The beamlines: From diagnostics to microfocusing

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The FERMI@Elettra beamlines: From diagnostics to microfocusing M.

Abrami,, D. Bacescu, D. Cocco (project leader),, I. Cudin,, C. Fava, D.

1 The beamlines: From diagnostics to microfocusing M. Zangrando On behalf of the Photon Beam Transport System: A. Abrami,, D. Bacescu, D. Cocco (project leader),, I. Cudin,, C. Fava, D. Giuressi, R. Godnig, D. Lonza,, F. Parmigiani, L. Rumiz,, R. Sergo,, C. Svetina Trieste, October 9 th 2008

2 parameters Parameter FEL 1 FEL 2 Wavelength (nm) Pulse length FWHM (fs) Bandwidth rms (mev) 20 5 Polarization Variable Variable Peak power (GW) Photons per pulse (100 nm) (10 nm) Brightness (Ph/s/mm 2 /mrad 2 /0.1%BW) Power fluctuation (%) 25 > 50 Central wavelength fluctuation Within BW Within BW Pointing fluctuation (µrad) < 5 < 5 Source size FWHM (µm) Divergence rms (µrad) Repetition rate (Hz) M.Zang rand o - AC TOP08 - Oct ober 9 th

3 Photon beam transport system Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Spectrometer Switching mirror(s) LDM Diproi Gas cell I0 monitors 10 m EIS M.Zang rand o - AC TOP08 - Oct ober 9 th

4 Damage threshold Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Gas cell I0 monitors 10 m FEL 1: 100 fs; 5 GW! ~ 0.5 mj FEL 2: 200 fs; 1 GW! ~ 0.2 mj mj pulse in the sub ps regime! 10 or more mj/cm 10 m A. Andrejczuk et al. DESY annual report 2001 D. Von der Linde et al. Appl. Surf. Science 154 (2000) Y. Hirayama et al. Appl. Surf. Science 197 (2002) H. Jeschke et al. Appl. Surf. Science 197 (2002) (2 articles) J. Kuba et al. NIM A 507 (2003) L. Juha et al. NIM A 507 (2003) V. Schmidt et al. Appl. Surf. Science 197 (2002) K. Venkatakrishnan at al. Optics & laser technology 34 (2002) Y. Dong et al. Appl. Surf. Science 252 (2005) M.Zang rand o - AC TOP08 - Oct ober 9 th

5 Damage threshold Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Gas cell I0 monitors 10 m FEL 1: 100 fs; 5 GW! ~ 0.5 mj FEL 2: 200 fs; 1 GW! ~ 0.2 mj mj pulse in the sub ps regime! 10 or more mj/cm 10 m Safety margin=100 (no reflectivity considered) Material Damage 90 nm Safety angle 100 nm (10 /20/40 m) Estimated damage 40 nm Safety angle 40 nm (10 /20/40 m) Cu/Glidcop bilk ~ 500 mj/cm 2 24 / 90 / 90 ~ 1000 mj/cm 2 41 / 90 / 90 Au coating 40 mj/cm / 7.6 / mj/cm / 20 / 77 Silicon bulk 30 mj/cm / 6 / 23 Graphite coating 60 mj/cm / 11.5 / mj/cm 2 9 / 40 / 90 YAG bulk 70 mj/cm / 13.4 / 68 Fel 1 Fel 2 M.Zang rand o - AC TOP08 - Oct ober 9 th

6 Damage threshold Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Gas cell I0 monitors 10 m Reflectivity Carbon (2 3 """") 10 nm 5 nm 3 nm Photon energy (ev) M.Zang rand o - AC TOP08 - Oct ober 9 th

Mirrors coating Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Gas cell I0 monitors 10 m 1.0 0.8 Reflectivity 0.6 0.4 0.

7 Mirrors coating Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Gas cell I0 monitors 10 m Reflectivity Carbon (2 3 """") Gold (2 3 """") Nickel (2 3 """") 10 nm 5 nm 3 nm Photon energy (ev) M.Zang rand o - AC TOP08 - Oct ober 9 th

8 Photon diagnostics Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Spectrometer Switching mirror(s) LDM Diproi Gas cell I0 monitors 10 m EIS There will be the possibility to measure the following characteristics: Intensity: On line; Shot by shot; 1% repeatability, 2-3% precision (calibration dependent) Angular position: On line; Shot by shot; ~ 2 µrad sensibility Divergence: NOT On line; NOT Shot by shot; based on YAG crystal measurements Photon energy distribution: On line; Shot by shot; Single spectrometer, ev sub mv resolution. Arrival time: On line; Shot by shot; Visible streak camera (Timing and Synchronization Area) ps resolution Wavefront: Hartmann sensor (Imagine Optic), Precision #/50 at 20-5 nm range or CCD Pulse length measurement: NOT On line; NOT Shot by shot; M.Zang rand o - AC TOP08 - Oct ober 9 th

BPMs and I0 monitors On line I0 monitor Beam Position Monitor Collect na/pa signals using an already internally-developed fa precision acquisition board (ref. D.

