FEL2013 - List of Keywords (background)

Paper	Title	Other Keywords	Page
TUPSO44	Transverse Emittance Measurement by Slit-scan Method for an SRF Photo Injector	emittance, solenoid, SRF, laser	322
	P.N. Lu, A. Arnold, P. Michel, P. Murcek, J. Teichert, H. Vennekate, R. Xiang HZDR, Dresden, Germany
	Funding: European Community-Research Infrastructure Activity German Federal Ministry of Education and Research Grant 05 ES4BR1/8, LA³NET funding, Grant Agreement Number GA-ITN-2011-289191 A 3½-cell SRF-gun has been developed and commissioned in Helmholtz-Zentrum Dresden-Rossendorf (HZDR) since 2004. The emittance of this gun was measured before by both solenoid/quadrupole scanning method and multiple slits method. Recently we did new measurements by single slit scanning method which outputs a detailed phase space with higher space resolution and no overlapping problem. This contribution will first describe our diagnostics beam line and software functions, focusing on data processing algorithm. Then an investigation will be presented on the emittance dependence on several important gun parameters as bunch charge, laser phase and DC voltage on the photo cathode. For the bunch charge, a linear increasing relation with the emittance was found. Lower laser phase and higher DC voltage result in lower beam emittance. The influence of a downstream solenoid is studied for the preliminary understanding of the emittance compensation. The contribution will discuss the measurement errors and compare results with other methods. Also, ASTRA simulations of the SRF-gun beams with same parameters will be presented which have similar trends like our measurements.

WEPSO09	Two-Color Self-seeding and Scanning the Energy of Seeded Beams at LCLS	FEL, photon, electron, free-electron-laser	514
	F.-J. Decker, Y. Ding, Y. Feng, M. Gibbs, J.B. Hastings, Z. Huang, H. Lemke, A.A. Lutman, A. Marinelli, A. Robert, J.L. Turner, J.J. Welch, D.H. Zhang, D. Zhu SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515. The Linac Coherent Light Source (LCLS) produces typically SASE FEL pulses with an intensity of up to 5 mJ and at high photon energy a spread of 0.2% (FWHM). Self seeding with a diamond crystal reduces the energy spread by a factor of 10 to 40. The range depends on which Bragg reflection is used, or the special setup of the electron beam like over-compression. The peak intensity level is lower by a factor of about five, giving the seeded beam an advantage of about 2.5 in average intensity over the use of a monochromator with SASE. Some experiments want to scan the photon energy, which requires that the crystal angle be carefully tracked. At certain energies and crystal angles different lines are crossing which allows seeding at two or even three different colors inside the bandwidth of the SASE pulse. Out-off plane lines come in pairs, like [1 -1 1] and [-1 1 1], which can be split by using the yaw angle adjustments of the crystal, allowing a two-color seeding for all energies above 4.83 keV.

WEPSO37	Femtosecond Fiber Timing Distribution System for the Linac Coherent Light Source	laser, electron, free-electron-laser, linac	583
	H. Li, P.H. Bucksbaum, J.C. Frisch, A.R. Fry, J. May, K. Muehlig, S.R. Smith SLAC, Menlo Park, California, USA L. Chen, H.P.H. Cheng Idesta Quantum Electronics, New Jersey, USA F.X. Kaertner CFEL, Hamburg, Germany F.X. Kaertner MIT, Cambridge, Massachusetts, USA A. Uttamadoss PU, Princeton, New Jersey, USA
	Funding: This work is supported by Department of Energy under STTR grant DE-C0004702. We present the design and progress of a femtosecond fiber timing distribution system for the Linac Coherent Light Source (LCLS) at SLAC to enable the machine diagnostic at the 10 fs level. The LCLS at the SLAC is the world’s first hard x-ray free-electron laser (FEL) with unprecedented peak brightness and pulse duration. The time-resolved optical/x-ray pump-probe experiments on this facility open the era of exploring the ultrafast dynamics of atoms, molecules, proteins, and condensed matter. However, the temporal resolution of current experiments is limited by the time jitter between the optical and x-ray pulses. Recently, sub-25 fs rms jitter is achieved from an x-ray/optical cross-correlator at the LCLS, and external seeding is expected to reduce the intrinsic timing jitter, which would enable full synchronization of the optical and x-ray pulses with sub-10 fs precision. Of such a technique, synchronization between seed and pump lasers would be implemented. Preliminary test results of the major components for a 4 link system will be presented. Currently, the system is geared towards diagnostics to study the various sources of jitter at the LCLS. P. Emma et al.,Nat. Photonics 4,641-647(2010). J. Kim et al.,Opt. Lett,, 31,3659(2006). J. Kim et al.,Opt. Lett,, 32,1044(2007). J.Kim et al.,Nat. Photonics 2,733-736(2008).

