lsc in drifts simulations for injector case of 100 m modulation
DESCRIPTION
Simulations of LSC in the LCLS Injector C é cile Limborg-D é prey, P. Emma, Z. Huang, Juhao Wu March 1st, 2003. LSC in drifts Simulations for Injector Case of 100 m modulation Other wavelengths [ 50 ,150 ,200 , 300] m Conclusion. Simulations of LSC in drifts. - PowerPoint PPT PresentationTRANSCRIPT
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Simulations of LSC in the LCLS Injector
Cécile Limborg-Déprey, P. Emma, Z. Huang, Juhao Wu March 1st, 2003
Simulations of LSC in the LCLS Injector
Cécile Limborg-Déprey, P. Emma, Z. Huang, Juhao Wu March 1st, 2003
LSC in driftsLSC in drifts
Simulations for Injector Simulations for Injector Case of 100 Case of 100 m modulationm modulation Other wavelengths [ 50 ,150 ,200 , 300] Other wavelengths [ 50 ,150 ,200 , 300] mm
ConclusionConclusion
LSC in driftsLSC in drifts
Simulations for Injector Simulations for Injector Case of 100 Case of 100 m modulationm modulation Other wavelengths [ 50 ,150 ,200 , 300] Other wavelengths [ 50 ,150 ,200 , 300] mm
ConclusionConclusion
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Simulations of LSC in driftsSimulations of LSC in driftsSimulations of LSC in driftsSimulations of LSC in drifts
Simulations descriptionSimulations description40k/200k particles 40k/200k particles
Distribution generated using the Halton sequence of numbers Distribution generated using the Halton sequence of numbers
Longitudinal distributionLongitudinal distribution
2.65 m of drift2.65 m of drift
With 3 cases studied With 3 cases studied 6MeV, 1nC6MeV, 1nC
6 MeV , 2nC6 MeV , 2nC
12 MeV, 1nC12 MeV, 1nC
Simulations descriptionSimulations description40k/200k particles 40k/200k particles
Distribution generated using the Halton sequence of numbers Distribution generated using the Halton sequence of numbers
Longitudinal distributionLongitudinal distribution
2.65 m of drift2.65 m of drift
With 3 cases studied With 3 cases studied 6MeV, 1nC6MeV, 1nC
6 MeV , 2nC6 MeV , 2nC
12 MeV, 1nC12 MeV, 1nC
44 4/)cos(1 ozzekzA
+/- 5%
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Summary 100mSummary 100mComparison with theoryComparison with theoryComparison with theoryComparison with theory
• Transverse beam size evolution along beamline taken into account
(Radial variation of green’s function for 2D )
• Evolution of peak current NOT taken into account yet
• Absence of dip in 6MeV curve :
• “Coasting beam “ against “bunched beam” with edge effects
• Intrinsic energy spread
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Nominal Tuning Nominal Tuning 10 ps pulse (rise/fall time 1ps ) 10 ps pulse (rise/fall time 1ps )
1 nC 1 nC
Nominal Tuning Nominal Tuning 10 ps pulse (rise/fall time 1ps ) 10 ps pulse (rise/fall time 1ps )
1 nC 1 nC
Laser + Gun
Linac0-1 Linac0-2
6MeV0MeV 60MeV 150MeV
ASTRA Simulations of LSC along Injector BeamlineASTRA Simulations of LSC along Injector BeamlineASTRA Simulations of LSC along Injector BeamlineASTRA Simulations of LSC along Injector Beamline
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
ASTRA Simulations for modulation of 100 mASTRA Simulations for modulation of 100 m
Modulation Wavelength = 100 Modulation Wavelength = 100 m , with m , with 8% amplitude peak-to-peak8% amplitude peak-to-peak
““Noise of Noise of 8% amplitude around flat top is likely to be present “ P.Bolton 8% amplitude around flat top is likely to be present “ P.Bolton
FWHM = 3mmFWHM = 3mm
Longitudinal bining = 200 points (~ more than 6 bins per period) Longitudinal bining = 200 points (~ more than 6 bins per period)
1 Million particles1 Million particles
Modulation Wavelength = 100 Modulation Wavelength = 100 m , with m , with 8% amplitude peak-to-peak8% amplitude peak-to-peak
““Noise of Noise of 8% amplitude around flat top is likely to be present “ P.Bolton 8% amplitude around flat top is likely to be present “ P.Bolton
FWHM = 3mmFWHM = 3mm
