1. A Transverse Profile Imager for SwissFEL Rasmus Ischebeck

2. A Transverse Profile Imager for SwissFEL
Profile measurement in FELs
Imaging scintillating crystals
Applications
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3. Transverse Profile Monitors
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University of Illinois 3

4. Profile Measurement in FELs
Measure beam size <—> Measure beam structure
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5. Profile Measurement in FELs
Correlations in x and y?
In most cases, uncorrelated —> measure with 1d monitor, or integrate along one dimension
Correlation —> need 2d detector
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6. 1-Dimensional Profile Monitor
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Gian Luca Orlandi, Prajwal Mohanmurthy 6

7. x-y Correlations Intrinsic correlation
Explicit x-y dependency introduced by RF deflector
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8. 2-Dimensional Profile Monitors
Optical transition radiation (OTR)
Scintillation
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9. Imaging Scintillators
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10. Electron Beam Profile Monitors Scintillators, OTR Screens & Wire Scanners
Installed scintillators
Ce:YAG
5 µm
20 µm
200 µm
Ce:LuAG
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F. Piffaretti

11. Electron Beam Profile Monitors Visual Light Optics
OTR screen / scintillator is at an angle of 45º to the optical axis
For overview camera (1:5.3 demagnification)
Use Scheimpflug criterion to correct image plane orientation
For 1:1 imaging
Perspective control lens is not available commercially
Only central part (~1…2 mm) of the screen can be imaged within depth of field
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12. Scheimpflug Snell Screen Monitor
Theodor Scheimpflug (1865—1911)
Willebrord Snellius (1580—1626)
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13. Imaging Scintillating Crystals
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14. Imaging Scintillating Crystals
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15. Imaging Scintillating Crystals
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16. Imaging Scintillating Crystals
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17. Trigonometry…
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18. Observed Beam Size Incidence angle alpha = 8.1 degrees
Index of refraction YAG
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19. Ideal Observation Angle
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20. Observation Geometry for Scintillator and OTR
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21. Observation Geometry for Scintillator and OTR
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22. Screen Holder
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23. Screen Monitor
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24. A Transverse Profile Imager for SwissFEL
Profile measurement in FELs
Imaging scintillating crystals
Applications
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25. Measurements with the Prototype
> Emittance Measurement
The smallest beam in this measurement is 50 µm rms.
Beams of 10 µm rms have been measured.
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26. Measurements with the Prototype
Slice emittance measurement of a 10 pC beam
Eduard Prat, Marta Divall
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27. Measurements with the Prototype
Slice emittance measurement of a 1.3 pC beam
Eduard Prat, Marta Divall
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28. Beam Transmitted Through Slit
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29. RF Deflector
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30. Next Steps
Series production
Magnifying Optics
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31. Next Steps
Series production
Magnifying Optics
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32. Next Steps
Series production
Magnifying Optics
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33. Microlens Array
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Sony Inc. 33

34. Schwarzschild Optics
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35. Schwarzschild Optics
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36. Schwarzschild Optics
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Vincent Thominet 36

37. Thank You to… Hansueli for the technical design
The AMI team for manufacturing the components
Markus for the assembly
Markus, Albert & the Vacuum group for installation
Eduard the emittance measurement software, and for using the new profile monitor extensively for emittance measurements
Gian Luca, Marta, Simona, Carlo, Thomas & Eduard for the measurements presented in this talk
Vincent for the slide on the Schwarzschild imaging
Andrea for support with patenting the design, and with connections to industry
Helge for camera server software, and Babak for synchronized data acquisition
The entire Commissioning and Operations crew
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