Frequency scaling of linear super-colliders

The development of electron-positron linear colliders in the TeV energy range will be facilitated by the development of high-power rf sources at frequencies above 2856 MHz. Present S-band technology, represented by the SLC would require a length in excess of 50 km per linac to accelerate particles to energies above 1 TeV. By raising the rf driving frequency, the rf breakdown limit is increased, thereby allowing the length of the accelerators to be reduced. Currently available rf power sources set the realizable gradient limit in an rf linac at frequencies above S-band. A model for the frequency scaling of linear colliders is presented, with luminosity scaled in proportion to the square of the center-of-mass energy. Since Wakefield effects are the dominant deleterious effect, a separate single-bunch simulation model is described which calculates the evolution of the beam bunch with specified Wakefields, including the effects of using programmed phase positioning and Landau damping. The results presented have been obtained for a SLAC structure, scaled in proportion to wavelength