FEL2012 - List of Authors (Lehnert, U.)

Paper

Title

Page

First Lasing of the IR FEL at the Fritz-Haber-Institut Berlin

1

W. Schöllkopf, W. Erlebach, S. Gewinner, G. Heyne, H. Junkes, A. Liedke, G. Meijer, V. Platschkowski, W.Q. Zhang, G. von Helden
FHI, Berlin, Germany
H. Bluem, D. Dowell, K. Jordan, R. Lange, J.H. Park, J. Rathke, A.M.M. Todd, L.M. Young
AES, Medford, NY, USA
M.A. Davidsaver
BNL, Upton, New York, USA
S.C. Gottschalk
STI, Washington, USA
U. Lehnert, P. Michel, W. Seidel, R. Wünsch
HZDR, Dresden, Germany
H. Loos
SLAC, Menlo Park, California, USA

An IR and THz FEL with a design wavelength range from 4 to 500 μm has been commissioned at the Fritz-Haber-Institut (FHI) in Berlin, Germany, for applications in, i.a., molecular and cluster spectroscopy as well as surface science.[1] The linac[2] comprises two S-band standing-wave copper structures. The first one operates at near fixed field to accelerate the electrons to 20 MeV, while the second one is designed to accelerate (or decelerate) to any final energy between 15 and 50 MeV. A key aspect of the system is low longitudinal emittance, <50 keV-psec, at more than 200 pC bunch charge with a max.μpulse rep. rate of 1 GHz. The up to 15 μs long macro pulses come at a rate of up to 20 Hz. The electrons are steered through either one of two FELs. A single-plane-focusing, 40 mm period wedged-pole hybrid undulator[3] combined with a 5.4 m long cavity has been commissioned for the mid-IR (<50 μm). In addition, a two-plane-focusing undulator in combination with a 7.2 m long cavity with a 1-d waveguide for the optical mode is planned for the far-IR. In February 2012 we observed 'first lasing' at 28 MeV and 18 μm wavelength. We will present first results characterizing the system.
[1] W. Schöllkopf et al., "Status of the Fritz Haber Institute THz FEL", Paper TUPB30, Proc. FEL 2011.
[2] Advanced Energy Systems, Inc., Medford, NY, USA
[3] STI Optronics, Inc., Bellevue, WA, USA

Slides MOOB01 [3.440 MB]

MOOB02

First Lasing of the Terahertz FEL FLARE

R.T. Jongma, R. Bakker, C. Berkhout, A.C.N. Engels, R.W. Lof, C. Sikkens, F.J.P. Wijnen, B. Willemsen, G.F.A.J. Wulterkens, P.A.W. van Dael, A.J.A. van Roij, A.P. van Vliet, A.F.G. van der Meer, W.J. van der Zande
Radboud University, Nijmegen, The Netherlands
K. Dunkel, A. Metz, C. Piel
RI Research Instruments GmbH, Bergisch Gladbach, Germany
U. Lehnert
HZDR, Dresden, Germany

Funding: The Nijmegen THz-FEL is funded via the 'Big Facilities' programme of the Netherlands Organisation for Scientific Research (NWO).
Early 2011 we commenced the assembly of FLARE, the Free-electron Laser for Advanced spectroscopy and high-Resolution Experiments, in its dedicated, new building. FLARE will operate as a pulsed FEL in the 100-1500 micron range and is, amongst others, intended for spectroscopy in very high magnetic fields and (bio) molecular spectroscopy [1, 2]. After completion of the move of FELIX and FELICE to the Radboud University, FLARE will operate as part of the FELIX facility Nijmegen. Challenging in the design, assembly and operation of the FLARE cavity are the parallel plate waveguide that extends over the full cavity length and the outcoupling slit. In June 2011 the commissioning of the accelerator and optical cavity of FLARE was started, resulting in first lasing on September 26 of 2011. Since then, FLARE demonstrated lasing between 100 micron and 1400 micron at output powers meeting the design values. Until the end of 2012, the optical distribution system serving all the user-stations as well as the high field magnets in the neighboring HFML will be assembled, after which FLARE will come on-line as part of the new user facility in Nijmegen.
[1] W.J. van der Zande, et. Al. Proc. FEL 2006, Berlin, Germany,
(2006) 485.
[2] R.T. Jongma, et al., Proc. FEL-2008, Gyeongju, South Korea, (2008) 200.

