FEL2011 - List of Authors (Loehl, F.)

Paper	Title	Page
MOPC06	X-Ray FELs Based on ERL Facilities	111
	A. Meseck HZB, Berlin, Germany G.H. Hoffstaetter, F. Löhl, C.E. Mayes CLASSE, Ithaca, New York, USA
	The characteristic high repetition rate and the high spectral brightness of the electron beams delivered by ERLs have led to a large number of ERL based proposals for hard X-ray sources including X-ray FELs. FEL oscillators, including those proposed for hard X-rays, require comparatively low peak currents and are particularly suitable for ERLs. However single-pass FELs in SASE or seeded mode do not seem out of reach when bunch-compression schemes for higher peak currents are utilized. Using the proposed Cornell ERL as an example, we present and discuss oscillator and single-pass FEL schemes which provide extremely high spectral-brightness ultra-short X-ray pulses for experiments.

TUPA21	Optical Synchronization of the SwissFEL 250 Mev Test Injector Gun Laser With the Optical Master Oscillator	243
	V.R. Arsov, S. Hunziker, M.G. Kaiser, V. Schlott Paul Scherrer Institut, Villigen, Switzerland F. Löhl CLASSE, Ithaca, New York, USA
	Funding: This work is partly supported by IRUVX-PP, an EU co-funded project under FP7 (Grant Agreement 211285) The SwissFEL gun laser stability is crucial for stable SASE operation in the hard X-ray regime. In 10 pC mode in which sub-10 fs photon pulses will be delivered for the users, the gun laser arrival time jitter at the cathode shouldn't exceed 30 fs (rms). In the present design it is foreseen that the gun oscillator is optically stabilized. It is also necessary to check the stability of the combination laser oscillator and transfer line with an optical reference. For this, the Ti:Sa oscillator was used as a master laser and its pulses were delivered through a ca. 5 m long free space transfer line to optically synchronize an Er-fiber oscillator via two color balanced optical cross correlator with a BBO crystal. The two lasers were placed on different optical tables, which didn't have a mechanical connection through the transfer line. Stable optical lock for at least 60 minutes was demonstrated with an in-loop stability in the range 3.7-17.6 fs. In the range 10 Hz-1 kHz the phase noise stability of the optically locked Er-fiber oscillator varied between 76.5 fs and 118.5 fs rms, 76 fs of which was the contribution of the 1.5 GHz PLO, to which the Ti:Sa oscillator was RF-locked.

Paper

Title

Page

X-Ray FELs Based on ERL Facilities

111

A. Meseck
HZB, Berlin, Germany
G.H. Hoffstaetter, F. Löhl, C.E. Mayes
CLASSE, Ithaca, New York, USA

The characteristic high repetition rate and the high spectral brightness of the electron beams delivered by ERLs have led to a large number of ERL based proposals for hard X-ray sources including X-ray FELs. FEL oscillators, including those proposed for hard X-rays, require comparatively low peak currents and are particularly suitable for ERLs. However single-pass FELs in SASE or seeded mode do not seem out of reach when bunch-compression schemes for higher peak currents are utilized. Using the proposed Cornell ERL as an example, we present and discuss oscillator and single-pass FEL schemes which provide extremely high spectral-brightness ultra-short X-ray pulses for experiments.

TUPA21

Optical Synchronization of the SwissFEL 250 Mev Test Injector Gun Laser With the Optical Master Oscillator

243

V.R. Arsov, S. Hunziker, M.G. Kaiser, V. Schlott
Paul Scherrer Institut, Villigen, Switzerland
F. Löhl
CLASSE, Ithaca, New York, USA

Funding: This work is partly supported by IRUVX-PP, an EU co-funded project under FP7 (Grant Agreement 211285)
The SwissFEL gun laser stability is crucial for stable SASE operation in the hard X-ray regime. In 10 pC mode in which sub-10 fs photon pulses will be delivered for the users, the gun laser arrival time jitter at the cathode shouldn't exceed 30 fs (rms). In the present design it is foreseen that the gun oscillator is optically stabilized. It is also necessary to check the stability of the combination laser oscillator and transfer line with an optical reference. For this, the Ti:Sa oscillator was used as a master laser and its pulses were delivered through a ca. 5 m long free space transfer line to optically synchronize an Er-fiber oscillator via two color balanced optical cross correlator with a BBO crystal. The two lasers were placed on different optical tables, which didn't have a mechanical connection through the transfer line. Stable optical lock for at least 60 minutes was demonstrated with an in-loop stability in the range 3.7-17.6 fs. In the range 10 Hz-1 kHz the phase noise stability of the optically locked Er-fiber oscillator varied between 76.5 fs and 118.5 fs rms, 76 fs of which was the contribution of the 1.5 GHz PLO, to which the Ti:Sa oscillator was RF-locked.