THCOWBS05
IHEP, Beijing, People’s Republic of China
High Energy Photon Source is a 6GeV kilometer-scale synchrotron light source to be built in Beijing. The designed beam emittance is lower than 100pm.rad approaching diffraction limitation with 200mA beam current stored. In order to realize a novel injection scheme and prolong the beam lifetime, a double-frequency RF system has been proposed with 166.6MHz as the fundamental and 499.8MHz as the third harmonic. Both RF system will adopt superconducting cavities. Over the last three years, a 166.6MHz quarter-wave β=1 proof-of-principle SRF cavity has been in-house developed, vertical tested, dressed with helium jacket and ancillaries, and eventually horizontal tested with a success in early 2019. In parallel, the HOM-damped prototype cavity has been designed adopting a hybrid damping scheme. Due to a rather low-frequency HOMs, both HOM couplers and beam-pipe HOM absorbers are to be used to ensure a tight impedance budget.