Slides MOOB02 [40.645 MB]

TUPD35

Femtosecond Level Synchronization of a Linac based Super-radiant THz Facility

313

M. Kuntzsch, M. Gensch, U. Lehnert, F. Röser
HZDR, Dresden, Germany
M. Bousonville, H. Schlarb, N. Stojanovic, S. Vilcins
DESY, Hamburg, Germany

The superconducting radiofrequency (SRF) electron accelerator ELBE at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) is currently upgraded with an SRF Gun and a femtosecond (fs) electron beamline to enable continuous wave operation with bunch charges of up to 1 nC and bunch durations down to 100 fs (RMS). The new femtosecond electron beamline will be used to drive two coherent THz sources and one X-ray source based on Thomson scattering. The two different THz sources, one narrow bandwidth undulator source and one broad bandwidth coherent transition/diffraction source, are guided into a dedicated THz Laboratory where they can be combined with various fs-laser systems. For the planned THz pump laser probe experiments, synchronization of the external pump-probe lasers on the fs- level is essential. Our approach is based on an optical synchronization system, adapted from a similar system installed at FLASH [*]. That system will be installed in collaboration between DESY and HZDR. In this contribution we will discuss the layout of the synchronization scheme and first ideas for measurements of the arrival time jitter of the THz pulses to evaluate the achieved degree of timing stability.
* F.Loehl, H.Schlarb et. al."Sub-10 femtosecond stabilization of a fiber-link using a balanced optical cross-correlator", proceedings of PAC2007, Albuquerque, USA, JUN 25-29 2007, FR0AC04.

THPD13

Design and Performance of the Wedged Pole Hybrid Undulator for the Fritz-Haber-Institut IR FEL

575

S.C. Gottschalk, T.E. DeHart, R.N. Kelly, M.A. Offenbacker, A.S. Valla, J.F. Zumdieck
STI, Washington, USA
H. Bluem, D. Dowell, J. Rathke, A.M.M. Todd
AES, Medford, NY, USA
S. Gewinner, H. Junkes, G. Meijer, W. Schöllkopf, W.Q. Zhang
FHI, Berlin, Germany
U. Lehnert
HZDR, Dresden, Germany

An IR and THz FEL with a design wavelength range from 4 to 500 microns has been commissioned at the Fritz-Haber-Institut (FHI) in Berlin, Germany. Lasing at 28 MeV and a wavelength of 18 micron was achieved in Feb 2012*. We describe the performance of the undulator built and installed at FHI by STI Optronics for use in the mid-IR range (< 50 micron) and 15-50 MeV beam energy. The undulator was a high field strength wedged pole hybrid (WPH) with 40mm period, 2.0m long, minimum gap 16.5mm. A new improvement was including radiation resistance in the magnetic design. We will discuss the measured magnetic and mechanical performance; central and zero steering/offset end field magnetic designs; key features of the mechanical design and gap adjustment system; new genetic shimming algorithms and local/EPICS control systems.
*W.Schöllkopf et al., "First Lasing of the IR FEL at the Fritz-Haber-Institut Berlin", this conference

Paper	Title	Page
MOOB01	First Lasing of the IR FEL at the Fritz-Haber-Institut Berlin	1
	W. Schöllkopf, W. Erlebach, S. Gewinner, G. Heyne, H. Junkes, A. Liedke, G. Meijer, V. Platschkowski, W.Q. Zhang, G. von Helden FHI, Berlin, Germany H. Bluem, D. Dowell, K. Jordan, R. Lange, J.H. Park, J. Rathke, A.M.M. Todd, L.M. Young AES, Medford, NY, USA M.A. Davidsaver BNL, Upton, New York, USA S.C. Gottschalk STI, Washington, USA U. Lehnert, P. Michel, W. Seidel, R. Wünsch HZDR, Dresden, Germany H. Loos SLAC, Menlo Park, California, USA
	An IR and THz FEL with a design wavelength range from 4 to 500 μm has been commissioned at the Fritz-Haber-Institut (FHI) in Berlin, Germany, for applications in, i.a., molecular and cluster spectroscopy as well as surface science.[1] The linac[2] comprises two S-band standing-wave copper structures. The first one operates at near fixed field to accelerate the electrons to 20 MeV, while the second one is designed to accelerate (or decelerate) to any final energy between 15 and 50 MeV. A key aspect of the system is low longitudinal emittance, <50 keV-psec, at more than 200 pC bunch charge with a max.μpulse rep. rate of 1 GHz. The up to 15 μs long macro pulses come at a rate of up to 20 Hz. The electrons are steered through either one of two FELs. A single-plane-focusing, 40 mm period wedged-pole hybrid undulator[3] combined with a 5.4 m long cavity has been commissioned for the mid-IR (<50 μm). In addition, a two-plane-focusing undulator in combination with a 7.2 m long cavity with a 1-d waveguide for the optical mode is planned for the far-IR. In February 2012 we observed 'first lasing' at 28 MeV and 18 μm wavelength. We will present first results characterizing the system. [1] W. Schöllkopf et al., "Status of the Fritz Haber Institute THz FEL", Paper TUPB30, Proc. FEL 2011. [2] Advanced Energy Systems, Inc., Medford, NY, USA [3] STI Optronics, Inc., Bellevue, WA, USA
	Slides MOOB01 [3.440 MB]

