C.Bracco,W.Bartmann,A.Boccardi,C.Boucly,E.Carlier,B.Goddard,W.Hö9le,V.Kain,N.Magnin,M.Meddahi,V.Mertens,J.Uythoven,D.Valuch,W.WeteringsAcknowledgments:BI,BLM,CO,RF,Collimation,OPteams.

12/08/2010

Outlines  LBDSperformanceafteroneyearofoperation:

  Failuresandoccurrencewithrespecttorequirementsexpectations  TCDQHW/SWissuesandupgradesolutions  Quali9icationtestsformachineprotection

  Whichtests,how,whenandtimeneeded  XPOC:

  Foreseenupgrades  EiCsignoff

  AbortGapCleaningandBSRA:  Operationalstatus  Interlocklogic

  OutlineandDiscussion  XPOCfunctionalities  Possibleimprovements

12/08/2010

OperationalAssumptionsandFaultsOccurrence  Oneyearofoperationwith4009illsof10hourseachfollowedby2hourswithout

beam  Powerconverterfailureswithinthedifferentsystemsareexpectedtocause2.5false

dumpsperyear(mainsourceofunavailability)  FalsealarmsgeneratedbyBETSarenotincluded

  Falsedumpsperyear:2x(3.4±1.8)  NumberofdumpswithamissingMKDmodulesperyear:1  Numberofasynchronousbeamdumpperyear:1  Numberoftotaldumpsystemfailures(unacceptable):1every1000000years

12/08/2010

System Unsafety/year Falsedump/yearSynchronousAsynchronous

MKD 1.4×10‐7 1.9 0.7MSD 0.4×10‐7 0.1 ‐‐MKB 6.5×10‐10 0.7 ‐‐LBDS 1.8×10­7 2.7 0.7

FaultsOccurredDuring2010run  1energytrackingerrorat3.5TeVduetoinstabilitiesof35kVpower

suppliesbeamdump(30/03/2010:mediaday)

  Asynchronousbeamdump,duringenergyscanwithoutbeam(duetosparkontheoutsideofthegateturn‐offGTOthyristor):

  1at5TeV  2at7TeV

  4internaltriggersduetovacuuminterlocksontheMKBforB2  FALSEvacuumpressurereading–logicnowchangedtouseonlyVACsignal

  1Asynchronousbeamdumpwithbeam

  2beamdumpsinducedbyTCDQfaults

12/08/2010

Safemarginfor3.5TeVoperation,isolatorsimplementedduringtechnicalstops(startinginJanuary20119inishedduring2012TS)

THEAsynchronousBeamDump  FailureofasinglepowerdriverinoneTriggerFan‐Outunit(TFO)LBDS

self‐triggeringoftwogeneratorsforBeam1:MKDCandDIPOCfaultandXPOCfault

  Subsequentretriggeringofremaining13generatorsworkedperfectly

  Component(MAX4429EPAsinglepowerdriver)wasnotexpectedtofail  Brokenchipstillinthetunnel(diagnosisandrepairduringChristmasstop)

-2.50

-2.00

-1.50

-1.00

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2014‐11‐1921:36:00.000

2014‐11‐2000:00:00.000

2014‐11‐2002:24:00.000

2014‐11‐2004:48:00.000

2014‐11‐2007:12:00.000

2014‐11‐2009:36:00.000

2014‐11‐2012:00:00.000

2014‐11‐2014:24:00.000

2014‐11‐2016:48:00.000

2014‐11‐2019:12:00.000

2014‐11‐2021:36:00.000

2014‐11‐2100:00:00.000R

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J.Uythoven

THEAsynchronousBeamDump  FailureofasinglepowerdriverinoneTriggerFan‐Outunit(TFO)LBDS

self‐triggeringoftwogeneratorsforBeam1:MKDCandDIPOCfaultandXPOCfault

  Subsequentretriggeringofremaining13generatorsworkedperfectly

  Component(MAX4429EPAsinglepowerdriver)wasnotexpectedtofail  Brokenchipstillinthetunnel(diagnosisandrepairduringChristmasstop)

-2.50

-2.00

-1.50

-1.00

-0.50

0.00

0.50

2014‐11‐1921:36:00.000

2014‐11‐2000:00:00.000

2014‐11‐2002:24:00.000

2014‐11‐2004:48:00.000

2014‐11‐2007:12:00.000

2014‐11‐2009:36:00.000

2014‐11‐2012:00:00.000

2014‐11‐2014:24:00.000

2014‐11‐2016:48:00.000

2014‐11‐2019:12:00.000

2014‐11‐2021:36:00.000

2014‐11‐2100:00:00.000R

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J.Uythoven

Originallogic:•  2outof4triggersignalsmissingin1generatorincaseoffailure(missing)of1drivercircuit

