Optimizing a Calorimetry Chamber for the RF Characterization of Superconductors

In this thesis an optimized calorimetry chamber is developed, providing at and easy mountable samples. Furthermore, it enables exchangeability of samples between the resonators at HZB and CERN. The thesis is structured as follows: First, a short introduction into SRF is given. The focus is on the surface resistance and a theoretical derivation is given using the two-fluid model of superconductivity. Subsequently, the Quadrupole Resonator is introduced. The RF design is presented and the calorimetric measurement principle, enabling precision measurements of the RF surface resistance, is derived. In chapter 4 the impact of a demountable sample on the RF inside the resonator is investigated and boundary conditions concerning the technical realization are extracted. Afterwards, a prototype made out of aluminum is studied (chapter 5) and the experience gained there is used to define a final design (chapter 6). The new design could already be used for a first measurement at CERN with the results given in chapter 7. At the end of the thesis a summary of the obtained results is given. Observed difficulties are discussed together with an outlook towards possible future steps using the optimized calorimetry chamber. 2