analysis of bbus.s. baturin* university of chicago a. zholents argonne national laboratory facet-ii...
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AnalysisofBBUincompactstructure-basedacceleratorand
asuppressionmethodS.S.Baturin*
UniversityofChicagoA.Zholents
ArgonneNationalLaboratoryFACET-IIworkshop
10/18/2017
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Outline
• Compactstructurebasedwakefield accelerator
• Introductiontodynamicsproblem
• Adaptivefocusing
• BNSdampingandstabilityanalysis
• ApplicationtoCollinearWakefieldAccelerator
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Compactstructurebasedwakefield accelerator
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JointlypursuedbyArgonne'sAWAandAPSgroupsforacompactFELfacility
Introduction
• Initialstudy• A.W.Chao,B.RichterandC.Y.Yao,Nucl.Instr.andMeth.A,178(1980)
• ExtensiveanalysisandfullBBUtheoryforsmoothfocusingJ.R.Delayen
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Introduction
•Chao– limitedtosmallwakeamplitudes.
•Delayen – limitedtosmoothfocusing.
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Canweapplyexistingtheorydirectlytoanalyse CWA?
Themodel
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Themodel
Equationsofmotion
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Adaptivefocusing
• Howwekeepconstantphaseadvance?
• Howtotweakmagneticsystemtomatchtheenergyofthefirstparticle?
• Weknowthattomitigatethewakefield weneedenergyspread. 8
Adaptiveenergy chirp
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Adaptiveenergy chirp
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Adaptiveenergy chirp
weintroducenewvariables
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AdaptivelenslengthL
Periodicfunctionofu
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Adaptivefocusingsummary
• Adaptivechip
• Adaptivelenslengthvariation
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Wakefieldcancelation
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Wakefieldcancelation
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Vladimir I. Arnol’d, Ordinary Differential Equations, Springer-Verlag, Berlin (1992)
Wakefieldcancelation
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Wakefieldcancelation
GeneralideaofBNSdamping1fordeterminingf(s)
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1 V. Balakin, S. Novokhatsky, V. Smirnov, Transverse Beam Dynamics, Proc. 12th Int. Conf. on High Energy Acc., Batavia, Illinois, (1983) p.119- 120
Wakefieldcancelation.Stability.
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Unstable region
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StabilityconditionforCollinearWakefiledAccelerator
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StabilityconditionforCollinearWakefiledAccelerator
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Unstable region
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StabilityconditionforCollinearWakefiledAccelerator
Summary
• Adaptivechip
• Adaptivelenslengthvariation
• Restrictionsonchirp
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Numericexample
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Numericexample
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100MV/m
p g
Acknowledgments
• CenterforBrightBeamsandNSF
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Fullsimulationoftwoparticlemotion
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