9 BPMs and I0 monitors On line I0 monitor Beam Position Monitor Collect na/pa signals using an already internally-developed fa precision acquisition board (ref. D. Giuressi) Micrometer precision movement Gap f(h%) P $ 10-5 mbar Photon beam Photon beam Applied Voltage (Bias) + or - depending on tests/noise Calibrated with High precision IRD photodiodes (4% absolute calibration, <0.1% repeatability) In collaboration with the Instrumentation Group and T-REX lab for prototyping the systems M.Zang rand o - AC TOP08 - Oct ober 9 th

Gas reduction cell Valves FEL 1 FEL 2 Slits Gas cell I0 monitors 1 st mirror(s) 10 m 5 10 0 10-1 10-2

1 mbar) 20 40 60 80 100 Gas Absorber Cell: length = 6 m - Maximum attenuation on the whole photon

10 Gas reduction cell Valves FEL 1 FEL 2 Slits Gas cell I0 monitors 1 st mirror(s) 10 m Kr (0.1 mbar) Gas Absorber Cell: length = 6 m - Maximum attenuation on the whole photon energy range = Use of different gases at different pressures - Preservation of coherence, statistics, spectrum, etc. M.Zang rand o - AC TOP08 - Oct ober 9 th

11 Photon diagnostics Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Spectrometer Switching mirror(s) LDM Diproi Gas cell I0 monitors 10 m EIS There will be the possibility to measure the following characteristics: Intensity: On line; Shot by shot; 1% repeatability, 2-3% precision (calibration dependent) Angular position: On line; Shot by shot; ~ 2 µrad sensibility Divergence: NOT On line; NOT Shot by shot; based on YAG crystal measurements Photon energy distribution: On line; Shot by shot; Single spectrometer, ev sub mv resolution. Arrival time: On line; Shot by shot; Visible streak camera (Timing and Synchronization Area) ps resolution Wavefront: Hartmann sensor (Imagine Optic), Precision #/50 at 20-5 nm range or CCD Pulse length measurement: NOT On line; NOT Shot by shot; M.Zang rand o - AC TOP08 - Oct ober 9 th

Energy spectrometer Variable Line Spacing grating ~97% to the beamlines! D> ;!< Preliminary design (I.Cudin) ~0.1% to the detector D< ;!> G1!N 0 =500 l/mm, N 1 =0.35 l/mm 2, N 2 =1.

12 Energy spectrometer Variable Line Spacing grating ~97% to the beamlines! D> ;!< Preliminary design (I.Cudin) ~0.1% to the detector D< ;!> G1!N 0 =500 l/mm, N 1 =0.35 l/mm 2, N 2 =1.7x10-4 l/mm 3 Graphite coated ev in 1st and 2nd order &E: 0.2 mev to 3 mev G2!N 0 =1800 l/mm, N 1 =1.26 l/mm 2, N 2 =6.3x10-4 l/mm 3 Ni coated ev in 1st and 2nd order &E: 0.3 mev to 3-4 mev M.Zang rand o - AC TOP08 - Oct ober 9 th

13 Energy spectrometer Preliminary design (I.Cudin) ~97% to the beamlines ~0.1% to the detector YAG Crystal to convert XUV into Visible 1.8 Conversione efficiency (Photon out/photon in) Nd:YAG SuperESCA Photon energy (ev) M.Zang rand o - AC TOP08 - Oct ober 9 th

14 Energy spectrometer Photon energy (ev) Photon per pulse Bandwidth (mev) Grating efficiency Screen efficiency (Vis ph out/xuv ph in) CCD efficiency Spot dimension ( m) Energy resolution (mev) Expected photon per pixel (10x10 m 2 ) with demagnification 2:1 12 ~ % 0.25 ~ 85% 4.5 m X13mm 0.3 ~ 250, ~ % 0.4 ~ 85% 5.9 m X5.2mm 1.0 ~ 1,200, ~ % 1 ~ 85% 4.8 m X1.6mm 2.4 ~ 125,000 Use of a set of visible filters 1.8 Conversione efficiency (Photon out/photon in) Nd:YAG SuperESCA Photon energy (ev) M.Zang rand o - AC TOP08 - Oct ober 9 th

