A Path Toward StandardizedA Path Toward Standardized Low-Energy Emittance Low-Energy Emittance
MeasurementsMeasurementsDoug MoehsDoug Moehs
January 17, 2007
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OutlineOutlineLARP Mission and Interests LARP Mission and Interests MotivationMotivationEmittance ProblemEmittance ProblemPossible SolutionPossible Solution
Allison scannerAllison scannerSCUBEXSCUBEX
Conceptual OutlineConceptual OutlineConclusionsConclusions
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LARP Mission and InterestsLARP Mission and Interests
Involve US laboratories in LHC upgradesInvolve US laboratories in LHC upgradesLHC upgradeLHC upgrade plan: Utilize H plan: Utilize H-- beams!!! beams!!!
(http://paf.web.cern.ch/paf/Presentations/PAF_report_ABMB_22May2006.pdf)(http://paf.web.cern.ch/paf/Presentations/PAF_report_ABMB_22May2006.pdf)
Priority 1: HPriority 1: H-- source development source development Priority 2: Linac4 and SPL constructionPriority 2: Linac4 and SPL construction
Develop Accelerator InstrumentationDevelop Accelerator InstrumentationWork at the technological frontierWork at the technological frontier Involve young scientists and studentsInvolve young scientists and students
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MotivationMotivation
R. Scrivens, CERN
All of the CERN upgrade plans include a new HAll of the CERN upgrade plans include a new H-- Linac! Linac! A 3 MeV test stand is now under construction at CERNA 3 MeV test stand is now under construction at CERN This is paralleled by Fermilab's HINS efforts This is paralleled by Fermilab's HINS efforts
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MotivationMotivation Need Quality low-energy Need Quality low-energy
transverse emittance transverse emittance datadata CERN has no available CERN has no available
emittance probes emittance probes (Thomas Meinschad, CERN Post. Doc. working (Thomas Meinschad, CERN Post. Doc. working
on the CERN 3 MeV H- front end)on the CERN 3 MeV H- front end)
Fermilab probes are old Fermilab probes are old and unreliableand unreliable
HINS is relying on old data HINS is relying on old data from a different LEBT from a different LEBT energy to match to the RFQ energy to match to the RFQ
HINS LEBT-RFQ beam matching
B. Mustapha and P. Ostroumov, ANL
HINS R&D Meeting, December 14, 2006
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Basic DefinitionsBasic DefinitionsMartin Stockli
rmsL
L
FF
xdxdxxA
/)()1ln(2
%) a is (F beamGausian aFor
1),(
Emittance Laboratory Transverse
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Emittance ProblemEmittance Problem Tough to compare Low-Tough to compare Low-
energy emittance valuesenergy emittance values Sensitivity to:Sensitivity to:
How they are measuredHow they are measured Probe typeProbe type
Double slitDouble slit Slit harpSlit harp Pepper potPepper pot
Where they are measuredWhere they are measured After sourceAfter source After LEBT or MEBTAfter LEBT or MEBT
Analysis method usedAnalysis method used ThresholdingThresholding Bias subtractionBias subtraction Eyeballing!Eyeballing!
D. Moehs et al., IEEE Trans, Plas. Sci., 33, 1786, 2005
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Emittance Emittance ProblemProblem
Impedes:Impedes: ion source ion source
selectionselection LEBTLEBT
simulationsimulation DesignDesign
Beam Matching Beam Matching
Historical Magnetron Emittances
D. Moehs, PNNIB, Sante Fe, Sept. 2006
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Possible SolutionPossible Solution
Create a Standard Candle Create a Standard Candle Establish a “standard” probe typeEstablish a “standard” probe typeEstablish a “standard” analysis procedureEstablish a “standard” analysis procedure
A good place to startA good place to startFollow SNS work Follow SNS work (contact: Martin Stockli)(contact: Martin Stockli)
Utilize a highly developed Alision scannerUtilize a highly developed Alision scannerAnalysis software called SCUBEX Analysis software called SCUBEX
Further testing of this software is needed! Further testing of this software is needed!
