FEL 2006 - List of Authors (Tiedtke, K. I.)

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Tiedtke, K. I.

Paper	Title	Page
FRAAU03	Wave-Front Observations at FLASH	794
	M. Kuhlmann, E. Plönjes, K. I. Tiedtke, S. Toleikis DESY, Hamburg P. Mercere SOLEIL, Gif-sur-Yvette P. Zeitoun LOA, Palaiseau
	During the first user operation of the Free-Electron Laser in Hamburg (FLASH) wavefront measurements have been recorded in the vacuum-ultraviolet region using a Hartmann sensor (by Imagine Optic). The Hartmann principle is based on a pinhole array, which divides the incoming beam into a large number of sub-rays monitored in intensity and position of individual spots. The identification of the local slope of the incident wavefront makes the aberrations from a perfect spherical wavefront visible. Ray tracing in upstream direction accesses the beam focal point in size and position. The intense and coherent vacuum-ultraviolet FEL beam leads to unique requirements for the wavefront sensor setup. We report an optimized setup to observe the metrology of flat and curved mirrors at FLASH beamlines. The effects of solid and gaseous filters are selectively described in the wavelength regime of 10nm to 32nm. The use of wavefront measurements to provide reliable machine parameter is discussed. The wavefront sensor proved to be a valuable tool to observe the FEL beam quality and the performance of optical elements, filters and diagnostic tools.
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	Talk
FRAAU05	Quantitative Detection of Femtosecond X-Ray Pulses	802
	M. Richter, L. Cibik, U. Kroth, M. Krumrey, H. Schoeppe, G. Ulm PTB, Berlin C. Blome, U. Jastrow, J. R. Schneider, K. I. Tiedtke, T. Tschentscher DESY, Hamburg S. V. Bobashev, A. A. Sorokin IOFFE, St. Petersburg J. B. Hastings, R. Ischebeck, S. P. Moeller SLAC, Menlo Park, California
	A detection system for femtosecond X-ray pulses has been developed within close cooperation between the Deutsche Elektronen-Synchrotron in Hamburg and the Physikalisch-Technische Bundeanstalt in Berlin. It is based on photoionization of xenon gas and, hence, radiation hard. Photoions generated are extracted by an electric field and, in contrast to former devices developed for the vacuum-ultraviolet spectral range, detected by an amplifying open electron multiplier. Operation is performed at low gas pressure in the range between 0.1 and 0.01 Pa. Thus, the detector is almost transparent and may be used as a fast online monitor for quantitative and pulse-resolved determination of photon numbers and pulse energies of X-ray free electron lasers. After design and construction, a prototype has been successfully characterized and calibrated for photon energies from 4 to 10 keV in the PTB laboratory at the electron storage ring BESSY II in Berlin. First application has recently been realized in collaboration with the Linear Coherent Light Source at the Sub-Picosecond Pulse Source in Stanford with up to 1·10⁶ photons per pulse detected at a photon energy of 9.4 keV. M. Richter et al., Appl. Phys. Lett. 83, 2970-2972 (2003)
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