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

1.0
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E=10 MeV
E=42 MeV
E=800 MeV
E=4000 MeV
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Angle (rad)
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10 -1
10 0
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Energy (MeV)
-1/2 Figure2.5:Fractionofthetotaltransitionpoweremittedintothehemispherethatisconcentrated
(A)
(B)
withinaconeofsemi-angle(A)andcontainswithinaconeofsemi-angle1=(B). where=1=2!=!c(1+22)3=2,!cisthecriticalfrequencyasdenedinthesynchrotron electriceldcomponentparalleltothedeectingmagneticeld.Asonecannoticefromgure2.6, theelectrontrajectorywhilethesecondterm(/K21=3())correspondstothe-polarizationi.e.the thepowerassociatedwiththe-polarizationoftheelectriceldi.e.thecomponentintheplaneof radiationformalism(!c=2=3c3=),Z0isvacuumfreespaceimpedance,metheelectronmass andrc=e2=(40mec2)istheclassicalelectronradius.Therstterminthebracket(/K2=3())is
(A) (B)
andthereforewhenmostofthelobecanbecapturedbyadetector,onequantityofinterestisthe
1.5
totalsynchrotronradiationpowerspectrumintegratedoverthewholesolidanglewhichisgiven Figure2.6:Angularandfrequencydistributionofsynchrotronradiationforthe(A)andthe
0.2
1
by[10]: Becausewegenerallydealwithrelativisticbeam(1),i.e.whentheradiationisverycollimated (B)polarization. theangulardistributionofthetwopolarizationsverystronglydependonthefrequency.Forinstance theangularopeningofthe-moderadiationgetsnarrowerasthefrequencyisincreased.
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dP
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γθ
γθ
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d!1e=Ptot !cS(!=!c) (2.16)
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Log (ω/ω )
Log (ω/ω )
10 c 10 c
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