Electro-acoustic stability of asuperconducting spoke cavity
2015 (English)Report (Other academic)
This thesis describes measurement procedures and results for the measurement ofthe Q value and microphonics of a superconducting spoke cavity. The thesis starts byintroducing the background of RF electronics and how they pertain tosuperconducting cavities. We then present the cavity model and figures of meritcharacterising its performance, the theory of how electric fields cause mechanicalvibrations in the cavity walls and present an experimental setup for measurements.Four measurement procedures are presented, of which two are implemented.Measurements are carried out by running the cavity in a self-excited loop in anaccurate manner with precise calibrations. Finally, we present the measured Q valueof a single spoke cavity and the results of microphonics measurements.We find that the cavity has a Q value of 1.06*10^9 at a resonance frequency of360.215MHz. It is sensitive to microphonics of a few frequencies, most notably someclose to 14 Hz which coincides with the repetition rate of the ESS.
Place, publisher, year, edition, pages
2015. , 46 p.
FREIA Report, 2015-11
superconducting cavity, spoke resonator, self-excited loop, VNA
Accelerator Physics and Instrumentation
Research subject Engineering Science with specialization in Microwave Technology
IdentifiersURN: urn:nbn:se:uu:diva-264271OAI: oai:DiVA.org:uu-264271DiVA: diva2:859687
ProjectsMaster project at the FREIA division