MOOB02	First Lasing of the Terahertz FEL FLARE
	R.T. Jongma, R. Bakker, C. Berkhout, A.C.N. Engels, R.W. Lof, C. Sikkens, F.J.P. Wijnen, B. Willemsen, G.F.A.J. Wulterkens, P.A.W. van Dael, A.J.A. van Roij, A.P. van Vliet, A.F.G. van der Meer, W.J. van der Zande Radboud University, Nijmegen, The Netherlands K. Dunkel, A. Metz, C. Piel RI Research Instruments GmbH, Bergisch Gladbach, Germany U. Lehnert HZDR, Dresden, Germany
	Funding: The Nijmegen THz-FEL is funded via the 'Big Facilities' programme of the Netherlands Organisation for Scientific Research (NWO). Early 2011 we commenced the assembly of FLARE, the Free-electron Laser for Advanced spectroscopy and high-Resolution Experiments, in its dedicated, new building. FLARE will operate as a pulsed FEL in the 100-1500 micron range and is, amongst others, intended for spectroscopy in very high magnetic fields and (bio) molecular spectroscopy [1, 2]. After completion of the move of FELIX and FELICE to the Radboud University, FLARE will operate as part of the FELIX facility Nijmegen. Challenging in the design, assembly and operation of the FLARE cavity are the parallel plate waveguide that extends over the full cavity length and the outcoupling slit. In June 2011 the commissioning of the accelerator and optical cavity of FLARE was started, resulting in first lasing on September 26 of 2011. Since then, FLARE demonstrated lasing between 100 micron and 1400 micron at output powers meeting the design values. Until the end of 2012, the optical distribution system serving all the user-stations as well as the high field magnets in the neighboring HFML will be assembled, after which FLARE will come on-line as part of the new user facility in Nijmegen. [1] W.J. van der Zande, et. Al. Proc. FEL 2006, Berlin, Germany, (2006) 485. [2] R.T. Jongma, et al., Proc. FEL-2008, Gyeongju, South Korea, (2008) 200.
	Slides MOOB02 [40.645 MB]

TUPD35	Femtosecond Level Synchronization of a Linac based Super-radiant THz Facility	313
	M. Kuntzsch, M. Gensch, U. Lehnert, F. Röser HZDR, Dresden, Germany M. Bousonville, H. Schlarb, N. Stojanovic, S. Vilcins DESY, Hamburg, Germany
	The superconducting radiofrequency (SRF) electron accelerator ELBE at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) is currently upgraded with an SRF Gun and a femtosecond (fs) electron beamline to enable continuous wave operation with bunch charges of up to 1 nC and bunch durations down to 100 fs (RMS). The new femtosecond electron beamline will be used to drive two coherent THz sources and one X-ray source based on Thomson scattering. The two different THz sources, one narrow bandwidth undulator source and one broad bandwidth coherent transition/diffraction source, are guided into a dedicated THz Laboratory where they can be combined with various fs-laser systems. For the planned THz pump laser probe experiments, synchronization of the external pump-probe lasers on the fs- level is essential. Our approach is based on an optical synchronization system, adapted from a similar system installed at FLASH []. That system will be installed in collaboration between DESY and HZDR. In this contribution we will discuss the layout of the synchronization scheme and first ideas for measurements of the arrival time jitter of the THz pulses to evaluate the achieved degree of timing stability. F.Loehl, H.Schlarb et. al."Sub-10 femtosecond stabilization of a fiber-link using a balanced optical cross-correlator", proceedings of PAC2007, Albuquerque, USA, JUN 25-29 2007, FR0AC04.

THPD13	Design and Performance of the Wedged Pole Hybrid Undulator for the Fritz-Haber-Institut IR FEL	575
	S.C. Gottschalk, T.E. DeHart, R.N. Kelly, M.A. Offenbacker, A.S. Valla, J.F. Zumdieck STI, Washington, USA H. Bluem, D. Dowell, J. Rathke, A.M.M. Todd AES, Medford, NY, USA S. Gewinner, H. Junkes, G. Meijer, W. Schöllkopf, W.Q. Zhang FHI, Berlin, Germany U. Lehnert HZDR, Dresden, Germany
	An IR and THz FEL with a design wavelength range from 4 to 500 microns has been commissioned at the Fritz-Haber-Institut (FHI) in Berlin, Germany. Lasing at 28 MeV and a wavelength of 18 micron was achieved in Feb 2012. We describe the performance of the undulator built and installed at FHI by STI Optronics for use in the mid-IR range (< 50 micron) and 15-50 MeV beam energy. The undulator was a high field strength wedged pole hybrid (WPH) with 40mm period, 2.0m long, minimum gap 16.5mm. A new improvement was including radiation resistance in the magnetic design. We will discuss the measured magnetic and mechanical performance; central and zero steering/offset end field magnetic designs; key features of the mechanical design and gap adjustment system; new genetic shimming algorithms and local/EPICS control systems. W.Schöllkopf et al., "First Lasing of the IR FEL at the Fritz-Haber-Institut Berlin", this conference