1. B. FaatzS2E workshop, August 18-22, 20031 XFEL simulations with GENESIS Bart.Faatz@desy.de Outline: Undulator layout (real/simulated) Matching Genesis input files Post-processing Genesis output Free-Electron Laser at the TESLA Test Facility

2. B. FaatzS2E workshop, August 18-22, 20032 Undulator description: real ParametersSymbolValueUnit Undulator segment length LsLs 5m Undulator cell length LcLc 6.1m Undulator gapg10mm Undulator period (SASE1) u 48mm Quadrupole optical length192mm Quadrupole gradient at 20 GeVQ20T/m Undulator segment Phase shifter combined with horizontal correctorVertical corrector FocusingDefocusing quadrupole LsLs LcLc Matching section Free-Electron Laser at the TESLA Test Facility

3. B. FaatzS2E workshop, August 18-22, 20033 Undulator description: simulated Undulator segment Defocusing quadrupoleFocusing Increased quadrupole length in order to increase stepsize (adjusted gradient) Automatic phase matching between undulators Free-Electron Laser at the TESLA Test Facility Actual undulator geometry is defined in the magnet lattice file

4. B. FaatzS2E workshop, August 18-22, 20034 Elegant2genesis (SDDS toolkit)* Check # slices/# particles per slice Adjust initial  and  for optimal slice Adjust initial offset and angle for optimal slice Add wakefield along the undulator Matching at the undulator entrance *elegant2genesis -totalCharge= -slices= Free-Electron Laser at the TESLA Test Facility 1e-9100 Electron beam information starts with output from Elegant (In this example until the undulator entrance with 200k particles)

5. B. FaatzS2E workshop, August 18-22, 20035 Genesis input E-beam slice file (Elegant2genesis+match) “Elegant2genesis” produces global beam parameters for each slice “match” adjusts, and, for slice with maximum current Magnetic lattice file Genesis namelist input (Numerical and IO-parameters, …) Free-Electron Laser at the TESLA Test Facility From global parameters, Genesis fills the 5D+1 phase space with a Gaussian distribution

6. B. FaatzS2E workshop, August 18-22, 20036 Input distribution Free-Electron Laser at the TESLA Test Facility Tail of the bunch

7. B. FaatzS2E workshop, August 18-22, 20037 Post-processing Xgenesis (IDL) Interactive (GUI) Gen2Spread: Separate Genesis output file In slices along undulator At different undulator position temporal profile Free-Electron Laser at the TESLA Test Facility

8. B. FaatzS2E workshop, August 18-22, 20038 Steady state results: no wakefields Unmatched angle/offset Free-Electron Laser at the TESLA Test Facility Matched angle/offset

9. B. FaatzS2E workshop, August 18-22, 20039 Free-Electron Laser at the TESLA Test Facility Energy loss due to the wakefield* *resistive wall wake only assumed an inner radius of 4 mm copper coated stainless steel

10. B. FaatzS2E workshop, August 18-22, 200310 Steady state results: including wakefields (matched) Without taper Free-Electron Laser at the TESLA Test Facility Including taper

11. B. FaatzS2E workshop, August 18-22, 200311 Free-Electron Laser at the TESLA Test Facility Time dependent simulations: no wakefields Part of the bunch selected for time dependent simulations Simulate 20000 photon slices to assure overlap, 8000 particles each NTAIL NSLICE

12. B. FaatzS2E workshop, August 18-22, 200312 Free-Electron Laser at the TESLA Test Facility 70 GW power, 3  m FWHM pulse (10 fs)

13. B. FaatzS2E workshop, August 18-22, 200313 Free-Electron Laser at the TESLA Test Facility Frequency spectrum ?

14. B. FaatzS2E workshop, August 18-22, 200314 Free-Electron Laser at the TESLA Test Facility 17000

15. B. FaatzS2E workshop, August 18-22, 200315 Free-Electron Laser at the TESLA Test Facility 17500

16. B. FaatzS2E workshop, August 18-22, 200316 Free-Electron Laser at the TESLA Test Facility 18000

17. B. FaatzS2E workshop, August 18-22, 200317 Free-Electron Laser at the TESLA Test Facility Conclusion Extend time window Get frequency information Include all wakes, quantum fluctuations, … Much more work needs to be done