Paper |
Title |
Page |
WEPPD072 |
Frequency Fine-tuning of a Spin-flip Cavity for Antihydrogen Atoms |
2690 |
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- S. Federmann, F. Caspers, E. Mahner
CERN, Geneva, Switzerland
- B. Juhasz, E. Widmann
SMI, Vienna, Austria
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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.
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THPPC023 |
RF Loads for Energy Recovery |
3326 |
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- S. Federmann, M. Betz, F. Caspers
CERN, Geneva, Switzerland
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Different conceptional designs for RF high power loads are presented. One concept implies the use of solid state rectifier modules for direct RF to DC conversion with efficiencies beyond 80%. In addition, robust metallic low-Q resonant structures, capable of operating at high temperatures (>150 ̊C) are discussed. Another design deals with a very high temperature (up to 800 ̊C) air cooled load using a ceramic foam block inside a metal enclosure. This porous ceramic block is the actual microwave absorber and is not brazed to the metallic enclosure.
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