Analytical Treatment Of Resistive Wake Potentials In Round Pipe

The modified analytical form for the longitud inal and transverse resistive wake potentials of point- like charge moving parallel to the axis of round pipe with frequency independent walls conductivity is obtained. The short range wake potentials are presented by uniformly converged series. For the frequency dependent conductivity, the resonator term of the longitudinal monopole wake potential is presented in analytical form. The diffusion term of the potential is modified to simple integral form. E-mail: [email protected] 1

Autophasing and lattice scaling in high energy linear accelerators

We have studied the autophasing conditions in long linear accelerators for a phase advance scaling along the machine instead of the usual beta scaling. A new lattice scaling provides the damping of the resonant enlargement of bunches in transverse wakefields with small required correlated energy spread in the bunch. In addition, such an approach allows one to keep the amplitude of coherent betatron oscillations small by a proper choice of the phase advance at the first cell. It is shown that the scaling of the phase advance per cell gives significant advantages with respect to singlebunch and multibunch instabilities