1. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 Experimental observations at the Metrology Light Sourc Jörg Feikes, Paul Goslawski, Ji Li, Tobias Goetsch, Markus Ries, Martin Ruprecht, Gode Wüstefeld, Helmholtz-Zentrum Berlin, Germany

2. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 2 Outline: -the Metrology Light Source -Observation of Intra Beam Scattering at MLS -Island buckets -Application of Island buckets at MLS and BESSY II

3. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 3 Circumference = 48 m Cavity Frequ/Voltage = 500MHz / 460kV electron energy range = 50 MeV… 630 MeV (ramped from 105 MeV) storable current = single electron… 200 mA (no filling gap -> Ions  ) bunch length = sub-ps.. 100 ps hor. emittance = 100 nmrad (Design value) Metrology Light Source (MLS) BESSY II owner and main user: Physikalisch-Technische Bundesanstalt (PTB) operated by „BESSYII“-staff (Helmholtz-Zentrum-Berlin, HZB) The Metrology Light Source

4. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 4 M1: Surface Characterization with UV/VUV Undulator Radiation Ellipsometry (PTB/ISAS), Electron Spectroscopy (PTB/TUB/HZB), … M2: MLS as Primary Radiation Source Standard Calibration of UV/VUV Radiation Sources and Space Telescopes M3:Metrology for EUV Lithography Characterization of Optics with Industry Partners (CZ, ASML, …) M4:UV/VUV Detector Radiometry and Reflectometry Cryogenic Radiometer as Primary Detector Standard M5:THz Spectroscopy and Detector Characterization Applications of Coherent Synchrotron Radiation M6: Micro and Nano Spectroscopy in the IR Regime Near-field Microscopy and Nano-FTIR Spectroscopy (PTB/FUB) M7: Electron Beam Diagnostics Size (Imaging) and low Current Beam Lines and Working Groups @MLS

5. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 5 all 24 quadrupoles have individual PS -> high flexibility in design of new optics fully automated operation allows ad hoc change to desired optic within seconds positive α - Ramp negative α - Ramp Flexible and Fast Optic Change

6. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 6 Low Emittance optic ramp implemented 100 nm rad -> 25 nmrad Completely current conserving at maximum current of 200mA crossing 1/3 and 1/4 and several coupling resonances -> strong benefit for Storage Ring based Scanning Near Field Microscope (s-SNOM) competitive and outperforming similar microscopes at other sources only in low emittance mode Operating with Low Emittance Optic transverse beam image Tune diagram 100 nmrad 25 nmrad

7. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 7 scanning near-field optical microscopy (s-SNOM) Combination of scanning probe and spectroscopic techniques for chemical imaging and spectroscopy at the nanoscale focused synchrotron (or laser) radiation illuminates the tip s-SNOM at the MLS IR beamline

8. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 8 Diagnostic at MLS Metrology Applications need very acurate measurements of all beam parameters @MLS strong efforts went into diagnostic tools Example: Linearity of source size with beam current (single bunch) and imaging time at old and refurbished imaging system -> source image of one single stored electron possible ! measured source size vs single bunch current vs imaging times

9. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 9 Single Bunch transverse beam size - two independent imaging systems at optically different positions -systems absolutely calibrated In the Low emittance optic an increase of transversal beam size with single bunch current was observed horizontal beam size vs currentvertical beam size vs current these values are near lower resolution limit

10. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 10 Also the bunch length increases with SB-current -no bursting or microwave instability present, energy width unchanged -lengthening in low emittance mode only -> vanishes during transversal blow up streak camera: bunch length vs beam current Single Bunch longitudinal beam size

11. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 11 beam current IBS calculations using MADX do not fit (yet)! Bunch volume vs Beam Current bunch volume +30% 1 mA

12. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 12 Intra Beam scattering at MLS - blow up of bunch compered to zero current values observed - spoil of beam quality transversal and longitudinal – origin IBS - No fit of data with simple IBS models achieved so far Diagnostic Tools - two independent source point monitors - streak camera Why study IBS at MLS ? - energy range 50 MeV - 630 MeV - Beam Current 1 e- -> 200mA - transverse emittance 25 nmrad to 100 nmrad - bunch length sub ps to 100 ps In case of interest in IBS at MLS please contact us. New measurements always possible (or use of existing data) for verification of a realistic IBS model, Summary IBS at MLS

13. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 13 Suggested by Gode Wüstefeld to separate long/short bunch pulses in BESSY VSR “pseudo single bunch” on demand radiation at sub-harmonics rep rate injection/extraction schemes (see work of Giovannozzi, Franchi, CERN, ESRF) …. Motivation for Island buckets

14. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 14 Experiments and application of island buckets Some Talks and paper on Island buckets at MLS and BESSY II (where I took all the material for this talk) Markus Ries et al, Transverse Resonance Island Buckets at the MLS and BESSY II, Proc. of IPAC2015, Richmond, USA, p. 138 – 140 Paul Goslawski et al, Bunch Separation with Reconance Island Buckets for BESSY VSR ESLS Workshop 2014, 24 th November 2014, Grenoble, France Multi Beam Storage in Transverse Resonance Island Buckets at MLS and BESSY II, DPG 2015, Wuppertal, Germany

15. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 15 Generating island buckets

16. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 16 Generating island buckets

17. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 17 Orbit in island buckets

18. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 18 Generating island buckets also 5th

19. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 19 Generating island buckets Short time (ns) Resonant excitation

20. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 20 How does that look like that at the end of a beamline ? Undulator radiation Bending radiation Note: each bucket delivers individual beam spot ! direct: no optical elements Island Bucket as source point

21. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 21 Application at MLS: sub harmonic revolution frequency - 2 out of 3 islands cleared using a (non-linear) FB-kicker and exciting with modified Feedback Unit (h changed from 80-> 240) -drift of all e- to a single Bunch in only one island: at observation point all e- jumping from one island to next in consecutive rev. -orbit bump together with BL-apertures steer light of only one single island position to experiment. Result: -> only at every 3rd revolution SY-light is hitting experiment Bunch filling measured with streak camera that is receiving light from one single island only regular first island populated second island populated

22. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 22 Final Photon counter signal at experiment Purity during measurements < % level Adjusting orbit at experiment for high Purity Sub harmonic user signal very stable over 10h for several days -> ARTOF exp. performed succesfully (to be published ) 160 ns because 2 out 3 islands seen by beamline Time structure of island buckets at BL This was used in ARTOF experiment

23. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 23 Single bunch user would very much like to measure also in multi bunch mode („pseudo single bunch“) Pseudo Single Bunch

24. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 24 How to direct SY radiation of one single bunch to the experiment while the filling pattern is multi bunch ? radiation Intensity reduced by ~ 1/1000 Single Bunch and Multi Bunch Methods of Signal Separation

25. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 25 Solution realized recently at BESSY II : -create island bucket (straightforward using the experience gained at MLS) -by proper excitation populate single bunch in selected island (using resonant single bunch excitation) -steer beamline to island bucket Island buckets at BESSY II: Pinhole imaging system Single Bunch and Multi Bunch Methods of Signal Separation

26. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 26 Different time structures at beam line (detection with Avalanche diode), realized out of standard MB Filling by selective island bucket filling Single Bunch and Multi Bunch Methods of Signal Separation

27. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 27 Some observations comparing island buckets at MLS and BESSY II -island buckets for BESSY II users at least as stable as pseudo single bunch achieved with other methods but (much) more intensity -User run planned at BESSY II with 8 island single bunches in MB Filling -many more applications of island buckets evident as separation of long and short bunche signals at BESSY VSR, new injection schemes etc. -Once you know the relevant patterns, Island buckets can most probably be realized at any existing SY Light Source without major hardware changes -> Try it ! -if it doesnt work: just ask Paul or Markus. Conclusions of Island bucket experiments at MLS and BESSY II

28. J. Feikes, HZB (Berlin, Germany) Experimental Observations at the Metrology Light Source, LER15 Grenoble, France 15-17/9/15 28 Thank you for your attention !