New Uses for the ORS Section at FLASH

The Optical Replica Synthesizer (ORS) section at the Free-electron LASer in Hamburg (FLASH) was constructed to make longitudinal electron bunch profile measurements and to diagnose the stability of the synchronization of the electron beam and the sFLASHHigh Harmonic Generation (HHG) laser system. The section enables the co-propagation of an electron bunch and a laser pulse through a sequence of magnetic components: undulator, chicane, undulator, chicane.There are several ways that this section could be used that have not yet been attempted. These include: Echo Enabled Harmonic Generation (EEHG), beam slicing with a few-cycle laser pulse, a new type of Electro Optical Sampling (EOS) with Frequency Resolved Optical Gating (FROG), and a new form of optical replica experiment which measures the changes in the spectrum and profile of the laser beam directly after the first ORS undulator. This paper aims to introduce the design and limitations of these experiments and to specify the items that can be installed in order to make them happen

Recent Results from the Optical Replica Synthesizer Experiment in FLASH

We present very promising recent results from the optical replica synthesizer experiment in FLASH where we manipulate ultrashort electron bunches in FLASH with a laser in order to stimulate them to emit a coherent light pulse from which the temporal structure of the electron bunches can be obtained using laser diagnostic FROG method