LSC in drifts Simulations for Injector Case of 100 m modulation
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Transcript of LSC in drifts Simulations for Injector Case of 100 m modulation
![Page 1: LSC in drifts Simulations for Injector Case of 100 m modulation](https://reader036.fdocuments.us/reader036/viewer/2022062517/56813def550346895da7c9ac/html5/thumbnails/1.jpg)
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
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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%
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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
![Page 4: LSC in drifts Simulations for Injector Case of 100 m modulation](https://reader036.fdocuments.us/reader036/viewer/2022062517/56813def550346895da7c9ac/html5/thumbnails/4.jpg)
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
![Page 5: LSC in drifts Simulations for Injector Case of 100 m modulation](https://reader036.fdocuments.us/reader036/viewer/2022062517/56813def550346895da7c9ac/html5/thumbnails/5.jpg)
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
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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
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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
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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%
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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%
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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%
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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%
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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
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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
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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
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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