Compression Scenarios for the European XFEL Charge and Bunch Length Scope Igor Zagorodnov 1st Meeting of the European XFEL Accelerator Consortium DESY, MPY 14. April 2012

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 2 Inhalt Analytical and Numerical Approaches Compression Scenarios for Different Charges Strong Compression Summary

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 3 Analytical and Numerical Approaches Layout

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 4 Analytical and Numerical Approaches Working points (11 macro-parameters) What is the optimal choice? Zagorodnov I., Dohlus M., A Semi-Analytical Modelling of Multistage Bunch Compression with Collective Effects, Phys. Rev. ST Accel. Beams, 2011.

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 5 Analytical and Numerical Approaches Choosing of machine parameters very strong compression at the bunch head (spike)

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 6 Analytical and Numerical Approaches ~ 1.5 kA ~2.5 kA slice emittance > 2 m slice emittance ~ m Q=1 nC Q=0.5 nC Rollover Compression vs. Linearized (FLASH)

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 7 Analytical and Numerical Approaches Q=1 nC

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 8 Analytical and Numerical Approaches Analytical solution without self-fields Solution with self-fields nonlinear operator (tracking with self-fields) numerical tracking analytical correction of RF parameters residual in macroscopic parameters Zagorodnov I., Dohlus M., A Semi-Analytical Modelling of Multistage Bunch Compression with Collective Effects, Phys. Rev. ST Accel. Beams, 2011.

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 9 Analytical and Numerical Approaches Beam dynamics simulation ASTRA ( tracking with 3D space charge, DESY, K. Flötmann) W1 -TESLA cryomodule wake (TESLA Report , DESY, 2003) W3 - ACC39 wake (TESLA Report , DESY, 2004) TM - transverse matching to the design optics W3W3 W 1 TM 4W 1 TM 64W 1 12W 1 TM Full 3D simulation method (200 CPU, ~10 hours) CSRtrack (tracking through dipoles, DESY, M. Dohlus, T. Limberg)

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 10 Compression for Different Charges Q=1 nC Phase space Current, emittance, energy spread bunch head

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 11 Compression for Different Charges Phase space Current, emittance, energy spread bunch head Q=250 pC

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 12 Compression for Different Charges Current, emittance, energy spread Phase space Q=20 pC

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 13 Compression for Different Charges ParameterUnit Bunch chargenC Peak current (gun)A Bunch length (gun, FWHM)ps Slice emittance (gun) m Projected emittance (gun) m Compression Peak currentkA Bunch length (FWHM)fs Slice emittance m Projected emittance m Slice energy spread (laser heater off) MeV Beam parameters from S2E simulations

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 14 Compression for Different Charges Radiation Q=1nC. SASE Genesis ALICE Genesis ALICE Zagorodnov I., Dohlus M., Numerical FEL studies with a new code ALICE, in Proceedings of FEL09, Liverpool, 2009.

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 15 Compression for Different Charges Radiation energy statistics ( runs) 250 pC 1 nC Mean energy 20 pC Radiation pulse width (RMS) Charge, nC Mean radiation energy, mJ Pulse radiation width (FWHM), fs pC 1 nC 20 pC

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 16 Compression for Different Charges Bunch charge, nC Wavelength, nm0.1 Beam energy, GeV14 Peak current, kA~ 5 Slice emmitance,mm-mrad Saturation length, m Energy in the rad. pulse, mJ Radiation pulse duration FWHM, fs Averaged peak power, GW Spectrum width, % Radiation Properties from S2E

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 17 Strong Compression Q=1 nC, I=10kA Phase space Current, emittance, energy spread

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 18 Strong Compression ParameterUnit Bunch chargenC1 Peak current (gun)A43 Compression Peak currentkA59.8 Bunch length (FWHM)fs17875 Slice emittance m 11 Projected emittance m 3.58 Slice energy spread (laser heater off) MeV0.451 Q=1 nC

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 19 Strong Compression for 250 pC R 56,3 = -20 mm R 56,3 = mm

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 20 Strong Compression for 250 pC Momentum compaction factor in BC 1 R 56,1, [mm] Compr. in BC 1 C 1 Momentum compaction factor in BC 2 R 56,2, [mm] Compr. in BC 2 C 2 Momentum compaction factor in BC 3 R 56,3, [mm] Total compr. C Second derivative (C -1 ) '', [m -2 ] ,…, Macro-parameters

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 21 Strong Compression for 250 pC R 56,3 =-20mm Phase space Current, emittance, energy spread

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 22 Strong Compression for 250 pC R 56,3 =-21 mm Phase space Current, emittance, energy spread

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 23 Strong Compression for 250 pC R 56,3 =-21.9 mm Phase space Current, emittance, energy spread

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 24 Strong Compression for 250 pC R 56,3 =-22.6 mm Phase space Current, emittance, energy spread

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 25 Strong Compression for 250 pC R 56,3 =-22.6 mm (70% of particles) Phase space Current, emittance, energy spread

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 26 Strong Compression for 250 pC R 56,3 =-23.2 mm (70% of particles) Phase space Current, emittance, energy spread

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 27 Strong Compression for 250 pC Beam core parameters vs. R 56

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 28 Strong Compression for 250 pC Beam core parameters vs. R 56

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 29 Strong Compression for 250 pC Radiation energy vs. R 56 (with und. wake and taper)

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 30 Strong Compression (SLAC) Q=20 pC

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 31 Strong Compression for 250 pC Radiation energy vs. compression rate

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 32 Strong Compression for 250 pC Radiation energy vs. compression rate

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 33 Strong Compression for 250 pC Radiation power vs. compression rate

Igor Zagorodnov| 1st Meeting of EXFEL Accelerator Consortium | 17. April 2012 | Seite 34 Summary Bunches with charge pC can be compressed to 5 kA and higher Radiation energy drops down at full compression Overcompression scenario can be used Acknowledgements to M.Dohlus and T.Limberg for many useful discussions