TU Darmstadt, Darmstadt, Germany
In 2009 a vertical bath cryostat was commissioned at the S-DALINAC. Since then, components for the new cryostat module within the framework of the injector upgrade have been tested. Measurements have been performed to check the leakage rate of “Quick-CF” UHV flanges and the performance of piezo actors in superfluid helium have been investigated. To enlarge the scale of possible measurements at the vertical bath cryostat, systems to measure the quality factor via the decay time method and quench localisation via second sound will be implemented this year. We will report on the recent results.
TU Darmstadt, Darmstadt, Germany
Since 1991 the superconducting Darmstadt linear accelerator S-DALINAC provides an electron beam of up to 130 MeV for nuclear and astrophysical experiments. The accelerator consists of an injector and four main linac cryostats, where the superconducting 3 GHz cavities are operated in a liquid helium bath at 2 K. For the injector upgrade program, the RF power delivered to the beam had to be increased from 500 W to 2 kW. Therefore, the coaxial power couplers have to be replaced by new waveguide couplers introducing only small transversal kicks to the beam. Consequently, modifications to the cryostat-module and had become necessary. We review on the design of the module and some interesting features and give details on the tuning of the newly built 20-cell cavities. The paper will close with an outlook towards the installation of an additional recirculation path planed in 2013.