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![Page 1: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/1.jpg)
The ORS at FLASH and sFLASH
Peter van der Meulen
Stockholm UniversityDiv. Molecular Physics
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
a new diagnostic tool for characterizing electron bunches
![Page 2: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/2.jpg)
ORS: Optical Replica Synthesizer
FLASH, XFEL, JFEL, LCLS: SASE
electron bunch properties: longitudinal density profileslice emittanceslice energy spread
SASE is very sensitive to the properties of the electron bunch
need to control and measure these properties!
electron bunch: moving at v ≈ cca. 20 m longca. 100 m wide
hard to measure directly measure an optical copy instead
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 3: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/3.jpg)
ORS: Optical Replica Synthesizer
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 4: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/4.jpg)
ORS: Optical Replica Synthesizer
Erbium fiber oscillator:• 1550 nm• ca. 54 MHz• amplified• frequency doubled, 1 mm PPLN• 1 – 5 mW
Clark-MXR CPA2001• Ti:Sapph CPA system • 5 Hz (1 kHz)• ca. 700 J/pulse• 0.2 – 3.0 ps
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 5: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/5.jpg)
ORS: temporal overlap
Er:fiberoscillator
stretcher compressorTi:Sapphamplifier
to tunnel
ca.54 MHzpulse train
FLASH 5 Hz trigger
ca.19 ns
Fourier Transform 24th harmonic
ca. 1.3 GHz
diff. freq.mixing
FLASH RF1.3 GHz
vectormodulator
Matlab progam
piezo +delay
…+ cos[(.t + ] = 0
delay
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 6: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/6.jpg)
ORS: Magnet structures
Undulators:• electromagnets• 1450 mm• 40 mm gap, 0.5 T max.• 14 poles (1/4,-3/4,1,-1…)• 4 power supplies• modulator vertical• radiator horizontal
Chicanes:• 4 dipole magnets• 1300 mm
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 7: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/7.jpg)
ORS: spatial overlap
calibration and OTR screens on7Match and 3SUND1
Joern Boedewadt
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 8: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/8.jpg)
ORS: temporal overlap
0 1 2 3 4 5 6
0
0.2
0.4
0.6
0.8
1
Time (ps)
Coh
eren
t O
TR
int
ensi
ty (
arb.
uni
ts)
CoherentOTR
@ 385 nm
PRSTAB 11, 070702, 2008FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 9: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/9.jpg)
GRENOUILLE*
based on SH FROG technique (autocorrelator + spectrometer)
single shot measurement
2D phase retrieval algorithm => fully characterized pulse
Electric field profile electron bunch profile (I4)
femtosecond optical pulse characterization
* Swamp Optics
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 10: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/10.jpg)
ORS: FROG trace
seed laser pulse: ca. 400 fs FWHMFROG trace: ca. 150 fs FWHM FLASH’s electron bunch spike?
Compatible with SASE!!!FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 11: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/11.jpg)
ORS: FROG trace
• ca. 1-5 J/pulse
• ca. 150 fs FWHM
• no direct comparison with TDC (LOLA) FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
-800 -600 -400 -200 0 200 400 600 8000
0.2
0.4
0.6
0.8
1
E-f
ield
(ar
b. u
nits
)
Time (fs)-800 -600 -400 -200 0 200 400 600 800
-5
-3
-1
1
3
5
Pha
se (
rad)
![Page 12: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/12.jpg)
ORS at FLASH
Some remaining issues:
• cross check with TDC (LOLA) and/or EO measurement
• laser power: 1 mJ/ pulse 30 mJ/pulse
• better digital data collection: 8 bit 12/16 bit
• what happens under further bunch compression? CSR?
• what is the future of the ORS?
The ORS seems to work, but…
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 13: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/13.jpg)
ORS: FROG trace
A FROG trace obtained upon further compressing the electron bunch:
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 14: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/14.jpg)
ORS at sFLASH
temporary shutdown September 2009
rebuild ORS in new position
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 15: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/15.jpg)
ORS at FLASH
Other applications of the ORS:
• phase of optical replica pulse energy chirp of electron bunch
• slice energy spread
• slice emittance
• 3D spatial electron bunch characterization via coherent OTR
• ‘echo’ test experiments (G. Stupakov, SLAC-PUB-13445, Oct. 2008)
• ORFIR
• general study laser – electron interactions
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 16: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/16.jpg)
conclusions
• first ORS results obtained in 2009!!!
• the ORS seems a very useful addition to (s)FLASH, as a diagnostic device. Some issues deserve further study.
• more (parasitic) beam time is required to make the ORS a standard and routine diagnostic technique.
• ‘alternative’ applications of the ORS appear very promising.
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 17: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/17.jpg)
DESY, 27 January 2009
Collaborators
Stockholm University: Peter Salen Mathias Hamberg Mats Larsson
Uppsala University: Volker Ziemann Gergana Angelova-Hamberg
DESY: Holger Schlarb Florian Löhl
Hamburg University: Joern Boedewadt Axel Winter Shaukat Khan
BESSY: Atoosa Meseck
DESY: E. Saldin, E. Schneidmiller & M. Yurkov
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 18: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/18.jpg)
THANK YOU!
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 19: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/19.jpg)
ORS: temporal overlap
Holger SchlarbFlorian Löhl
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 20: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/20.jpg)
ORS @ sFLASH
What to do:
• move undulators, dipoles and optical stations (+ cables)
• re-build OS1 chicane in vertical plane; re-design OS2 chicane
• change to HHG laser; 10% beamsplitter, ca. 4 mJ/pulse + compression
• improve laser beam diagnostics
• insert new OTR screens: diffuse scattering screen doped YAG screen for e-beam and laser? better optical quality: surface and flatness
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 21: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/21.jpg)
DESY, 27 January 2009
BOA pulse compressorBother-free Optimized Arrangement
Swamp Optics
fused silicatransmission
grating,ca. 1000 l/mm
• no angular dispersion• no pulse front tilt• no spatial chirp
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
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• imaging using coherent OTR/ODR: longitudinal bunch profile high k – small wavelength compared to THz measurements high intensity
I(r) N d2r’ dz (r’,z) Eone-electr(r-r’) 2
+
N2 d2r’ dz exp(-ikz) (r’,z) Eone-electr(r-r’) 2
Icoh(r) N2 d2 (,k) ( exp(ir))/( 2 + 2) 2 = k/
if (,k) = f() . g(k) X
but….
ORS contributions to sFLASH
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources
![Page 23: The ORS at FLASH and sFLASH Peter van der Meulen Stockholm University Div. Molecular Physics FLS2010, March 1-5, 2010, 48 th ICFA Advanced Beam Dynamics.](https://reader036.fdocuments.net/reader036/viewer/2022062519/5697c0091a28abf838cc7443/html5/thumbnails/23.jpg)
The ORS as a routine diagnostic?PR
STA
B 1
1, 0
7070
2, 2
008
what about the possibility to do an image reconstructionusing algorithms similar to those applied in single-particle
X-ray diffraction?
multiple k’s and modulation using chirped seed pulses
FLS2010, March 1-5, 2010, 48th ICFA Advanced Beam Dynamics Workshop on Future Light Sources