JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - CONF AU - Kuzikov, S.V. AU - Avrakhov, P.V. AU - Jing, C.-J. AU - Kostin, R.A. AU - Powers, T. AU - Rimmer, R.A. AU - Yakovlev, V.P. AU - Zhao, Y. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Lesage, Ana ED - Schaa, Volker R.W. TI - A Method for In-Situ Q₀ Measurements of High-Quality SRF Resonators J2 - Proc. of SRF2021, East Lansing, MI, USA, 28 June-02 July 2021 CY - East Lansing, MI, USA T2 - International Conference on RF Superconductivity T3 - 20 LA - english AB - Accelerator projects such as LCLS-II naturally require low-loss superconducting (SRF) cavities. Due to strong demand for improving intrinsic quality factor (Q₀), importance of accurate cavity characterization increases. We propose a method to measure Q₀ in situ for an SRF resonator installed in its cryogenic module and connected with a RF feed source via a fixed RF coupler. The method exploits measurements of a response for an SRF resonator fed by an amplitude-modulated signal. Such a signal can be synthesized as a beat-wave composed of two frequencies that are close to the resonant frequency. Analyzing the envelope of the reflected signal, one can find the difference in reflection for the chosen frequencies and use them to compute the intrinsic Q. We also develop the methodology to carry out measurements of Q₀ at the nominal cavity operating voltage. We verified our method in experiments with a room temperature copper resonator and with two SRF resonators including Fermilab’s 650 MHz cavity and JLab’s 1500 MHz cavity. PB - JACoW Publishing CP - Geneva, Switzerland SP - 221 EP - 225 KW - beat-wave KW - cavity KW - SRF KW - resonance KW - experiment DA - 2022/10 PY - 2022 SN - 2673-5504 SN - 978-3-95450-233-2 DO - doi:10.18429/JACoW-SRF2021-MOPTEV009 UR - https://jacow.org/srf2021/papers/moptev009.pdf ER -