FEL2012 - List of Authors (Schulz, S.)

Paper	Title	Page
WEPD08	Upgrades of the Photoinjector Laser System at FLASH	385
	S. Schreiber, C. Grün, O. Hensler, K. Klose, S. Schulz, T. Schulz, M. Staack DESY, Hamburg, Germany M. Groß, G. Klemz, G. Koss DESY Zeuthen, Zeuthen, Germany I.H. Templin, I. Will, H. Willert MBI, Berlin, Germany
	The photoinjector of FLASH uses an RF gun equipped with caesium telluride photocathodes illuminated by appropriate UV laser pulses as a source of ultra-bright electron beams. The superconducting accelerator of FLASH is able to accelerate a 0.8 ms long train of thousands of electron bunches in a burst mode. This puts special demands on the design of the electron source, especially the laser system. The construction of a second undulator beamline FLASH2 has started. The pulse train will be divided into two parts to serve both beamlines simultaneously. Since experiments with the FLASH soft X-ray beam need flexibility, we plan to use two laser systems each serving one beamline. This makes it possible to deliver two trains with different properties in charge, number of bunches, and bunch spacing in the same RF pulse. This also required an upgrades of the laser beamline design. We report on improvements of the laser beamline and first tests operating two lasers simultaneously at FLASH.

WEPD54	Characterization of Single-cycle THz Pulses at the CTR Source at FLASH	500
	S. Wunderlich, S. Schefer, B. Schmidt, S. Schulz, S. Wesch DESY, Hamburg, Germany M.C. Hoffmann SLAC, Menlo Park, California, USA
	At the coherent transition radiation source at the free-electron laser in Hamburg (FLASH) at DESY, single-cycle THz pulses with electric field strengths exceeding one MV/cm are generated. We present the temporal and spatial characterization of this source with the technique of electro-optic sampling using a laser system synchronized with the accelerator to better than 100 fs. This method offers a quantitative detection of the electric field of the THz pulses in the time domain. Compared to other electron-accelerator driven sources like undulator radiation, the transition radiation source provides pulses with a high bandwidth and durations shorter than one picosecond. This enables time-resolving and non-destructive experiments with radiation in the THz regime including THz pump / THz probe experiments. Broadband and intense THz pulses are expected to be valuable tools for the study of dynamics of excitation of complex materials in transient electric and magnetic fields.

Paper

Title

Page

Upgrades of the Photoinjector Laser System at FLASH

385

S. Schreiber, C. Grün, O. Hensler, K. Klose, S. Schulz, T. Schulz, M. Staack
DESY, Hamburg, Germany
M. Groß, G. Klemz, G. Koss
DESY Zeuthen, Zeuthen, Germany
I.H. Templin, I. Will, H. Willert
MBI, Berlin, Germany

The photoinjector of FLASH uses an RF gun equipped with caesium telluride photocathodes illuminated by appropriate UV laser pulses as a source of ultra-bright electron beams. The superconducting accelerator of FLASH is able to accelerate a 0.8 ms long train of thousands of electron bunches in a burst mode. This puts special demands on the design of the electron source, especially the laser system. The construction of a second undulator beamline FLASH2 has started. The pulse train will be divided into two parts to serve both beamlines simultaneously. Since experiments with the FLASH soft X-ray beam need flexibility, we plan to use two laser systems each serving one beamline. This makes it possible to deliver two trains with different properties in charge, number of bunches, and bunch spacing in the same RF pulse. This also required an upgrades of the laser beamline design. We report on improvements of the laser beamline and first tests operating two lasers simultaneously at FLASH.

WEPD54

Characterization of Single-cycle THz Pulses at the CTR Source at FLASH

500

S. Wunderlich, S. Schefer, B. Schmidt, S. Schulz, S. Wesch
DESY, Hamburg, Germany
M.C. Hoffmann
SLAC, Menlo Park, California, USA

At the coherent transition radiation source at the free-electron laser in Hamburg (FLASH) at DESY, single-cycle THz pulses with electric field strengths exceeding one MV/cm are generated. We present the temporal and spatial characterization of this source with the technique of electro-optic sampling using a laser system synchronized with the accelerator to better than 100 fs. This method offers a quantitative detection of the electric field of the THz pulses in the time domain. Compared to other electron-accelerator driven sources like undulator radiation, the transition radiation source provides pulses with a high bandwidth and durations shorter than one picosecond. This enables time-resolving and non-destructive experiments with radiation in the THz regime including THz pump / THz probe experiments. Broadband and intense THz pulses are expected to be valuable tools for the study of dynamics of excitation of complex materials in transient electric and magnetic fields.