Modeling collective effects in linacs.

Bosco F., CamachoO., Carillo M., Chiadroni E., Faillace L., Fukasawa A., Giribono A., Giuliano L., Majernik N., Mostacci A., Palumbo L., Rosenzweig J.B., Spataro B., Vaccarezza C., Migliorati M.
  Lunedì 12/09   14:00 - 19:00   Aula L - Christa Mc Auliffe   VI - Fisica applicata, acceleratori e beni culturali   Presentazione
Advanced experiments in the field of high-energy physics demand use of TeV-class linear colliders. The luminosity expected for such machines implies acceleration of intense electron/positron beams over the km length scale at high repetition rates. Similarly, the brilliance of particle driven radiation sources, such as FELs and Compton machines, relies on high-brightness electron beams delivered in multi-bunch mode. The operation of such types of machines exposes charged particles to a mutual parasitic interaction caused by the excitation of wakefields which takes place either within a single bunch or among different bunches. Such fields affect the phase space quality as well as the nominal beam trajectories and, thus, their effect has to be investigated carefully in order to ensure the required performance. Here we present a dedicated tracking code that accounts for both the short-range and long-range wakefield interaction in linacs. Such effects are described in terms of an efficient matrix formalism which reduces the computational times. Examples based on state-of-the-art linac facilities are shown and, in addition, techniques aimed to mitigate the wakefield effects are discussed.