论文信息 - OF THE LONGITUDINAL ELECTRON BUNCH STRUCTURE AT THE FLASH LINAC WITH A TRANSVERSE DEFLECTING RF-STRUCTURE

OF THE LONGITUDINAL ELECTRON BUNCH STRUCTURE AT THE FLASH LINAC WITH A TRANSVERSE DEFLECTING RF-STRUCTURE

In the single-pass Free-Electron Laser FLASH, SelfAmplification of Spontaneous Emission (SASE) occurs in a small fraction of an electron bunch with a length in the order of micrometers. As a consequence, there is a need for bunch diagnostics with a time resolution in the femtosecond regime for understanding and improving the machine performance. At FLASH, a vertically deflecting structure (LOLA) is used to measure the longitudinal charge density profile and phase space distribution of single bunches with high time resolution. The horizontal slice emittance can be determined by additionally using quadrupole scan techiques. In this paper, we present results of measurements under conditions close to SASE operation at 13.7 nm. We reached a RMS resolution of 20 fs for the longitudinal profile measurements, and resolved the longitudinal phase space distribution and slice emittance with 50 fs and 60 fs, respectively. Strong indications for a substructure within the horizontal phase space distribution of the peak current region have been found.

H. Schlarb | C. Gerth | M. Röhrs

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