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Allison ScannerAllison Scanner Double slit Double slit Single charge Single charge
collectorcollector XX
stepping motorstepping motor X’ X’
Electrostatic Electrostatic beam deflectionbeam deflection
Moderate data Moderate data collection speedcollection speed Slower than slit-Slower than slit-
harpharp Faster than Faster than
double slitdouble slit
Some form of this scanner is in use at Some form of this scanner is in use at SNS, LBNL, ORNL(SNS)SNS, LBNL, ORNL(SNS)Picture provided by Martin StockliPicture provided by Martin Stockli
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SCUBEEXSCUBEEX Self Consistent, Unbiased Exclusion Ellipse EXclusion analysisSelf Consistent, Unbiased Exclusion Ellipse EXclusion analysis
Excel macro software developed at SNS to Excel macro software developed at SNS to compute normalized, RMS emittancecompute normalized, RMS emittance
Free but not widely usedFree but not widely used Needs additional debugging and testing Needs additional debugging and testing
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Conceptual OutlineConceptual Outline Construct 3 sets of emittance probes including electronicsConstruct 3 sets of emittance probes including electronics
Follow SNS designFollow SNS design Primary users: CERN, Fermilab and SNSPrimary users: CERN, Fermilab and SNS
Test probes in one locationTest probes in one location Write up operating and analysis techniquesWrite up operating and analysis techniques Disseminate probes and informationDisseminate probes and information
End result comparable emittance data from primary usersEnd result comparable emittance data from primary users Cost to LARPCost to LARP
2 sets of emittance probes and electronics2 sets of emittance probes and electronics Testing and disseminationTesting and dissemination Possible Travel: Possible Travel:
Learn about emittance system operation and data analysis programLearn about emittance system operation and data analysis program Installation and data collection at CERNInstallation and data collection at CERN
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The DESY RF source has been adopted at CERN The DESY RF source has been adopted at CERN The same source is of interest for use on a Proton Driver The same source is of interest for use on a Proton Driver
See (Fermilab AAC 2006 summary talk by Hans Weise)See (Fermilab AAC 2006 summary talk by Hans Weise)
Informal collaboration partners: Fermilab, CERN, DESY, SNSInformal collaboration partners: Fermilab, CERN, DESY, SNS Other labs expressing interest in good emittance data: LANL, ISISOther labs expressing interest in good emittance data: LANL, ISIS
LaboratoryLaboratory CurrentCurrent(mA)(mA)
EmittanceEmittancepi-mm-mr pi-mm-mr (nor., rms ) (nor., rms )
Pulse Pulse LengthLength(ms)(ms)
Rep. Rep. RateRate(Hz)(Hz)
LEBTLEBTEnergyEnergy(keV)(keV)
SNS upgradeSNS upgrade 67 / ~98 67 / ~98 0.2 / 0.350.2 / 0.35 1 1 6060 6565
CERN-SPLCERN-SPLPhase A / BPhase A / B
40 / 80 40 / 80 0.250.25 0.4 / 0.70.4 / 0.7 2 / 50 2 / 50 9595
Fermilab-HINSFermilab-HINSInitial / FinalInitial / Final
13 / 4013 / 40 0.240.24 3 / 13 / 1 2.5 / 102.5 / 10 5050
BSNS*BSNS*Beijing, ChinaBeijing, China
40 40 0.20.2 0.20.2 2525 7575
ISIS upgradeISIS upgrade 7070 0.170.17 1.51.5 5050 7070
Proposed New or Improved Machines
CollaborationsCollaborations
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ConclusionsConclusions
The goals of this project are consistent The goals of this project are consistent with the mission and interests of the LARP with the mission and interests of the LARP collaboration.collaboration.
This project provides timely data for CERN This project provides timely data for CERN and several US laboratories including and several US laboratories including Fermilab.Fermilab.