IPAC’18 – May 2018 - Vancouver

Catia MilardionbehalfoftheDAFNETeam

AREVIEWOFDAFNEPERFORMANCESDURINGTHEKLOE-2RUN

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

TheDAFNETeam

C.Milardi,D.Alesini,S.Bini,O.R.Blanco-Garcia,M.Boscolo,B.Buonomo,S.Cantarella,S.Caschera,A. De Santis,G.DelleMonache,C.DiGiulio,G.DiPirro,A.Drago,A.D’Uffizzi,L.Foggetta,A.Gallo,R.Gargana,A. Ghigo,S.Guiducci,,C.Ligi,M.Maestri,A.Michelotti, L.Pellegrino,R.Ricci,U.Rotundo,A.Stecchi,A.Stella,M.Zobov.

LNF-INFN,Frascati,Italy

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

Outline

• DAFNEoverview

• KLOE-2operations

• Beamphysicsstudies

• DAFNEtimeline

• Conclusions

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

BTF

X-ray 900 - 3000 eV

IR 1.24 meV - 1.24 eV

UV 2 - 10 eV

TheDAFNEAcceleratorComplex

LNFarealsopartoftheEuropeansynchrotronlightInfrastructures

e+ e-

C ≈ 97 mECM = 1.02 GeV (F)

Frascati NationalLaboratories(LNF)

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

DAFNEnative

DAFNE Crab-Waist

Energy (MeV) 510 510qcross/2 (mrad) 12.5 25ex (mm•mrad) 0.34 0.28

bx* (cm) 160 23sx* (mm) 0.70 0.25FPiwinski 0.6 1.5by* (cm) 1.80 0.85

sy* (µm) low current 5.4 3.1

Coupling, % 0.5 0.5

Bunch spacing (ns) 2.7 2.7

Ibunch (mA) 13 13sz (mm) 25 15

Nh 120 120

DAFNELayoutandParameters

FINUDA (DEAR)

KLOE

“Proposal for a F-factory”, LNF-90/031 (IR),1990.

CollidingBeamshave:lowEhighcurrentsshortbunchspacing2.7nseclongdampingtime

native

DAFNE Crab-Waist

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

P. Raimondi , 2° SuperB Workshop, March 2006,P.Raimondi, D.Shatilov, M.Zobov, physics/0702033,C. Milardi et al., Int.J.Mod.Phys.A24, 2009.

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

KLOE-2IR

10m

C. Milardi et al 2012 JINST 7 T03002.

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

DAFNEActivityProgramforKLOE-2

PreliminaryTestPhase fall2010÷ Dec2012

ColliderConsolidationKLOE-2detectorlayersinstalled Dec2012÷ Jun2013

KLOE-2datataking

IRun Nov16th 2014÷ Jul3rd 2015goal1fb-1

IIRun Spt28th 2015÷ Jun29th 2016goal1.5fb-1

IIIRunSpt12nd 2016÷ Aug1st 2017goal2fb-1

IVRunSpt6th 2017÷Mar31st 2018goal1.5fb-1

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

IRun

IIRun

IIIRun

IVRun

KLOE-2RunOverview

! " #$%&'$($#�

*+,≈ 68043456

! " 789:&($#�

*+,≈ 54893456

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

MonthbyMonthLuminosityTrend

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

BestOperationsMonth

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

HighestHourlyIntegratedLuminosity

∫1h L~0.67pb-1

Nb =107

∫1day L~16pb-1

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

∫ Ldel ~14.3pb-1∫ Lacq ~11.9pb-1Uptime~98%

HighestDailyIntegratedLuminosity

• 106bunches• I-MAX=1.45÷ 1.6A• I+MAX =0.99÷ 1.16A• Sustainablebackground

29/Jan/2018 ÷ 4/Feb/2018

∫ Ldel ~ 86.6 pb-1

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

Crab-WaistLuminosityGainCrab-Waistprovidesa59%increaseintermsofpeakluminosityasevidenceded bydatatakenbythesamedetectorwiththesameaccuracy

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

10BunchesCollisionsAiming at minimizing the impact of multi-bunches effects and e-cloud instabilities on Luminosity

