High Brightness Electron Beam Diagnostics and their ... - CASA

Population
Population
100000
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80000
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0
-5.0
100000
-2.5 0.0 2.5 5.0
90000
80000
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60000
BFF (a.u.)
BFF (a.u.)
10 13
10 12
10 11
10 10
10 9
10 8
10 7
10 6
10 -5 10 -4
10 -3 10 -2
10 -1
105
10 13
50000
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0
-5.0 -2.5 0.0 2.5 5.0 10 -5 10 -4
10 -3 10 -2
10 -1
10 0
10 1
10 2
105
10 6
10 7
10 8
10 9
100000
90000
80000
70000
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0
-5.0 -2.5 0.0 2.5 5.0 10
z/ z
-5 10 -4
10 -3 10 -2
10 -1
10 0
10 1
10 2
10
/ z
5
10 6
10 7
10 8
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coherentradiationsetupthecollectingopticshasanangularacceptanceof0:3rad.Westudythe synchrotronradiationmostofthepowerresidesinaconethatisoftheorderof1=:IntheFEL natelywearealsohelpedbythedirectionalityoftheradiation:inthecaseofbothtransitionand typesofbunchlongitudinaldistribution(left). satised:transverseeectcanyieldnon-negligiblecontributiontothebunchformfactor.Fortu- Figure5.4:Monte-Carlosimulatedbunchformfactor(right)with106macroparticleforthree
eectoftransversebeamspotsizenumericallybyperformingtheintegration:
(r=10z),anda\pancake"bunch(z=0).Beamsizesignicantlyaectstheregionofcoherent resultsofthenumericalintegrationofEqn.(5.11)isdepictedinFig.5.5wherewecomparethe Forsimplicity,let'sassumethatthebunchiscylindrically-symmetrici.e.x=ydef eectofthetransversebeamsizeonthebunchformfactor.ThetotalTRandSRpowerspectral densityiscomputedforthreetypicalbunchshape:alinechargebunch(r=0),anellipsoidalbunch P(!)=Z1:1! 0:9!d!Zdd2P1e(!) d!d =r.The (5.11)
enhancementintheBFF:ifoneusethetherebycomputedBFFtoretrievethebunchlength,the
Population
BFF (a.u.)
10 12
10 11
10 10
10 0
10 1
10 2