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

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

casa.jlab.org
from casa.jlab.org More from this publisher
04.08.2013 Views

AppendixB B.1LinearandSecondOrderTransport:Convention BeamDynamics:Notes&Tools B.1.1TransferMatrix Inthepresentreportweworkinthecoordinatesystem(x;x0;y;y0;;)where: x,y,arethecoordinateinthestandard3Dpositionspace(notethat=2z=RFrepresentsthelongitudinalpositionoftheparticleinunitoftheRFwavelengthoftheacceleratorTopropagateavector!rinalongasectionofbeamline,weuse,providedthesecond-orderapprox- x0andy0arethedivergenceinthetransverseplane (withinafactor2)) imationoftheequationofmotionisapplicable: reportcoincidentwiththeenergyaverageofthebunch). istherelativeenergyosetoftheparticlewithareferenceparticle(whichisinthepresent RijistherstordermatrixandTijkarethesecondorderterms. B.1.2BeamMatrix rout;i=XjRijrin;j+XkXj>kTijkrin;jrin;k+O(r3) (B.1) Thebeamormatrix,e.g.forthex-x0phasespaceisdenedasfollows: Thesamematrixcanbedenedforthey-y0phasespaces(3j4)or-longitudinalphasespaces (5j6).wehavethefollowingdenitions/properties: xdef =1j2def = 1112 1222!= 174hxx0ihx02i! hx2ihxx0i (B.2)

B.2Anoteonspacecharge Wedenetheslopeofthephasespaceas:dx=dx0=hxx0i=hx02i thetransversermsemittanceisthedeterminantdet(z) originatesfromCoulombrepulsionbetweenelectronswithinabunch.Spacechargetendstoinduce emittancegrowth.Inthissection,wewouldliketoshowthattheseforcesareonlyaconcernfor lowenergybeam,inourcase(Q'60pCthespacechargecollectiveeectisonlyimportantin Wehavealreadymentionedthatchargedparticlebeamaresubjecttospacechargeforcethat theinjectorbeamline.Forsuchapurposeweconsideraverysimplemodelofauniformlycharged Thelongitudinaleldcanalsobecomputedconsideringthebeaminsideapuremetalliccylindrical magneticeldsinsidethebeam,andinthebeamreferenceframe,caneasilybecomputedfromthe Maxwellequationandare(forr

B.2Anoteonspacecharge Wedenetheslopeofthephasespaceas:dx=dx0=hxx0i=hx02i thetransversermsemittanceisthedeterminantdet(z)<br />

originatesfromCoulombrepulsionbetweenelectronswithinabunch.Spacechargetendstoinduce emittancegrowth.Inthissection,wewouldliketoshowthattheseforcesareonlyaconcernfor lowenergybeam,inourcase(Q'60pCthespacechargecollectiveeectisonlyimportantin Wehavealreadymentionedthatchargedparticlebeamaresubjecttospacechargeforcethat theinjectorbeamline.Forsuchapurposeweconsideraverysimplemodelofauniformlycharged<br />

Thelongitudinaleldcanalsobecomputedconsideringthebeaminsideapuremetalliccylindrical magneticeldsinsidethebeam,<strong>and</strong>inthebeamreferenceframe,caneasilybecomputedfromthe Maxwellequation<strong>and</strong>are(forr

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!