• Lpeak~3•1032 cm-2 s-1 mightbeachievedbycolliding100bunches

• Beam-beamisnotalimitingfactor• Crab-WaistSextupoleswork

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

Crab-WaistLuminosityGain

120*Amp2 /Nbunch

lum

inos

ity/1

e28

24/11/14 KLOE-228/01/18 KLOE-2

16/09/2005 Kloe best06/08/2002 Kloe best

5000

10000

15000

20000

25000

0 0.5 1 1.5 2 2.5

Lum

inos

ity [1

028

cm-2

s-1 ]

Crab-Waist collision scheme:y ~ 1.5 b*y = 8.5 [mm]KLOE-2 24/Nov/2014KLOE-2 28/Jan/2018

ORIGINAL COLLISION SCHEME:KLOE 2005 y ~ 0.6 b*y = 18. [mm]KLOE 2002 y ~ 0.3 b*y = 25. [mm]

!"!#$%&'()*+,$-.*,%/0 23

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

DAFNE CW upgradeSIDDHARTA (2009)

DAFNEKLOE (2005)

DAFNE (CW)KLOE-2 (2014)

Lpeak [cm-2s-1] 4.53•1032 1.50•1032 2.38•1032

I- [A] 1.52 1.4 1.18I+ [A] 1.0 1.2 0.87Nbunches 105 111 106∫dayL [pb-1] 14.98 9.8 (seldom) 14.3

Lpeak exceedsbya59%thebestluminosityeverachieved,atDAFNE,duringoperationsforanexperimentalapparatusincludinghighfielddetectorsolenoid.

PeakLuminosity

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

BackgroundControl

Thenewdetectorlayersinstalledaroundthebeampipeposednewtightrequirementsonbackgroundlevelandcontrol.

Criteriaforacceptablebackgroundbecame:• countingrateonthedetectorendcaps• currentamplitudemeasuredbythedifferent

driftchambersectors• dischargethresholdontheinnermostITlayer

BackgroundontheITwasheavilydependentontheinjectionprocesswhichhadtobeaccuratelyoptimizedandstabilized(THPAK020)Evensmalldriftsintheenergyoftheincomingbeam,0.01 ÷ 0.02 %, werecausingunaffordablebackgroundlevel.

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

Numerical simulations aiming atimproving:

dynamical aperturespecific luminosity

led to define a new working pointfor the e- ring

Qx=0.135 Qy=0.17

e- RingWorkingPointScan

FMAQx=0.088Qy=0.152

FMAQx=0.130Qy=0.170

M. Zobov et al., IEEE Trans. Nucl. Sci., Vol. 63, no. 2, pp. 818-822,2016.

achieving:larger DA 2 – 3 sImproved injection efficiencyhigher beam lifetimereduced background ~ 20%higher luminosity ~ 7%

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

ImpactoftheNewe- RingConfiguration• old WP• new WP

KLOE-2normalizedtriggerlevelvs.instantaneousluminosity

normalizedbackgroundvs.instantaneousluminosity

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

ElectronBeamDynamics

DuringtheKLOE-2runthemaximume- currentsstoredatregimeincollisionhasbeenintherange

1.3÷ 1.5AItwasmainlylimitedby:

ionintheresidualgasimpedanceinducedeffects(TMCI)

Ionsareneutralizedintroducingasuitablegapinthebatch

Asdynamicalvacuumwasimprovingfilledbuncheshavebeenprogressivelyincreasedtherangeof93÷ 108 withthesametotalcurrent,thusreducing:

Touschekcontributiontothebackgroundtheimpactofthemicrowaveinstabilitythreshold

Bestmachineperformanceshavebeenachievedthroughcollisionsof106consecutivebunches.

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

PositronBeamDynamics

DuringtheKLOE-2runthemaximumcurrentstoredinthee+ beamhasbeenoftheorderofI+ ~1.2A.

