Design and Mechanical Performance of a Dressed 166.6 MHz $\beta$ =1 Proof-of-Principle Superconducting Cavity in Horizontal Tests

Superconducting $\beta$=1 quarter-wave geometry of 166.6 MHz has been proposed as main accelerating cavities for the high-energy photon source (HEPS) storage ring. HEPS is a 6-GeV kilometer-scale synchrotron light source promising ultralow emittance currently being constructed in Beijing. A proof-of-principle cavity has been previously in-house developed and vertical-tested achieving excellent cry...