Slide 1

New HV test specification for the LHC N. Catalan for the EI sectionThe current specification

EDMS 90327 from 2004 (LHC-PM-ES-0001 rev. 2.0)

Refers to equipment tests from manufacturing to installation in LHCOperation conditions define the lower voltageApply decreasing voltages through manufacturing Only single circuits vs. ground are considered

The voltage to ground for each circuitTwo different sources of voltage during operationEnergy extraction at maximum current U=RIQuench voltage from simulationsEither/or for all circuits but for dipolesSafety factor 1.2 appliedExcept for dipole circuit Missing RCO

2xV+500Imax x REE1.2xVFrom ElQA EDMS 788197 (2008)

Insulation tests during TP4-e tests Different classification from EDMS 90327Different tests for air cooled leadseach circuit tested at a lower voltage one by one versus all other circuits and ground.all circuits of one chimney are tested together at higher voltage level vs ground.

RQ vs SpoolsM1/M2 lines and M lines run along togetherGeneral protection will run down all of them at the same time

Line N circuitsBus-bar run together along the same cryogenic lineMetallic braids already gave insulation problemsMQT, MQTL, MQS, MSCB with energy extractionMO, MQM with no EEMonday Morning Meeting : 3rd of May 2010

A. Perin AT-ACR, 8Spool busbar routing inside DFBAs

Busbars in lines M1 & M2Busbars merged with line NAll 600 A busbars in the same duct

CorrectorsSpool

Bundles of n x 4 busbars

New voltage to ground valuesWhich electrical circuits have bus-bars running in the same cryo-line?Only circuits whose voltage is coming from EE should be taken into account.Nested circuitsMaximum operation voltage x1.2

Maximum operational voltage against any neighboring circuitTested circuit vs. all others + groundVoltage level proposal

HV tests with new voltages need to be implemented prior to cool-down in 2011/2012RCO/RCB Lemo connector insulation weaknessWill be inspected in the next technical stopRepair during the Xmas break?Tests of the two bus-bars of RQ?Implemented during the assembly in the long shutdown in 2012Is it possible to interrupt the circuit?

Practical considerations Magnet instrumentation checkLocal measurement at warm and coldContinuity and resistance of diagnostic VtapsResistance and insulation of QHQH against coil & groundElQA test procedure needs to be updatedCan be done at the same time as HV qualification for the magnetMIC tests introduced during 2009Quench heaters vs. groundNot specified in the noteMinimum 2x450+500 = 1400 for most circuitsVoltage on the coil during quench added to this valueNot taken into account in US magnets during manufacturingNeeds to be reviewed

Where is it coming from?Tests in SM18 at cold Reception tests in b181(at warm) for US magnetsMinimum voltage retainedQH/coil vs. ground values?MIC proposed HV values

ElQA test procedure 788197 to be rewritten and reissuedHigher values to be applied almost in all correctors RQ(M) and RQ circuitsMIC test to be addedHardware modifications in DFB chimneys to remove limitations to be implementedDuring Xmas stopDuring long shutdown

ConclusionsMachine will be emptied Three days cooling tower cleaning will stop active cooling on DFBsAll DFBs SAM and SC links will warm up above 120KAccording to A. Perin that will mean a full thermal cycleWhat parts of ElQA need to be redone?Xmas break ElQA testsFrom ElQA test procedure

ElQA Only TP4e tests HV in the arcOne week per sector for a team of 2-3 peopleEnough resources in house with the eventual help of other sectionsTwo sectors in parallel.To be fitted in the scheduleFull TP4e and MIC in the SMA magnets

scenarioa) Cool downPhaseAtFlushingAtCool downCryogenicwarmwarm300 K to 1.9 (4.5) KconditionsTP4-ADOC-WTP4-BTP4-CTP4-DTP4-EDOC-Cb) Technical stop of cool down and warm upPhaseAtFlushingAtCool down80 KWarm upAtwarmwarm300 K to 80 K80 K to 300 KWarmTP4-ADOC-WTP4-BTP4-CTP4-DTP4-EDOC-Cc) Sub sector floating reaching 80 K and cooled down againPhaseWarm up80 KCool downCryogenic1.9 (4.5) K to 80 K80 K to 1.9 (4.5) KconditionsTP4-ADOC-WTP4-BTP4-CTP4-DTP4-EDOC-Cd) Individual qualification of circuit during powering testsPhaseCryogenicconditionsTP4-ADOC-WTP4-BTP4-CTP4-DTP4-EDOC-C

summary tableCircuits powered via the DFBLocal dipole orbit correctorTP4-ATP4-BTP4-CTP4-DTP4-EDOC-WDOC-CAtAfterDuringAtAtAtAtwarmflushingcool-down80 KcoldwarmcoldORCHVQTFMICCDPC

Spec valuesCIRCUIT typeMaximum Discharge voltage to ground [V]Maximum expected voltage to ground at quench [V]Min. Design withstand voltage at working cryogenic conditions [V]Test voltage to ground [V]Test voltage to ground [V]for system warmfor system cold (1.2*Umax)To groundTo heatersMain Dipoles4881300310027006201900 *(MB)Main Quadrupoles (MQ)1002009001700180240Spoolpieces4404001300NA260480(MCS, MCD)Arc correctors (MSCB,MO)4405001500NA300600Trim Quads44030011001500220360(MQT, MQTL, MQS)Closed Orbit correctors (MCBH/V)05001500NA300600Disp. Matching CODs (MCBCH/V, MCBY)05001500NA300600Matching MQM040013001500260480(1.9K)Matching MQM040013001500260480(4.5K)Matching MQY01007001500140120LowBeta Quads035012001400240420(KEK)LowBeta Quads035012001400240420(FNL)Separator magnets0500 **15001500300600Inner Triplet Dipole Correctors05001500NA300600

Annex BCIRCUIT typeTP4-BTP4-DTP4-ETestVoltageTestTestVoltageTestTestVoltageTestvoltagerampdurationvoltagerampdurationvoltagerampdurationrateraterate[V][V/s][s][V][V/s][s][V][V/s][s]Main Dipoles (MB)6002300600230019002300Main Quadrupoles (MQ)120530012053002405300Spoolpieces240103002401030048010300(MCS, MCD)Arc correctors (MSCB,MO)300101803001018060010180Trim Quads180101801801018036010180(MQT, MQTL, MQS)Matching MQM240101802401018048010180(1.9K)Matching MQM240101802401018048010180(4.5K)Matching MQY6010180601018012010180LowBeta Quads210530021053004205300Separator magnets300101803001018060010180CIRCUIT typeDOC-WDOC-CTestVoltageTestTestVoltageTestvoltagerampdurationvoltagerampdurationraterate[V][V/s][s][V][V/s][s]Closed Orbit correctors (MCBH/V)30050606005060Disp. Matching CODs (MCBCH/V, MCBY)30050606005060Inner Triplet Dipole Correctors30050606005060