Volker Schlott

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We report on the temporal and spatial stability of the first tunable femtosecond undulator hard-x-ray source for ultrafast diffraction and absorption experiments. The 2.5-1 Angstrom output radiation is driven by an initial 50 fs laser pulse employing the laser-electron slicing technique. By using x-ray diffraction to probe laser-induced coherent optical(More)
The accurate measurement of the arrival time of a hard X-ray free electron laser (FEL) pulse with respect to a laser is of utmost importance for pump-probe experiments proposed or carried out at FEL facilities around the world. This manuscript presents the latest device to meet this challenge, a THz streak camera using Xe gas clusters, capable of pulse(More)
One of the features of advanced third generation light sources is the bunch pattern control in the storage ring, where various filling patterns are of interest for different experiments. The most important step is to keep a uniform charge distribution over all (electron) bunches during the top-up operation. Such a bunch pattern control has been implemented(More)
Concepts for a fast orbit feedback in the SLS storage ring are presented. The Singular Value Decomposition (SVD) based orbit correction scheme is supposed to fight orbit oscillations up to 100 Hz stabilizing the orbit to 1/10th of the beam sigma at the locations of the insertion devices. For an emittance ratio of 1%, this corresponds to 1 m tolerance in the(More)
The relative alignment of components in the storage ring of the Swiss Light Source (SLS) is guaranteed by mechanical means. The magnets are rigidly fixed to 48 girders by means of alignment rails with tolerances of less than ±15 μm. The bending magnets, supported by 3 point ball bearings, overlap adjacent girders and thus establish virtual train links(More)
Corrections of insertion device (ID) induced orbit distortions at the SLS are performed by means of feed forward schemes down to the micron level at the corresponding photon beam position monitors (XBPMs). The remaining orbit fluctuations are suppressed by XBPM feedbacks which are an integral part of the fast orbit feedback system. As a result, sub-μm(More)
A wavefront metrology setup based on the X-ray grating interferometry technique for spatially resolved, quantitative, in situ and at-wavelength measurements of the wavefront at synchrotron radiation and hard X-ray free-electron laser beamlines is reported. Indeed, the ever-increasing demands on the optical components to preserve the wavefront shape and the(More)
We report on the current status of the ELETTRA/SLS transverse multi bunch feedback system, consisting of pickup, analog RF front end, a 500 MS/s multi tap filter implemented via a parallel DSP farm, broadband amplifiers and microwave kickers. With the RF front end prototype, a set of measurements with beam has been done and various transverse instabilities(More)
Illumination of a ZrC needle with short laser pulses (16 ps, 266 nm) while high voltage pulses (-60 kV, 2 ns, 30 Hz) are applied, produces photo-field emitted electron bunches. The electric field is high and varies rapidly over the needle surface so that quantum efficiency (QE) near the apex can be much higher than for a flat photocathode due to the(More)