Beam Transfer Function Measurements Used to Probe the Transverse Landau Damping at the LHC

The Landau damping mechanism stabilizes the impedance driven head-tail modes in hadron synchrotrons. Because of the frequent coherent beam instabilities observed in the Large Hadron Collider in 2012, the Landau damping of the beams was doubted. Therefore, a transverse beam transfer function (BTF) system was installed in order to probe the transverse Landau damping of the beams and compare the measurements with expectations. The results of the BTF measurements acquired during several experiments in the LHC are summarized including different machine configurations. The method developed for the data analysis is described, and the comparison between the models and the measurements is also presented.