15 Photon diagnostics Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Spectrometer Switching mirror(s) LDM Diproi Gas cell I0 monitors 10 m EIS There will be the possibility to measure the following characteristics: Intensity: On line; Shot by shot; 1% repeatability, 2-3% precision (calibration dependent) Angular position: On line; Shot by shot; ~ 2 µrad sensibility Divergence: NOT On line; NOT Shot by shot; based on YAG crystal measurements Photon energy distribution: On line; Shot by shot; Single spectrometer, ev sub mv resolution. Arrival time: On line; Shot by shot; Visible streak camera (Timing and Synchronization Area) ps resolution Wavefront: Hartmann sensor (Imagine Optic), Precision #/50 at 20-5 nm range or CCD Pulse length measurement: NOT On line; NOT Shot by shot; M.Zang rand o - AC TOP08 - Oct ober 9 th

16 Pulse length measurement VUV pulse lengths can be measured by: - Cross-correlation,, with a short-pulse laser. Can be applied to many systems (Above Threshold Ionization of noble gases, pump-probe of molecules, etc.) BUT time resolution is determined by jitter - Streak camera type techniques: collaboration ST-Hamamatsu for a sub-ps EUV-SXR streak camera (Ref. F. Parmigiani, M. Zangrando) - Autocorrelation (beam splitting). Precision depends entirely on mechanical design of optics. Requires non-linear phenomena. Courtesy by K. Prince M.Zang rand o - AC TOP08 - Oct ober 9 th

17 Pulse length measurement Autocorrelation by using Helium! - first ionization potential is high, 24.6 ev, second is ev, - calculations exist, laser harmonic results exist, - canonical three body system. For FEL1, we can choose energies below 24.6 for non-resonant to continuum or resonant to continuum two photon ionization. For FEL2, we can choose two-photon, double ionization (above 79 ev). Feasibility Cross-section is cm 4 s. We estimate count rates of 1 to 100 counts/sec, for a 20x20 micron spot. Courtesy by K. Prince M.Zang rand o - AC TOP08 - Oct ober 9 th

18 Pulse length measurement m 0 m 1 ML1 DELAY: w/o multilayer -0.9! 17 ps (3 movements) with multilayer -7 ps! ns ' 1max h=150 mm ' 1min ' 2 ML2 ' 1min = 3.8 ' 1max = 8 Valves ' 2 = 4 FEL 1 m 0 = 1200 mm 1 st mirror(s) FEL 2 Slits m 1 = 630 mm (Dh=42mm) Gas cell 10 m m 2 = 2150 I0 monitors mm 5 Spectrometer Switching mirror(s) m 2 LDM Diproi EIS M.Zang rand o - AC TOP08 - Oct ober 9 th

Refocusing section Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Spectrometer Switching

Wavefront/coherence preservation Decoupled focusing (H vs.

plane-elliptical mirrors Source M1 ~ 75 m; M2 Exp. chamber ~ 0.

19 Refocusing section Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Spectrometer Switching mirror(s) LDM Diproi Gas cell I0 monitors 10 m EIS Focus on: Very high fluence Wavefront/coherence preservation Decoupled focusing (H vs. V) Variable source position Kirpatrick-Baez system with two variable shape plane-elliptical mirrors Source M1 ~ 75 m; M2 Exp. chamber ~ 0.8 m Spot FEL 1: on focus 4x2.5 µm 2 (~ 3x10 16 W/cm 2 ) Spot FEL 2: on focus 3.5x2 µm 2 (~ 7x10 15 W/cm 2 ) M.Zang rand o - AC TOP08 - Oct ober 9 th

Wavefront preservation Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Spectrometer Switching mirror(s) LDM Diproi Gas cell I0 monitors 10 m Fermi@elettra case Wavelength Angle of incidence shape error p

20 Wavefront preservation Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Spectrometer Switching mirror(s) LDM Diproi Gas cell I0 monitors 10 m Fermi@elettra case Wavelength Angle of incidence shape error p -v! =0.25 shape error p -v! = nm nm nm nm nm nm nm nm nm EIS Ok for plane and spherical surfaces. Almost impossible for toroidal, elliptical $ = 2 # h%sin"! M.Zang rand o - AC TOP08 - Oct ober 9 th

