A bi-periodic X-Band cavity for SPARC

In order to produce a high brightness electron beam for the Frascati Linac coherent light source (SPARC) the use of an accelerating section with frequency equal to the fourth harmonic of the main S-Band Linac frequency is needed. This paper discusses the design and the realization of a compact X-Band linear accelerating section for obtaining 5 MV average accelerating gradient, working at a frequency of 11.424 GHz and operating on the π/2π/2 standing wave mode. Numerical predictions compared with measurements made on a copper prototype at room temperature are reported.