FEL2012 - List of Authors (Weiland, T.)

Paper	Title	Page
THPD33	Generation of Ultra-short Electron Bunches at FLASH	610
	J. Rönsch-Schulenburg, E. Hass, A. Kuhl, T. Plath, M. Rehders, J. Roßbach Uni HH, Hamburg, Germany A. Angelovski, R. Jakoby, A. Penirschke TU Darmstadt, Darmstadt, Germany N. Baboi, M. Bousonville, M.K. Czwalinna, C. Gerth, K. Klose, T. Limberg, U. Mavrič, H. Schlarb, B. Schmidt, S. Schreiber, B. Steffen, C. Sydlo, S. Vilcins, S. Wesch DESY, Hamburg, Germany S. Schnepp, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: The work is supported by German Federal Ministry of Education and Research (BMBF) within Joint Project - FSP 301 under the contract number 05K10GU2. In order to produce radiation pulses of a few femtoseconds at FELs like FLASH, different concepts have been proposed. Probably the most robust method is to create an electron bunch, which is in the most extreme case as short as one longitudinal optical mode. For FLASH this translates into a bunch length of a few micrometers only. In order to mitigate space charge effects, the bunch charge needs to be about 20 pC. The technical requirements to achieve this goal are discussed. This includes beam dynamics studies to optimize the injection and compression of small charge electron bunches. A reduced photo injector laser pulse duration helps to relax the RF tolerance which scales linear with the compression factor. A new photo injector laser with sub-picosecond pulse duration in combination with a stretcher is used to optimize the initial bunch length. The commissioning of the new laser system and first experiments are described. Limitations of the presently available electron beam diagnostics at FLASH for short, low charge bunches are analyzed. Improvements of the longitudinal phase space diagnostics and the commissioning of a more sensitive beam arrival time monitor are described.

Paper

Title

Page

Generation of Ultra-short Electron Bunches at FLASH

610

J. Rönsch-Schulenburg, E. Hass, A. Kuhl, T. Plath, M. Rehders, J. Roßbach
Uni HH, Hamburg, Germany
A. Angelovski, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
N. Baboi, M. Bousonville, M.K. Czwalinna, C. Gerth, K. Klose, T. Limberg, U. Mavrič, H. Schlarb, B. Schmidt, S. Schreiber, B. Steffen, C. Sydlo, S. Vilcins, S. Wesch
DESY, Hamburg, Germany
S. Schnepp, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: The work is supported by German Federal Ministry of Education and Research (BMBF) within Joint Project - FSP 301 under the contract number 05K10GU2.
In order to produce radiation pulses of a few femtoseconds at FELs like FLASH, different concepts have been proposed. Probably the most robust method is to create an electron bunch, which is in the most extreme case as short as one longitudinal optical mode. For FLASH this translates into a bunch length of a few micrometers only. In order to mitigate space charge effects, the bunch charge needs to be about 20 pC. The technical requirements to achieve this goal are discussed. This includes beam dynamics studies to optimize the injection and compression of small charge electron bunches. A reduced photo injector laser pulse duration helps to relax the RF tolerance which scales linear with the compression factor. A new photo injector laser with sub-picosecond pulse duration in combination with a stretcher is used to optimize the initial bunch length. The commissioning of the new laser system and first experiments are described. Limitations of the presently available electron beam diagnostics at FLASH for short, low charge bunches are analyzed. Improvements of the longitudinal phase space diagnostics and the commissioning of a more sensitive beam arrival time monitor are described.