Observation of transverse resonance island buckets at the ESRF EBS

The presence of third order horizontal resonance island buckets at the ESRF EBS has been observed in simulations and in the machine. The islands appear at a few mm distance from the core with a specific horizontal tune and octupole setting. When the electrons are kicked with an injection kicker, a fraction of the beam can be captured in the island. The procedures to send the beam into the island and to measure the capture rate and the lifetime of the beam in the island are described. The dependency of the presence of stable islands with different horizontal and vertical tunes and different octupole settings are shown.