• A. Saini
  University of Delhi, Delhi
• A. Latina, J.-F. Ostiguy, K. Ranjan, N. Solyak, V.P. Yakovlev
  Fermilab, Batavia

It is well known that Insertion of a coupler into a RF cavity breaks the rotational symmetry of the cavity, resulting in an asymmetric field. This asymmetric field results in a transverse RF Kick*. This RF kick transversely offsets the bunch from the nominal axis & it depends on the longitudinal position of the particle in the bunch. Also, insertion of coupler generates short range transverse wake field** which is independent from the transverse offset of the particle. These effects cause emittance dilution and it is thus important to study their behavior & possible correction mechanisms. These coupler effects, i.e. coupler’s RF kick & coupler's wake field are implemented in a beam dynamics program, Lucretia. Calculations are done for Main Linac. For ILC like Lattices Results are compared with analytical results. and a good agreement has been found.

*N.Solyak et al, “RF Kick in the ILC Acceleration Structure. ” MOPP042.pdf (EPAC 08).
** N.Solyak et al, “Transverse Wake Field Simulation for the ILC Acceleration Structure”. MOPP043 pdf (EPAC 08).

• A. Latina, I.G. Gonin, K. Ranjan, N. Solyak, V.P. Yakovlev
  Fermilab, Batavia

In the paper the results are presented for calculation of the transverse wake and RF kick from the power and HOM couplers of the acceleration structure. The beam emittance dilution caused by the couplers is calculated for the main linac and bunch compressor of ILC. It is shown that for the bunch compressor this effect may constitute a problem, and modification of the coupler unit may be necessary in order to preserve the cavity axial symmetry.