BenchmarkofRF-Track&AstrawithPRAE

YanliangHan

LAL,France

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PRAEPlatformforResearchandApplicationwithElectrons

Beam parameters Phase A-B Energy,MeV 50-70(100-140) Charge(variable),nC 0.00005–2 Normalizedemittance,mm.mrad 3-10 RFfrequency,GHz 3.0 Repetitionrate,Hz 50 Transversesize,mm 0.5 Bunchlength,ps <10 Energyspread,% <0.2

Bunchesperpulse 1

q PhaseA:RFgunat50Hz;50-70MeV,twolines:

q Direct:magneticchicaneforProRadandradiobiologyinmode“Push-Pull”

q Deviated:forInstrumentation

q PhaseB:q SpectrometerforInstrumentationline

q Scanningdipoleforradiobiologyq Completesetofchannels

q 140MeV

RFGun Linac

ProRad

Radiobiology

Instrumentation

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The RF gun

Coupling slot compensating the Field distortion

RF power (5 MW)

Short circuit

Photocathode

Acceleratinggradient(TM010_πmode):80MV/matPin=5MW

2.5 cells RF gun designed and produced at LAL for ThomX

Operation frequency 2998,55 MHz (30°C, in vacuum)

Charge 1 nC

Laser wavelength, pulse energy 266 nm, 100 µJ

RF Gun Q and Rs 14400, 49 MΩ/m

RF Gun accelerating gradient 80 MV/m @ 5 MW

Normalized emittance (rms ) 4.4 π mm mrad

Energy spread 0.4 %

Bunch length (rms) 5 ps

Photoinjectorspecification

CST-Particle in cells, simulation results

Energy gain = 5 MeV for Pin =5 MW

20 cm

bucking coil focusing coil new coil configurations

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RFGunPhasescan

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1.5

2

2.5

3

3.5

4

4.5

5

5.5

6

80 100 120 140 160 180 200 220 240 260 280 300

Ekin

(M

eV

)

phi (degree)

RF-TrackAstra

Formula simulation•  Thephaserange–  Astra:180:280–  RF-Track:90:180

•  Theenergygain–  Astra:5.11MeV–  RF-Track:5.28MeV

•  Theparticleloss–  Astra:0-70%–  RF-Track:0.01%

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Phasespace-horizontal

AstraRF-Track

Usethephasewithlargestenergygain

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Phasespace-longitudinal

Totallydifferent!

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EmittancealongtheRFGun

InAstra AttheendofRFGunBz=0,thedefinitionisthesame

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ThestabilityofRF-Track

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Phasespacestability–RF-TrackTheparameter“sc_nsteps”meansapplyingspace-chargekickaftereach“sc_nsteps”integrationsteps.IntegrationalogrithmisRunge-Kutta-45.

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Phasespacestability–RF-Track

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Phasespacestability–RF-TrackNomagneticfieldforspacechargeeffect

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Phasespacestability–RF-TrackNomagneticfieldforspacechargeeffect

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Phasespacestability–RF-TrackUsingdifferentintegrationalogrithm– analytic

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Phasespacestability–RF-TrackUsingdifferentintegrationalogrithm– analytic

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Conclusion

•  Thereareseveraldifferencesbetweentwocodes–  Thephaserange–  Theenergygain–  Theparticleloss–  Phasespacedistribution–  Theemittancedistribution

•  TheresultfromRF-Trackisstable– Withdifferentspace-chargesetup–  Fordifferentintegrationalogrithm

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Advantage&Disadvantage

Advantage:•  Opensource•  Octave&Pythoninterface•  Therearemanyalgorithmto

choose•  ParallelProcessingDisadvantage:•  Thereisusermanualnow.

Advantage:•  Thereisausermanual.•  Crossplatform-WindowsDisadvantage:•  Singlethread

RF-Track Astra

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