Author: Widmann, E.
Paper Title Page
WEPPD072 Frequency Fine-tuning of a Spin-flip Cavity for Antihydrogen Atoms 2690
  • S. Federmann, F. Caspers, E. Mahner
    CERN, Geneva, Switzerland
  • B. Juhasz, E. Widmann
    SMI, Vienna, Austria
  As part of the ASACUSA collaboration physics program a spin-flip cavity for measurements of the ground-state hyperfine transition frequency of anti-hydrogen atoms is needed. The purpose of the cavity is to excite anti-hydrogen atoms depending on their polarisation by a microwave field operating at 1.42 GHz. The delicacy of designing such a cavity lies in achieving and maintaining the required properties of this field over a large aperture of 10cm and for a long period of time (required amplitude stability is 1% within 12h). The present paper presents the frequency fine tuning techniques to obtain the desired centre frequency of 1.42 GHz with a Q value below 500 as well as the tuning circuit used for the frequency sweep over the desired bandwidth of 6 MHz.