FEL2017 - List of Authors (Dohlus, M.)

Paper	Title	Page
MOP003	Concept for a Seeded FEL at FLASH2	34
	C. Lechner, R.W. Aßmann, J. Bödewadt, M. Dohlus, N. Ekanayake, G. Feng, I. Hartl, T. Laarmann, T. Lang, L. Winkelmann, I. Zagorodnov DESY, Hamburg, Germany A. Azima, M. Drescher, Th. Maltezopoulos, T. Plath, J. Roßbach, W. Wurth University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany S. Khan, T. Plath DELTA, Dortmund, Germany
	The free-electron laser (FEL) FLASH is a user facility delivering photon pulses down to 4 nm wavelength. Recently, the second FEL undulator beamline 'FLASH2' was added to the facility. Operating in self-amplified spontaneous emission (SASE) mode, the exponential amplification process is initiated by shot noise of the electron bunch resulting in photon pulses of limited temporal coherence. In seeded FELs, the FEL process is initiated by coherent seed radiation, improving the longitudinal coherence of the generated photon pulses. The conceptual design of a possible seeding option for the FLASH2 beamline envisages the installation of the hardware needed for high-gain harmonic generation (HGHG) seeding upstream of the already existing undulator system. In this contribution, we present the beamline design and numerical simulations of the seeded FEL.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP003
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WEP005	Coaxial Coupler RF Kick in the PITZ RF Gun	422
	Y. Chen, P. Boonpornprasert, J.D. Good, H. Huck, I.I. Isaev, M. Krasilnikov, A. Oppelt, H.J. Qian, Y. Renier, F. Stephan DESY Zeuthen, Zeuthen, Germany W. Ackermann, H. De Gersem TEMF, TU Darmstadt, Darmstadt, Germany M. Dohlus DESY, Hamburg, Germany Q.T. Zhao IMP/CAS, Lanzhou, People's Republic of China
	We investigate a transverse RF kick induced by the transition between rectangular waveguide and coaxial line of the RF coupler in the 1.6-cell L-band normal conducting (NC) RF gun at the Photo Injector Test Facility at DESY, Zeuthen site (PITZ). A three-dimensional electromagnetic simulation shows the disturbed RF field distributions in the fundamental accelerating mode. Based on the 3D RF field map, an electron beam based characterization and quantification of the coaxial coupler RF kick in the PITZ gun is simulated. Preliminary results of the investigations are presented.
	Poster WEP005 [1.345 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-WEP005
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Concept for a Seeded FEL at FLASH2

34

C. Lechner, R.W. Aßmann, J. Bödewadt, M. Dohlus, N. Ekanayake, G. Feng, I. Hartl, T. Laarmann, T. Lang, L. Winkelmann, I. Zagorodnov
DESY, Hamburg, Germany
A. Azima, M. Drescher, Th. Maltezopoulos, T. Plath, J. Roßbach, W. Wurth
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
S. Khan, T. Plath
DELTA, Dortmund, Germany

The free-electron laser (FEL) FLASH is a user facility delivering photon pulses down to 4 nm wavelength. Recently, the second FEL undulator beamline 'FLASH2' was added to the facility. Operating in self-amplified spontaneous emission (SASE) mode, the exponential amplification process is initiated by shot noise of the electron bunch resulting in photon pulses of limited temporal coherence. In seeded FELs, the FEL process is initiated by coherent seed radiation, improving the longitudinal coherence of the generated photon pulses. The conceptual design of a possible seeding option for the FLASH2 beamline envisages the installation of the hardware needed for high-gain harmonic generation (HGHG) seeding upstream of the already existing undulator system. In this contribution, we present the beamline design and numerical simulations of the seeded FEL.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP003

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP005

Coaxial Coupler RF Kick in the PITZ RF Gun

422

Y. Chen, P. Boonpornprasert, J.D. Good, H. Huck, I.I. Isaev, M. Krasilnikov, A. Oppelt, H.J. Qian, Y. Renier, F. Stephan
DESY Zeuthen, Zeuthen, Germany
W. Ackermann, H. De Gersem
TEMF, TU Darmstadt, Darmstadt, Germany
M. Dohlus
DESY, Hamburg, Germany
Q.T. Zhao
IMP/CAS, Lanzhou, People's Republic of China

We investigate a transverse RF kick induced by the transition between rectangular waveguide and coaxial line of the RF coupler in the 1.6-cell L-band normal conducting (NC) RF gun at the Photo Injector Test Facility at DESY, Zeuthen site (PITZ). A three-dimensional electromagnetic simulation shows the disturbed RF field distributions in the fundamental accelerating mode. Based on the 3D RF field map, an electron beam based characterization and quantification of the coaxial coupler RF kick in the PITZ gun is simulated. Preliminary results of the investigations are presented.

Poster WEP005 [1.345 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-WEP005

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)