| Popis: |
An ongoing programme of development superconducting thin film coating for SRF cavities requires a facility for a quick sample evaluation at the RF conditions. One of the key specifications is a simplicity of the testing procedure, allowing an easy installation and quick turnover of the testing samples. Choked test cavities operating at 7.8 GHz with three RF chokes have been designed and tested at DL in a LHe cryostat verifying that the system could perform as required. Having a sample and a cavity physically separate reduces the complexity involved in changing samples (major causes of low throughput rate and high running costs for other test cavities) and also allows direct measurement of the RF power dissipated in the sample via power calorimetry. However, changing a sample and preparation for a test requires about two-week effort per sample. In order to simplify the measurements and achieve a faster turnaround, a new cryostat cooled with a closed-cycle refrigerator has been designed, built and tested. Changing a sample, cooling down and testing can be reduced to 2-3 days per sample. Detailed design and results of testing of this facility will be reported at the conference. |
