Speaker
Description
This study presents the fabrication and room-temperature radiofrequency (RF) characterization of 1.3 GHz TESLA-type 9-cell copper prototype cavities as a preparatory step toward future niobium superconducting RF cavity development. Prior to fabrication, three-dimensional electromagnetic simulations were performed to evaluate the resonant frequency, TM010 passband characteristics, and axial electric-field distribution. Based on the simulation results, three copper prototype cavities were fabricated and examined through helium leak testing and preliminary RF measurements. One cavity, in which all nine passband modes were clearly identified, was selected for detailed RF characterization. Vector network analyzer measurements showed an initial TM010 π-mode resonant frequency of 1.297913 GHz. The axial electric-field distribution was subsequently evaluated using bead-pull measurements, followed by repeated frequency-correction calculations and mechanical tuning. As a result, the field-flatness metric was improved from 35.45% to 95.9%, confirming a substantially more uniform field distribution among the nine cells. These results experimentally validate an integrated workflow consisting of cavity fabrication, room-temperature RF measurement, bead-pull characterization, and mechanical tuning. The established procedure provides a practical basis for the future fabrication and RF evaluation of 1.3 GHz niobium superconducting cavities.