A DAMPED AND DETUNED STRUCTURE FOR THE MAIN LINACS FOR CLIC (V. F. Khan, A. D’Elia, A. Grudiev, R. M. Jones, G. Riddone, V. Soldatov, W. Wuensch, R. Zennaro, School of Physics and Astronomy, The University of Manchester, Manchester, U.K., The Cockcroft Institute of Accelerator Science and Technology, Daresbury, U.K.,CERN, Geneva, Switzerland, JINR, Dubna, Russia, PSI, Villigen, Switzerland)