•  1singlegeneratorpulsedincaseoffaultytriggerpulseatdriveroutput

Actuallogic(toreduceriskofmissinggeneratortrigger):•  1outof4triggersignalmissingin2generatorincaseoffailure(missing)of1drivercircuit

•  2generatorspulsedincaseoffaultytriggerpulseatdriveroutput

LBDSTriggerSynchronizationandDistribution

Fault‐tolerantFail‐safe Re‐triggerlines

A

B

A

B

Generator1

…Generator15

TFOA

TFOB

TriggerFan‐out

PTU

PTU

PTU

PTU

PowerTriggerUnit

RTB

RTB

RTB

RTB

Re‐triggerBox

RTBDelay>1LHCRevoluMon(89µs)

TSUA

TSUB

ClientInterfaces

Frev

TriggerSynchronisaMon

Unit

E.Carlier

EffectonBeamSweeping“Design”kickerpre‐firefailurescenario

NominalTCDQsetting

Realfailure

‐ Lowerloadonelementswithaperture<7σ‐ HigherloadontheTCDQrobustnessproblem(seelater)‐ Willchangetriggerlogicbacktooriginal.Beingdiscussed...(needsrecon9igurationplusextensivetests)

12/08/2010

B.Goddard

TCDQInducedBeamDumps  09/09/2010:B1TCDQstayedarmedbymistakeafterparasiticcollimator

teststimingeventsentTCDQandthresholdsto3.5TeVsetting(<4σ at450GeV)beamthenwasinjectedanddumpedduetolossesinpoint6.  SWupgradeinprogressnowinTS  Statemachine....

  23/09/2010:beam1dumpedduetoaglitchinpositionreadings(resolverreadinjectionvalues)atendoframp(outofthresholds).

12/08/2010

TCDQHWandSWissues  TCDQ:

  SomeSWbugsbeingresolved  DCmotors±0.05mmresolution,notobviousifimprovablewithsteppingmotors.Reproducibilitybetterthan±0.02mm  Long‐termupgrade:possibilitybeingaddressedbetweenABTandSTI

  Positioning(MDC)/interlock(PRS)onsameCPUpotentialcommonmodefailure(alsoRadHardissueshavetobetakenintoaccount)  Couldsolveifuseidenticallow‐leveltocollimators  Decisionstilltobetakenontypeofsensors:LVDTorpotentiometers?

  TCDQpositionvsbeamenergyjustSWinterlocking:addHWinterlock?  HWinterlockBPMsinP6currentlymuchlooser(±3.6mm)…

  Robustness:  Nominally32bunchesshouldimpactontheTCDQduringanasynchronousbeamdump(originaltriggeringlogic)

  TCDQwillbedamagedbyimpactof28nominalintensitybunches(25nsspacing)at7TeV(Scalingtootherenergies/emittances/energiesdif9icult!)

  Toberesolvedin2012shutdownbyHWupgrade(designinprogress)

12/08/2010

MachineProtectionValidationTestsManytestsstillneededfor2011

  Fullseriesofsystemtestswithbeamtobeperformedaftereachshutdown  14/15MKD,basicaperture,poweroff,energytracking,RFinterlock,FMCMs,sweep

waveform,synchronisation,...  Maybe10shifts–detailedplanningstilltomake!

  Asynchronousdumptests  Debunchandtriggerdump(alloperationalcon9iguration)tomeasureleakagetoTCTsand

otherelements–for2011mayneedextrachecksforlowerβ*‐discussioninRBtalk  Onedumppercon9iguration,plusmaybespecialtestsforTCT‐TCDQmargin–10ramps?

  IR6interlockBPMtests  Testprocedurealreadyrevised–shouldstreamlineintensityincreasessomewhat  Lessimpactthan2010(wasabout1‐2hourspernew9illingpattern/intensitystep)

12/08/2010

XPOC

12/08/2010

  Upgradesfornextyear:  MonitoringlossesatTCTinalltheIPs

  BLMgroupedinfamilies  1MASTERelement(example:TCDQ)  LossesofallBLMbelongingtoafamilywillbecomparedtolossesattheMASTERelement(example:TCTwrtTCDQ)

  MonitoringTCDQposition

  MonitoringOrbitpositionatTCDQ(uptonoworbitstabilitywasbetterthan1σ ≈0.8mmat3.5TeV,fornominaloperationat7TeVitshouldbebetterthan0.3σ ≈0.2mm)

XPOCSignoff  XPOCsignoff:“LBDSexpert”RBACroleand“EiCMachineProtection”RBAC

role

  EiCgottheconsigntoacknowledgeaFAULTYXPOConlywheninducedbylossesabovethresholdsduetounbunchedbeam(BLMatTCDS,TCDQ,MSDA,TCSG,MSDCandMQY.4R6)ormissingdatareadings(ex.BCT)

  EiChavetocalltheexpertforXPOCsignoffwhen:  FAULTYXPOCwasinducedbyMKDandMKBfailures  Unusualfaultofanysystem

  DoweneeddifferentRBACrolesfor“EiCMachineProtection”and“LBDSexpert”?

