A Transverse Profile Imager for SwissFEL Rasmus Ischebeck

A Transverse Profile Imager for SwissFEL Profile measurement in FELs Imaging scintillating crystals Applications Rasmus Ischebeck 2

Transverse Profile Monitors Rasmus Ischebeck University of Illinois 3

Profile Measurement in FELs Measure beam size <—> Measure beam structure Rasmus Ischebeck 4

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 Rasmus Ischebeck 5

1-Dimensional Profile Monitor Rasmus Ischebeck Gian Luca Orlandi, Prajwal Mohanmurthy 6

x-y Correlations Intrinsic correlation Explicit x-y dependency introduced by RF deflector Rasmus Ischebeck 7

2-Dimensional Profile Monitors Optical transition radiation (OTR) Scintillation Rasmus Ischebeck 8

Imaging Scintillators Rasmus Ischebeck 9

Electron Beam Profile Monitors Scintillators, OTR Screens & Wire Scanners Installed scintillators Ce:YAG 5 µm 20 µm 200 µm Ce:LuAG Rasmus Ischebeck F. Piffaretti

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 Rasmus Ischebeck

Scheimpflug Snell Screen Monitor Theodor Scheimpflug (1865—1911) Willebrord Snellius (1580—1626) Rasmus Ischebeck 12

Imaging Scintillating Crystals Rasmus Ischebeck 13

Imaging Scintillating Crystals Rasmus Ischebeck 14

Imaging Scintillating Crystals Rasmus Ischebeck 15

Imaging Scintillating Crystals Rasmus Ischebeck 16

Trigonometry… Rasmus Ischebeck 17

Observed Beam Size Incidence angle alpha = 8.1 degrees Index of refraction YAG Rasmus Ischebeck 18

Ideal Observation Angle Rasmus Ischebeck 19

Observation Geometry for Scintillator and OTR Rasmus Ischebeck 20

Observation Geometry for Scintillator and OTR Rasmus Ischebeck 21

Screen Holder Rasmus Ischebeck 22

Screen Monitor Rasmus Ischebeck 23

A Transverse Profile Imager for SwissFEL Profile measurement in FELs Imaging scintillating crystals Applications Rasmus Ischebeck 24

Measurements with the Prototype > Emittance Measurement The smallest beam in this measurement is 50 µm rms. Beams of 10 µm rms have been measured. Rasmus Ischebeck 25

Measurements with the Prototype Slice emittance measurement of a 10 pC beam Eduard Prat, Marta Divall Rasmus Ischebeck 26

Measurements with the Prototype Slice emittance measurement of a 1.3 pC beam Eduard Prat, Marta Divall Rasmus Ischebeck 27

Beam Transmitted Through Slit Rasmus Ischebeck 28

RF Deflector Rasmus Ischebeck 29

Next Steps Series production Magnifying Optics Rasmus Ischebeck 30

Next Steps Series production Magnifying Optics Rasmus Ischebeck 31

Next Steps Series production Magnifying Optics Rasmus Ischebeck 32

Microlens Array Rasmus Ischebeck Sony Inc. 33

Schwarzschild Optics Rasmus Ischebeck 34

Schwarzschild Optics Rasmus Ischebeck 35

Schwarzschild Optics Rasmus Ischebeck Vincent Thominet 36

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 Rasmus Ischebeck 37