Longitudinal bining = 200 points (~ more than 6 bins per period) Longitudinal bining = 200 points (~ more than 6 bins per period)
1 Million particles1 Million particles
Current
density
with modulation = 100 m with modulation = 100 m Region of interestRegion of interest Fourier AnalysisFourier Analysis
Position (mm)Position (mm) Position (mm)Position (mm) Cycles per mmCycles per mm
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Longitudinal Phase Space Longitudinal Phase Space
After removal of correlation up to order 5
Energy
Current
Fourier transform
Fourier transform
Fit up to 3rd order
Substract and Fit
Amplitude + rms
w.r.t reference level
z = 0.15 m
E = 6MeV
Gun Exit
E = 0 → 0.35 keV
Current modulation = 5.65% → 3%
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Energy
Current
Fourier transform
Fourier transform
z = 1.4 m
E = 6MeV
Entrance L01
E = 0.35 keV → 1 keV
Current modulation = 3% → 1.5%
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Exit L01
Energy
Current
Fourier transform
Fourier transform
z = 4.4 m
E = 60MeV
Exit L01
E = 1 keV → 3 keV
Current modulation = 1.5 % → 1.5%
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Exit L02
Energy
Current
Fourier transform
Fourier transform
z = 8.4 m
E = 150MeV
Exit L02
E = 3 keV → 3.9 keV
Current modulation = 1.5 % → 1.6%
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Summary 100mSummary 100m
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
Summary 50,100,150,300mSummary 50,100,150,300m
Attenuation by factor
More than 5 for <100m
~ 5 for >100m
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
At end LCLS injector beamline:At end LCLS injector beamline:
Current density modulation strongly attenuated residual energy oscillation has
amplitude between 2 keV and 4 keV for wavelengths [50 m, 500 m]
Impedance defined by
At end LCLS injector beamline:At end LCLS injector beamline:
Current density modulation strongly attenuated residual energy oscillation has
amplitude between 2 keV and 4 keV for wavelengths [50 m, 500 m]
Impedance defined by i
A
o
o I
I
Z
kZ
kzIzI io cos1
Same results with PARMELASame results with PARMELA
Technical Review, March 1st, 2004Technical Review, March 1st, 2004 CCéécile Limborg-Déprey, SLACcile Limborg-Déprey, SLAC
Injector RequirementsInjector Requirements [email protected]@slac.stanford.edu
Linac Coherent Light Source Stanford Linear Accelerator Center
ConclusionConclusion
Good agreement Simulations / Theory for drift and AccelerationSolutions to handle Numerical Problems
Noise Problem ( high number of particles)Shorter wavelengths (new option in ASTRA)
Clear “Attenuation” in gun makes situation less critical than first thought But not enough attenuation :
for wavelengths >100 m : attenuation line density modulation by factor of~5 for wavelengths <100 m : attenuation line density modulation by factor of more than 5 To reach less than 0.1% at end of beamline requires less than 0.4% rms on laser so +/- 0.56% = far beyond what is achievable by laser
Also large energy modulation in all cases (“large” = of the order or more than intrinsic energy spread)
Heater is required as microstructure present in all wavelengths cases and in particular those < 100 m
Good agreement Simulations / Theory for drift and AccelerationSolutions to handle Numerical Problems
Noise Problem ( high number of particles)Shorter wavelengths (new option in ASTRA)
Clear “Attenuation” in gun makes situation less critical than first thought But not enough attenuation :
for wavelengths >100 m : attenuation line density modulation by factor of~5 for wavelengths <100 m : attenuation line density modulation by factor of more than 5 To reach less than 0.1% at end of beamline requires less than 0.4% rms on laser so +/- 0.56% = far beyond what is achievable by laser
Also large energy modulation in all cases (“large” = of the order or more than intrinsic energy spread)
Heater is required as microstructure present in all wavelengths cases and in particular those < 100 m