12/08/2010

AbortGapCleaning  Operationalat450GeV  Stillcommissioningat3.5TeV:9irsttests

  RFvoltageloweredfrom8MVto7MV:  1/3ofthegapwasusedforthecleaning.  Thekickamplitudewasabout34timesweakerthanat450GeV.  Cleaningwasobservedbutparametersstillneedtobeoptimized.

12/08/2010

450GeV,AbortGapCleaningOFF 450GeV,AbortGapCleaningON

A.Boccardi

AbortGapCleaningStatus  Operationforprotons

  AbortgapcleaningfullyoperationalatinjectionenergyAGCalwaysON

  At3.5TeV,theabortgapcleaninghasstilltobe9inelytunedandtested

  Notpossibletousethetunefeedbacksystematthesametimeastheabortgapcleaning

  AGCswitchedonbythesequencerwhentunefeedbackoffAGCalwaysON

  WhenexperiencegainedwithabortgapmonitorSISinterlock

  Notyetoperationalforions:  Nosynchrotronlightseenatinjectionbutonlyfrom650‐700GeV(underinvestigation)  Whensolved,willhavesameoperationalconsiderationsasfortheprotons.

12/08/2010

DelphineJacquet

AbortGapCleaningInterlock  Limitofparticlesintheabortgap:107p+/mat7TeVand109p+/mat

450GeV(seeWBtalkfordiscussionaboutthesenumbers)

  Interlocklogic:  Experienceandcommissioning:“alarm”whenabortgappopulationabovea

warningthresholdabortgapcleaningONbeamdumpifabortgappopulationabovedumpthreshold

  Goal:beamdumpwhenabortgappopulationabovethresholds

  ConnectionofBSRAtoSISinterlocksystemtomonitorabortgappopulationand,eventually,triggerabeamdump:notyetoperational(noredundancy)  Beamdumpwouldbetriggeredifabortgappopulationabovedumpthreshold  NotguaranteedthatBSRAreadsthecorrectvalue:nobeamdumpwhenneeded

12/08/2010

ConclusionsandDiscussions  LBDSfailuresoccurrenceinagreementandnotworsethanrequirementsand

expectations  Nodamageorquenchduringsynchronousandasynchronousbeamdumps  Leakagetodownstreamelementswithinspeci9ications  TCDQneedsTLC–long‐termplanstode9ine

  LogicforMKDtriggeringincaseofspontaneouskickerpre‐9iringtochange  Pre‐triggerof2generatorsismuchworseforTCDQ

  Machineprotectionvalidationtests,proceduresandtestsfrequency:  Isthisadequate?(toooften,toorarely)  Couldtestsbeimproved?  Dotheyreallyinsuremachinesafety?

  XPOCfunctionalitiesandupgrade:  Missingchecks?  DifferentRBACroleneededforXPOCsignofffromEiC?

  Abortgapcleaning  AlwaysONat450GeV  Whenoperationalat3.5TeVONthroughthesequencer  SolutiontoconnecttheBSRAtoSISinterlocksystem:howtoimplementredundancy?

12/08/2010

Thankyouforyourattention!

BackupSlides

LHCBeamDump(LBDS)SystemLBDSsystemconsistsof(perbeam):

  15MKDextractionkickers  8MKBdilutionkickers  15MSDseptummagnets  1Absorbingblock:TDE  ProtectionelementsTCDS,TCSG,TCDQandTCDQM

  Reliabilityofthesystem:  Continuousmonitoringofsystemelementsandkickergenerators+Fullredundancy

  N2Over‐pressureofTDEcore(damaginglossofcontainmentofTDE)  Automatic“Post‐mortem”ofeverydumpevent(IPOCandXPOC)  RedundantsynchronizationbetweenRFandkickers  Beamenergytracking  InterlockonbeamorbitandTCDQposition

  IfaparameteroutofinterlocktolerancesBeamDumptriggered

12/08/2010

FailureScenarios

  Acceptablefaults:  Onemissingextractionkicker(14/15MKD)correctextractionbutpossiblequenchofQ4ifthishappenssimultaneouslywithanotherfault

  Asynchronousdump  Spontaneoustriggeringofone/twoMKDkickersre‐triggeroftheremainingmoduleswithin1.2µs(450GeV),0.7µs(7TeV)

