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Lecture 6. New FEL Schemes and Challenges X-Ray Free Electron Lasers Igor Zagorodnov Deutsches Elektronen Synchrotron TU Darmstadt, Fachbereich 18 22.

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Presentation on theme: "Lecture 6. New FEL Schemes and Challenges X-Ray Free Electron Lasers Igor Zagorodnov Deutsches Elektronen Synchrotron TU Darmstadt, Fachbereich 18 22."— Presentation transcript:

1 Lecture 6. New FEL Schemes and Challenges X-Ray Free Electron Lasers Igor Zagorodnov Deutsches Elektronen Synchrotron TU Darmstadt, Fachbereich June 2014

2 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 2 Contents  Motivation  Self-seeding scheme  Nonlinear harmonic generation  High-gain harmonic generation (HGHG)  Echo-enabled harmonic generation (EEHG)  Harmonic lasing  Purified SASE scheme (pSASE)  Energy spread cooling scheme  Table-top FEL  Outlook

3 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 3 electrons radiation Motivation Longitudinal profile with large statical fluctuations Transverse profile is coherent Coherence

4 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 4 Motivation Coherence Cooperation length: l c ~  π ρ (slippage length within one gain length) FEL spectrum c/  πl c c/l b FEL power πlc πlc lb lb seed

5 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 5 Self-seeding scheme J. Feldhaus et al, Opt.Comm. 140, p.341 (1997) G.Geloni et al, DESY (2010)  SASE in the first undulator  monochromator filters the radiation  „seeded“ amplification in the second undulator  Grating monochromator  Gas cell monochromator SASE SASE-FEL electronen radiation amplifier monochromator

6 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 6 Non-linear harmonic generation Higher harmonics in undulator (spontaneous radiation) Spectral density in forward direction. The absolute bandwidth is the same

7 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 7 Non-linear harmonic generation Higher harmonics in FEL radiation Coupling factor in Lecture 3?

8 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 8 Non-linear harmonic generation A steady energy transfer? The electron energy changes as described by the equation

9 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 9 Nonlinear harmonic generation

10 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 10 Nonlinear harmonic generation A steady energy transfer?

11 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 11 Nonlinear harmonic generation Effective coupling factors

12 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 12 Nonlinear harmonic generation K = 1 K = 3 K = 10 Ratio of power gain length at the n-th harmonic to that at the fundamental:

13 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 13 Nonlinear harmonic generation Normalized high-gain FEL model

14 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 14 Nonlinear harmonic generation

15 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 15 Nonlinear harmonic generation

16 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 16 Nonlinear harmonic generation  Near saturation, roughly 1% of the power of fundamental is emitted in the third harmonic  Spectrum has the same width as that of the fundamental  The maximal power is decreasing function of harmonic number  Nonlinear harmonics have larger statistical power fluctuations from shot to shot

17 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 17 High-gain harmonic generation (HGHG)  energy modulation with frequency ω  conversion in density modulations  coherent radiation with frequency nω in radiator section

18 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 18 High-gain harmonic generation (HGHG)  in modulator energy changes  phase remains approx. the same

19 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 19 High-gain harmonic generation (HGHG)  in chicane higher energy particles are bent less than lower energy particles  energy of particles remains approx. the same

20 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 20 High-gain harmonic generation (HGHG)

21 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 21 High-gain harmonic generation (HGHG)

22 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 22 High-gain harmonic generation (HGHG) L.H.Yu et al, PRL 91, (2003) HGHG was demonstrated at the third harmonic of 800 nm temporally coherent radiation

23 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 23 Echo-enabled harmonic generation G. Stupakov, PRL 102, (2009)

24 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 24 Echo-enabled harmonic generation

25 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 25 Echo-enabled harmonic generation

26 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 26 Echo-enabled harmonic generation For HGHG For EEHG

27 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 27 Echo-enabled harmonic generation  the first laser produces energy modulation  the first chicane is strong, rotates phase space  the second laser produces again energy modulation  The second chicane converts the energy modulation in density modulation G. Stupakov, PRL 102, (2009)

28 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 28 Echo-enabled harmonic generation D.Xiang et al, PRL D.Xiang et al, PRL 108, (2012) experiment for EEHGonly the second laser ON both lasers ON

29 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 29 Harmonic lasing non-linear harmonic generation harmonic lasing

30 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 30 Harmonic lasing retuned to fundamental harmonic only

31 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 31 Harmonic lasing retuned to fundamental harmonic only

32 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 32 Harmonic lasing

33 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 33 Purified SASE scheme U1 U2 U3 … … U7 U8 U9 U10 U11 U12 U13 … U18 K = 2, λ 1 =0.6 nm 6 GeV K =6.3,λ 1 =4.2 nm λ 1 =0.6 nm

34 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 34 Purified SASE scheme U1 U2 U3 … … U7 U8 U9 U10 U11 U12 U13 … U18 K = 2, λ 1 =0.6 nm 6 GeV K =6.3,λ 1 =4.2 nm λ 1 =0.6 nm At the exit of U10 At the exit of U11 At the exit of U9  πl c ≈ 1 fs At the exit of U12  πl c ≈ 4~ 5 fs

35 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 35 Energy spread cooling scheme H.Deng, arXiv: (2013)

36 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 36 Energy spread cooling scheme

37 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 37 Energy spread cooling scheme Two electrons through modulator

38 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 38 Energy spread cooling scheme H.Deng, arXiv: (2013)

39 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 39 Energy spread cooling scheme H.Deng, arXiv: (2013)

40 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 40 Energy spread cooling scheme 1D simulations 3D simulations H.Deng, arXiv: (2013)

41 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 41 Table-top FEL External injection

42 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 42 Table-top FEL “Bubble” regime

43 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 43 Table-top FEL M.Fuchs et al, Nature Physics 5, 826(2009) H.-P. Schlenvoigt et al, Nature Physics 4, 130 (2008)  λ=740 nm  λ=17 nm spontaneous undulator radiation with laser-plasma accelerator

44 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 44 Table-top FEL M.Fuchs et al, Nature Physics 5, 826(2009) no FEL radiation so far

45 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 45 European XFEL 3rd SR generation 2nd SR generation 1st SRs Outlook Growth of brillance of X-ray and growth of computer power

46 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 46 Outlook Saturation? Wavelength of radiation λ= 0.25 A MaRIE (Los Alamos) concept Q. R. Marksteiner, FEL 2011, TUPA28, 2011 λ=0.5 A

47 PD Dr. Igor Zagorodnov| X-Ray Free Electron Lasers. Lecture 6 | 22. June 2014 | Seite 47 Outlook  shorter wave length  shorter radiation pulses  higher brilliance  longitudinal coherence  compact facilities „Meine Vision für DESY ist dass wir die deutsche Nobelpreisschmiede werden.“ Professor Helmut Dosch (Film „Licht der Zukunft“)


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