FEL2014 - List of Authors (Buck, J.)

Paper

Title

Page

Implementation Phase of the European XFEL Photon Diagnostics

41

J. Grünert, J. Buck, F. Dietrich, W. Freund, A. Koch, M. Planas
XFEL. EU, Hamburg, Germany

The European XFEL facility with 3 undulators and initially 6 experimental end-stations requires an extensive set of photon beam diagnostics for commissioning and user operation, capable of handling the extreme brilliance and its inherent damage potential, and the high intra bunch train repetition rate of 4.5MHz, potentially causing additional damage by high heat loads and making shot-to-shot diagnostics very demanding [1]. After extensive design [2-4] and prototype studies, in 2014 the installation of the photon beam devices starts with the equipment in the first photon tunnel XTD2 which is where the SASE1 hard X-ray undulator is located. This contribution reports on the device construction progress by focusing on the XTD2 tunnel devices and their implementation into the tunnel environment. [1] J.Grünert, Framework for X-Ray Photon Diagnostics at the European XFEL, TR-2012-003, 04/2012 [2] J.Buck, Online Photoemission Time-of-Flight Spectrometer for X-ray Photon Diagnostics, TR-2012-002, 06/2012 [3] C.Ozkan, Conceptual design report for Imaging Stations at the European XFEL, TR-2012-004, 02/2012 [4] W.Freund, The European XFEL Undulator Commissioning Spectrometer, XFEL. EU 05/2011

MOP014

X-ray Photon Temporal Diagnostics for the European XFEL

45

J. Liu, J. Buck, F. Dietrich, W. Freund, J. Grünert, M. Meyer
XFEL. EU, Hamburg, Germany

European XFEL (XFEL. EU) that will commissioning in 2016 shows great features on its extremely high number of light bullets (27000 p/s) and extremely high average brilliance. The FEL pulses in XFEL. EU are produced in a 10 Hz bunch trains that contains 2700 sub-pulses within the 600 μs time intervals, corresponding to a 220 ns sub-pulse separation and 4.5 MHz repetition rate. Characterizing the temporal properties of the high repetition rate FEL pulses that implicitly different from shot to shot is important for “pump and probe” experiments and data interpretation. Here we report the concept and recent progress about temporal diagnostic for XFEL. EU. THz streaking technique and spectral encoding will be implemented considering the high repetition rate and high brilliance of XFEL. EU. Laser based THz generation, optimization and numerical simulation for streaking FEL electrons with different photon energies will be presented. High repetition rate diagnostic requirements and solutions will also be discussed.

THA02

Experimental Characterization of FEL Polarization Control with Cross Polarized Undulators

644

E. Ferrari, E. Allaria, G. De Ninno, B. Diviacco, D. Gauthier, L. Giannessi, G. Penco, C. Spezzani
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
J. Buck, M. Ilchen
XFEL. EU, Hamburg, Germany
G. De Ninno, D. Gauthier
University of Nova Gorica, Nova Gorica, Slovenia
L. Giannessi
ENEA C.R. Frascati, Frascati (Roma), Italy
Z. Huang, A.A. Lutman
SLAC, Menlo Park, California, USA
G. Lambert, B. Mahieu
LOA, Palaiseau, France
J. Viefhaus
DESY, Hamburg, Germany

Polarization control of the coherent radiation is becoming an important feature of recent and future short wavelength free electron laser facilities. While polarization tuning can be achieved taking advantage of specially designed undulators, a scheme based on two consecutive undulators emitting orthogonally polarized fields has also been proposed. Developed initially in synchrotron radiation sources, crossed polarized undulator schemes could benefit from the coherent emission that characterize FELs. In this work we report the first detailed experimental characterization of the polarization properties of an FEL operated with crossed polarized undulators in the Soft-X-Rays. Aspects concerning the average degree of polarization and the shot to shot stability are investigated together with a comparison of the performance of various schemes to control and switch the polarization