  LossofsynchronizationbetweenRFcavitiesandkickers  MissingMKB:onlyonehorizontalandoneverticalMKBneedtobeoperationallongercooldownperiodofTDEor,intheworstcase,damage

  Selftriggeringofthesystemincaseofdetectionofaninternalfaultsynchronousbeamdump(FALSE)

12/08/2010

MachineProtectionValidationTestsTeststobeperformedaftereachshutdown(pilotbeamat450GeV)

  14/15MKD:openbumpthatsimulatesthekickobtainedwith14MKDcleanextractionandcorrectbeampositionattheBTVDDscreen

  Aperturemeasurementswithextractedbeam:openbumpwithincreasingamplitudeuntillossesarerecordednounforeseenbottlenecks

  Aperturemeasurementswithcirculatingbeam:closedbumpwithincreasingamplitudeuntillossesarerecordednounforeseenbottlenecks

  LBDSkickerstoSTANDBYwithcirculatingbeamdumpcorrectlyforB1andB2  RFfrequencyinterlocktriggeredatcorrectleveldumpcorrectlyforB1andB2  RFfrequencystoptriggerssynchronousdumpfromTSUPLLdumpcorrectlyfor

B1andB2.  MSDFMCMtriggeredcorrectlyforMSDOFFdumpcorrectlyforB1andB2.

12/08/2010

MachineProtectionValidationTests  Asynchronousbeamdump:

  How:  SwitchoffRFfor~90sbeamdebunchingandpopulatingtheabortgap  LocalBumpawayfromTCDQjaw(closetoorbitinterlocklimit:now1.2σ)  TriggerbeamdumpwithCCCemergencyswitch

  When:anychangeinbeamintensity,optics(β*,crossingandseparation),9illingpattern,energy…..

  What:leakagefromTCDQtodownstreamelements(i.e.TCTsinpoint5forB2:<10‐3).

12/08/2010

MachineProtectionValidationTests  P6BPMtest1:

  How:  CheckthatBPMreadingsarewithinde9inedpositionthresholds  Changethresholdof1BPMinpoint6(YASP,providedexpertRBACrole)

  When:foranynew9illingpattern  What:beamdumpedwhenBPMoutsidethresholds

12/08/2010

Checkdependsonthenumberofturnsandbunches(1:lowintensity,2:highintensity)

MachineProtectionValidationTests  P6BPMtest1:

  How:  CheckthatBPMreadingsarewithinde9inedpositionthresholds  Changethresholdof1BPMinpoint6(YASP,providedexpertRBACrole)

  When:foranynew9illingpattern  What:beamdumpedwhenBPMoutsidethresholds

  P6BPMtest2:  How:

  CheckthatBPMreadingsarewithinde9inedpositionthresholds  Checkreadingofnumberofbunches

  When:foranychangeinintensity(numberofbunches)  What:correctreadings

12/08/2010

XPOC  Fullyredundantanalysisoftheextractionanddilutionkickerwaveforms

(MKDandMKB)withindividualreferencesandtightertolerancelimits.  Itanalysisalsomeasurementsfrombeaminstrumentation.

  BLMinpoint6andtransferline:limitsscalewithenergyandintensity  VacuumpressureintheextractionchanneldowntoTDE(N2pressure)  Beampositionintheextractionchannel(BPMD)  Beamimageofthescreenjustinfrontofthedumpblock(BTVDD)  Thebeamintensityinthedumpchannel(BCT)  Beampopulationintheabortgap(BSRA)

12/08/2010

Masked:noFalseXPOCbutusedasauxiliaryelementsforfaultsanalysis

AbortGapCleaningTestat450GeV  Abortgap“protection”

  BeaminabortgappossiblequenchorTCT/LHCdamageifTCDQpositioniswrong

  Principleofcleaning:kickoutresonantlythebeamintheabortgapwiththetransversedampersystem

  Testat450GeV:twonominalbunchesinjected,bunch#1and#1201,simulatingabortgapof3µmlength  Thecleaningoftheabortgaptookplaceoverabout1.5µsandisnicelyobservedontheAbortGap

monitor(right9igure)  Noevidenceofvariationoftheinitialemittanceincreaserate(~linearandsimilartowhatnormally

seenbynominalbunchessittingatinjection)

12/08/2010

AbortGapCleaningOFF AbortGapCleaningON

AbortGapCleaningTestat3.5TeV  Experimentat3.5TeVby

  RFvoltageloweredfrom8MVto7MV:  The3µsgapbetweenbuckets#13281and#14481wasmonitored  Unbunchedbeamproductionisnotsymmetric  Particlesneededabout50sforcrossingtheabortgap.  1/3ofthegapwasusedforthecleaning.  Thekickamplitudewasabout34timesweakerthanat450GeV.  Cleaningwasobservedbutparametersstillneedtobeoptimized.

12/08/2010