TI8, Injection Steering, commission BDI, timing1245E+095002.5E+12TDI in, protecting LHCb

2Trajectory acquisition commissioning, trajectory correction, threading, energy matching1245E+095002.5E+12To IR7 collimators

3Linear Optics from kick/trajectory, coupling, BPM polarity checks, corrector polarity checks1121E+104004.0E+12

4Check BLM system165E+091005.0E+11First to TDI

5Aperture limits, acceptance1185E+0910005.0E+12Pi bumps, BLMs, BCT

6Momentum aperture165E+091005.0E+11Move energy of SPS beam

7Field errors (high statistics)2122E+102004.0E+12Collect data, off-line analysis

8Determination of quench level - calibrate BLMs1362E+11204.0E+12Start with pilot and work slowly up

9Effects of magnetic cycle, variations during decay, reproducibility1245E+093001.5E+1210 cycles

10Energy offset versus time on FB2123E+101003.0E+12Cycle & repeat

11Transfer line collimation studies - TCDI265E+098004.0E+12TDI in - mainly on to TCDI

12Injection protection studies - TDI265E+098004.0E+12On to TDIand IR7 dump

13IR bumps, aperture, separation, crossing angle bumps365E+091005.0E+11Careful in LHCb

TOTAL19249202.6E+13On to TCP

DAYS86.5E+12On to TDI

4.0E+12On to TCDI

Sheet2

Sheet3

Near test schedule

LHC sector test - MAC June 07

Schedule

LHC sector test - MAC June 07

Impact 1/2Given the state of installation, the sector test should have minimal impact on transport, interconnection work etc.Deliberately chosen solution in IR7 which avoids additional interventions

Restricted access to sectors 8-1, 7-8, 6-7 during beam tests ~ 14 days7-8 and injection region part of 8-1 become supervised areas after test (film badge etc.)

Work/Commissioning can clearly continue in other sectors during the test

LHC sector test - MAC June 07

Impact 2/2Sector test makes clear demands on:what is needed to be coldon what is needed to be hardware commissionedand to what level

Cryogenics, QPS, HWC support required during test

Could take time out of HWC programHWC would have to stop in 7-8 during test

Test preparation, other than cold mass, largely orthogonal to HWC

LHC sector test - MAC June 07

DetailsTeam in place which is examining implications, requirements and details of planned beam testsChamonix 2006http://cern.ch/lhc-injection-test/

LHC sector test - MAC June 07

ConclusionsA sector test is surely a very useful exerciseUndoubtedly speed full commissioningIt could prove to be a vital exerciseIf any major problems are uncoveredRequirements have clearly stated and are being addressedPlanned beam tests have been detailed

The potential impact would be minimal. Machine as is or as will be. Work carries on elsewhere.However, for the test to take place this year (if the schedule allows) Hardware Commissioning would have to be tailored to provide necessary circuits to the necessary level.

LHC sector test - MAC June 07

AcknowledgementsMagnetsLuca BotturaBeam InstrumentationRhodri Jones, Lars Jensen, Stephen JacksonInjectionBrennan Goddard, Jan UythovenRadiation ProtectionDoris Forkel-Wirth, Helmut VinckeINB Ghislain RoyAccessPierre NininLHCbRolf LinderHWCRoberto Saban & teamInstallation Katy ForazPlanningEsther Barbero SotoVacuumPaul Cruikshank, Miguel JimenezControlsRobin Lauckner ++OP/APRoger Bailey, Verena Kain, Massimo Giovannozzi, Stephane Fartoukh, Helmut Burkhardt, Alex Koshick, Stefano Raedelli, Ralph Assmann, Frank Zimmerman and the rest of the commissioning team.

LHC sector test - MAC June 07