About TWIICE: Topical Workshop on Instabilities, Impedance and Collective Effects In the series of Low Emittance Rings (LOWεRING) Workshops of the EuCARD-2 Project. Work Package coordinators: R. Bartolini, S. Guiducci, Y. Papaphilippou Task coordinators: R. Nagaoka, E.Karantzoulis, E. Al-Dmour, G. Rumolo, F. Antoniou, T. Demma, A.-S. Müller Local organizing committee: Sabine Podgorny, L. Nadolski, P. Brunelle, X.N. Gavalda, M. Klein, R. Nagaoka TWIICE is sponsored by EuCARD-2 and Synchrotron SOLEIL Thankfully, as many as 73 delegates registered in TWIICE from 26 labs/universities around the world (Europe: 19, US: 5, ASIA: 2), collecting 35 talks  Initially estimated two-days workshop with 40 participants is under-dimensioned Goal of the workshop: Bring together experts working on collective beam instabilities and related subjects in low emittance lepton rings. Themes: All potentially important collective effects that may arise and jeopardise the performance of currently running and future low emittance lepton rings. Welcome to SOLEIL, welcome to TWIICE!

To be on time with the tight schedule of the workshop (also not to miss le Musée d’Orsay), please  Respect the talk duration  Upload your presentation files well in advance on the local PC in the lecture hall We thank the chairmen for the management of their sessions. The SOLEIL staff shall be there to assist you with file uploads. We also thank in advance the colleagues contributing in summary sessions for their effort during the workshop. Two meeting rooms at participants’ disposal over the entire workshop: A VIRGO A PÉGASE Both are on the 1 st floor of the A1 Wing

At coffee breaks, a SOLEIL staff shall be at the workshop reception desk to assist you. Coffees, teas, soft drinks and some light food shall be served at coffee breaks, and cold buffets shall be served at lunch breaks in the hall just next to the lecture hall. Two buses will take us to le Musée d’Orsay. Please gather at the front of the Entrance Building punctually by 5 minutes to 18:30. Let us have a fruitful workshop!