Paper

Title

Other Keywords

Page

TUPSO44

Transverse Emittance Measurement by Slit-scan Method for an SRF Photo Injector

emittance, solenoid, SRF, laser

322

P.N. Lu, A. Arnold, P. Michel, P. Murcek, J. Teichert, H. Vennekate, R. Xiang
HZDR, Dresden, Germany

Funding: European Community-Research Infrastructure Activity German Federal Ministry of Education and Research Grant 05 ES4BR1/8, LA³NET funding, Grant Agreement Number GA-ITN-2011-289191
A 3½-cell SRF-gun has been developed and commissioned in Helmholtz-Zentrum Dresden-Rossendorf (HZDR) since 2004. The emittance of this gun was measured before by both solenoid/quadrupole scanning method and multiple slits method. Recently we did new measurements by single slit scanning method which outputs a detailed phase space with higher space resolution and no overlapping problem. This contribution will first describe our diagnostics beam line and software functions, focusing on data processing algorithm. Then an investigation will be presented on the emittance dependence on several important gun parameters as bunch charge, laser phase and DC voltage on the photo cathode. For the bunch charge, a linear increasing relation with the emittance was found. Lower laser phase and higher DC voltage result in lower beam emittance. The influence of a downstream solenoid is studied for the preliminary understanding of the emittance compensation. The contribution will discuss the measurement errors and compare results with other methods. Also, ASTRA simulations of the SRF-gun beams with same parameters will be presented which have similar trends like our measurements.

WEPSO09

Two-Color Self-seeding and Scanning the Energy of Seeded Beams at LCLS

FEL, photon, electron, free-electron-laser

514

F.-J. Decker, Y. Ding, Y. Feng, M. Gibbs, J.B. Hastings, Z. Huang, H. Lemke, A.A. Lutman, A. Marinelli, A. Robert, J.L. Turner, J.J. Welch, D.H. Zhang, D. Zhu
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
The Linac Coherent Light Source (LCLS) produces typically SASE FEL pulses with an intensity of up to 5 mJ and at high photon energy a spread of 0.2% (FWHM). Self seeding with a diamond crystal reduces the energy spread by a factor of 10 to 40. The range depends on which Bragg reflection is used, or the special setup of the electron beam like over-compression. The peak intensity level is lower by a factor of about five, giving the seeded beam an advantage of about 2.5 in average intensity over the use of a monochromator with SASE. Some experiments want to scan the photon energy, which requires that the crystal angle be carefully tracked. At certain energies and crystal angles different lines are crossing which allows seeding at two or even three different colors inside the bandwidth of the SASE pulse. Out-off plane lines come in pairs, like [1 -1 1] and [-1 1 1], which can be split by using the yaw angle adjustments of the crystal, allowing a two-color seeding for all energies above 4.83 keV.

WEPSO37

Femtosecond Fiber Timing Distribution System for the Linac Coherent Light Source

laser, electron, free-electron-laser, linac

583

H. Li, P.H. Bucksbaum, J.C. Frisch, A.R. Fry, J. May, K. Muehlig, S.R. Smith
SLAC, Menlo Park, California, USA
L. Chen, H.P.H. Cheng
Idesta Quantum Electronics, New Jersey, USA
F.X. Kaertner
CFEL, Hamburg, Germany
F.X. Kaertner
MIT, Cambridge, Massachusetts, USA
A. Uttamadoss
PU, Princeton, New Jersey, USA

Funding: This work is supported by Department of Energy under STTR grant DE-C0004702.
We present the design and progress of a femtosecond fiber timing distribution system for the Linac Coherent Light Source (LCLS) at SLAC to enable the machine diagnostic at the 10 fs level. The LCLS at the SLAC is the world’s first hard x-ray free-electron laser (FEL) with unprecedented peak brightness and pulse duration. The time-resolved optical/x-ray pump-probe experiments on this facility open the era of exploring the ultrafast dynamics of atoms, molecules, proteins, and condensed matter. However, the temporal resolution of current experiments is limited by the time jitter between the optical and x-ray pulses. Recently, sub-25 fs rms jitter is achieved from an x-ray/optical cross-correlator at the LCLS, and external seeding is expected to reduce the intrinsic timing jitter, which would enable full synchronization of the optical and x-ray pulses with sub-10 fs precision. Of such a technique, synchronization between seed and pump lasers would be implemented. Preliminary test results of the major components for a 4 link system will be presented. Currently, the system is geared towards diagnostics to study the various sources of jitter at the LCLS.
*P. Emma et al.,Nat. Photonics 4,641-647(2010).
*J. Kim et al.,Opt. Lett,, 31,3659(2006).
*J. Kim et al.,Opt. Lett,, 32,1044(2007).
*J.Kim et al.,Nat. Photonics 2,733-736(2008).