21 Active optics project x 2 - sin +, b a 2 * ( + ) y 2 - cos +, b 2 2. * ( ' ) - 4 f x+, cos. * 2 b ( ' ) & 2sin. xy$ $ % e b 2 2 ' sin 2. #!!" = 0 where: f ' 1 = % & r + 1 $ " r' #! 1 Need for a 3 rd order approximation in shape F 1 F 2 Two unequal moments applied at the edges M.Zang rand o - AC TOP08 - Oct ober 9 th

22 Active optics project Higher orders corrected by: Dynamic variation of the moment of Inertia Dynamic variation of the moment of Inertia Correction of low frequency shape errors M.Zang rand o - AC TOP08 - Oct ober 9 th

23 Active optics project Mirror profile (mm) Correction of low frequency shape errors Higher order p=70m corrected q=0.9 m!=3 by: F 2 F 1 0 Source M1 ~ 75 m; M2 - exp cham. ~ 0.8 m, Spot FEL 1: on focus 4X2.5 µm 2 (~ 3x10 16 W/cm 2 ) Spot FEL 2: on focus 3.5X2 µm 2 (~ 7x10 15 W/cm 2 ) Mirror position (mm) 150 Dynamic variation of the moment of Inertia Obtained without 3rd order compensation M.Zang rand o - AC TOP08 - Oct ober 9 th

24 Active optics project F 1 F 2 200x nm 150 Mirror profile (mm) Electrode position 2.5 nm Mirror profile measurement over days with electrode in operation (30V) Position (mm) M.Zang rand o - AC TOP08 - Oct ober 9 th

25 Active optics project F F Incertitude 1/700 Reading (a.u.) Sampling (-) Measurement of the local radius of curvature using strain gauges glued on the back of the mirror M.Zang rand o - AC TOP08 - Oct ober 9 th

26 Focusing systems comparison A z x K T K T (~ 4x10 15 W/cm 2 ) (~ 3x10 16 W/cm 2 ) S M O N y T L L M.Zang rand o - AC TOP08 - Oct ober 9 th

27 EIS focusing system Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Spectrometer Switching mirror(s) LDM Diproi Gas cell I0 monitors 10 m EIS Simplified to have just 4 angles and 3 wavelength Higher/lower orders contamination < 1% Vertical focusing mirror ~ 0.75 m Half deflecting beam or energy selective mirror 2 incidence ~ 0.75 m F Horizontal focusing active mirrors 2 incidence Plane deflecting mirrors Variable position/angle and variable coatings M.Zang rand o - AC TOP08 - Oct ober 9 th sample

28 EIS focusing system Multilayer delay line Theta 3rd H (deg) Theta 1st H (deg) 60 nm 40 nm 20 nm m < length < 5 m Delay required: -10 ps < &t < 5 ns -3 mm < &t < 1.5 m Precision: 10 fs (3µm) M.Zang rand o - AC TOP08 - Oct ober 9 th

29 EIS focusing system Theta 3rd H (deg) Theta 1st H (deg) 60 nm 40 nm 20 nm Delay required: -10 ps < &t < 5 ns -3 mm < &t < 1.5 m Precision: 10 fs (3µm) M.Zang rand o - AC TOP08 - Oct ober 9 th

30 EIS focusing system Theta 3rd H (deg) Theta 1st H (deg) 60 nm 40 nm 20 nm Delay required: -10 ps < &t < 5 ns -3 mm < &t < 1.5 m Precision: 10 fs (3µm) M.Zang rand o - AC TOP08 - Oct ober 9 th

31 EIS focusing system Higher/lower orders contamination < 1% Beam splitting mirror Co/C 100 layers d=4.6 nm Ratio eff. 6.33nm/eff. 20nm 1 mirror! 57 2 mirrors! mirrors! 10 7 Refelctivity (-) Source: Intensity 20nm 1 st harm Intensity 6.33nm ( ) ( 3 rd harm) " Wavelength (nm) ! 24 Material Effi ciency 40 nm Sc/S i 70% 20 nm Mo/Si 70% 13.3 nm Mo/Si 75% 6.33 nm Co/C 50% M.Zang rand o - AC TOP08 - Oct ober 9 th

32 Schedule Valves FEL 1 FEL 2 Slits 1 st mirror(s) 5 Spectrometer Switching mirror(s) LDM Diproi Gas cell I0 monitors 10 m EIS M.Zang rand o - AC TOP08 - Oct ober 9 th

33 THANK YOU FOR YOUR ATTENTION M.Zang rand o - AC TOP08 - Oct ober 9 th

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