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 - Nantista, C.D. AU - Haase, A.A. AU - Krejcik, P. ED - Forck, Peter ED - Wawrzyniak, Adriana ED - Schaa, Volker R.W. ED - Kowalski, Grzegorz W. ED - Cudek, Agnieszka (SOLARIS, Kraków TI - A Cryogenic RF Cavity BPM for the Superconducting Undulator at LCLS J2 - Proc. of IBIC2022, Kraków, Poland, 11-15 September 2022 CY - Kraków, Poland T2 - International Beam Instrumentation Conference T3 - 11 LA - english AB - The new superconducting undulator beamline at LCLS requires the BPMs to be operated at cryogenic temperatures alongside the undulator magnets. They are used for beam-based alignment of the undulator magnets and quadrupole and require submicron resolution to achieve good FEL performance. This is to be achieved with X-band RF cavity BPMs, as is done now on the permanent undulator beamline. However, operating the cavities at cryogenic temperatures introduces significant challenges. We review the changes in RF properties of the cavities that result from cooling and how the design is changed to compensate for this. This includes a novel approach for employing a rectangular cavity with split modes to separately measure the X and Y position without coupling. PB - JACoW Publishing CP - Geneva, Switzerland SP - 241 EP - 244 KW - cavity KW - dipole KW - coupling KW - cryogenics KW - GUI DA - 2022/12 PY - 2022 SN - 2673-5350 SN - 978-3-95450-241-7 DO - doi:10.18429/JACoW-IBIC2022-TUP11 UR - https://jacow.org/ibic2022/papers/tup11.pdf ER -