Slides THA02 [5.383 MB]

Paper	Title	Page
MOP012	Implementation Phase of the European XFEL Photon Diagnostics	41
	J. Grünert, J. Buck, F. Dietrich, W. Freund, A. Koch, M. Planas XFEL. EU, Hamburg, Germany
	The European XFEL facility with 3 undulators and initially 6 experimental end-stations requires an extensive set of photon beam diagnostics for commissioning and user operation, capable of handling the extreme brilliance and its inherent damage potential, and the high intra bunch train repetition rate of 4.5MHz, potentially causing additional damage by high heat loads and making shot-to-shot diagnostics very demanding [1]. After extensive design [2-4] and prototype studies, in 2014 the installation of the photon beam devices starts with the equipment in the first photon tunnel XTD2 which is where the SASE1 hard X-ray undulator is located. This contribution reports on the device construction progress by focusing on the XTD2 tunnel devices and their implementation into the tunnel environment. [1] J.Grünert, Framework for X-Ray Photon Diagnostics at the European XFEL, TR-2012-003, 04/2012 [2] J.Buck, Online Photoemission Time-of-Flight Spectrometer for X-ray Photon Diagnostics, TR-2012-002, 06/2012 [3] C.Ozkan, Conceptual design report for Imaging Stations at the European XFEL, TR-2012-004, 02/2012 [4] W.Freund, The European XFEL Undulator Commissioning Spectrometer, XFEL. EU 05/2011

MOP014	X-ray Photon Temporal Diagnostics for the European XFEL	45
	J. Liu, J. Buck, F. Dietrich, W. Freund, J. Grünert, M. Meyer XFEL. EU, Hamburg, Germany
	European XFEL (XFEL. EU) that will commissioning in 2016 shows great features on its extremely high number of light bullets (27000 p/s) and extremely high average brilliance. The FEL pulses in XFEL. EU are produced in a 10 Hz bunch trains that contains 2700 sub-pulses within the 600 μs time intervals, corresponding to a 220 ns sub-pulse separation and 4.5 MHz repetition rate. Characterizing the temporal properties of the high repetition rate FEL pulses that implicitly different from shot to shot is important for “pump and probe” experiments and data interpretation. Here we report the concept and recent progress about temporal diagnostic for XFEL. EU. THz streaking technique and spectral encoding will be implemented considering the high repetition rate and high brilliance of XFEL. EU. Laser based THz generation, optimization and numerical simulation for streaking FEL electrons with different photon energies will be presented. High repetition rate diagnostic requirements and solutions will also be discussed.

THA02	Experimental Characterization of FEL Polarization Control with Cross Polarized Undulators	644
	E. Ferrari, E. Allaria, G. De Ninno, B. Diviacco, D. Gauthier, L. Giannessi, G. Penco, C. Spezzani Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy J. Buck, M. Ilchen XFEL. EU, Hamburg, Germany G. De Ninno, D. Gauthier University of Nova Gorica, Nova Gorica, Slovenia L. Giannessi ENEA C.R. Frascati, Frascati (Roma), Italy Z. Huang, A.A. Lutman SLAC, Menlo Park, California, USA G. Lambert, B. Mahieu LOA, Palaiseau, France J. Viefhaus DESY, Hamburg, Germany
	Polarization control of the coherent radiation is becoming an important feature of recent and future short wavelength free electron laser facilities. While polarization tuning can be achieved taking advantage of specially designed undulators, a scheme based on two consecutive undulators emitting orthogonally polarized fields has also been proposed. Developed initially in synchrotron radiation sources, crossed polarized undulator schemes could benefit from the coherent emission that characterize FELs. In this work we report the first detailed experimental characterization of the polarization properties of an FEL operated with crossed polarized undulators in the Soft-X-Rays. Aspects concerning the average degree of polarization and the shot to shot stability are investigated together with a comparison of the performance of various schemes to control and switch the polarization
	Slides THA02 [5.383 MB]