Microbunching threshold manipulation by a corrugated structure impedance at KARA

Two parallel corrugated plates can be used to manipulate the impedance of an electron storage ring such as the KIT storage ring KARA (KArlsruhe Research Accelerator). This impedance manipulation structure opens up the possibility to eventually control the electron beam dynamics and the emitted coherent synchrotron radiation (CSR). In this contribution, we present the impedance that is most effective to manipulate the threshold of the microbunching instability for different machine settings. Furthermore, it will be shown, how the resonance frequency of this impedance is related to the spectrum of the substructures in the electron bunches.