Higheste+ currentstoredroutinelyincollisionrarelyexceededI+ >0.95avalueconsiderablylowerthantheoneachievedduringthepastruns

Beamdynamicsinthee+ ringisclearlydominatedbythee-cloudinducedinstabilities

AtDAFNEthee-cloudeffectsarecontrolledby:solenoidwindingsFBKsystemselectrodesECEmovingxx xy tohigherpositivevalueslengtheningthebunchbyreducingtheRFcavityvoltage

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

ECEhavebeenfundamentalinordertoachievehighe+ currentsmostlyinthefirststageofoperations

Attheendoftherunonly2outofthe12deviceswereworkingproperly,noneofthemwasinthewigglers

Highcurrentoperationshavestillbeenpossiblethankstothescrubbingprocessasconfirmedbythedataabout

vacuumpressureriseinthee+ringarcstunespreadmeasurements

AposteriorianalysistoexplaintheECEbehavioueisunderway

ExperiencewithECEatDAFNE

2 ECE3 ECE

VUGPS203

2 ECE920 mA 28/3/2018

Dnx along the batch

• All ECE off• All ECE on 2014

Dnx along the batch

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

InalowenergymachineasDAFNEhighcurrentperformancesdependgreatlyonbunchbybunchfeedbacksystems.

DAFNEworksroutinelythankstothe3bunchbybunchfeedbacksinstalledineachring

Thetotalpoweravailableforeachapparatusisoftheorderof500Wand750Wfortransverseandlongitudinalfeedbacksrespectively

Beamcurrentlimitsobserved• longitudinalmode-0&quadrupoleoscillations• noisecomingfrompickups(harmfulforverticalsizes)• e-cloudeffects(inthee+ring)

Solutions:• Longitudinalquadrupolecontrolbyaspecialtechnique

implementedatDAFNEinthedipolefeedbacksystem• Transverselownoisefrontend(incollaborationwithKEK)

DAFNEFeedbackSystems

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

Revolution harmonic Synchrotron (dipole) oscillations damped by Long FBK

(A.Drago, et al., PRST-AB, 6, 052801-1-11, 2003)

The present source of quadrupoleinstability is still under investigationThis instability, if not controlled, saturates the longitudinal feedback

@ f ~ 2 • fsync

LongitudinalQuadrupoleOscillations

Quadrupole oscillation

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

TimeManagmentAchievingmilestonesfortheKLOE-2runrequiredacarefulschedulingofthetimefor:

maintanancemachinestudiesandmeasurementsfacingunexpectedfaultsevencausedbyexternalfactorsdatataking

lookingatthemachineuptime,attheintegratedluminositytrend,andatthefaultrateineveryacceleratorsubsystems

Regardlessthemajorupgraidplannedbeforethestartoftherun,manyrelevantintervenctionshadtobedoneduringdatatakingasforinstance:

replacemnetoftheCryoplantcompressorrevisionofthecoolingsystemservinglow-b sectionanddetectorelectronicequipmentsrevisionofthewigglermagnetcoolingsystem

Timeoriginallyallocatedformachinestudiesandmeasurementshasbeenoftenspentfor:planninginterventionssuggestedbyanomalousfaultratesinspecificsubsystemsoutliningproblemsresultinginsubtleeffectsaffectingbeamopticsandbeamdynamics.

AsinthecaseoftheelectronicphaseshifterinelectronringLLRF.whichcausedthecavitye- RFphase,andconsequentlythebeam,toshiftslowlyandrandomlybyabout10deg

ThisapproachandaconsiderablelackofmanpowerdidnotallowtoexploittheDAFNE’sfullpotentialasacollider,butassureddatataking.

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

DAΦNETimeline

March31st 2018endoftheKLOE-2Run

April÷ SeptemberKLOE-2roll-outandSIDDHARTA-2IRinstallation

September÷ December2018DAFNEcommissioningandSIDDHARTAsetup

(MOPFM088)

Inyear2019SIDDHARTA-2datataking

Startingfrom2020DAFNEmightbetransformedinatestfacility:

DAFNETF

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

Conclusion

DAFNEhasjustconcludedtherunfortheKLOE-2experimentachievingunprecedentedresultsintermsofluminosity.

ThishasbeenpossiblethankstoaneffectiveintegrationoftheCrab-WaistCollisionSchemewiththehighfielddetectorsolenoid.

TheCrab-WaistCollisionSchemehasproventobeaviableapproachtoincreaseluminosityincircularcolliderseveninpresenceofanexperimentalapparatusstronglyperturbingbeamdynamics.

GoodnewsforallthenewmachinesandprojectsaroundtheworldthathaveadoptedCrab-Waistastheirmaindesignconcept.

A REVIEW OF DAFNE PERFORMANCES DURING THE KLOE-2 RUN Catia MilardiIPAC’18 – May 2018 - Vancouver

Thankyouforyourattention