1. 02.04.07Michael Röhrs On-crest slice emittance measurements Michael Roehrs

2. 02.04.07Michael Röhrs Outline Results of on-crest slice emittance measurements Sources of (x,z)-tilts observed with LOLA Effects of the tilt on slice emittance measurements conclusions

3. 02.04.07Michael Röhrs Slice emittance measurements with different quadrupole scans (19.02.07) Standard method: simultaneous scan of Q9ACC4-Q10ACC6 (good long. Resolution) Scan of Q10ACC6 (two different optics) Beam direction Q9ACC7 Q9/10ACC6Q9/10ACC5 Q9/10ACC4 Kicker Off-axis screen Scanned Quadrupole ACC5 ACC4 LOLA ACC2 ACC3 BC2 ACC1 GUN ACC5 ACC4 UND6 …. UND1 Collimator TCAV BC3

4. 02.04.07Michael Röhrs Results: scan of Q10ACC6 (optics 1) Gauss-fit:Second moments: Average slice emittance: 2.7 mm mrad (gauss) / 3.1 mm mrad Projected emittance BC2-section: Projected emittance including tilts: < 4.3 mm mrad / < 4.8 mm mrad

5. 02.04.07Michael Röhrs Slice mismatch and initial Twiss parameters Correlated to energy profile ?

6. 02.04.07Michael Röhrs Comparison of measured and calculated bunch widths LOLA phase flipped (head deflected up- and downwards, respectively) No significant errors in transfer model / of the measured beam sizes Emittance error due to wrong k- values (5%) / energy (10%): < 10%

7. 02.04.07Michael Röhrs Scan of Q10ACC6 (optics 2) Gauss-fit: Second moments: Optics1: Average slice emittance: 3.0 mm mrad (gauss) / 3.1 mm mrad Projected emittance including (z-correlated) tilts: 4.3 mm mrad / 5.0 mm mrad

8. 02.04.07Michael Röhrs Multi-quadrupole-scan Gauss-fit: Second moments: Optics1: Reason for deviating slice emittance: higher resolution ? error in transfer matrix ? Average slice emittance: 2.4 mm mrad (gauss) / 2.7 mm mrad

9. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2) Y [pixel] (time) X [pixel]

10. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

11. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

12. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

13. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

14. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

15. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

16. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

17. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

18. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

19. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

20. 02.04.07Michael Röhrs Tilt in (x,z)-plane during a quadrupole scan (optics 2)

21. 02.04.07Michael Röhrs Possible Sources for tilts measured via LOLA Rotation of LOLA Rotation of Q9ACC7 Rotation of the Camera-system XY-coupling Sextupole components of Q9ACC7 Transverse wake fields in cavities / in LOLA Dispersion (off-crest) RF-Coupler kicks RF-focusing (off-crest) RF-Acceleration (off-crest) RF-fringe fields in cavities (off-crest) Field errors within LOLA y-correlated sources z-correlated sources

22. 02.04.07Michael Röhrs Measurement of y- and z-correlated contributions by flipping the phase of LOLA

23. 02.04.07Michael Röhrs Rotation of the camera / of LOLA Rotation of the camera: With respect to the screen holder: ~19 mrad With respect to V10ACC7 (vertical steerer): ~17 mrad Rotation of the camera and LOLA: LOLA-phase-flip: 11- 21 mrad Scan of LOLA-phase: 11- 17 mrad Rotation of the camera of ~ 1˚ Rotation of LOLA < 10 mrad

24. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan Scan of Q10ACC6 (slice emittance measurement, optics 2) Tilt (in this case) generated upstream of Q10ACC6!

25. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

26. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

27. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

28. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

29. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

30. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

31. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

32. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

33. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

34. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

35. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

36. 02.04.07Michael Röhrs z-correlated tilt during a quadrupole scan

37. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan Contribution from ACC5? First quadrupole scanned: Q9ACC4, upstream of module ACC5!

38. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

39. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

40. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

41. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

42. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

43. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

44. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

45. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

46. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

47. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

48. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

49. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

50. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

51. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

52. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

53. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan

54. 02.04.07Michael Röhrs z-correlated tilt during a multi- quadrupole-scan Contributions from wake fields in ACC5? Time-dependend kick added in the center of ACC5: Deviation between measured and fitted centroid offsets:

55. 02.04.07Michael Röhrs z-correlated tilt sources in cavities Kick difference Δx’ between head and tail per cavity : On-crest:Off-crest: Emittance growth << 10% ! Wake functions: I. Zagorodnov, T.Weiland: TESLA Report 2003-19; Coupler Kicks: Presentation of M. Dohlus

56. 02.04.07Michael Röhrs LOLA: transverse wake fields Time-dependend kick in LOLA: Resulting centroid offset on the screen: Aperture of LOLA scanned -> no significant offset of the structure! Wake functions : I. Zagorodnov, T.Weiland: TESLA Report 2004-01

57. 02.04.07Michael Röhrs Effects of the tilt on slice emittance measurements Non-gaussian profiles caused by tilts? Dependence of measured slice widths on the LOLA-phase:

58. 02.04.07Michael Röhrs XY-coupling in combination with an (x,z)-tilt Slice widths : Simulation:

59. 02.04.07Michael Röhrs Conclusions The measured slice emittance ranges from ~2 mm mrad to ~3 mm mrad in the center It is not in contradiction to measured projected emittance values z-correlated tilts are mainly generated upstream of LOLA, most likely in the accelerating modules

60. 02.04.07Michael Röhrs Errors due to erroneous transfer matrices Deviations of k-values: Deviation of the energy: Emittance error due to erroneous transfer matrices < 10%

61. 02.04.07Michael Röhrs Tilt from xy-coupling: simulation Projected transverse distribution with strong xy-coupling Tranverse distribution after passing LOLA: A tilt of 9 mrad remains from xy- coupling

62. 02.04.07Michael Röhrs Emittance growth due to linear tilts Gaussian bunch