Resonantly Coupled Standing Wave Accelerator Structures for Electron and Proton Linac Applications

Standing wave accelerator tanks which utilize non-excited resonant elements for field stabilization have become standard in proton linac designs during the last few years. A general description of resonant coupling, with special emphasis on the energy propagation characteristics of resonantly coupled systems is given. Extension of resonant coupling to the coupling of short 0 or ?? mode like sections is briefly discussed. The transient response of two resonantly coupled linac tanks, a post coupled drift tube linac and a side coupled linac tank are compared to conventional 0 or ?? mode tank responses. Finally, a brief description of applications of resonantly coupled linac tanks to electron and proton linacs under construction in the U.S. is given.